Quaternary geologic map of the Lake Superior 4 degrees x 6 degrees quadrangle, United States and Canada

USGS Publications Warehouse

Richmond, Gerald M.; Fullerton, David S.; state compilations by Farrand, William R.; Mickelson, D.M.; Cowan, W.R.; Goebel, J.E.; edited and integrated by Richmond, Gerald Martin

1984-01-01

The Quaternary Geologic Map of the Lake Superior 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Quaternary geologic map of the Hudson River 4 degree x 6 degree quadrangle, United States and Canada

USGS Publications Warehouse

State and province compilations by Fullerton, David S.; Sevon, William D.; Muller, Ernest H.; Judson, Sheldon; Black, Robert F.; Wagner, Phillip W.; Hartshorn, Joseph H.; Chapman, William F.; Cowan, William D.; edited and integrated by Fullerton, David S.

1992-01-01

The Quaternary Geologic Map of the Hudson River 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Quaternary geologic map of the Ozark Plateau 4 ° x 6 ° quadrangle, United States

USGS Publications Warehouse

State compilations by Whitfield, John William; Ward, R.A.; Denne, J.E.; Holbrook, D.F.; Bush, W.V.; Lineback, J.A.; Luza, K.V.; Jensen, Kathleen M.; Fishman, W.D.; Richmond, Gerald Martin; Weide, David L.; Bush, Charles A.

1993-01-01

The Quaternary Geologic Map of the Ozark Plateau 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Quaternary geologic map of the Boston 4 degrees x 6 degrees quadrangle, United States and Canada

USGS Publications Warehouse

State compilations by Hartshorn, Joseph H.; Thompson, W.B.; Chapman, W.F.; Black, R.F.; Richmond, Gerald Martin; Grant, D.R.; Fullerton, David S.; edited and integrated by Richmond, Gerald Martin

1991-01-01

The Quaternary Geologic Map of the Boston 4 deg x 6 deg Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Relict colluvial boulder deposits as paleoclimatic indicators in the Yucca Mountain region, southern Nevada

USGS Publications Warehouse

Whitney, J.W.; Harrington, C.D.

1993-01-01

Early to middle Pleistocene boulder deposits are common features on southern Nevada hillslopes. These darkly varnished, ancient colluvial deposits stand out in stark contrast to the underlying light-colored bedrock of volcanic tuffs, and they serve as minor divides between drainage channels on modern hillslopes. To demonstrate the antiquity of these stable hillslope features, six colluvial boulder deposits from Yucca Mountain, Nye County, Nevada, were dated by cation-ratio dating of rock varnish accreted on boulder surfaces. Estimated minimum ages of these boulder deposits range from 760 to 170 ka. Five additional older deposits on nearby Skull and Little Skull Mountains and Buckboard Mesa yielded cation-ratio minimum-age estimates of 1.38 Ma to 800 ka. An independent cosmogenic chlorine-36 surface exposure date was obtained on one deposit, which confirms an estimated early to middle Quaternary age. These deposits have provided the oldest age estimates for unconsolidated hillslope deposits in the southwestern United States. We suggest that the colluvial boulder deposits were produced during early and middle Pleistocene glacial/pluvial episodes and were stabilized during the transition to drier interglacial climates. The preservation of old, thin hillslope deposits and the less-than-2-m incision by hillslope runoff adjacent to these deposits, indicate that extremely low denudation rates have occurred on resistant volcanic hillslopes in the southern Great Basin during Quaternary time. -from Authors

Geologic Map of the Poverty Bay 7.5' quadrangle, King and Pierce counties, Washington

USGS Publications Warehouse

Booth, Derek B.; Waldron, H.H.; Troost, K.G.

2004-01-01

The Poverty Bay quadrangle lies near the center of the region?s intensively developing urban core. Less than 20 km north lies the city of Seattle; downtown Tacoma lies just southwest of the quadrangle. The map area expresses much of the tremendous range of Quaternary environments and deposits found throughout the central Puget Lowland. Much of the ground surface is mantled by a rolling surface of glacial till deposited during the last occupation of the Puget Lowland by a great continental ice sheet about 14,000 years ago. A complex sequence of older unconsolidated sediments extends far below sea level across most of the quadrangle, with no bedrock exposures at all.

Origin, Extent, and Thickness of Quaternary Geologic Units in the Willamette Valley, Oregon

USGS Publications Warehouse

O'Connor, Jim E.; Sarna-Wojcicki, Andrei M.; Wozniak, Karl C.; Polette, Danial J.; Fleck, Robert J.

2001-01-01

Stratigraphic and chronologic information collected for Quaternary deposits in the Willamette Valley, Oregon, provides a revised stratigraphic framework that serves as a basis for a 1:250,000-scale map, as well as for thickness estimates of widespread Quaternary geologic units. We have mapped 11 separate Quaternary units that are differentiated on the basis of stratigraphic, topographic, pedogenic, and hydrogeologic properties. In summation, these units reflect four distinct episodes in the Quaternary geologic development of the Willamette Valley: 1) Fluvial sands and gravels that underlie terraces flanking lowland margins and tributary valleys were probably deposited between 2.5 and 0.5 million years ago. They are the oldest widespread surficial Quaternary deposits in the valley. Their present positions and preservation are undoubtedly due to postdepositional tectonic deformation - either by direct tectonic uplift of valley margins, or by regional tectonic controls on local base level. 2) Tertiary and Quaternary excavation or tectonic lowering of the Willamette Valley accommodated as much as 500 m (meters) of lacustrine and fluvial fill. Beneath the lowland floor, much of the upper 10 to 50 m of fill is Quaternary sand and gravel deposited by braided channel systems in subhorizontal sheets 2 to 10 m thick. These deposits grade to gravel fans 40 to 100 m thick where major Cascade Range rivers enter the valley and are traced farther upstream as much thinner valley trains of coarse gravel. The sand and gravel deposits have ages that range from greater than 420,000 to about 12,000 years old. A widely distributed layer of sand and gravel deposited at about 12 ka (kiloannum, thousands of years before the present) is looser and probably more permeable than older sand and gravel. Stratigraphic exposures and drillers' logs indicate that this late Pleistocene unit is mostly between 5 and 20 m thick where it has not been subsequently eroded by the Willamette River and its major tributaries. 3) Between 15,000 and 12,700 years ago, dozens of floods from Glacial Lake Missoula flowed up the Willamette Valley from the Columbia River, depositing up to 35 m of gravel, sand, silt, and clay. 4) Subsequent to 12,000 years ago, Willamette River sediment and flow regimes changed significantly: the Pleistocene braided river systems that had formed vast plains of sand and gravel evolved to incised and meandering rivers that are constructing today's fine-grained floodplains and gravelly channel deposits. Sub-surface channel facies of this unit are loose and unconsolidated and are highly permeable zones of substantial groundwater flow that is likely to be well connected to surface flow in the Willamette River and major tributaries. Stratigraphic exposures and drillers' logs indicate that this unit is mostly between 5 and 15 m thick.

Thickness of unconsolidated deposits of the Puget Sound aquifer system, Washington and British Columbia

USGS Publications Warehouse

Jones, M.A.

1996-01-01

The Puget-Willamette Lowland is located in western Washington, western Oregon, and a small part of southwestern British Columbia, Canada. The Puget-Willamette Lowland study area is composed of two distinct subareas, the Puget Sound Lowland and the Willamette Lowland. This report presents the results of mapping the thickness of the unconsolidated deposits in the Puget Sound Lowland. The thickness of the unconsolidated deposits ranges from a discontinuous veneer in areas of bedrock outcrop to more than 3,600 feet. Available information shows that the unconsolidated deposits are thickest in the Fraser-Whatcom, Everett, Seattle, and Tacoma Basins. The mapped thickness of the unconsolidated deposits in the Tacoma Basin is probably underestimated because of the scarcity of wells penetrating the full thickness of the unconsolidated deposits and the lack of sufficient marine-seismic data.

Quaternary geologic map of the Hatteras 4° x 6° quadrangle, United States

USGS Publications Warehouse

State compilations by Johnson, Gerald H.; Richmond, Gerald Martin; edited and integrated by Richmond, G. M.; Fullerton, D.S.; Weide, D.L.; Bush, Charles A.

1986-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1986. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Hatteras 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Preliminary maps of Quaternary deposits and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database

USGS Publications Warehouse

Knudsen, Keith L.; Sowers, Janet M.; Witter, Robert C.; Wentworth, Carl M.; Helley, Edward J.; Nicholson, Robert S.; Wright, Heather M.; Brown, Katherine H.

2000-01-01

This report presents a preliminary map and database of Quaternary deposits and liquefaction susceptibility for the nine-county San Francisco Bay region, together with a digital compendium of ground effects associated with past earthquakes in the region. The report consists of (1) a spatial database of fivedata layers (Quaternary deposits, quadrangle index, and three ground effects layers) and two text layers (a labels and leaders layer for Quaternary deposits and for ground effects), (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map, liquefaction interpretation, and the ground effects compendium, and (4) the databse description pamphlet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a modern and regionally consistent treatment of Quaternary surficial deposits that builds on the pioneering mapping of Helley and Lajoie (Helley and others, 1979) and such intervening work as Atwater (1982), Helley and others (1994), and Helley and Graymer (1997a and b). Like these earlier studies, the current mapping uses geomorphic expression, pedogenic soils, and inferred depositional environments to define and distinguish the map units. In contrast to the twelve map units of Helley and Lajoie, however, this new map uses a complex stratigraphy of some forty units, which permits a more realistic portrayal of the Quaternary depositional system. The two colored maps provide a regional summary of the new mapping at a scale of 1:275,000, a scale that is sufficient to show the general distribution and relationships of the map units but cannot distinguish the more detailed elements that are present in the database. The report is the product of years of cooperative work by the USGS National Earthquake Hazards Reduction Program (NEHRP) and National Cooperative Geologic Mapping Program, William Lettis and & Associates, Inc. (WLA) and, more recently, by the California Division of Mines and Geology as well. An earlier version was submitted to the Geological Survey by WLA as a final report for a NEHRP grant (Knudsen and others, 2000). The mapping has been carried out by WLA geologists under contract to the NEHRP Earthquake Program (Grants #14-08-0001-G2129, 1434-94-G-2499, 1434-HQ-97-GR-03121, and 99-HQ-GR-0095) and with other limited support from the County of Napa, and recently also by the California Division of Mines and Geology. The current map consists of this new mapping and revisions of previous USGS mapping.

Establishing a Geologic Baseline Of Cape Canaveral's Natural Landscape: Black Point Drive

NASA Technical Reports Server (NTRS)

Parkinson, Randall W.

2001-01-01

The goal of this project is to identify the process responsible for the formation of geomorphic features in the Black Point Drive area of Merritt Island National Wildlife Refuge/Kennedy Space Center (MINWR/KSC), northwest Cape Canaveral. This study confirms the principal landscape components (geomorphology) of Black Point Drive reflect interaction between surficial sediments deposited in association with late-Quaternary sea-level highstands and the chemical evolution of late-Cenozoic subsurface limestone formations. The Black Point Drive landscape consists of an undulatory mesic terrain which dips westward into myriad circular and channel-like depression marshes and lakes. This geomorphic gradient may reflect: (1) spatial distinctions in the elevation, character or age of buried (pre-Miocene) limestone formations, (2) dissolution history of late-Quaternary coquina and/or (3) thickness of unconsolidated surface sediment. More detailed evaluation of subsurface data will be necessary before this uncertainty can be resolved.

Establishing A Geologic Baseline of Cape Canaveral''s Natural Landscape: Black Point Drive

NASA Technical Reports Server (NTRS)

Parkinson, Randall W.

2002-01-01

The goal of this project is to identify the process responsible for the formation of geomorphic features in the Black Point Drive area of Merritt Island National Wildlife Refuge/Kennedy Space Center (MINWR/KSC), northwest Cape Canaveral. This study confirms the principal landscape components (geomorphology) of Black Point Drive reflect interaction between surficial sediments deposited in association with late-Quaternary sea-level highstands and the chemical evolution of late-Cenozoic sub-surface limestone formations. The Black Point Drive landscape consists of an undulatory mesic terrain which dips westward into myriad circular and channel-like depression marshes and lakes. This geomorphic gradient may reflect: (1) spatial distinctions in the elevation, character or age of buried (pre-Miocene) limestone formations, (2) dissolution history of late-Quaternary coquina and/or (3) thickness of unconsolidated surface sediment. More detailed evaluation of subsurface data will be necessary before this uncertain0 can be resolved.

Quaternary Geologic Map of the Des Moines 4 Degrees x 6 Degrees Quadrangle, United States

USGS Publications Warehouse

Hallberg, George R.; Lineback, Jerry A.; Mickelson, David M.; Knox, James C.; Goebel, Joseph E.; Hobbs, Howard C.; Whitfield, John W.; Ward, Ronald A.; Boellstorff, John D.; Swinehart, James B.; Dreeszen, Vincent H.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.; Christiansen, Ann Coe

1994-01-01

The Quaternary Geologic Map of the Des Moines 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1994. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files.

Quaternary Geologic Map of the Platte River 4 Degrees x 6 Degrees Quadrangle, United States

USGS Publications Warehouse

Swinehart, James B.; Dreeszen, Vincent H.; Richmond, Gerald Martin; Tipton, Merlin J.; Bretz, Richard F.; Steece, Fred V.; Hallberg, George R.; Goebel, Joseph E.; edited and integrated by Richmond, Gerald Martin

1994-01-01

The Quaternary Geologic Map of the Platte River 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1994. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files.

NURE aerial gamma-ray and magnetic reconnaissance survey of portions of New Mexico, Arizona and Texas. Volume II. Texas-New Mexico-El Paso NH 13-1 Quadrangle. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-09-01

The results of a high-sensitivity, aerial gamma-ray spectrometer and magnetometer survey of the El Paso, two degree quadrangle, New Mexico, are presented. Instrumentation and methods are described in Volume I of this final report. The work was done by Carson Helicopters Inc., and Carson Helicopters was assisted in the interpretation by International Exploration, Inc. The work was performed for the US Department of Energy - National Uranium Resource Evaluation (NURE) program. A total of 72 statistically significant eU anomalies were identified in this quadrangle. Of this number 20 were considered to be of sufficient intensity to warrant field investigations, however,more » many of these anomalies appear to be wholly, or in part, associated with various unconsolidated Quaternary deposits. Only three of the 20 can, with certainty be identified with bedrock; one with a Quaternary flow, one with Cambrian sandstone and one with a Precambrian granite.« less

Permeability Estimation Directly From Logging-While-Drilling Induced Polarization Data

NASA Astrophysics Data System (ADS)

Fiandaca, G.; Maurya, P. K.; Balbarini, N.; Hördt, A.; Christiansen, A. V.; Foged, N.; Bjerg, P. L.; Auken, E.

2018-04-01

In this study, we present the prediction of permeability from time domain spectral induced polarization (IP) data, measured in boreholes on undisturbed formations using the El-log logging-while-drilling technique. We collected El-log data and hydraulic properties on unconsolidated Quaternary and Miocene deposits in boreholes at three locations at a field site in Denmark, characterized by different electrical water conductivity and chemistry. The high vertical resolution of the El-log technique matches the lithological variability at the site, minimizing ambiguity in the interpretation originating from resolution issues. The permeability values were computed from IP data using a laboratory-derived empirical relationship presented in a recent study for saturated unconsolidated sediments, without any further calibration. A very good correlation, within 1 order of magnitude, was found between the IP-derived permeability estimates and those derived using grain size analyses and slug tests, with similar depth trends and permeability contrasts. Furthermore, the effect of water conductivity on the IP-derived permeability estimations was found negligible in comparison to the permeability uncertainties estimated from the inversion and the laboratory-derived empirical relationship.

Quaternary geologic map of the Florida Keys 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

Compilations: Scott, Thomas M.; Knapp, Michael S.; Weide, David L.; Edited and integrated by Richmond, Gerald M.; Fullerton, David S.; Bush, Charles A.

2010-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1986. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Florida Keys 4 degrees x 6 degrees Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Mobile 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

State compilations by Copeland, Charles W.; Rheams, K.F.; Neathery, T.L.; Gilliland, W.A.; Schmidt, Walter; Clark, W.C.; Pope, D.E.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.; Weide, David L.; Digital database by Bush, Charles A.

1988-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1988. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Mobile 4 degrees x 6 degrees Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map

Quaternary geologic map of the Lookout Mountain 4° x 6° quadrangle, United States

USGS Publications Warehouse

State compilations by Miller, Robert A.; Maher, Stuart W.; Copeland, Charles W.; Rheams, Katherine F.; Neathery, Thorton L.; Gilliland, William A.; Friddell, Michael S.; Van Nostrand, Arnie K.; Wheeler, Walter H.; Holbrook, Drew F.; Bush, William V.; Edited and integrated by Richmond, Gerald M.; Fullerton, David S.; Bush, Charles A.

1988-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I–1420). It was first published as a printed edition in 1988. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Lookout Mountain 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Vicksburg 4° x 6° quadrangle, United States

USGS Publications Warehouse

State compilations by Holbrook, Drew F.; Gilliland, W.A.; Luza, K.V.; Pope, D.E.; Wermund, E.G.; Miller, R.A.; Bush, W.V.; Jensen, K.N.; Fishman, W.D.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.; Weide, David L.; Bush, Charles A.

1990-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1990. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Vicksburg 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the White Lake 4° x 6° quadrangle, United States

USGS Publications Warehouse

State compilations by Pope, David E.; Gilliland, William A.; Wermund, E.G.; edited and integrated by Richmond, Gerald Martin; Weide, David L.; Moore, David W.; Bush, Charles A.

1990-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1990. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the White Lake 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Monterrey 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

Moore, David W.; Wermund, E.G.; edited and integrated by Moore, David W.; Richmond, Gerald Martin

1993-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1993. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Monterrey 4 degrees x 6 degrees Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Austin 4° x 6° quadrangle, United States

USGS Publications Warehouse

State compilations by Moore, David W.; Wermund, E.G.; edited and integrated by Moore, David W.; Richmond, Gerald Martin; Christiansen, Ann Coe; Bush, Charles A.

1993-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1993. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Austin 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Wichita 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

State compilations by Denne, Jane E.; Luza, V.; Richmond, Gerald Martin; Jensen, Kathleen M.; Fishman, W.D.; Wermund, E.G.; Richmond, Gerald Martin; Christiansen, Ann Coe; Bush, Charles A.

1993-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1993. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Wichita 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Quaternary geologic map of the Jacksonville 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

State compilations by Scott, Thomas M.; Knapp, M.S.; Friddell, M.S.; Weide, David L.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.

1986-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1986. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Jacksonville 4 degrees x 6 degrees Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

Estimating selected low-flow frequency statistics and harmonic-mean flows for ungaged, unregulated streams in Indiana

USGS Publications Warehouse

Martin, Gary R.; Fowler, Kathleen K.; Arihood, Leslie D.

2016-09-06

Information on low-flow characteristics of streams is essential for the management of water resources. This report provides equations for estimating the 1-, 7-, and 30-day mean low flows for a recurrence interval of 10 years and the harmonic-mean flow at ungaged, unregulated stream sites in Indiana. These equations were developed using the low-flow statistics and basin characteristics for 108 continuous-record streamgages in Indiana with at least 10 years of daily mean streamflow data through the 2011 climate year (April 1 through March 31). The equations were developed in cooperation with the Indiana Department of Environmental Management.Regression techniques were used to develop the equations for estimating low-flow frequency statistics and the harmonic-mean flows on the basis of drainage-basin characteristics. A geographic information system was used to measure basin characteristics for selected streamgages. A final set of 25 basin characteristics measured at all the streamgages were evaluated to choose the best predictors of the low-flow statistics.Logistic-regression equations applicable statewide are presented for estimating the probability that selected low-flow frequency statistics equal zero. These equations use the explanatory variables total drainage area, average transmissivity of the full thickness of the unconsolidated deposits within 1,000 feet of the stream network, and latitude of the basin outlet. The percentage of the streamgage low-flow statistics correctly classified as zero or nonzero using the logistic-regression equations ranged from 86.1 to 88.9 percent.Generalized-least-squares regression equations applicable statewide for estimating nonzero low-flow frequency statistics use total drainage area, the average hydraulic conductivity of the top 70 feet of unconsolidated deposits, the slope of the basin, and the index of permeability and thickness of the Quaternary surficial sediments as explanatory variables. The average standard error of prediction of these regression equations ranges from 55.7 to 61.5 percent.Regional weighted-least-squares regression equations were developed for estimating the harmonic-mean flows by dividing the State into three low-flow regions. The Northern region uses total drainage area and the average transmissivity of the entire thickness of unconsolidated deposits as explanatory variables. The Central region uses total drainage area, the average hydraulic conductivity of the entire thickness of unconsolidated deposits, and the index of permeability and thickness of the Quaternary surficial sediments. The Southern region uses total drainage area and the percent of the basin covered by forest. The average standard error of prediction for these equations ranges from 39.3 to 66.7 percent.The regional regression equations are applicable only to stream sites with low flows unaffected by regulation and to stream sites with drainage basin characteristic values within specified limits. Caution is advised when applying the equations for basins with characteristics near the applicable limits and for basins with karst drainage features and for urbanized basins. Extrapolations near and beyond the applicable basin characteristic limits will have unknown errors that may be large. Equations are presented for use in estimating the 90-percent prediction interval of the low-flow statistics estimated by use of the regression equations at a given stream site.The regression equations are to be incorporated into the U.S. Geological Survey StreamStats Web-based application for Indiana. StreamStats allows users to select a stream site on a map and automatically measure the needed basin characteristics and compute the estimated low-flow statistics and associated prediction intervals.

Groundwater quality of southeastern Wyoming

USGS Publications Warehouse

Eddy-Miller, Cheryl A.; Blain, Liberty

2011-01-01

Groundwater is an important resource for domestic, municipal, stock, and irrigation uses in southeastern Wyoming. Thirty-seven percent of water used in the tri-County area, which includes Laramie, Platte, and Goshen Counties, is from groundwater. Most groundwater use in the tri-County area is withdrawn from three primary aquifer groups: Quaternary-age unconsolidated-deposit aquifers, Tertiary-age units of the High Plains aquifer system, and Upper Cretaceous bedrock aquifers (Lance Formation and Fox Hills Sandstone). Authors include selected physical properties and chemicals found in water samples, describe sources and importance, and report maximum levels established by the U.S. Environmental Protection Agency. They also show concentration ranges for selected physical properties and chemicals in samples collected from the three primary aquifer groups in the tri-County area.

The Pliocene Horcón Formation, Central Chile: a case study of earthquake-induced landslide susceptibility

NASA Astrophysics Data System (ADS)

Valdivia, D.; Elgueta, S.; Hodgkin, A.; Marquardt, C.; del Valle, F.; Yáñez Morroni, G.

2017-12-01

Stability slope analysis is typically focused on modeling using cohesion and friction angle parameters but in earthquake-induced landslides, susceptibility is correlated more to lithological and stratigraphic parameters. In sedimentary deposits whose cohesion and diagenesis are very low, the risk of landslides increases. The Horcón Formation, which crops out continuously along cliffs in Central Chile between 32.5° and 33°S, is a Miocene-Pliocene well preserved, horizontally stratified unit composed of marine strata which overlies Paleozoic-Mesozoic igneous basement. During the Quaternary, the sequence was tectonically uplifted 80 meters and covered by unconsolidated eolian deposits. Given that Seismotectonic and Barrier-Asperity models suggest the occurrence of a forthcoming megathrust earthquake in a segment which includes this area, the Horcón Formation constitutes a good case study to characterize the susceptibility of this type of sediment for mass movements triggered by earthquakes. Field mapping, stratigraphic and sedimentological studies, including petrographic analyses to determine lithological composition and paragenesis of diagenetic events, have been carried out along with limited gravimetric profiling and CPTU drill tests. High resolution digital elevation modeling has also been applied. This work has led to the recognition of a shallow marine lithofacies association composed of weakly lithified fossiliferous and bioturbated medium to fine grained litharenite, mudstone, and fine conglomerate. The low grade of diagenesis in the sedimentary deposits was in response to a short period of burial and a subsequent accelerated uplift evidenced along the coast of Chile during the Quaternary. We have generated a predictive model of landslide susceptibility for the Horcón Formation and for the overlying Quaternary eolian deposits incorporating variables such as composition and diagenesis of lithofacies, slope, structures, weathering and landcover. The model has significant implications for land use planning and building construction where this type of sediments occurs.

Geologic map of the greater Denver area, Front Range urban corridor, Colorado

USGS Publications Warehouse

Trimble, Donald E.; Machette, Michael N.

1979-01-01

This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999) was digitized under the USGS Front Range Infrastructure Resources Project. In general, the mountainous areas in the western part of the map exhibit various igneous and metamorphic bedrock units of Precambrian age, major faults, and fault brecciation zones at the east margin (5-20 km wide) of the Front Range. The eastern and central parts of the map (Colorado Piedmont) depict a mantle of unconsolidated deposits of Quaternary age and interspersed outcroppings of Cretaceous or Tertiary-Cretaceous sedimentary bedrock. The Quaternary mantle comprises eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and a few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone, shale, and limestone bedrock formations form hogbacks and intervening valleys.

Valley aggradation in the San Gabriel Mountains, California: climate change versus catastrophic landslide

NASA Astrophysics Data System (ADS)

Scherler, D.; Lamb, M. P.; Rhodes, E. J.; Avouac, J. P.

2014-12-01

The San Gabriel Mountains (SGM) in Southern California, rate amongst the most rapidly uplifting and eroding mountains in the United States. Their steep slopes and sensitivity to wildfires, flash floods, landslides, and debris flows account for imminent hazards to nearby urban areas that might be accentuated by climatic and other environmental changes. Previous studies suggested that river terraces along the North Fork of the San Gabriel River, record temporal variations in sediment supply and river transport capacity that are representative for the SGM and related to climatic changes during the Quaternary. Based on field observations, digital topographic analysis, and dating of Quaternary deposits, we suggest that valley aggradation in the North Fork San Gabriel Canyon was spatially confined and a consequence of the sudden supply of unconsolidated material to upstream reaches by one of the largest known landslides in the SGM. New 10Be-derived surface exposure ages from the landslide deposits, previously assumed to be early to middle Pleistocene in age, indicate at least three Holocene events at ~8-9 ka, ~4-5 ka, and ~0.5-1 ka. The oldest landslide predates the valley aggradation period, which is constrained by existing 14C ages and new luminescence ages to ~7-8 ka. The spatial distribution, morphology, and sedimentology of the river terraces are consistent with deposition from far-travelling debris flows that originated within the landslide deposits. Valley aggradation in the North Fork San Gabriel Canyon therefore resulted from locally enhanced sediment supply that temporarily overwhelmed river capacity but the lack of similar deposits in other parts of the SGM argues against a regional climatic signal. So far, there exists no evidence that in the San Gabriel Mountains, climatic changes can cause sustained increases in hillslope sediment supply that lead to river aggradation and terrace formation.

Water-quality characteristics of quaternary unconsolidated-deposit aquifers and lower tertiary aquifers of the Bighorn Basin, Wyoming and Montana, 1999-2001

USGS Publications Warehouse

Bartos, Timothy T.; Eddy-Miller, Cheryl A.; Norris, Jody R.; Gamper, Merry E.; Hallberg, Laura L.

2004-01-01

As part of the Yellowstone River Basin National Water Quality Assessment study, ground-water samples were collected from Quaternary unconsolidated-deposit and lower Tertiary aquifers in the Bighorn Basin of Wyoming and Montana from 1999 to 2001. Samples from 54 wells were analyzed for physical characteristics, major ions, trace elements, nutrients, dissolved organic carbon, radionuclides, pesticide compounds, and volatile organic compounds (VOCs) to evaluate current water-quality conditions in both aquifers. Water-quality samples indicated that waters generally were suitable for most uses, and that natural conditions, rather than the effects of human activities, were more likely to limit uses of the waters. Waters in both types of aquifers generally were highly mineralized, and total dissolved-solids concentrations frequently exceeded the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL) of 500 milligrams per liter (mg/L). Because of generally high mineralization, waters from nearly one-half of the samples from Quaternary aquifers and more than one-half of the samples from lower Tertiary aquifers were not classified as fresh (dissolved-solids concentration were not less than 1,000 mg/L). The anions sulfate, fluoride, and chloride were measured in some ground-water samples at concentrations greater than SMCLs. Most waters from the Quaternary aquifers were classified as very hard (hardness greater than 180 mg/L), but hardness varied much more in waters from the lower Tertiary aquifers and ranged from soft (less than 60 mg/L) to very hard (greater than 180 mg/L). Major-ion chemistry varied with dissolved-solids concentrations. In both types of aquifers, the predominant anion changes from bicarbonate to sulfate with increasing dissolved-solids concentrations. Samples from Quaternary aquifers with fresh waters generally were calcium-bicarbonate, calcium-sodium-bicarbonate, and calcium-sodium-sulfate-bicarbonate type waters, whereas samples with larger concentrations generally were calcium-sodium-sulfate, calcium-sulfate, or sodium-sulfate-type waters. In the lower Tertiary aquifers, samples with fresh waters generally were sodium-bicarbonate or sodium-bicarbonate-sulfate type waters, whereas samples with larger concentrations were sodium-sulfate or calcium-sodium-sulfate types. Concentrations of most trace elements in both types of aquifers generally were small and most were less than applicable USEPA standards. The trace elements that most often did not meet USEPA secondary drinking-water standards were iron and manganese. In fact, the SMCL for manganese was the most frequently exceeded standard; 68 percent of the samples from the Quaternary aquifers and 31 percent of the samples from the lower Tertiary aquifers exceeded the manganese standard. Geochemical conditions may control manganese in both aquifers as concentrations in Quaternary aquifers were negatively correlated with dissolved oxygen concentrations and concentrations in lower Tertiary aquifers decreased with increasing pH. Elevated nitrate concentrations, in addition to detection of pesticides and VOCs in both aquifers, indicated some effects of human activities on ground-water quality. Nitrate concentrations in 36 percent of the wells in Quaternary aquifers and 28 percent of the wells in lower Tertiary aquifers were greater than 1 mg/L, which may indicate ground-water contamination from human sources. The USEPA drinking-water Maximum Contaminant Level (MCL) for nitrate, 10 mg/L, was exceeded in 8 percent of samples collected from Quaternary aquifers and 3 percent from lower Tertiary aquifers. Nitrate concentrations in Quaternary aquifers were positively correlated with the percentage of cropland and other agricultural land (non-cropland), and negatively correlated with rangeland and riparian land. In the lower Tertiary aquifers, nitrate concentrations only were correlated with the percentage of cropland. Concentratio

Quaternary Geologic Map of the Lake Nipigon 4 Degrees x 6 Degrees Quadrangle, United States and Canada

USGS Publications Warehouse

Sado, Edward V.; Fullerton, David S.; Farrand, William R.; Edited and Integrated by Fullerton, David S.

1994-01-01

The Quaternary Geologic Map of the Lake Nipigon 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is a product of collaboration of the Ontario Geological Survey, the University of Michigan, and the U.S. Geological Survey, and is designed for both scientific and practical purposes. It was prepared in two stages. First, separate maps and map explanations were prepared by the compilers. Second, the maps were combined, integrated, and supplemented by the editor. Map unit symbols were revised to a uniform system of classification and the map unit descriptions were prepared by the editor from information received from the compilers and from additional sources listed under Sources of Information. Diagrams accompanying the map were prepared by the editor. For scientific purposes, the map differentiates Quaternary surficial deposits on the basis of lithology or composition, texture or particle size, structure, genesis, stratigraphic relationships, engineering geologic properties, and relative age, as shown on the correlation diagram and indicated in the map unit descriptions. Deposits of some constructional landforms, such as kame moraine deposits, are distinguished as map units. Deposits of erosional landforms, such as outwash terraces, are not distinguished, although glaciofluvial, ice-contact, and lacustrine deposits that are mapped may be terraced. As a Quaternary geologic map it serves as a base from which a variety of maps relating Quaternary geologic history can be derived. For practical purposes, the map is a surficial materials map. Materials are distinguished on the basis of lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized and classified in pedology or agronomy. Rather, it is a generalized map of soils as recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. As a materials map it serves as a base from which a variety of maps for use in planning engineering, land use, or land management projects can be derived.

Geohydrology and potential hydrologic effects of underground coal mining in the Rapid Creek Basin, Mesa County, Colorado

USGS Publications Warehouse

Brooks, Tom

1986-01-01

The U.S. Bureau of Land Management may lease additional coal tracts in the Rapid Creek basin, Colorado. Springs in this basin are used as a water supply for the town of Palisade. The geohydrology of the basin is described and the potential hydrologic effects of underground coal mining in the basin summarized. Geologic formations in the basin consists of Cretaceous sandstone and shale, Tertiary sandstone, shale, and basalt, and unconsolidated deposits of Quaternary age. Some sandstone and coal beds are permeable, although bedrock in the basin typically is a confining bed. Unconsolidated deposits contain aquifers that are the source of spring discharge. Stream discharge was measured on Rapid and Cottonwood Creeks, and inventories were made of 7 reservoirs, 25 springs, and 12 wells. Specific conductance of streams ranged from 320 to 1,050 microsiemens/cm at 25C; pH ranged from 7.8 to 8.6. Specific conductance of springs ranged from 95 to 1,050 microsiemens/cm at 25C; pH ranged from 6.8 to 8.3. Discharge from the basin includes about 18,800 acre-ft/yr as evapotranspiration, 1,300 acre-ft/yr as springflow, 1,280 acre-ft/yr as streamflow, and negligible groundwater flow in bedrock. With appropriate mining methods, underground mining would not decrease flow in basin streams or from springs. The potential effects of mining-caused subsidence might include water-pipeline damage and temporary dewatering of bedrock adjacent to coal mining. (Author 's abstract)

Map of surficial deposits and materials in the eastern and central United States (east of 102 degrees West longitude)

USGS Publications Warehouse

Fullerton, David S.; Bush, Charles A.; Pennell, Jean N.

2003-01-01

This data set contains surficial geologic units in the Eastern and Central United States, as well as a glacial limit line showing the position of maximum glacial advance during various geologic time periods. The geologic units represent surficial deposits and other surface materials that accumulated or formed during the past 2+ million years, such as soils, alluvium, and glacial deposits. These surface materials are referred to collectively by many geologists as regolith, the mantle of fragmented and generally unconsolidated material that overlies the bedrock foundation of a continent. This data set and the printed map produced from it, U.S. Geological Survey (USGS) Geologic Investigation Series I-2789, were based on 31 published maps in the USGS's Quaternary Geologic Atlas of the United States map series (USGS Miscellaneous Investigations Series I-1420). The data were compiled at 1:1,000,000 scale, to be viewed as a digital map at 1:2,000,000 nominal scale and to be printed as a conventional paper map at 1:2,500,000 scale.

Reconnaissance of the geology and ground-water resources in the Aurora area, St. Louis county, Minnesota

USGS Publications Warehouse

Maclay, Robert W.

1966-01-01

Ground water from the unconsolidated deposits is hard and commonly contains large, undesirable amounts of iron and manganese. Water from the 'bedrock aquifers contains less iron and manganese than does water from the unconsolidated deposits.

Geology and ground water of the Savannah River Plant and vicinity, South Carolina

USGS Publications Warehouse

Siple, George E.

1967-01-01

The area described in this report covers approximately 2,600 square miles in west-central South Carolina and includes the site of the Savannah River Plant, a major production facility of the U.S. Atomic Energy Commission. The climate, surface drainage, and land forms of the study area are typical of the southern part of the Atlantic Coastal Plain. Precipitation is normally abundant and fairly evenly distributed throughout the year, and the mean annual temperature is moderately warm (64?F). The major streams that drain the area (the Savannah, Salkehatchie, and Edisto Rivers) have low gradients and flow in a southeasterly direction toward the Atlantic Ocean. Surface features of the area include narrow, flat-bottomed, steep-sided valleys and broad gently rolling interfluvial areas. Those parts of the Coastal Plain included within the report area can be subdivided into the Aiken Plateau, the Congaree Sandhills, and the Coastal Terraces. The area is underlain by a sequence of unconsolidated and partly consolidated sediments of Late Cretaceous, Tertiary, and Quaternary age. The unconsolidated sediments were deposited unconformably on a basement of igneous and metamorphic rocks of Precambrian and Paleozoic age and sedimentary rocks of Triassic age. The basement rocks are similar to the granite-diorite complex of the Charlotte Belt, the metamorphosed rocks of the Carolina Slate Belt, and the consolidated sediments of the Newark Group. The unconsolidated sediments strike about N. 60 ? E. and dip 6-20 feet per mile to the southeast. They form a wedge-shaped mass that increases in thickness toward the southeast to slightly more than 1,200 feet in the vicinity of Allendale, S.C., on the southeast or downdip side of the study area. The oldest or lowermost unconsolidated sedimentary unit, the Tuscaloosa Formation of Late Cretaceous age, is overlain in the subsurface by beds that are also probably Late Cretaceous in age and that herein are named the Ellenton Formation. The Upper Cretaceous deposits are, in turn, overlain by the, McBean Formation and the Congaree(?) Formation of middle Eocene age, the Barnwell Formation of late Eocene age, the Hawthorn Formation of early and middle Miocene age, and by fluvial and marine(?) terrace deposits of Pliocene(?), Pleistocene, and Recent age. In the mapped area, the Congaree(?) Formation includes undifferentiated rocks (mostly Congaree and Barnwell Formations and some Mcbean outliers). (See map explanation.) Structurally, the Upper Cretaceous sediments are overlapped to the northwest by Tertiary deposits. A preliminary geologic map of the general area is included in the report. The principal aquifer in the area is composed of the beds of medium to coarse sand and gravel contained in the Tuscaloosa and Ellenton Formations. Subordinate aquifers include deposits of sand and limestone of Tertiary and Quaternary age. The ground water in the principal aquifer occurs under water-table conditions in the outcrop area of the Tuscaloosa Formation in the northern and western parts of the study area, but it is under artesian pressure downdip in the southern and eastern parts of the study area. Contours drawn on the piezometric surface of the water in the principal aquifer indicate that water is recharged to the aquifer mainly by leakage through the overlying Tertiary formations. Likewise, the piezometric contours show that the outcrop area of the Tuscaloosa Formation functions chiefly as an area of discharge. Doubtless, water is also discharged from the aquifer by moving downdip to areas near the coast where the prevailing hydraulic gradient may favor the upward leakage of water through the upper confining beds. The hydraulic properties of the principal aquifer were determined by a series of pumping tests. The results indicate that the aquifer is highly productive and could supply 15 million gallons per day in the vicinity of the Savannah River Plant without exceeding the available drawdown. Gr

Quaternary Activity of the Erciyes Fault Southeast of the Kayseri Basin, Turkey

NASA Astrophysics Data System (ADS)

Okumura, K.; Hayakawa, Y. S.; Kontani, R.; Fikri, K.

2016-12-01

The Erciyes fault in SE of the Kayseri basin is one of the most active Quaternary faults in Central Anatolia. Emre et al. (2011) mapped about 100 km long faults including a section runs across the Erciyes volcano. A M 7+ earthquake from the fault would be a big threat for the 1.5 million people in Kayseri basin, but little has been know about its activity and earthquake potential. We studied Plio-Pleistocene volacanics, Quaternary sediments, and UAV-SfM topography in southeast of the Kayseri basin and recognized significant dip-slip separation as well as sinistral slip in Late Quaternary. The Incesu ignimbrite (IC) of 2.52±0.49 Ma (Aydar et al., 2012) is a very distinctive densely welded ignimbrite layer in and around Kayseri basin. The Plinian pumice fall deposits from the Erciyes in Late Pleistocene (Sen et al. 2003) at Gesi Bagpnar (GBP) is another key-bed. There are two strands and one group of faults. The NE strike frontal strand separates the basin floor and the upland in SW extending from Kayseri city to more than 50 km NE. The Gesi Guney strand runs parallel to the frontal strand at 3 to 4 km away from the basin floor for 20 km from Ali Dag. The NS trending fault group is observed both inside and outside of the basin under IC. These NS faults are swarm of normal Pliocene faults. The Gesi Guney strand offsets IC around 120 m vertically. There is no information to infer the initiation of its activity, but the normal offset of an alluvial fan and unconsolidated fresh talus deposits indicate Late Quaternary activities. Near the SW end of the frontal strand, IC is vertically offset around 40 m. 15 km NE from the SW end, sand and gravel layers that intercalates GBP (0.11-0.14 Ma) are tilted to NW for 30 to 40 m and truncated by a sub-vertical sinistral faults. Most of frontal strand deformation occurred in Late Pleistocene because the offset of IC and GBP are similar. Estimated slip-rate of 0.3 to 0.4 mm/yr is significant for Central Anatolia.

Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

USGS Publications Warehouse

Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

2006-01-01

This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored maps provide a regional summary of the new mapping at a scale of 1:200,000, a scale that is sufficient to show the general distribution and relationships of the map units but not to distinguish the more detailed elements that are present in the database. The report is the product of cooperative work by the National Earthquake Hazards Reduction Program (NEHRP) and National Cooperative Geologic Mapping Program of the U.S. Geological Survey, William Lettis and & Associates, Inc. (WLA), and the California Geological Survey. An earlier version was submitted to the U.S. Geological Survey by WLA as a final report for a NEHRP grant (Witter and others, 2005). The mapping has been carried out by WLA geologists under contract to the NEHRP Earthquake Program (Grant 99-HQ-GR-0095) and by the California Geological Survey.

A spatial database of bedding attitudes to accompany Geologic map of the greater Denver area, Front Range Urban Corridor, Colorado

USGS Publications Warehouse

Trimble, Donald E.; Machette, Michael N.; Brandt, Theodore R.; Moore, David W.; Murray, Kyle E.

2003-01-01

This digital map shows bedding attitude symbols display over the geographic extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette 1973-1977 and published in 1979 (U.S. Geological Survey Map I-856-H) under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999), was digitized under the USGS Front Range Infrastructure Resources Project (see cross-reference). In general, the mountainous areas in the west part of the map exhibit various igneous and metamorphic bedrock units of Precambrian age, major faults, and fault brecciation zones at the east margin (5-20 km wide) of the Front Range. The eastern and central parts of the map (Colorado Piedmont) depict a mantle of unconsolidated deposits of Quaternary age and interspersed outcroppings of Cretaceous or Tertiary-Cretaceous sedimentary bedrock. The Quaternary mantle is comprised of eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone, shale, and limestone bedrock formations form hogbacks and intervening valleys.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glicken, H.

Large volcanic debris avalanches are among the world's largest mass movements. The rockslide-debris avalanche of the May 18, 1980, eruption of Mount St. Helens produced a 2.8 km/sup 3/ deposit and is the largest historic mass movement. A Pleistocene debris avalanche at Mount Shasta produced a 26 km/sup 3/ deposit that may be the largest Quaternary mass movement. The hummocky deposits at both volcanoes consist of rubble divided into (1) block facies that comprises unconsolidated pieces of the old edifice transported relatively intact, and (2) matrix facies that comprises a mixture of rocks from the old mountain and material pickedmore » up from the surrounding terrain. At Mount St. Helens, the juvenile dacite is found in the matrix facies, indicating that matrix facies formed from explosions of the erupting magma as well as from disaggregation and mixing of blocks. The block facies forms both hummocks and interhummock areas in the proximal part of the St. Helens avalanche deposit. At Mount St. Helens, the density of the old cone is 21% greater than the density of the avalanche deposit. Block size decreases with distance. Clast size, measured in the field and by sieving, coverages about a mean with distance, which suggests that blocks disaggregated and mixed together during transport.« less

Quaternary Geologic Map of the Lake of the Woods 4 Degrees x 6 Degrees Quadrangle, United States and Canada

USGS Publications Warehouse

Sado, Edward V.; Fullerton, David S.; Goebel, Joseph E.; Ringrose, Susan M.; Edited and Integrated by Fullerton, David S.

1995-01-01

The Quaternary Geologic Map of the Lake of the Woods 4 deg x 6 deg Quadrangle, United States and Canada, was mapped as part of the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series (Miscellaneous Investigations Series I-1420, NM-15). The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is a product of collaboration of the Ontario Geological Survey, the Minnesota Geological Survey, the Manitoba Department of Energy and Mines, and the U.S. Geological Survey, and is designed for both scientific and practical purposes. It was prepared in two stages. First, separate maps and map explanations were prepared by the compilers. Second, the maps were combined, integrated, and supplemented by the editor. Map unit symbols were revised to a uniform system of classification and the map unit descriptions were prepared by the editor from information received from the compilers and from additional sources listed under Sources of Information. Diagrams accompanying the map were prepared by the editor. For scientific purposes, the map differentiates Quaternary surficial deposits on the basis of lithology or composition, texture or particle size, structure, genesis, stratigraphic relationships, engineering geologic properties, and relative age, as shown on the correlation diagram and indicated in the description of map units. Deposits of some constructional landforms, such as kame moraine deposits, are distinguished as map units. Deposits of erosional landforms, such as outwash terraces, are not distinguished, although glaciofluvial, ice-contact, and lacustrine deposits that are mapped may be terraced. As a Quaternary geologic map, it serves as a base from which a variety of maps relating Quaternary geologic history can be derived. For practical purposes, the map is a surficial materials map. Materials are distinguished on the basis of lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized and classified in pedology or agronomy. Rather, it is a generalized map of soils as recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. As a materials map, it serves as a base from which a variety of maps for use in planning engineering, land-use, or land-management projects can be derived.

Evidences of Neotectonic Movements Recorded in Fluvial and Lacustrine Deposits of the Niger River in Bamako, Mali

NASA Astrophysics Data System (ADS)

Dembele, N. D. J.

2015-12-01

Two alluvial profiles showing evidences of tectonic movements were discovered along the right bank of the Niger River at Bamako. The first profile of 25 meters thick is composed of a laminated silt layer of about 22 meters, of a gray sand layer of 25 cm and a pebble layer of 2 meters. A layer of 80 cm wide, an intrusive body, crosscuts the silt layers. The Grain size and heavy minerals analysis showed that this vertical layer is different in structure, texture and composition from the other layers. The second profile of about 20 meters is composed of interbedded fluvial gravel and sand deposits. The tectonic evidences found on those layers are of three types: faults and fractures, folds and the intrusion between silts deposits of the sand layers previously presented. The faults and fractures are located mainly on the fluvial gravel and sand deposits, whereas the silts deposits are folded and show some microfaults. The intrusion of a sand layer between the silt layer is a geological process that is not yet well understood but it is believed that this phenomena occurs during earthquakes as the sand layer during such event behave as a liquid. The discovery of such layer testifies that earthquakes used to happen in the area. As they concern only the alluvial deposits, their age should be no more than the Quaternary period. The presence of such tectonic evidences is surprising as Bamako like all the Republic of Mali is located on the west African craton that is supposed to be tectonically stable and their occurrence on Quaternary unconsolidated sediments shows that tectonic movements used to occur on that area during the last 2 millions years or may be less whereas people continue to build houses and other social infrastructures on them without any caution.

Hydrology and simulation of ground-water flow in Kamas Valley, Summit County, Utah

USGS Publications Warehouse

Brooks, L.E.; Stolp, B.J.; Spangler, L.E.

2003-01-01

Kamas Valley, Utah, is located about 50 miles east of Salt Lake City and is undergoing residential development. The increasing number of wells and septic systems raised concerns of water managers and prompted this hydrologic study. About 350,000 acre-feet per year of surface water flows through Kamas Valley in the Weber River, Beaver Creek, and Provo River, which originate in the Uinta Mountains east of the study area. The ground-water system in this area consists of water in unconsolidated deposits and consolidated rock; water budgets indicate very little interaction between consolidated rock and unconsolidated deposits. Most recharge to consolidated rock occurs at higher altitudes in the mountains and discharges to streams and springs upgradient of Kamas Valley. About 38,000 acre-feet per year of water flows through the unconsolidated deposits in Kamas Valley. Most recharge is from irrigation and seepage from major streams; most discharge is to Beaver Creek in the middle part of the valley. Long-term water-level fluctuations range from about 3 to 17 feet. Seasonal fluctuations exceed 50 feet. Transmissivity varies over four orders of magnitude in both the unconsolidated deposits and consolidated rock and is typically 1,000 to 10,000 feet squared per day in unconsolidated deposits and 100 feet squared per day in consolidated rock as determined from specific capacity. Water samples collected from wells, streams, and springs had nitrate plus nitrite concentrations (as N) substantially less than 10 mg/L. Total and fecal coliform bacteria were detected in some surface-water samples and probably originate from livestock. Septic systems do not appear to be degrading water quality. A numerical ground-water flow model developed to test the conceptual understanding of the ground-water system adequately simulates water levels and flow in the unconsolidated deposits. Analyses of model fit and sensitivity were used to refine the conceptual and numerical models.

Peatland hydrogeological function at the regional scale

NASA Astrophysics Data System (ADS)

Larocque, M.; Avard, K.; Pellerin, S.

2012-12-01

Peatlands are important components of northern landscapes. In the Canadian province of Quebec, peatlands of the St. Lawrence Valley are rapidly disappearing, threatened by rapidly growing pressures from development. Peatlands are to varying extents groundwater dependent and as such are likely to respond drastically to changes in groundwater flow conditions and to contribute to the maintenance of groundwater levels within a superficial aquifer. Yet, there is very little understanding of the hydrogeological function of peatlands at the regional scale. For this reason, they are often simply discarded in complex groundwater management decisions. The implications are not clearly understood but could lead to the disruption of ecologically important fluxes and to significant impacts for the maintenance of long term water reservoirs across the land. This study was initiated in the Centre-du-Quebec region of southern Quebec to quantify how the peatland landscape has evolved in the last decades and to understand the hydrogeological function of peatlands at the regional scale. The study area (2856 km2) is located in the St. Lawrence Lowlands. The last deglaciation has contributed to a complex stratigraphy of unconsolidated sediments and peatlands have developed at the foot of the Appalachians. A recent regional study of Quaternary deposits has shown that a majority of these peatlands are found on aeolian deposits or reworked till, while only a few are set on marine clay, littoral deposits or directly on the bedrock. The area occupied by peatlands was measured with aerial photographs dating from 1966 and 2010. In 2010, peatlands were found on 6.1 % of the territory. Of these peatlands, 10 485 ha were intact and 7 015 underwent limited perturbations (e.g. drainage ditch, forest roads). Between 1966 and 2010, nearly a quarter of the peatlands observed in 1966 underwent irreversible perturbations (e.g. agriculture, paved roads). The main cause of peatland disappearance was from cranberry crops which have been developing extremely rapidly in the study area. Nine peatlands from different parts of the study area were sampled to determine the nature of the underlying sediments. Results show that eight out of the nine studied peatlands are located on relatively permeable sand deposits and can therefore sustain hydrogeological exchanges with the surrounding aquifer. Darcy fluxes calculated from piezometric data for the nine peatlands show that five of them receive water from the superficial aquifer while four contribute water to it. Using Quaternary deposits data and a 3D hydrostratigraphic model, the proportion of peatlands receiving groundwater or contributing water to the aquifer was found to be similar at the regional scale. For the nine studied peatlands, aquifer-peatland fluxes represent between 6 and 11% of the total water input to the organic deposits. Results also show that exchanged aquifer-peatland fluxes increase with the size of the peatland, either towards the peatland or from the organic deposits to the aquifer. This study suggests that peatlands have a buffer function to keep relatively stable levels in a superficial unconsolidated aquifer. Maintaining a peatland coverage on the landscape could contribute to sustain groundwater resources.

Subsurface geology of the late Tertiary and Quaternary water-bearing deposits of the southern part of the San Joaquin Valley, California

USGS Publications Warehouse

Croft, M.G.

1972-01-01

The study area, which includes about 5,000 square miles of the southern part of the San Joaquin Valley, is a broad structural trough of mostly interior drainage. The Sierra Nevada on the east is composed of consolidated igneous and metamorphic rocks of pre-Tertiary age. The surface of these rocks slopes 4?-6? southwestward from the foothills and underlies the valley. The Coast Ranges on the west consist mostly of complexly folded and faulted consolidated marine and nonmarine sedimentary rocks of Jurassic, Cretaceous, and Tertiary age, which dip eastward and overlie the basement complex. Unconsolidated deposits, of late Pliocene to Holocene age, blanket the underlying consolidated rocks in the valley and are the source of most of the fresh ground water. The unconsolidated deposits, the subject of this report, are divided into informal stratigraphic units on the basis of source of sediment, environment of deposition, and texture. Flood-basin, lacustrine, and marsh deposits are fine grained and underlie the valley trough. They range in age from late Pliocene to Holocene. These deposits, consisting of nearly impermeable gypsiferous fine sand, silt, and clay, are more than 3,000 feet thick beneath parts of Tulare Lake bed. In other parts of the trough, flood-basin, lacustrine, and marsh deposits branch into clayey or silty clay tongues designated by the letter symbols A to F. Three of these tongues, the E, C, and A clays, lie beneath large areas of the southern part of the valley. The E clay includes the Corcoran Clay Member of the Tulare Formation, the most extensive hydrologic confining layer in the valley. The E clay underlies about 3,500 square miles of bottom land and western slopes. The beds generally are dark-greenish-gray mostly diatomaceous silty clay of Pleistocene age. Marginally, the unit bifurcates into an upper and a lower stratum that contains thin beds of moderately yellowish-brown silt and sand. The E clay is warped into broad, gentle northwesterly trending anticlines and synclines. The C clay, of Pleistocene age, is a fine-grained lacustrine or paludal deposit occurring 220-300 feet beneath Tulare Lake bed and parts of Fresno Slough. The beds consist of bluish-gray silty clay. Structural contours indicate that the C clay has been extensively warped and folded. The A clay of Pleistocene and Holocene (?) age is a fine-grained lacustrine or paludal deposit occurring 10-60 feet beneath Buena Vista, Kern, and Tulare Lake beds, and parts of Fresno Slough. The clay is mainly blue or dark greenish gray, plastic, and highly organic. In some areas the unit is separated into an upper and a lower stratum by several feet of sand. A radiocarbon date of 26,780 ? 600 years was obtained from wood cored 3 feet beneath the clay. Continental deposits are arkosic beds of late Pliocene and Pleistocene (?) age and were derived from the Sierra Nevada, Tehachapi, and San Emigdio Mountains. In places, a reduced-oxidized contact transgresses the deposits derived from the Sierra Nevada. The reduced deposits consist of moderately permeable bluish-green or bluish-gray fine to medium sand, silt, and clay. The oxidized deposits consist mainly of poorly permeable yellowish-brown silt and fine sand. Deposits derived from the Tehachapi and the San Emigdio Mountains consist of poorly to moderately permeable yellowish-brown sand and silt. Continental and alluvial deposits of Tertiary and Quaternary age that were derived from the Coast Ranges consist mainly of poorly to moderately permeable yellowish-brown gravel, sand, silt, and clay. They include the Tulare Formation and overlying alluvial deposits. Alluvium is composed of coarse arkosic deposits derived from the Sierra Nevada, Tehachapi, and San Emigdio Mountains. A reduced-oxidized contact also transgresses the alluvial deposits derived from the Sierra Nevada. The oxidized deposits consist of poorly to highly permeable yellowish-brown gravel, sand, silt, and clay. The reduc

A spatial database of bedding attitudes to accompany Geologic Map of Boulder-Fort Collins-Greeley Area, Colorado

USGS Publications Warehouse

Colton, Roger B.; Brandt, Theodore R.; Moore, David W.; Murray, Kyle E.

2003-01-01

This digital map shows bedding attitude data displayed over the geographic extent of rock stratigraphic units (formations) as compiled by Colton in 1976 (U.S.Geological Survey Map I-855-G) under the Front Range Urban Corridor Geology Program. Colton used his own mapping and published geologic maps having varied map unit schemes to compile one map with a uniform classification of geologic units. The resulting published color paper map was intended for planning for use of land in the Front Range Urban Corridor. In 1997-1999, under the USGS Front Range Infrastructure Resources Project, Colton's map was digitized to provide data at 1:100,000 scale to address urban growth issues(see cross-reference). In general, the west part of the map shows a variety of Precambrian igneous and metamorphic rocks, major faults and brecciated zones along an eastern strip (5-20 km wide) of the Front Range. The eastern and central part of the map (Colorado Piedmont) depicts a mantle of Quaternary unconsolidated deposits and interspersed Cretaceous or Tertiary-Cretaceous sedimentary rock outcrops. The Quaternary mantle is comprised of eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone and shale formations (and sparse limestone) form hogbacks, intervening valleys, and in range-front folds, anticlines, and fault blocks. Localized dikes and sills of Tertiary rhyodacite and basalt intrude rocks near the range front, mostly in the Boulder area.

Digital data sets that describe aquifer characteristics of the Central Oklahoma Aquifer in central Oklahoma

USGS Publications Warehouse

Runkle, D.L.; Christenson, S.C.; Rea, Alan

1997-01-01

ARC/INFO export files The data sets in this report include digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of Cleveland, Lincoln, Logan, Oklahoma, Payne, and Pottawatomie Counties. The Central Oklahoma aquifer includes the alluvial and terrace deposits along major streams, the Garber Sandstone and Wellington Formations, and the Chase, Council Grove, and Admire Groups. The Quaternary-age alluvial and terrace deposits consist of unconsolidated clay, silt, sand, and gravel. The Permian-age Garber Sandstone and Wellington Formations consist of sandstone with interbedded siltstone and mudstone. The Permian-age Chase, Council Grove, and Admire Groups consist of sandstone, shale, and thin limestone. The Central Oklahoma aquifer underlies about 3,000 square miles of central Oklahoma where the aquifer is used extensively for municipal, industrial, commercial, and domestic water supplies. Most of the usable ground water within the aquifer is from the Garber Sandstone and Wellington Formations. Substantial quantities of usable ground water also are present in the Chase, Council Grove, and Admire Groups, and in alluvial and terrace deposits associated with the major streams. The aquifer boundaries, hydraulic conductivity and recharge values, and ground-water level elevation contours are from previously published reports.

Geomorphological map and preliminary analysis of Quaternary sediments in the Planica-Tamar valley (Julian Alps, NW Slovenia)

NASA Astrophysics Data System (ADS)

Novak, Andrej; Šmuc, Andrej

2016-04-01

The Planica-Tamar valley is located in the Julian Alps in north-west Slovenia. The Planica-Tamar valley represents typical mountain glacial valley bounded by steep, mainly carbonate cliffs with some glacial deposits still preserved. The valley is currently being filled with numerous Holocene sediments deposited by rock falls, landslides, mass gravity flows and fluvial flows. These deposits are forming active or inactive interfingering talus slopes, alluvial and debris-flow fans, all of them with a complex history of sedimentation and erosion forming unconformity bounded sedimentary units. In order to make a thorough analysis of these deposits a detailed geomorphological map in a scale of 1:10 000 has been made. Six different types of sedimentary deposits were defined and mapped. These are moraines, lacustrine sediments, fluvio-glacial deposits, talus slopes, debris fans and alluvial fans. Other mapped features also include shape of ravines, their depths, ridges and direction of sedimentary flow. Additionally areas of active, semi-active and inactive sedimentation were marked. Moraines forms a ridge in the bottom of the valleys and are composed of unconsolidated, poorly sorted, subangular grains ranging from clay size to a few cubic meters big blocks. Lacustrine sediments are represented by laminated well sorted sand and silt, while fluvio-glacial deposits are composed of washed out subrounded sands and gravels. Talus slope deposits are characterised by clast-supported poorly sorted very angular gravel. Debris flow fans are represented by extremely poorly sorted matrix-supported gravels with grain size ranging from clay to few cubic meters big blocks. Alluvial fans are composed by variety of sedimentary textures. Sediments at the fan apex are clast-supported poorly sorted very angular gravels with up to a few cubic meters big block. In the middle part of the fan the sieve deposits are common, while in the distal parts a few centimeters thick layers of sand and moderately sorted clast or sandy matrix-supported angular gravels occur. In cross-sections of alluvial fans distinct palaeosoil horizons are present indicating longer inactivity of that part of the fan. The geomorphological map forms a base for further research and thorough analysis of Quaternary deposits in order to reconstruct the Holocene dynamic of triggering and sedimentation of different types of slope deposits and relate them to base rock geology, tectonic and local/regional climate events. Key words: geomorphological mapping, Holocene slope deposits, alluvial fans, debris fans, Alpine geomorphology.

Hydrologic framework of Long Island, New York

USGS Publications Warehouse

Smolensky, Douglas A.; Buxton, Herbert T.; Shernoff, Peter K.

1990-01-01

Long Island, N.Y., is underlain by a mass of unconsolidated geologic deposits of clay, silt, sand, and gravel that overlie southward-sloping consolidated bedrock. These deposits are thinnest in northern Queens County (northwestern Long Island), where bedrock crops out, and increase to a maximum thickness of 2,000 ft in southeastern Long Island. This sequence of unconsolidated deposits consists of several distinct geologic units ranging in age from late Cretaceous through Pleistocene, with some recent deposits near shores and streams. These units are differentiated by age, depositional environment, and lithology in table 1. Investigations of ground-water availability and flow patterns may require information on the internal geometry of the hydrologic system that geologic correlations and interpretation alone cannot provide; hydrologic interpretations in which deposits are differentiated on the basis of water-transmitting properties are generally needed also. This set of maps and vertical sections depicts the hydrogeologic framework of the unconsolidated deposits that form Long Island's ground-water system. These deposits can be classified into eight major hydrogeologic units (table 1). The hydrogeologic interpretations presented herein are not everywhere consistent with strict geologic interpretation owing to facies changes and local variations in the water-transmitting properties within geologic units. These maps depict the upper-surface altitude of seven of the eight hydrogeologic units, which, in ascending order, are: consolidated bedrock, Lloyd aquifer, Raritan confining unit, Magothy aquifer, Monmouth greensand, Jameco aquifer, and Gardiners Clay. The upper glacial aquifer—the uppermost unit—is at land surface over most of Long Island and is, therefore, not included. The nine north-south hydrogeologic sections shown below depict the entire sequence of unconsolidated deposits and, together with the maps, provide a detailed three-dimensional interpretation of Long Island's hydrogeologic framework. The structure-contour map that shows the upper-surface altitude of the Cretaceous deposits is included to illustrate the erosional unconformity between the Cretaceous and overlying Pleistocene deposits. Pleistocene erosion played a major role in determining the shape and extent of the Lloyd aquifer, the Raritan confining unit, and the Magothy aquifer, and thus partly determined their hydrogeologic relation with subsequent (post-Cretaceous) deposits.

Hydrology and subsidence potential of proposed coal-lease tracts in Delta County, Colorado

USGS Publications Warehouse

Brooks, Tom

1983-01-01

Potential subsidence from underground coal mining and associated hydrologic impacts were investigated at two coal-lease tracts in Delta County, Colorado. Alteration of existing flow systems could affect water users in the surrounding area. The Mesaverde Formation transmits little ground water because of the neglibile transmissivity of the 1,300 feet of fine-grained sandstone, coal , and shale comprising the formation. The transmissivities of coal beds within the lower Mesaverde Formation ranged from 1.5 to 16.7 feet squared per day, and the transmissivity of the upper Mesaverde Formation, based on a single test, was 0.33 foot squared per day. Transmissivities of the alluvium ranged from 108 to 230 feet squared per day. The transmissivity of unconsolidated Quaternary deposits, determined from an aquifer test, was about 1,900 feet squared per day. Mining beneath Stevens Gulch and East Roatcap Creek could produce surface expressions of subsidence. Subsidence fractures could partly drain alluvial valley aquifers or streamflow in these mines. (USGS)

Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through September 30, 2006

USGS Publications Warehouse

Beman, Joseph E.

2007-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin are currently (2007) obtained solely from ground-water resources. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. From April 1982 through September 1983, a network of wells was established to monitor changes in ground-water levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. Currently (2007), the network consists of 133 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 133 sites through 2007.

Maps and tables showing data and analyses of semiquantitative emmission spectrometry and atomic-absorption spectrophotometry of rock samples, Ugashik, Bristol Bay, and part of Karluk quadrangles, Alaska

USGS Publications Warehouse

Wilson, Frederic H.; O'Leary, R. M.

1986-01-01

The accompanying maps and tables show analytical data and data analyses from rock samples collected in conjunction with geologic mapping in the Ugashik, Bristol Bay and western Karluck quadrangles from 1979 through 1981. This work was conducted under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP). A total of 337 samples were collected for analysis, primarily in areas of surficial alteration. The sample locations are shown on sheet 1: they are concentrated along the Pacific Ocean side of the area because the Bristol Bay lowlands part of the map is predominantly unconsolidated Quaternary deposits. Sample collection was by the following people, with their respective two letter identifying code shown in parentheses: W.H. Allaway (AY), J.E. Case (CE), D.P. Cox (CX), R.L. Detterman, (DT), T.G. Theodore (MK), F.H. Wilson (WS), and M.E. Yount (YB).

Human Health Impact of Fluoride in Groundwater in the Chiang Mai Basin

NASA Astrophysics Data System (ADS)

Matsui, Y.; Takizawa, S.; Wattanachira, S.; Wongrueng, A.; Ibaraki, M.

2005-12-01

Chiang Mai Basin, in Northern Thailand, is known as a fluorotic area. Groundwater of the Chiang Mai Basin has been gradually replaced by contaminated surface water since the 1980's. People have been exposed to fluoride contaminated groundwater since that time. As a result, harmful health effects on dental and skeletal growth were observed in the 90's. These include dental and skeletal fluorosis. Dental fluorosis is characterized by yellow or white spots on teeth and pitting or mottled enamel, consequently causing the teeth to look unsightly. Skeletal fluorosis leads to changes in bone structure, making them extremely weak and brittle. The most severe form of this is known as ``crippling skeletal fluorosis,'' a condition that can cause immobility, muscle wasting, and neurological problems related to spinal cord compression. This study focuses on the problematic issue of the Chiang Mai Basin's groundwater from the viewpoint of fluoride occurrence and current health impacts. Chiang Mai and Lamphun Provinces comprise the Chiang Mai Basin. Fluoride rich granites or fluorite deposits are scattered across the mountainside of the Lamphun Province. Tropical savanna climate conditions with seasonal monsoons bring more than 1,000 mm of annual precipitation, which can prompt weathering of minerals containing fluoride. The Ping River dominates the Basin, and the main eastern tributary of the Ping River runs through the Lamphun Province. The Basin has geological units composed of lower semi-consolidated Tertiary fluvial and upper unconsolidated Quaternary alluvium deposits. The main aquifers are in the upper unconsolidated unit. High fluoride concentrations tend to be observed in the aquifer located in lower part of this unconsolidated unit. We have been investigating two areas in the Basin. These two locations are similar with respect to geological and hydrological settings. However, one area in which groundwater is Ca-bicarbonate dominant has a low fluoride occurrence. Groundwater of the other area contains a high fluoride concentration and is Na-bicarbonate dominant. We will present how naturally-occurring fluoride found in this groundwater has impacted the health of a large portion of residents in the Chiang Mai Basin, and we will explain the mechanism that differentiates Ca concentration, which controls fluoride concentration in groundwater, between different areas in the Basin.

Micromorphology in unconsolidated landslide sediments - investigating mass movement deposits at a different scale

NASA Astrophysics Data System (ADS)

Jaeger, Daniel; Menzies, John

2015-04-01

In order to reliably reconstruct a landslide event, its triggers, movements and the main factors of influence, a profound knowledge of the slide masses' inner architecture and their internal processes is of great importance. As van der Meer (1996) states, micromorphology permits a complete examination of particles, matrix and all components contained in unconsolidated sediments, as well as an insight into their internal arrangement. So far, thin sections and micromorphology are mainly used for studying marine, periglacial and glacial sediments (e.g. Maltman 1988; van der Meer 1993, Menzies 2000, van Fliet-Lanoe 2010, van der Meer & Menzies 2011). Comparatively little work has been carried out with a focus on landslides (e.g. Bertran & Texier 1999). Therefore, our work is a first attempt at investigating unconsolidated deposits of landslides in the low mountain areas of southern Germany using micromorphological tools. The objective was to observe sedimentary microstructures in order to gain an understanding of the sediments' internal movement, deformation etc. during a slide event. On the investigated landslides near Ebermannstadt (Franconian Alb), Gailnau (Frankenhöhe region) and Talheim (Swabian Alb) samples were taken from small pits or outcrops (depths between 50 cm - 300 cm below the surface) in the upper, central and lower part (foot) of the slide mass. The thin section analyses revealed several differences between the three environments and within the specific landslides themselves. Most prominently, several structures (e.g. water-escape-structures, flow-noses and rotational structures) indicate a crucial impact of water in all three slide masses. Furthermore, the thin sections showed heterogeneous compositions of different sediment materials and aggregates, presumably transported, mixed together and deformed during the slide movement. In Ebermannstadt and Talheim, several ductile and brittle deformation structures (rotational structures, marbled structures, fractures, crushed grains) were obvious in those deposits, proving a rather turbulent mass movement with pervasive pressure and stress and varying phases of deformation. In contrast, thin sections from Gailnau only provided very slight deformation structures, which lead to the assumption of a completely different and steadier type of movement with less pressure. Downslope, samples from all landslides showed accumulations of broken fragments with plasma filling out (parts of) the joints, while samples from the front areas (foot) revealed plasma-dominated, structureless, homogenized sediments with varying amounts of sand particles but with few fragments in it. This leads to the assumption of water-saturated plasma being squeezed out of the main accumulation body during its deposition, creating a flow-type movement in the foremost part of both landslides. The results significantly improved the understanding of the behavior of the landslides as several details in terms of processes and structures could be revealed. The micromorphological analyses also helped to validate presumptions gathered from geomorphological mapping and geophysical soundings. Although continuing research into the microstructure of landslide deposits is necessary, our investigations already illustrate the potential value of micromorphology in this environment. References - Bertran, P. & Texier, J.-P. (1999). Facies and microfacies of slope deposits. Catena 35: 99-121. - Maltman, A. J. (1988). The importance of shear zones in naturally deformed wet sediments. Tectonophysics 145: 163-175. - Menzies, J. (2000). Micromorphological analyses of microfabrics and microstructures, indicative of deformation processes. In: Maltman, A. J. Hubbard, B., Hambrey, M.J. (Eds.): Deformations of Glacial Materials. Geological Society, London, 245-258. - van der Meer, J. J. M. (1993). Microscopic evidence of subglacial deformation. Quaternary Science Reviews 12: 553-587. - van der Meer, J.J.M. (1996): Micromorphology. In: Menzies, J. (Ed.): Past Glacial Environments - Sediments, Forms and Techniques. Butterworth-Heinemann, Oxford, 335-356. - van der Meer, J. J. M. & Menzies, J. (2011). The micromorphology of unconsolidated sediments. Sedimentary Geology 238: 213-232. - van Fliet-Lanoe, B. (2010). Frost action. In: Stoops, G. Marcelino, V., Mees, F.: Interpretation of micromorphological features of soils and regoliths. Elsevier, Amsterdam, 81-108.

Geohydrology and water quality of the unconsolidated deposits in Erie County, Pennsylvania

USGS Publications Warehouse

Buckwalter, T.F.; Schreffler, C.L.; Gleichsner, R.E.

1996-01-01

Water in unconsolidated deposits is used for the water supplies of homes, farms, municipalities, and industries in Erie County. The unconsolidated deposits cover most of the bedrock of Erie County. Thickness of the unconsolidated deposits ranged from 60 to 400 feet at 30 sites surveyed by seismic refraction and reflection methods. Water wells, mostly in the unconsolidated deposits, provide adequate domestic supplies. Wells in fractured bedrock can generally provide small domestic supplies; however, droughts can affect some of the domestic water wells. Ground-water withdrawals accounted for 10 million gallons per day of the water used in Erie County in 1984. Mean annual precipitation ranged from 42 to 47 inches per year in Erie County from 1961 through 1990; the southeastern region of the county generally receives more precipitation than the lake shore region to the north. Overland runoff to three segments of the French Creek watershed in the upland area ranged from about 13 to 19 in. per year and base flow ranged from 14 to about 18 in. per year from 1975 to 1992. Evapotranspiration ranged from about 13 to 16 in. per year for those segments. Beach and outwash deposits generally provide the largest supplies of water to wells in Erie County. A median specific capacity of 17 (gal/min)/ft (gallons per minute per foot) of drawdown was determined from records of nondomestic wells in beach deposits and 9 (gal/min)/ft of drawdown in outwash. Mean specific capacity for wells in till deposits was 1.5 (gal/min)/ft. The range in yield and specific capacity, however, was great for the unconsolidated deposits and high yielding outwash deposits are sometimes difficult to locate beneath till and valley-fill deposits. Hydraulic conductivities from three aquifer tests of outwash deposits (sand and gravel) at separate sites ranged from 110 to 2,030 ft/d (feet per day). Hydraulic conductivities from another aquifer test of sand and silt in the water table at Presque Isle ranged from 120 to 215 ft/d. Transmissivities from a third aquifer test of beach sand and gravel ranged from 235 to 262 feet squared per day. Laboratory analyses of stream samples collected during base flows in 1987 and 1988 indicate that concentrations of arsenic, barium, cadmium, chromium, fluoride, lead, mercury, and selenium did not exceed the maximum contaminant levels (MCL's) established for drinking water by the U.S. Environmental Protection Agency (USEPA). Concentrations of two nontoxic elements, iron and manganese, exceeded USEPA secondary maximum contaminant levels (SMCL's) in samples from selected stream sites. Manganese concentrations exceeded the SMCL of 0.05 milligrams per liter at 19 of 30 stream sites sampled in the Upland Plateau Section of Erie County. Twenty-one wells were sampled for inorganic constituents and selected pesticides. Some samples from three of the wells exceeded the MCL for nitrate. Total arsenic concentrations above the MCL of 50 micrograms per liter were documented intermittently in three water wells in North East Township. Water from six of seven tile drains sampled in agricultural fields contained detectable concentrations of herbicides. These samples document the transport of the herbicides from the shallow ground-water system to local streams. Herbicide concentrations were at or more than minimum reporting levels for atrazine, cyanazine, prometone, and simazine. Atrazine concentrations in all seven samples from tile drains did not exceed the USEPA MCL of 3.0 micrograms per liter.

Groundwater/surface-water interactions in the Tunk, Bonaparte, Antoine, and Tonasket Creek Subbasins, Okanogan River Basin, North-Central Washington, 2008

USGS Publications Warehouse

Sumioka, S.S.; Dinicola, R.S.

2009-01-01

An investigation into groundwater/surface-water interactions in four tributary subbasins of the Okanogan River determined that streamflows and shallow groundwater levels beneath the streams varied seasonally and by location. Streamflows measured in June 2008 indicated net losses of streamflow along 10 of 17 reaches, and hydraulic gradients measured between streams and shallow groundwater indicated potential recharge of surface water to groundwater at 11 of 21 measurement sites. In September 2008, net losses of streamflow were indicated along 9 of 17 reaches, and potential recharge of surface water to groundwater was indicated at 18 of 21 measurement sites. The greatest losses of streamflow occurred near the confluences with the Okanogan River, likely due to the presence of thick layers of unconsolidated deposits in the flood plain of the Okanogan River. Based on available geologic information compiled from drillers' logs, a surficial geologic map, and streamflow records, the extensive and thick deposits of unconsolidated material in the Tunk and Bonaparte Creek subbasins are factors in sustaining the almost perennial streamflow in those creeks. The less extensive and generally thinner unconsolidated deposits in the Tonasket and Antoine subbasins are contributing factors to the occasional extended periods of zero flow (a dry stream channel) in those creeks. Even though groundwater withdrawals would affect streamflows, relatively low precipitation in the area, along with limited groundwater storage capacity and the presence of permeable, unconsolidated deposits underlying the stream channels, would likely lead to loss of surface water to the groundwater system without any withdrawals.

Paleoenvironmental significance of Holocene widespread deposition of continental carbonates in Serra da Bodoquena, West-central Brazil

NASA Astrophysics Data System (ADS)

Sallun Filho, W.; Ribeiro, L. M. A. L.; Sawakuchi, A. O.; Boggiani, P. C.

2016-12-01

Continental carbonates are used in paleoenvironmental reconstructions in several parts of the world. Tufas and unconsolidated micrites can provide valuable information about the environmental conditions during the period of deposition. When the deposits are discontinuous, their presence is evidence of a wet period with conditions that are favourable to deposition; the deposits can be a record of the hydrologic systems and paleoclimate of the period of deposition. Discontinuous periods of deposition could also indicate changes in hydrological conditions that were independent of changes in climate, such as by temporary activity of springs or changes in a river's position. Deposits of continental carbonates in Brazil are rare, but in the State of Mato Grosso do Sul, there are extensive deposits, especially in the Serra da Bodoquena karst area, which form expansive plains of unconsolidated micrite and phytohermal fluvial tufa. These deposits are collectively called the Serra da Bodoquena Formation. New radiocarbon and OSL ages confirm the Holocene as the age of The Serra da Bodoquena Formation which shows periods of more extensive deposition than today. Well-dated deposits of unconsolidated micrites from paleolakes indicate a deposition that occurred approximately 6,500 to 2,000 years BP. These deposits can be identified by their smooth textures, as compared to surrounding karst areas. Over the paleolake deposits, there are phytohermal tufas that can be identified adjacent to present-day fluvial channels, presenting irregular winding arcs and relict fluvial channels. These arcs correspond to the edges of ancient tufa dams. One ancient and inactive dam have radiocarbon ages between 680 and 895 cal years AD. Apparently, there was a distinct lack of deposition between approximately 2,000 and 1,270 years BP, after which the deposition is continuous. Younger radiocarbon ages of 670 to 550 cal years BP are found in terrace tufa deposits (present-day river channel). This work was supported by FAPESP (São Paulo Research Foundation, grant #14/14433-9) and CNPq (Scholarships).

Geologic map of the White Hall quadrangle, Frederick County, Virginia, and Berkeley County, West Virginia

USGS Publications Warehouse

Doctor, Daniel H.; Orndorff, Randall C.; Parker, Ronald A.; Weary, David J.; Repetski, John E.

2010-01-01

The White Hall 7.5-minute quadrangle is located within the Valley and Ridge province of northern Virginia and the eastern panhandle of West Virginia. The quadrangle is one of several being mapped to investigate the geologic framework and groundwater resources of Frederick County, Va., as well as other areas in the northern Shenandoah Valley of Virginia and West Virginia. All exposed bedrock outcrops are clastic and carbonate strata of Paleozoic age ranging from Middle Cambrian to Late Devonian. Surficial materials include unconsolidated alluvium, colluvium, and terrace deposits of Quaternary age, and local paleo-terrace deposits possibly of Tertiary age. The quadrangle lies across the northeast plunge of the Great North Mountain anticlinorium and includes several other regional folds. The North Mountain fault zone cuts through the eastern part of the quadrangle; it is a series of thrust faults generally oriented northeast-southwest that separate the Silurian and Devonian clastic rocks from the Cambrian and Ordovician carbonate rocks and shales. Karst development in the quadrangle occurs in all of the carbonate rocks. Springs occur mainly near or on faults. Sinkholes occur within all of the carbonate rock units, especially where the rocks have undergone locally intensified deformation through folding, faulting, or some combination.

The ichthyofauna of limnic systems in Quaternary deposits of extreme southern Brazil

PubMed Central

Assumpção, Cindy M.; Quintela, Fernando M.; Corrêa, Fabiano; Loebmann, Daniel

2016-01-01

Abstract The Quaternary in the state of Rio Grande do Sul (RS), southern Brazil, is geologically represented by the coastal plain and was originated by successive events of Pleistocene-Holocene marine transgressions and the occurrence of alluvial deposits. This paper aimed to characterize the fish assemblage occurring in a swampy Quaternary area adjacent to Lagoa Pequena, a lacustrine system connected to the west margin of the Laguna dos Patos estuary. A checklist is also provided of the ichthyofauna so far recorded in limnic systems of Quaternary deposits in the state of Rio Grande do Sul. A total of 42 species was recorded, distributed in nine orders, 18 families and 31 genera. Characidae and Cichlidae were the most representative families, comprising 15 and 4 species respectively. A bibliographic revision associated to our sample data revealed the occurrence of 156 species in limnic systems inserted in RS Quaternary deposits (114 limnic, 15 marine/estuarine/limnic, ten marine/estuarine, nine estuarine/limnic and eight marine). Characiformes and Siluriformes are the most diverse orders, corroborating the Neotropical pattern. Seven species can be considered endemic to RS Quaternary deposits. PMID:28174498

Characterisation of the Permafrost Carbon Pool

USGS Publications Warehouse

Kuhry, P.; Grosse, G.; Harden, J.W.; Hugelius, G.; Koven, C.D.; Ping, C.-L.; Schirrmeister, L.; Tarnocai, C.

2013-01-01

The current estimate of the soil organic carbon (SOC) pool in the northern permafrost region of 1672 Petagrams (Pg) C is much larger than previously reported and needs to be incorporated in global soil carbon (C) inventories. The Northern Circumpolar Soil Carbon Database (NCSCD), extended to include the range 0–300 cm, is now available online for wider use by the scientific community. An important future aim is to provide quantitative uncertainty ranges for C pool estimates. Recent studies have greatly improved understanding of the regional patterns, landscape distribution and vertical (soil horizon) partitioning of the permafrost C pool in the upper 3 m of soils. However, the deeper C pools in unconsolidated Quaternary deposits need to be better constrained. A general lability classification of the permafrost C pool should be developed to address potential C release upon thaw. The permafrost C pool and its dynamics are beginning to be incorporated into Earth System models, although key periglacial processes such as thermokarst still need to be properly represented to obtain a better quantification of the full permafrost C feedback on global climate change.

Neotectonics in the foothills of the southernmost central Andes (37°-38°S): Evidence of strike-slip displacement along the Antiñir-Copahue fault zone

NASA Astrophysics Data System (ADS)

Folguera, AndréS.; Ramos, VíCtor A.; Hermanns, Reginald L.; Naranjo, José

2004-10-01

The Antiñir-Copahue fault zone (ACFZ) is the eastern orogenic front of the Andes between 38° and 37°S. It is formed by an east vergent fan of high-angle dextral transpressive and transtensive faults, which invert a Paleogene intra-arc rift system in an out of sequence order with respect to the Cretaceous to Miocene fold and thrust belt. 3.1-1.7 Ma volcanic rocks are folded and fractured through this belt, and recent indicators of fault activity in unconsolidated deposits suggest an ongoing deformation. In spite of the absence of substantial shallow seismicity associated with the orogenic front, neotectonic studies show the existence of active faults in the present mountain front. The low shallow seismicity could be linked to the high volumes of retroarc-derived volcanic rocks erupted through this fault system during Pliocene and Quaternary times. This thermally weakened basement accommodates the strain of the Antiñir-Copahue fault zone, absorbing the present convergence between the South America and Nazca plates.

Geology and ground water in Napa and Sonoma Valleys, Napa and Sonoma Counties, California

USGS Publications Warehouse

Kunkel, Fred; Upson, Joseph Edwin

1960-01-01

Napa and Sonoma Valleys are adjacent alluvium-filled valleys about 40 miles northeast of San Francisco. They occupy alined and structurally controlled depressions in the northern Coast Ranges physiographic province and drain south into San Pablo Bay. The valleys are surrounded and underlain by unconsolidated marine and continental sediments and volcanic rocks of Pliocene and Pleistocene age, which are water bearing in large part and together make up relatively extensive ground-water basins. Napa Valley, the eastern valley, is the larger and has a valley-floor area of about 85 square miles. Sonoma Valley has a valley-floor area of about 35 square miles; in addition, about 10 square miles is unreclaimed tidal marsh. The rock units of Napa and Sonoma Valleys are divided into four classes on the basis of their distribution and relative capacity to yield water: (a) Consolidated virtually non-water-bearing chiefly sedimentary (some metamorphic) rocks that range in age from Jurassic ( ?) to Pliocene; (b) marine shale and sand of the Petaluma formation (Pliocene) and the Merced formation (Pliocene and Pleistocene) that do not crop out within Napa or Sonoma Valleys but perhaps are penetrated by some deep wells drilled in Sonoma Valley; (c) Sonoma volcanics of Pliocene age, parts of which are non-water-bearing and parts of which locally yield large quantities of water; and (d) unconsolidated alluvial deposits mainly of Quaternary age. The deposits of classes (c) and (d) contain the most important aquifers in the area. Most of the water used in these valleys is pumped from wells in the younger and older alluvium in the Huichica and Glen Ellen formations. and in the Sonoma volcanics. The principal aquifers are the younger and older alluvium. but appreciable quantities of water are pumped locally from the Sonoma volcanics. The Huichica and Glen Ellen formations yield water in small quantities and at most places supply water only for limited domestic uses. The younger alluvium COIM3ists of interbedded deposits of unconsolidated gravel. sand, silt. and. locally, peat. These deposits underlie the flood plains and channels of the Napa River. Sonoma Creek, and their tributaries, low alluvial fans or plains graded to these streams. and the tidal marshlands. The older alluvium of Napa and Sonoma Valleys is composed of lenticular deposits of unconsolidated and poorly sorted clay, silt. sand. and gravel. Where exposed, claypan or hardpan soil is characteristically developed at the surface. The Huichica formation is composed of deformed continental beds consisting mostly of yellow silt with some interbedded lenses of silt and gravel, and silt and boulders. At the base are beds of redeposited volcanic material, silt, clay, and lenses of coarse gravel and boulders. The Glen Ellen fcrmation consists of alluvial clay, silt, sand, and gravel in clearly stratified but generally lenticular beds. The Sonoma volcanics constitute a thick and highly variate series of continental volcanic rocks, including andesite, basalt, and minor rhyolite flows and interbedded coarse- to fine-grained pyroclastic tuff and breccia, redeposited tuff and pumice, and diatomaceous mud, silt, and sand. A prominent body of rhyolite flows and tuff with some obsidian and perlitic glass, called the St. Helena rhyolite member, occurs in the upper part. Estimated ground-water pumpage for all uses in the year 1949-50 was about 5,600 acre-feet in Napa Valley and about 2,400 acre-feet in Sonoma Valley. Of this quantity the amounts pumped for irrigation were about 2,900 and 1,900 acre-feet, respectively. Water levels in wells in the central parts of the valleys range from a few feet above the land surface to about 50 feet below, with an average of about 25 feet. The quality of the water in most wells is satisfactory for domestic use and irrigation. Locally at the southern end of the valley some contamination of the native waters is caused by the movement of salty wate

Quaternary Geologic Map of Connecticut and Long Island Sound Basin

USGS Publications Warehouse

Stone, Janet Radway; Schafer, John P.; London, Elizabeth Haley; DiGiacomo-Cohen, Mary L.; Lewis, Ralph S.; Thompson, Woodrow B.

2005-01-01

The Quaternary geologic map (sheet 1) and explanatory figures and cross sections (sheet 2) portray the geologic features formed in Connecticut during the Quaternary Period, which includes the Pleistocene (glacial) and Holocene (postglacial) Epochs. The Quaternary Period has been a time of development of many details of the landscape and of all the surficial deposits. At least twice in the late Pleistocene, continental ice sheets swept across Connecticut. Their effects are of pervasive importance to the present occupants of the land. The Quaternary geologic map illustrates the geologic history and the distribution of depositional environments during the emplacement of glacial and postglacial surficial deposits and the landforms resulting from those events.

Map showing thickness of saturated Quaternary deposits, Sugar House quadrangle, Salt Lake County, Utah, February 1972

USGS Publications Warehouse

Mower, R.W.

1973-01-01

Saturated Quaternary deposits in the Sugar Horse quadrangle supply significant quantities of water to wells from which water is withdrawn for domestic, municipal, industrial, and irrigation uses. The deposits consist of clay, silt, sand, and gravel; individual beds range from a few inches to several tens of feet thick. The principal aquifer, which is almost completely within the Quaternary deposits, supplied about 4 percent, or 9,000 acre-feet, of the municipal and industrial water used annually in Salt Lake County during 1964-68.As a general rule, more water is stored and more water will be yielded to a well where aquifers are thicker. This map can be used as a general guide to those areas where greatest amounts of water are stored in the aquifer, and where yields to wells may be greater. Local variations in the ability of saturated deposits to transmit water can alter the general relationship between aquifer thickness and yield of wells.The thickness of saturated Quaternary deposits within the area of the Sugar Horse quadrangle ranges from zero to about 650 feet, as shown on the map. The thickest section of these deposits is near the southwestern corner of the quadrangle, and the thinnest section is along the mountain front adjacent to the approximate eastern limit of saturated Quaternary deposits.The thickness of saturated Quaternary deposits shown on this map is based on drillers’ logs for 55 deep wells (which show the thickness of the Quaternary deposits) and on water-level measurements made in February 1972 in wells in unconfined shallow aquifers.Reports in the following list of selected references contain other information about the saturated Quaternary deposits in this and adjacent parts of Jordan Valley, Utah. The basic-data reports and releases contain well logs, water-level measurements, and other types of basic ground-water data. The interpretive repots contain discussions of the occurrence of ground water, tests to determine hydraulic properties of the aquifer, and related information. Ground-water terms used in this report have been defined by Lohman and others (1972).

Thickness of unconsolidated deposits in the towns of Solon and Taylor, Cortland County, New York

USGS Publications Warehouse

Miller, Todd S.

1999-01-01

IntroductionSiting of waste-disposal facilities in Cortland County poses a potential threat to local ground-water resources. An especially sensitive waste-disposal siting issue arose in 1988, when the New York State Low-Level Radioactive Waste Siting Commission (NYSLLWSC) identified 15 sites in six towns (Towns of Solon, Taylor, Freetown, Cincinnatus, Marathon, and Willet) in the eastern part of the county for possible disposal of low-level radioactive waste (New York State Low-Level Radioactive Waste Siting Commission, 1988). Eventually, two sites in the Town of Taylor became finalist sites; one was selected from the list of 15 potential sites, and the other was offered by a private landowner. Little information was available on geohydrologic conditions in eastern Cortland County, such as the extent of aquifers and the thickness of unconsolidated deposits of low permeability (such as clay and till), even though these two criteria were among those used by NYSLLWSC for selection of potential disposal sites. The source of information on thickness of drift over bedrock was the surficial geologic map of New York (Muller and Cadwell, 1986). The siting effort was terminated before a final selection was made, but the issue had made county managers aware that detailed information on the extent and thickness of unconsolidated deposits (particularly till, which typically has low permeability and can limit the migration of contaminants) is needed before sound decisions on waste-disposal siting can be made.Glaciers deposited till nearly everywhere over bedrock in the uplands of central New York, but the thickness of the till varies greatly from place to place. An analysis by Coates (1966) of 400 drillers' logs of wells in a 2,000-mi2 area in the uplands of south-central New York (south of the Cortland County) indicated that (1) till is thin or absent on hilltops and is thickest on the lower parts of hills, (2) overall till thickness averages 60 ft, and (3) till thickness on the south, east, west, and north slopes averages 92, 52, 62, and 22 ft, respectively. Hills that have thick till on their south slopes have been referred to as till-shadowed hills by Coates (1974), who attributes this characteristic to glaciers that deposited thick amounts of till on the downflow side of a hill (analogous to flowing streams or wind that deposit sediment on the lee side of an object). Because the till on the south slopes is relatively thick and typically has low permeability, these slopes have been considered as potential areas for waste-disposal sites.In 1997, the U.S. Geological Survey (USGS), in cooperation with the Cortland County Department of Planning, began a 1-year study to map the thickness of unconsolidated deposits and the extent of valley-fill aquifers in the Towns of Solon and Taylor (an area of 60 mi2) in eastern Cortland County.This report (1) depicts the thickness of unconsolidated deposits and the extent of valley-fill aquifers in the Towns of Solon and taylor in eastern Cortland County, (2) examines whether the "till-shadowed hill" concept developed by Coates (1966) is applicable in this area, and (3) provides three schematic geologic sections showing the thickness of unconsolidated deposits in the uplands in the northwestern part of the study area.

Summary of geology and ground-water resources of Passaic County, New Jersey

USGS Publications Warehouse

Carswell, L.D.; Rooney, J.G.

1976-01-01

Ground water in Passaic County occurs in intergranular openings of unconsolidated stratified deposits of Quaternary age and in joints and fractures in consolidated rocks of Precambrian, Paleozoic, and Triassic age.The Brunswick Formation of Triassic age is the most important aquifer in the southeastern one-third of Passaic County. Reported yields of public supply and industrial wells range from 50 to 510 gallons per minute (3 to 32 litres per second) and the median yield is 130 gallons per minute (8 litres per second). Most of these wells are 200 to 400 feet (61 to 122 metres) deep. The median yield of all public supply and industrial wells over 300 feet (91 metres) deep and 8 inches (203 millimetres) or larger in diameter is 230 gallons per minute (15 litres per second). Crystalline rocks of Precambrian age are the major source of ground water for domestic use in the northwestern two-thirds of Passaic County. Reported well yields range from 1 to 200 gallons per minute (.06 to 13 litres per second). The median reported yield of domestic wells is 5 gallons per minute (.31 litres per second) and that of public supply wells is 30 gallons per minute (2 litres per second).Other consolidated rocks--rocks of Paleozoic age and the Watchung Basalt of Traissic age--are utilized primarily for domestic water supplies in Passaic County. Reported yields of wells tapping the Paleozoic rocks range from less than 1 to 35 gallons per minute (.06 to 2 litres per second) and the median yield is 10 gallons per minute (.63 litres per second). Reported yields of domestic wells tapping the Watchung Basalt range from less than 1 to 40 gallons per minute (.06 to 3 litres per second) and the median yield is 12 gallons per minute (.76 litres per second). However, reported yields of nine industrial and commercial wells range from 50 to 180 gallons per minute (3 to 11 litres per second).Unconsolidated stratified deposits of Quaternary age are locally an important source of ground water for public supply and industrial use in parts of Passaic County. These deposits have not been extensively explored but are potentially an important source of ground water for future development. Reported yields of wells tapping the stratified deposits range from 4 to 920 gallons per minute (.25 to 58 litres per second). The median reported yield of domestic wells is 16 gallons per minute (1 litre per second) and that of public supply and industrial wells is 130 gallons per minute (8 litres per second. Depths of wells depend upon the thickness of the deposits. Reported depths range from 22 to 170 feet (7 to 52 metres).The quality of ground water in Passaic County varies from one aquifer to another. Water from the Precambrian rocks is soft to moderately hard (34 to 104 milligrams per litre) and is low in dissolved solids (66 to 159 milligrams per litre). Water from the Brunswick Formation is moderately hard to very hard (89 to 540 milligrams per litre). The dissolved solids content ranges from 129 to 563 milligrams per litre). The occurrence of more highly mineralized water at depth in the Brunswick Formation is indicated by an analysis, made in 1885, of 16,000 milligrams per litre of dissolved solids at a depth of 2,050 feet (625 metres) in a well in Paterson. Water from two wells tapping the Quaternary deposits is moderately hard (65 and 83 milligrams per litre) and has dissolved solids contents of 122 and 133 milligrams per litre).Water use from both surface and ground-water supplies in Passaic County averaged about 106 million gallons per day (4.6 cubic metres per second) in 1965. Ground water probably accounts for 5 to 10 percent of this total. Ground-water pumpage by the major public supply companies in the county has increased from 2.1 million gallons per day (.09 cubic metres per second) in 1951 to 4.39 million gallons per day (.19 cubic metres per second) in 1968. About 80 percent of the 4.39 million gallons per day (.19 cubic metres per second) was from wells tapping the Brunswick Formation in the southern part of the county.

Use of terrestrial laser scanning for the documentation of quaternary caves

NASA Astrophysics Data System (ADS)

Tyszkowski, Sebastian; Kramkowski, Mateusz; Wiśniewska, Daria; Urban, Jan

2016-04-01

Due to the nature of their occurrence and genesis, caves in the Polish Lowlands represent a peculiarity of geological heritage, unique on the European scale. They are developed in Quaternary deposits, mostly at the contact of slabs or irregular bodies of cemented glacial or glaciofluvial deposits: conglomerates and sandstones, with unconsolidated deposits, mostly sands, gravels and clays. So far, 20 such caves have been recorded in Polish Lowlands. Most caves are only several meters long, the largest one is over 60 m long. Regardless of their origins, the character of host rocks is the reason that processes leading to their formation are simultaneously the destroying processes. Thus, the studied caves, as well as other caves of this region, are unstable, gradually evolving objects. The changes taking place in them are continuous and intense enough, therefore the documentation of their shape with the greatest possible accuracy and resolution becomes crucial. Such possibility can provide the technique of laser scanning. In 2014 three caves, including one recently discovered, were scanned using the TLS. Measurements of caves and their surroundings were conducted in May and July 2014 with a scanner RIEGL VZ-4000. Point clouds from several scanner positions were combined using the module Multi Station Adjustment in the RiSCAN software. This module allows to connect point clouds from successive positions without any objects of reference. After the merger of point clouds from individual positions and their filtration, a collection of several million points was obtained. The number of points projected on the wall was over 20 000 per m2. The using of TLS enabled to present the morphometric features impossible to obtain using traditional methods. High density of the point clouds allows registering even small details on the cave walls, as well as monitoring leaching, falling, grinding and flaking processes taking place in them. Thus, the most important advantage of the TLS is the "visual protection" of these objects unstable in geological time-scale. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analyses - ICLEA- of the Helmholtz Association, Grant No VH-VI-415

Saline water in the Little Arkansas River Basin area, south-central Kansas

USGS Publications Warehouse

Leonard, Robert B.; Kleinschmidt, Melvin K.

1976-01-01

Ground water in unconsolidated deposits of Pleistocene age in part of the Little Arkansas River basin has been polluted by the influx of saline water. The source of the saline water generally is oil-field brine that leaked from disposal ponds on the land surface. Locally, pollution by saline water also has been caused by upwelling of oil-field brine injected under pressure into the "lost-circulation zone" of the Lower Permian Wellington Formation and, possibly, by leakage of brine from corroded or improperly cased disposal wells. Anomalously high concentrations of chloride ion in some reaches of the Little Arkansas River probably can be attributed to pollution by municipal wastes rather than from inflow of saline ground water. Hydraulic connection exists between the "lost-circulation zone" and unconsolidated deposits, as evidenced by the continuing development of sinkholes, by the continuing discharge of saline water through springs and seeps along the Arkansas River south of the Little Arkansas River basin and by changes in the chloride concentration in water pumped from wells in the "lost-circulation zone." The hydraulic head in the "lost-circulation zone" is below the base of the unconsolidated deposits, and much below the potentiometric surface of the aquifer in those deposits. Any movement of water, therefore, would be downward from the "fresh-water" aquifer to the saline "lost-circulation zone."

Late Cenozoic strike-slip faulting in the NE Mojave Block: Deformation at the southwest boundary of the Walker Lane belt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schermer, E.R.

1993-04-01

New structural and stratigraphy data from the NE Mojave Block (NEMB) establish the timing and style of Cenozoic deformation south of the Garlock fault and west of the Avawatz Mts. Unlike adjacent areas, most of the NEMB did not undergo early-mid Miocene extension. Major fault zones strike EW; offset markers and small-scale shear criteria indicate left-lateral strike slip with a small reverse component. Lateral offsets average ca. 1--6 km and vertical offset is locally >200m. Pre-Tertiary markers indicate minimum cumulative sinistral shear of ca. 15 km in the area between the Garlock and Coyote Lake faults. Tertiary strata are deformedmore » together with the older rocks. Along the Ft. Irwin fault, alluvial fan deposits interpreted to be <11Ma appear to be displaced as much as Mesozoic igneous rocks. EW sinistral faults S. of the Garlock fault cut unconsolidated Quaternary deposits; geomorphologic features and trench exposures along segments of the McLean Lake fault and the Tiefort Mt. fault suggest Late Quaternary activity. The EW faults do not cut modern drainages and are not seismically active. NW-striking faults are largely absent within the NEMB; the largest faults bound the domain of EW-striking faults. Offset of Cretaceous and Miocene rocks suggests the W boundary (Goldstone Lake fault) has <2km right separation. Along the E boundary (Soda-Avawatz fault zone), the presence of distinctive clasts in mid-late Miocene conglomerates west of the Avawatz Mts. supports the suggestion of Brady (1984) of ca. 20 km dextral displacement. Other NW-striking faults are cut by EW faults, have unknown or minor dextral displacement (Desert King Spring Fault, Garlic Spring fault) or are low- to moderate-angle left-oblique thrust faults (Red Pass Lake fault zone).« less

Origin of bonebeds in Quaternary tank deposits

NASA Astrophysics Data System (ADS)

Araújo-Júnior, Hermínio Ismael de; Porpino, Kleberson de Oliveira; Bergqvist, Lílian Paglarelli

2017-07-01

Tank deposits are an exceptional type of fossiliferous deposit and bear a remarkably fossil record of the Pleistocene megafauna of South America, particularly of Brazil. The taphonomy of vertebrate remains preserved in this type of environmental context was clearly driven by climate, similarly to most of the Quaternary continental fossil record. The formation of the vertebrates fossil record in tank deposits was influenced by the climate seasonality typical of arid climate. The taphonomic history of most tank deposits is a consequence of this seasonality and, as a result, the paleoecological data preserved in their fossil assemblages is reliable with respect to paleobiological and paleoenvironmental settings of the Quaternary ecosystems of the Brazilian Intertropical Region (BIR). Other tank deposits experienced an unusual taphonomic history that, besides climate, was affected by recurrent events of reworking produced by the depositional agents dominant in the surrounding alluvial plains. The conclusions obtained here concerning the main taphonomic settings and formative processes that characterize fossil vertebrate assemblages of tank deposits will help further studies aimed to recover information on the paleoecology of Quaternary fauna collected in such deposits by allowing a better understanding of their time and spatial resolutions and other potential biases.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in Central Oklahoma

USGS Publications Warehouse

Adams, G.P.; Rea, Alan; Runkle, D.L.

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma. Ground water in approximately 400 square miles of Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of clay, silt, sand, and gravel. Sand-sized sediments dominate the poorly sorted, fine to coarse, unconsolidated quartz grains in the aquifer. The hydraulically connected alluvial and terrace deposits unconformably overlie Permian-age formations. The aquifer is overlain by a layer of wind-blown sand in parts of the area. Most of the lines in the aquifer boundary, hydraulic conductivity, and recharge data sets were extracted from published digital surficial geology data sets based on a scale of 1:250,000. The ground-water elevation contours and some of the lines for the aquifer boundary, hydraulic conductivity, and recharge data sets were digitized from a ground-water modeling report about the aquifer published at a scale of 1:250,000. The hydraulic conductivity values and recharge rates also are from the ground-water modeling report. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Hydrogeology of the Seldovia area, Alaska

USGS Publications Warehouse

Nelson, Gordon L.; Danskin, Wesley R.

1980-01-01

Surficial materials in the Seldovia area, Alaska, are mapped as glacial drift over sedimentary bedrock, glacial drift over igneous and metamorphic bedrock, valley-bottom, alluvium, alluvial fan deposits, beach and intertidal deposits, and peat. Unconsolidated materials are generally less than 10 feet thick except in well-drained glacial deposits along the Seldovia-Jakolof Bay Road and in depressions in the bedrock surface. These depressions are poorly drained and commonly contain peat bogs. Development of domestic wells (1-15 gallons per minute) may be possible from unconsolidated materials and sedimentary bedrock, but larger water requirements must be met from surface-water sources. In areas having the water table or top of bedrock at shallow depths, effluent from sewage disposal systems may cause pollution of the land surface and nearby surface water. Seepage from hillside aquifers and unstable land along the coast of Kachemak Bay may adversely affect roads and structures. (USGS)

Map showing depth to bedrock of the Tacoma and part of the Centralia 30' x 60' quadrangles, Washington

USGS Publications Warehouse

Buchanan-Banks, Jane M.; Collins, Donley S.

1994-01-01

The heavily populated Puget Sound region in the State of Washington has experienced moderate to large earthquakes in the recent past (Nuttli, 1952; Mullineaux and others, 1967). Maps showing thickness of unconsolidated sedimentary deposits are useful aids in delineating areas where damage to engineered structures can result from increased shaking resulting from these earthquakes. Basins containing thick deposits of unconsolidated materials can amplify earthquakes waves and cause far more damage to structures than the same waves passing through bedrock (Singh and others, 1988; Algermissen and others, 1985). Configurations of deep sedimentary basins can also cause reflection and magnification of earthquake waves in ways still not fully understood and presently under investigation (Frankel and Vidale, 1992).

Inverted channel deposits on the floor of Miyamoto crater, Mars

USGS Publications Warehouse

Newsom, Horton E.; Lanza, N.L.; Ollila, A.M.; Wiseman, S.M.; Roush, T.L.; Marzo, G.A.; Tornabene, L.L.; Okubo, C.H.; Osterloo, M.M.; Hamilton, V.E.; Crumpler, L.S.

2010-01-01

Morphological features on the western floor of Miyamoto crater in southwestern Meridiani Planum, Mars, are suggestive of past fluvial activity. Imagery from the High Resolution Imaging Science Experiment (HiRISE) gives a detailed view of raised curvilinear features that appear to represent inverted paleochannel deposits. The inverted terrain appears to be capped with a resistant, dark-toned deposit that is partially covered by unconsolidated surficial materials. Subsequent to deposition of the capping layer, erosion of the surrounding material has left the capping materials perched on pedestals of uneroded basal unit material. Neither the capping material nor the surrounding terrains show any unambiguous morphological evidence of volcanism or glaciation. The capping deposit may include unconsolidated or cemented stream deposits analogous to terrestrial inverted channels in the Cedar Mountain Formation near Green River, Utah. In addition to this morphological evidence for fluvial activity, phyllosilicates have been identified in the basal material on the floor of Miyamoto crater by orbital spectroscopy, providing mineralogical evidence of past aqueous activity. Based on both the morphological and mineralogical evidence, Miyamoto crater represents an excellent site for in situ examination and sampling of a potentially habitable environment. ?? 2009 Elsevier Inc.

Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through 2004

USGS Publications Warehouse

DeWees, R.K.

2006-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the Albuquerque Basin are obtained solely from ground-water resources. An increase of approximately 20 percent in the population from 1991 to present also resulted in an increased demand for water. From April 1982 through September 1983, a network of wells was established to monitor changes in ground-water levels throughout the Albuquerque Basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. Currently (2004), the network consists of 234 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 155 sites through 2004. Water-level and other data for 71 sites are collected by other agencies. Water-level data for 8 sites of the 155 sites measured by the U.S. Geological Survey were not available for this report.

Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through September 30, 2008

USGS Publications Warehouse

Beman, Joseph E.

2009-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin are currently (2008) obtained soley from ground-water resources. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in ground-water levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2008), the network consists of 144 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 125 sites through water-year 2008. In addition, data from 19 wells (Sites 127-30, 132-134, 136, 138-142 and 144-149) owned, maintained, and measured by Sandia National Laboratories are presented in this report.

Surficial Geologic Map of Mount Veniaminof Volcano, Alaska

NASA Astrophysics Data System (ADS)

Waythomas, C. F.; Miller, T. P.; Wallace, K.

2015-12-01

Mount Veniaminof volcano is a >300 km3 andesite to dacite stratovolcano, characterized by an 8 x 11 km diameter ice-filled summit caldera. Veniaminof is one of the most active volcanoes in the Aleutian arc and has erupted at least 15 times in the past 200 years. The volcano is located on the Alaska Peninsula (56.1979° N, 159.3931° W) about 780 km SW of Anchorage. Our geologic investigations have documented two large (>VEI 5) caldera-forming or -modifying eruptions (V1, V2) of Holocene age whose eruptive products make up most of the surficial deposits around the volcano. These deposits and other unconsolidated glacial, fluvial, and colluvial deposits are depicted on the accompanying map. The the V2 eruption occurred 4.1-4.4 ka (cal 2-sigma age range) and produced an extensive landscape-mantling sequence of pyroclastic deposits >50 km3 in volume that cover or partly obscure older unconsolidated eruptive products. The V1 eruption occurred 8-9 ka and its deposits lie stratigraphically below the pyroclastic deposits associated with the V2 eruption and a prominent, widespread tephra fall deposit erupted from nearby Black Peak volcano 4.4-4.6 ka. The V2 pyroclastic-flow deposits range from densely welded, columnar jointed units exposed along the main valley floors, to loose, unconsolidated, blanketing accumulations of scoriaceous (55-57% SiO2) and lithic material found as far as 75 km from the edifice. Large lahars also formed during the V2 eruption and flowed as far as 50 km from the volcano. The resulting deposits are present in all glacial valleys that head on the volcano and are 10-15 m thick in several locations. Lahar deposits cover an area of about 800-1000 km2, have an approximate volume of 1-2 km3, and record substantial inundation of the major valleys on all flanks of the edifice. Significant amounts of water are required to form lahars of this size, which suggests that an ice-filled summit caldera probably existed when the V2 eruption occurred.

Ground-water resources of McKenzie County, North Dakota. Part III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croft, M.G.

Ground water suitable for domestic and livestock supplies in McKenzie County is available from three aquifer systems in semiconsolidated rocks of Late Cretaceous and Tertiary age. Ground water from aquifers in unconsolidated sand and gravel of Quaternary age is suitable for domestic, livestock, municipal, industrial, and irrigation uses. Rocks older than Late Cretaceous age extend to 15,000 feet (4572 meters) and generally contain brackish water that is unsuitable for most purposes. The Fox Hills and basal Hell Creek aquifer system is used as a source for livestock and domestic supplies. It generally is 1100 to 1800 feet (335 to 549more » meters) in depth, and the transmissivity is 200 to 300 feet squared per day (19 to 28 meters squared per day). The water is lower in dissolved solids than water in overlying aquifers of Tertiary age and has a median dissolved-solids concentration of about 1325 milligrams per liter. Wells may yield 100 gallons per minute (6.3 liters per second). Six aquifers, each consisting of 50 to 176 feet (15 to 54 meters) of unconsolidated sand and gravel of Quaternary age, occur in McKensie County. The sand and gravel could yield 100 to more than 500 gallons per minute (6.3 to 32 liters per second). The water from four of the aquifers generally is a sodium bicarbonate type and has a median dissolved-solids concentration of 1100 to 2330 milligrams per liter. Water from the Charbonneau, Tobacco Garden, and Yellowstone-Missouri aquifers is suitable for irrigation. 26 figs., 9 tabs.« less

Review of the general geology and solid-phase geochemical studies in the vicinity of the Central Oklahoma aquifer

USGS Publications Warehouse

Mosier, Elwin L.; Bullock, John H.

1988-01-01

The Central Oklahoma aquifer is the principal source of ground water for municipal, industrial, and rural use in central Oklahoma. Ground water in the aquifer is contained in consolidated sedimentary rocks consisting of the Admire, Council Grove, and Chase Groups, Wellington Formation, and Garber Sandstone and in the unconsolidated Quaternary alluvium and terrace deposits that occur along the major stream systems in the study area. The Garber Sandstone and the Wellington Formation comprise the main flow system and, as such, the aquifer is often referred to as the 'Garber-Wellington aquifer.' The consolidated sedimentary rocks consist of interbedded lenticular sandstone, shale, and siltstone beds deposited in similar deltaic environments in early Permian time. Arsenic, chromium, and selenium are found in the ground water of the Central Oklahoma aquifer in concentrations that, in places, exceed the primary drinking-water standards of the Environmental Protection Agency. Gross-alpha concentrations also exceed the primary standards in some wells, and uranium concentrations are uncommonly high in places. As a prerequisite to a surface and subsurface solid-phase geochemical study, this report summarizes the general geology of the Central Oklahoma study area. Summaries of results from certain previously reported solid-phase geochemical studies that relate to the vicinity of the Central Oklahoma aquifer are also given; including a summary of the analytical results and distribution plots for arsenic, selenium, chromium, thorium, uranium, copper, and barium from the U.S. Department of Energy's National Uranium Resource Evaluation (NURE) Program.

Altitude and configuration of the 1980 water table in the High Plains regional aquifer, northwestern Oklahoma

USGS Publications Warehouse

Havens, John S.

1982-01-01

The High Plains aquifer in Oklahoma is part of a regional aquifer system extending from South Dakota on the north through Wyoming, Colorado Nebraska Kansas, and Oklahoma to Texas and New Mexico on the south (index map) . The principal aquifer, the Ogallala Formation of Tertiary age, is hydraulically connected with other unconsolidated . deposits, principally of Quaternary age . Alluvium and terrace deposits in hydrologic continuity with the Qgallala are included in the High Plains aquifer in Oklahoma. Parts of the underlying bedrock also are hydraulically connected with the Ogallala. The High Plains aquifer in Oklahoma has been eroded on the west, exposing underlying rocks of Cretaceous age, and on the east, exposing rocks of Permian age.During 1978, the U.S. Geological Survey began a 5-year study of the High Plains regional aquifer system to provide hydrologic information for evaluation of the effects of long-term development of the aquifer and to develop computer models for prediction of aquifer response to alternative changes in ground-water management (Weeks, 1978). This report is one of a series presenting hydrologic information of the High Plains aquifer in Oklahoma. The altitude and configuration of the water table are shown for the eastern area, consisting of Harper, Ellis, Woodward, Dewey, and Roger Mills Counties (sheet 1), and for the Panhandle area, consisting of Cimarron, Texas, and Beaver Counties (sheet 2). Water levels were measured in January, February, and March 1980 by the Oklahoma Water Resources Board.

Quaternary sediment thickness and bedrock topography of the glaciated United States east of the Rocky Mountains

USGS Publications Warehouse

Soller, David R.; Garrity, Christopher P.

2018-01-26

Beginning roughly 2.6 million years ago, global climate entered a cooling phase known as the Pleistocene Epoch. As snow in northern latitudes compacted into ice several kilometers thick, it flowed as glaciers southward across the North American continent. These glaciers extended across the northern United States, dramatically altering the landscape they covered. East of the Rocky Mountains, the ice coalesced into continental glaciers (called the Laurentide Ice Sheet) that at times blanketed much of the north-central and northeastern United States. To the west of the Laurentide Ice Sheet, glaciers formed in the mountains of western Canada and the United States and coalesced into the Cordilleran ice sheet; this relatively smaller ice mass extended into the conterminous United States in the northernmost areas of western Montana, Idaho, and Washington. Throughout the Pleistocene, landscape alteration occurred by (1) glacial erosion of the rocks and sediments; (2) redeposition of the eroded earth materials in a form substantially different from their source rocks, in terms of texture and overall character; and (3) disruption of preexisting drainage patterns by the newly deposited sediments. In many cases, pre-glacial drainage systems (including, for example, the Mississippi River) were rerouted because their older drainage courses became blocked with glacial sediment.The continental glaciers advanced and retreated many times across those areas. During each ice advance, or glaciation, erosion and deposition occurred, and the landscape was again altered. Through successive glaciations, the landscape and the bedrock surface gradually came to resemble their present configurations. As continental ice sheets receded and the Pleistocene ended, erosion and deposition of sediment (for example in stream valleys) continued to shape the landscape up to the present day (albeit to a lesser extent than during glaciation). The interval of time since the last recession of the glaciers is called the Holocene and, together with the Pleistocene, constitutes the Quaternary Period of geologic time; this publication characterizes the three-dimensional geometry of the Quaternary sediments and the bedrock surface that lies beneath.The pre-glacial landscape was underlain mostly by weathered bedrock generally similar in nature to that found in many areas of the non-glaciated United States. Glacial erosion and redeposition of earth materials produced a young, mineral-rich soil that formed the basis for the highly productive agricultural economy in the U.S. midcontinent. Extensive buried sands and gravels within the glacial deposits also provided a stimulus to other economic sectors by serving as high-quality aquifers supplying groundwater to the region’s industry and cities. An understanding of the three-dimensional distribution of these glacial sediments has direct utility for addressing various societal issues including groundwater quality and supply, and landscape and soil response to earthquake-induced shaking.The Quaternary sediment thickness map and bedrock topographic map shown here provide a regional overview and are intended to supplement the more detailed work on which they are based. Detailed mapping is particularly useful in populated areas for site-specific planning. In contrast, regional maps such as these serve to place local, detailed mapping in context; to permit the extrapolation of data into unmapped areas; and to depict large-scale regional geologic features and patterns that are beyond the scope of local, detailed mapping. They also can enhance the reader’s general understanding of the region’s landscape and geologic history and provide a source of information for regional decision making that could benefit by improved predictability of bedrock depth beneath the unconsolidated Quaternary sediments. To enable these maps to be analyzed in conjunction with other types of information, this publication also includes the map data in GIS compatible format.

Ground water in Tooele Valley, Tooele County, Utah

USGS Publications Warehouse

Thomas, H.E.

1946-01-01

Tooele Valley is a typical basin of the Basin and Range Province located about 30 miles southwest of Salt Lake City. It is roughly 15 miles long and 10 miles wide and has a population of about 7,000. Bordered on the west by the Stansbury Range, on the east by the Oquirrh Range, and on the south by South Mountain, it opens northward to Great Salt Lake. The bordering mountain ranges are formed by Paleozoic rocks ranging in age from Lower Cambrian to Pennsylvanian but with the Ordovician and Silurian periods unrepresented. There is no sedimentary record of the interval between Pennsylvanian and Tertiary times, and the Tertiary, Quaternary, and Recent sediments are of continental origin. These continental deposits play the dominant role in the ground-water hydrology of the basin, and were mapped and studied in detail. Pleistocene sediments are of major importance because they form the surface rock over most of the area, and give rise to conditions which yield water by artesian flow in the lower part of the valley.The development of the present land forms in this area began with the folding of Paleozoic and probably Mesozoic sediments during the Laramide revolution. The cycle of highland erosion and lowland deposition thus initiated has continued through recurrent uplift along Basin-Range faults to the present day. The principal physiographic subdivisions of the valley were developed as a result of the Basin-Range faulting, which began early in the Tertiary and has continued to Recent times.There are about 1,100 wells in Tooele Valley, about 90 per cent of which yield or have yielded water by artesian flow. Most of them are located in the lower part of the valley below an altitude of 4,400 feet. These wells and many of the springs derive their water from the unconsolidated Quaternary sediments, which include discontinuous, lenticular and commonly elongated bodies of sand, clay, gravel, and boulders of alluvial origin alternating and inter-fingered with lacustrine beds of the same materials which are more regularly stratified and better assorted. The larger springs are intimately related to the bedding planes and faults in the bedrock and alluvial formations. The well assorted sands and gravels deposited along the shore lines of Lake Bonneville are important as recharge areas for the artesian reservoir.

Quaternary geologic map of the Winnipeg 4 degrees x 6 degrees quadrangle, United States and Canada

USGS Publications Warehouse

Fullerton, D. S.; Ringrose, S.M.; Clayton, Lee; Schreiner, B.T.; Goebel, J.E.

2000-01-01

The Quaternary Geologic Map of the Winnipeg 4? ? 6? Quadrangle, United States and Canada, is a component of the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series (Miscellaneous Investigations Series I-1420), an effort to produce 4? ? 6? Quaternary geologic maps, at 1:1 million scale, of the entire conterminous United States and adjacent Canada. The map and the accompanying text and supplemental illustrations provide a regional overview of the areal distributions and characteristics of surficial deposits and materials of Quaternary age (~1.8 Ma to present) in parts of North Dakota, Minnesota, Manitoba, and Saskatchewan. The map is not a map of soils as soils are recognized in agriculture. Rather, it is a map of soils as recognized in engineering geology, or of substrata or parent materials in which agricultural soils are formed. The map units are distinguished chiefly on the basis of (1)genesis (processes of origin) or environments of deposition: for example, sediments deposited primarily by glacial ice (glacial deposits or till), sediments deposited in lakes (lacustrine deposits), or sediments deposited by wind (eolian deposits); (2) age: for example, how long ago the deposits accumulated; (3) texture (grain size)of the deposits or materials; (4) composition (particle lithology) of the deposits or materials; (5) thickness; and (6) other physical, chemical, and engineering properties. Supplemental illustrations show (1) temporal correlation of the map units, (2) the areal relationships of late Wisconsin glacial ice lobes and sublobes, (3) temporal and spatial correlation of late Wisconsin glacial phases, readvance limits, and ice margin stillstands, (4) temporal and stratigraphic correlation of surface and subsurface glacial deposits in the Winnipeg quadrangle and in adjacent 4? ? 6? quadrangles, and (5) responsibility for state and province compilations. The database provides information related to geologic hazards (for example, materials that are characterized by expansive clay minerals; landslide deposits or landslide-prone deposits), natural resources (for example, sources of aggregate, peat, and clay; potential shallow sources of groundwater), and areas of environmental concern (for example, areas that are potentially suitable for specific ecosystem habitats; areas of potential soil and groundwater contamination). All of these aspects of the database relate directly to land use, management, and policy. The map, text, and accompanying illustrations provide a database of regional scope related to geologic history, climatic changes, the stratigraphic and chronologic frameworks of surface and subsurface deposits and materials of Quaternary age, and other problems and concerns.

Hydrology of Cache Valley, Cache County, Utah, and adjacent part of Idaho, with emphasis on simulation of ground-water flow

USGS Publications Warehouse

Kariya, Kim A.; Roark, D. Michael; Hanson, Karen M.

1994-01-01

A hydrologic investigation of Cache Valley was done to better understand the ground-water system in unconsolidated basin-fill deposits and the interaction between ground water and surface water. Ground-water recharge occurs by infiltration of precipitation and unconsumed irrigation water, seepage from canals and streams, and subsurface inflow from adjacent consolidated rock and adjacent unconsolidated basin-fill deposit ground-water systems. Ground-water discharge occurs as seepage to streams and reservoirs, spring discharge, evapotranspiration, and withdrawal from wells.Water levels declined during 1984-90. Less-than-average precipitation during 1987-90 and increased pumping from irrigation and public-supply wells contributed to the declines.A ground-water-flow model was used to simulate flow in the unconsolidated basin-fill deposits. Data primarily from 1969 were used to calibrate the model to steady-state conditions. Transient-state calibration was done by simulating ground-water conditions on a yearly basis for 1982-90.A hypothetical simulation in which the dry conditions of 1990 were continued for 5 years projected an average lO-foot water-level decline between Richmond and Hyrum. When increased pumpage was simulated by adding three well fields, each pumping 10 cubic feet per second, in the Logan, Smithfield, and College Ward areas, water-level declines greater than 10 feet were projected in most of the southeastern part of the valley and discharge from springs and seepage to streams and reservoirs decreased.

Groundwater quality assessment of the quaternary unconsolidated sedimentary basin near the Pi river using fuzzy evaluation technique

NASA Astrophysics Data System (ADS)

Mohamed, Adam Khalifa; Liu, Dan; Mohamed, Mohamed A. A.; Song, Kai

2018-05-01

The present study was carried out to assess the groundwater quality for drinking purposes in the Quaternary Unconsolidated Sedimentary Basin of the North Chengdu Plain, China. Six groups of water samples (S1, S2, S3, S4, S5, and S6) are selected in the study area. These samples were analyzed for 19 different physicochemical water quality parameters to assess groundwater quality. The physicochemical parameters of groundwater were compared with China's Quality Standards for Groundwater (GB/T14848-93). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. Total hardness and total dissolved solid values show that the investigated water is classified as very hard and fresh water, respectively. The sustainability of groundwater for drinking purposes was assessed based on the fuzzy mathematics evaluation (FME) method. The results of the assessment were classified into five groups based on their relative suitability for portable use (grade I = most suitable to grade V = least suitable), according to (GB/T 14848-93). The assessment results reveal that the quality of groundwater in most of the wells was class I, II and III and suitable for drinking purposes, but well (S2) has been found to be in class V, which is classified as very poor and cannot be used for drinking. Also, the FME method was compared with the comprehensive evaluation method. The FME method was found to be more comprehensive and reasonable to assess groundwater quality. This study can provide an important frame of reference for decision making on improving groundwater quality in the study area and nearby surrounding.

Quaternary Glacial Mapping in Western Wisconsin Using Soil Survey Information

ERIC Educational Resources Information Center

Oehlke, Betsy M.; Dolliver, Holly A. S.

2011-01-01

The majority of soils in the western Wisconsin have developed from glacial sediments deposited during the Quaternary Period (2.6 million years before present). In many regions, multiple advances and retreats have left a complex landscape of diverse glacial sediments and landforms. The soils that have developed on these deposits reflect the nature…

Processes of Terrace Formation on the Piedmont of the Santa Cruz River Valley During Quaternary Time, Green Valley-Tubac Area, Southeastern Arizona

USGS Publications Warehouse

Lindsey, David A.; Van Gosen, Bradley S.

2010-01-01

In this report we describe a series of stepped Quaternary terraces on some piedmont tributaries of the Santa Cruz River valley in southeastern Arizona. These terraces began to form in early Pleistocene time, after major basin-and-range faulting ceased, with lateral planation of basin fill and deposition of thin fans of alluvium. At the end of this cycle of erosion and deposition, tributaries of the Santa Cruz River began the process of dissection and terrace formation that continues to the present. Vertical cutting alternated with periods of equilibrium, during which streams cut laterally and left thin deposits of channel fill. The distribution of terraces was mapped and compiled with adjacent mapping to produce a regional picture of piedmont stream history in the middle part of the Santa Cruz River valley. For selected tributaries, the thickness of terrace fill was measured, particle size and lithology of gravel were determined, and sedimentary features were photographed and described. Mapping of terrace stratigraphy revealed that on two tributaries, Madera Canyon Wash and Montosa Canyon Wash, stream piracy has played an important role in piedmont landscape development. On two other tributaries, Cottonwood Canyon Wash and Josephine Canyon Wash, rapid downcutting preempted piracy. Two types of terraces are recognized: erosional and depositional. Gravel in thin erosional terraces has Trask sorting coefficients and sedimentary structures typical of streamflood deposits, replete with bar-and-swale surface topography on young terraces. Erosional-terrace fill represents the channel fill of the stream that cuts the terrace; the thickness of the fill indicates the depth of channel scour. In contrast to erosional terraces, depositional terraces show evidence of repeated deposition and net aggradation, as indicated by their thickness (as much as 20+ m) and weakly bedded structure. Depositional terraces are common below mountain-front canyon mouths where streams drop their load in response to abrupt flattening of gradients and expansion of channel banks, and they extend down the piedmont along Josephine Canyon Wash. Gravel in depositional terraces also has sorting coefficients typical of streamflood deposits. Sedimentary features in both types of terraces are consistent with deposition by flash floods in ephemeral streams, suggesting the climate was arid. Bedding and clast armor are weakly developed, clast clusters and imbrication are common, and crossbedding is generally absent. Debris-flow deposits, even near the mountain front, are surprisingly rare. On the tectonically stable piedmont of southeastern Arizona, stream piracy and climate change are the most likely agents of terrace formation. Both piracy and climate change can cause rapid changes in discharge and sediment supply, which initiate cycles of incision, lateral cutting, and aggradation. Increased stream discharge initiates downcutting, but increased sediment supply interrupts downcutting and causes streams to cut laterally and aggrade. At times, on Madera Canyon Wash and Montosa Canyon Wash, stream piracy affected stream discharge and sediment supply, but on Cottonwood Canyon Wash and Josephine Canyon Wash, only climate change could have initiated terrace cutting. Terraces probably formed during extended arid intervals when sparse vegetation and flashy stream discharge combined to increase sediment supply. In most cases, sediment supply was sufficient to promote lateral cutting but not long-term aggradation. Thus, most streams formed erosional terraces. The middle Pleistocene Josephine Canyon Wash formed a depositional terrace because it had a source of abundant unconsolidated sediment.

Plio-quaternary deposits in the Eastern Rharb (Nw Morocco): Electrosequential characterization

NASA Astrophysics Data System (ADS)

Al Mazini, Imane; Mridekh, Abdelaziz; Kili, Malika; El Mansouri, Bouâbid; El Bouhaddioui, Mohamed; Magrane, Bouchaib

2018-02-01

The Rharb basin, of which our study area is part, is located at the western extremity of the south Rif corridor. It corresponds to a subsiding zone that appeared in the Upper Miocene, between two major structural domains: the Rif to the north and east and the Meseta domain to the south. The eastern part of this basin is characterized by a Plio-Quaternary continental fill. Its geographical position and its structural and paleo-environmental contexts are reflected by a great facies heterogeneity. This work aims to image the subsurface structure and to characterize the distribution mode of Plio-Quaternary deposits of the eastern Rharb. The use of a database consisting of geo-electrical cross sections, hydrogeological drilling and wireline logging integrated in a Geographic Information System (GIS) allowed us to establish a new three-dimensional model of the top of the Mio-Pliocene substratum, new geo-electrical cross sections, as well as the isopach maps of lower, intermediate, upper and superficial geo-electric interval. This approach allowed us to characterize the Plio-Quaternary deposits of the study area and to highlight the effects of the tectonic regime and the relative sea level fluctuations on the sequential organization of these deposits. Our new model shows the development of prograding, aggrading and retrograding parasequences denoting the existence of autogenic mechanisms in the organization of plio-quaternary deposits of the eastern part of the Rharb basin. Therefore, it opens new perspectives for the exploration of water resources and monitoring their quality throughout the basin.

Synthetic seismograms from vibracores: A case study in correlating the late quaternary seismic stratigraphy of the New Jersey inner continental shelf

USGS Publications Warehouse

Esker, D.; Sheridan, R.E.; Ashley, G.M.; Waldner, J.S.; Hall, D.W.

1996-01-01

A new technique, using empirical relationships between median grain size and density and velocity to calculate proxy values for density and velocity, avoids many of the problems associated with the use of well logs and shipboard measurements to construct synthetic seismograms. This method was used to groundtruth and correlate across both analog and digital shallow high-resolution seismic data on the New Jersey shelf. Sampling dry vibracores to determine median grain size eliminates the detrimental effects that coring disturbances and preservation variables have on the sediment and water content of the core. The link between seismic response to lithology and bed spacing is more exact. The exact frequency of the field seismic data can be realistically simulated by a 10-20 cm sampling interval of the vibracores. The estimate of the percentage error inherent in this technique, 12% for acoustic impedance and 24% for reflection amplitude, is calculated to one standard deviation and is within a reasonable limit for such a procedure. The synthetic seismograms of two cores, 4-6 m long, were used to correlate specific sedimentary deposits to specific seismic reflection responses. Because this technique is applicable to unconsolidated sediments, it is ideal for upper Pleistocene and Holocene strata. Copyright ?? 1996, SEPM (Society for Sedimentary Geology).

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2009

USGS Publications Warehouse

Beman, Joseph E.; Torres, Leeanna T.

2010-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2009), the network consists of 131 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 123 sites through water year 2009. In addition, data from four wells (Sites 140, 147, 148, and 149) owned, maintained, and measured by Sandia National Laboratories and three from Kirtland Air Force Base (Sites 119, 125, and 126) are presented in this report.

A plan to study the aquifer system of the Central Valley of California

USGS Publications Warehouse

Bertoldi, Gilbert L.

1979-01-01

Unconsolidated Quaternary alluvial deposits comprise a large complex aquifer system in the Central Valley of California. Millions of acre-feet of water is pumped from the system annually to support a large and expanding agribusiness industry. Since the 1950's, water levels have been steadily declining in many areas of the valley and concern has been expressed about the ability of the entire ground-water system to support agribusiness at current levels, not to mention its ability to function at projected expansion levels. At current levels of ground-water use, an estimated 1.5 to 2 million acre-feet is withdrawn from storage each year; that is, 1.5 to 2 million acre-feet of water is pumped annually in excess of annual replenishment. The U.S. Geological Survey has initiated a 4-year study to develop geologic, hydrologic, and hydraulic information and to establish a valleywide ground-water data base that will be used to build computer models of the ground-water flow system. Subsequently, these models may be used to evaluate the system response to various ground-water management alternatives. This report describes current problems, objectives of the study, and outlines the general work to be accomplished in the study area. A bibliography of about 600 references is included. (Kosco-USGS)

Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through September 30, 2007

USGS Publications Warehouse

Beman, Joseph E.

2008-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin are currently (2007) obtained solely from ground-water resources. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in ground-water levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2007), the network consists of 131 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 131 sites through water-year 2007. Data from five sites (Sites 9, 10, 31, 71 and 78) were not measured during the 2007 water-year, but are included in this report because recent data are useful for comparison and (or) data have been collected that will be included in the water-year 2008 report.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

USGS Publications Warehouse

Adams, G.P.; Runkle, D.L.; Rea, Alan

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma. Ground water in 830 square miles of the Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of poorly sorted, fine to coarse, unconsolidated quartz sand with minor amounts of clay, silt, and basal gravel. The hydraulically connected alluvial and terrace deposits unconformably overlie the Tertiary-age Ogallala Formation and Permian-age formations. Most of the lines in the aquifer boundary and recharge data sets and some of the lines in the hydraulic conductivity data set were extracted from a published digital surficial geology data set based on a scale of 1:250,000. The ground-water elevation contours and some of the lines for the aquifer boundary, hydraulic conductivity, and recharge data sets were digitized from a ground-water modeling report about the aquifer published at a scale of 1:250,000. The hydraulic conductivity values and recharge rates also are from the ground-water modeling report. The data sets are provided in both nonproprietary and ARC/INFO export file formats. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Quaternary extensional and compressional tectonics revealed from Quaternary landforms along Kosi River valley, outer Kumaun Lesser Himalaya, Uttarakhand

NASA Astrophysics Data System (ADS)

Luirei, Khayingshing; Bhakuni, S. S.; Kothyari, Girish Ch.; Tripathi, Kavita; Pant, P. D.

2016-04-01

A portion of the Kosi River in the outer Kumaun Lesser Himalaya is characterized by wide river course situated south of the Ramgarh Thrust, where huge thickness (~200 m) of the landslide deposits and two to three levels of unpaired fan terraces are present. Brittle normal faults, suggesting extensional tectonics, are recognized in the Quaternary deposits and bedrocks as further supported by surface morphology. Trending E-W, these faults measure from 3 to 5 km in length and are traced as discontinuous linear mini-horst and fault scarps (sackungen) exposed due to cutting across by streams. Active normal faults have displaced the coarsely laminated debris fan deposits at two sites located 550 m apart. At one of the sites, the faults look like bookshelf faulting with the maximum displacement of ~2 m and rotation of the Quaternary boulders along the fault plane is observed. At another site, the maximum displacement measures about 0.60 cm. Thick mud units deposited due to blocking of the streams by landslides are observed within and above the fan deposit. Landslide debris fans and terrace landforms are widely developed; the highest level of fan is observed ~1240 m above mean sea level. At some places, the reworking of the debris fans by streams is characterized by thick laminated sand body. Along the South Almora Thrust and Ramgarh Thrust zones, the valleys are narrow and V-shaped where Quaternary deposits are sparse due to relatively rapid uplift across these thrusts. Along the South Almora Thrust zone, three to four levels of fluvial terraces are observed and have been incised by river exposing the bedrocks due to recent movement along the RT and SAT. Abandoned channel, tilted mud deposits, incised meandering, deep-cut V-shaped valleys and strath terraces indicate rapid uplift of the area. Thick mud sequences in the Quaternary columns indicate damming of streams. A ~10-km-long north-south trending transverse Garampani Fault has offset the Ramgarh Thrust producing tectonic landforms.

Application of seismic-refraction techniques to hydrologic studies

USGS Publications Warehouse

Haeni, F.P.

1986-01-01

During the past 30 years, seismic-refraction methods have been used extensively in petroleum, mineral, and engineering investigations, and to some extent for hydrologic applications. Recent advances in equipment, sound sources, and computer interpretation techniques make seismic refraction a highly effective and economical means of obtaining subsurface data in hydrologic studies. Aquifers that can be defined by one or more high seismic-velocity surfaces, such as (1) alluvial or glacial deposits in consolidated rock valleys, (2) limestone or sandstone underlain by metamorphic or igneous rock, or (3) saturated unconsolidated deposits overlain by unsaturated unconsolidated deposits,are ideally suited for applying seismic-refraction methods. These methods allow the economical collection of subsurface data, provide the basis for more efficient collection of data by test drilling or aquifer tests, and result in improved hydrologic studies.This manual briefly reviews the basics of seismic-refraction theory and principles. It emphasizes the use of this technique in hydrologic investigations and describes the planning, equipment, field procedures, and intrepretation techniques needed for this type of study.Examples of the use of seismic-refraction techniques in a wide variety of hydrologic studies are presented.

Application of seismic-refraction techniques to hydrologic studies

USGS Publications Warehouse

Haeni, F.P.

1988-01-01

During the past 30 years, seismic-refraction methods have been used extensively in petroleum, mineral, and engineering investigations and to some extent for hydrologic applications. Recent advances in equipment, sound sources, and computer interpretation techniques make seismic refraction a highly effective and economical means of obtaining subsurface data in hydrologic studies. Aquifers that can be defined by one or more high-seismic-velocity surface, such as (1) alluvial or glacial deposits in consolidated rock valleys, (2) limestone or sandstone underlain by metamorphic or igneous rock, or (3) saturated unconsolidated deposits overlain by unsaturated unconsolidated deposits, are ideally suited for seismic-refraction methods. These methods allow economical collection of subsurface data, provide the basis for more efficient collection of data by test drilling or aquifer tests, and result in improved hydrologic studies. This manual briefly reviews the basics of seismic-refraction theory and principles. It emphasizes the use of these techniques in hydrologic investigations and describes the planning, equipment, field procedures, and interpretation techniques needed for this type of study. Further-more, examples of the use of seismic-refraction techniques in a wide variety of hydrologic studies are presented.

Seismic amplification within the Seattle Basin, Washington State: Insights from SHIPS seismic tomography experiments

USGS Publications Warehouse

Snelson, C.M.; Brocher, T.M.; Miller, K.C.; Pratt, T.L.; Trehu, A.M.

2007-01-01

Recent observations indicate that the Seattle sedimentary basin, underlying Seattle and other urban centers in the Puget Lowland, Washington, amplifies long-period (1-5 sec) weak ground motions by factors of 10 or more. We computed east-trending P- and S-wave velocity models across the Seattle basin from Seismic Hazard Investigations of Puget Sound (SHIPS) experiments to better characterize the seismic hazard the basin poses. The 3D tomographic models, which resolve features to a depth of 10 km, for the first time define the P- and S-wave velocity structure of the eastern end of the basin. The basin, which contains sedimentary rocks of Eocene to Holocene, is broadly symmetric in east-west section and reaches a maximum thickness of 6 km along our profile beneath north Seattle. A comparison of our velocity model with coincident amplification curves for weak ground motions produced by the 1999 Chi-Chi earthquake suggests that the distribution of Quaternary deposits and reduced velocity gradients in the upper part of the basement east of Seattle have significance in forecasting variations in seismic-wave amplification across the basin. Specifically, eastward increases in the amplification of 0.2- to 5-Hz energy correlate with locally thicker unconsolidated deposits and a change from Crescent Formation basement to pre-Tertiary Cascadia basement. These models define the extent of the Seattle basin, the Seattle fault, and the geometry of the basement contact, giving insight into the tectonic evolution of the Seattle basin and its influence on ground shaking.

Stratigraphy and Petrology of the Grande Soufriere Hills Volcano, Dominica, Lesser Antilles

NASA Astrophysics Data System (ADS)

Daly, G.; Smith, A. L.; Garcia, R.; Killingsworth, N.

2007-12-01

The Grande Soufriere Hills volcanic center is located on the south east coast of the island of Dominica in the Lesser Antilles. Although the volcano is deeply dissected, a distinct circular crater that opens to the east can be observed. Within the crater is a lava dome and unconsolidated pyroclastic deposits mantle the southeast flanks of the volcano. These pyroclastic deposits are almost entirely matrix-supported block and ash flows and surges suggesting that Pelean-style eruptions have dominated its most recent activity. Within this sequence is a relatively thin (30-50 cm) clast-supported deposit that has been interpreted as a possible blast deposit. Two age dates from these younger deposits suggest that much of this activity occurred between l0,000 and 12,000 years ago. On the southeastern coast at Pointe Mulâtre and extending approximately 4 km north and at a maximum 2 km west, is a megabreccia of large (up to 3 m) flow-banded andesite clasts set in a semi-lithified medium grained ash matrix. At Pointe Mulâtre this megabreccia is overlain by unconsolidated block and ash flow deposits. To the north of the megabreccia, exposures in the sea cliffs reveal a consolidated sequence of well-bedded alternating coarse and fine deposits suggesting deltaic foreset beds; which in turn appears to be overlain by a yellow- colored relatively coarse flow deposit with an irregular upper surface. The uppermost deposits in the sea cliffs are a sequence of unconsolidated block and ash flow deposits and interbedded fluviatile conglomerates equivalent to the younger flow deposits logged inland. Volcanic rocks from the Grande Soufriere Hills are all porphyritic andesites often containing hypabyssal inclusions. Dominant phenocrysts are plagioclase often with inclusion-rich cores and well developed zoning. Mafic phenocrysts include hornblende, augite and hypersthene. Geochemically these andesites range from 58- 63% SiO2 and show trends of decreasing values for Al2O3, FeO, MgO, CaO, TiO2, Sr, V, and Sc and increasing values for Na2O, K2O, Ba, Rb, and Zr with increasing silica. Samples from the megabreccia can be chemically distinguished from the younger rocks of this center. Petrologic models suggest that the younger rocks from the Grand Soufriere Hills can be produced by fractional crystallization of basaltic magma such as those erupted from other centers (such as Morne Anglais to the west). Minor variations within this suite of andesites can be related to upper crustal fractionation of phenocryst phases.

Quaternary vertebrate faunas from Sumba, Indonesia: implications for Wallacean biogeography and evolution

PubMed Central

Crees, Jennifer J.; Hansford, James; Jeffree, Timothy E.; Crumpton, Nick; Kurniawan, Iwan; Setiyabudi, Erick; Paranggarimu, Umbu; Dosseto, Anthony; van den Bergh, Gerrit D.

2017-01-01

Historical patterns of diversity, biogeography and faunal turnover remain poorly understood for Wallacea, the biologically and geologically complex island region between the Asian and Australian continental shelves. A distinctive Quaternary vertebrate fauna containing the small-bodied hominin Homo floresiensis, pygmy Stegodon proboscideans, varanids and giant murids has been described from Flores, but Quaternary faunas are poorly known from most other Lesser Sunda Islands. We report the discovery of extensive new fossil vertebrate collections from Pleistocene and Holocene deposits on Sumba, a large Wallacean island situated less than 50 km south of Flores. A fossil assemblage recovered from a Pleistocene deposit at Lewapaku in the interior highlands of Sumba, which may be close to 1 million years old, contains a series of skeletal elements of a very small Stegodon referable to S. sumbaensis, a tooth attributable to Varanus komodoensis, and fragmentary remains of unidentified giant murids. Holocene cave deposits at Mahaniwa dated to approximately 2000–3500 BP yielded extensive material of two new genera of endemic large-bodied murids, as well as fossils of an extinct frugivorous varanid. This new baseline for reconstructing Wallacean faunal histories reveals that Sumba's Quaternary vertebrate fauna, although phylogenetically distinctive, was comparable in diversity and composition to the Quaternary fauna of Flores, suggesting that similar assemblages may have characterized Quaternary terrestrial ecosystems on many or all of the larger Lesser Sunda Islands. PMID:28855367

Cultural Resources and Geomorphological Reconnaissance of the McClellan-Kerr, Arkansas River Navigation System. Pools 1 through 9

DTIC Science & Technology

1989-01-01

either the Petit Jean or Maumelle reaches as it flows out of the Ouachita Mountains into the unconsolidated sediments of the Mississippi River valley...small breaks, each depositing its load of coarser sediments in its own way. This results in sharply contrasting lenses of very small dimensions and...reflected in the channel size which decreases with increasing amounts of sediment deposited in the channel. Additionally, the amount of sediment deposited

MX Siting Investigation. Geotechnical Evaluation of Luke Bombing and Gunnery Range. Geotechnical Report, Lechuguilla Desert, Arizona. Volume I.

DTIC Science & Technology

1978-01-20

8217-5000 -150 C KILOETERS , 1 2 V i asagerat- EXPLANATION i SURFICIAL BASIN FILL; Alluvial tans and playa lacustrine deposits; average seismic velocity...Undetermined e Velocity zone I represents alluvial fan deposits and possible playa /lacustrine materials underlying the unconsolidated, thin 1younger...alluvial fan unit (A5y, A5yf). Velocity zone 2 seems to represert older, playa /lacustrine deposits overlying Veloc- ity zone 3, which may be the well

Accelerated loading evaluation of subbase layers in pavement performance : tech summary.

DOT National Transportation Integrated Search

2009-04-01

The mighty Mississippi River formed and sculpted most of south Louisiana, creating large areas of alluvial : deposits consisting of soft, wet, and unconsolidated soil layers. Many Louisiana pavements were built in : these areas of naturally low shear...

Quaternary geologic map of the Wolf Point 1° × 2° quadrangle, Montana and North Dakota

USGS Publications Warehouse

Fullerton, David S.; Colton, Roger B.; Bush, Charles A.

2016-09-08

The Wolf Point quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S.-Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes the Peerless Plateau and Flaxville Plain. The primary river is the Missouri River.The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (for example, ground-moraine deposits, end-moraine deposits, and stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 23 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in pedology or agronomy.  Rather, it is a generalized map of soils recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed.  Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. The surficial deposits are glacial, ice-contact, glaciofluvial, alluvial, lacustrine, eolian, colluvial, and mass-movement deposits.Till of late Wisconsin age is represented by three map units. Till of Illinoian age also is mapped.  Till deposited during pre-Illinoian glaciations is not mapped, but is widespread in the subsurface.  Linear ice-molded landforms (primarily drumlins), shown by symbol, indicate directions of ice flow during late Wisconsin and Illinoian glaciations. The Quaternary geologic map of the Wolf Point quadrangle, northeastern Montana and North Dakota, was prepared to provide a database for compilation of a Quaternary geologic map of the Regina 4° × 6° quadrangle, United States and Canada, at scale 1:1,000,000, for the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series.  This map was compiled from data from many sources, at several different map scales.  That information was generalized and simplified, and then transferred to a base map at 1:250,000 scale to serve as the base for final reduction to 1:1,000,000, the nominal reading scale of maps in the Quaternary Geologic Atlas of the United States map series.  This map is the generalized and simplified 1:250,000 scale compilation.  Letter symbols for the map units are those used for the same units in the Quaternary Geologic Atlas of the United States map series. The map summarizes new, and selected published and unpublished, geologic information for public use and for use by Federal, State, and local governmental agencies for land use planning, including assessment of natural resources, natural hazards, recreation potential, and land use management.  It also is a base from which a variety of maps relating to earth surface processes and Quaternary geologic history can be derived.

Pliocene and Quaternary Deposits in the Northern Part of the San Juan Basin in Southwestern Colorado and Northwestern New Mexico

USGS Publications Warehouse

Scott, Glenn R.; Moore, David W.

2007-01-01

Unconsolidated late Cenozoic deposits in the northern part of the San Juan Basin range in age from late Pliocene to Holocene. Most of the deposits are alluvial gravel composed of resistant quartzite, sandstone, and igneous, metamorphic, and volcanic rocks derived from the uplifted central core of the San Juan Mountains 20-50 miles (32-80 kilometers) north of the basin. Alluvial deposits are most voluminous in the Animas Valley, but deposits of gravel of the same general age are present in the La Plata, Florida, Los Pinos, and Piedra River valleys as well. Alluvial gravel forms tabular deposits, generally about 20 feet (6 meters) thick, that are exposed beneath a sequence of terraces at many levels above the rivers. Gravel layers 360 feet (110 meters) or less above the Animas River are glacial outwash. The gravel layers begin at the south toes of end moraines and extend discontinuously downvalley at least 10-20 miles (16-32 kilometers). Farther south, distinction between outwash and nonglacial alluvium is problematical. Alluvial gravel beneath higher terraces does not grade to end moraines. Glacial till forms a series of end moraines at the north edge of the town of Durango. The oldest moraines are farthest downvalley, are higher above the river, and have more mature surficial soils than do moraines farther north. The two youngest moraines, the Animas City moraines, are interpreted to be Pinedale in age. They have narrow, ridgelike crests and form nearly unbroken arcs across the valley floor. Small segments of still more weathered moraines, the Spring Creek moraines, are 170-230 feet (52-70 meters) above the river and are 660-990 feet (200-300 meters) farther downvalley. The oldest moraines, the Durango moraines, are on the north end of the unnamed mesa on which Fort Lewis College is located. The base is about 180 feet (55 meters) above the river. These oldest moraines may be of Bull Lake age. Alluvial fans, pediment gravel, and landslides are scattered at several levels in various valleys within the northern San Juan Basin. Except where the Lava Creek B volcanic ash (0.639 mega-annum) is interbedded in them, these crudely bedded accumulations of sandy or clayey material washed from side drainages and added little to our reconnaissance stratigraphic study. Scattered landslide deposits consist of unsorted, mixed soil and fragments of rock. Loess and local silty and clayey sheetwash alluvium 6-12 feet (2-4 meters) thick form a veneer on low terraces. On higher terraces, such as Red Mesa east of the La Plata River and Florida Mesa east of the Animas River, loess and sheetwash alluvium generally are about 20 feet (6 meters) thick but can be as thick as 40-50 feet (12-15 meters) in places on Florida Mesa. When using the Lava Creek B volcanic ash as a time datum, apparently the timing of late Cenozoic continental deposition in the region was broadly similar to that in the Denver Basin-Front Range region and some other glaciated mountain ranges in the Rocky Mountains. A more accurate dating of Quaternary alluviation must await a thorough dating of the deposits. Thick, extensive outwash gravel indicates enhanced deposition during glacial epochs.

Origin and late quaternary tectonism of a western Canadian continental shelf trough

NASA Astrophysics Data System (ADS)

Moslow, Thomas F.; Luternauer, John L.; Rohr, Kristin

1991-08-01

Analyses of high resolution and multi-channel seismic profiles from the central continental shelf of western Canada ascribe a late Quaternary glacial origin to large-scale troughs. Along the margins of Moresby Trough, one of three large-scale cross-shelf bathymetric depressions in Queen Charlotte Sound, seismic profiles within Quaternary sediments show a divergence of reflectors, thickening and folding of seismic units, and concavity of reflectors suggestive of drag. Compactional subsidence, growth faulting, and compaction faulting are also observed. Fault traces commonly terminate below the seabed. Deformation of Quaternary sediments due to faulting is plastic in nature and maximum offset of reflectors is 2.5 m. The observed Quaternary deformation appears to be a product of rapid deposition, loading and subsidence of late Quaternary sediment, which is unrelated to seismic activity. In addition, Quaternary faulting was probably activated by post-glacial loading and isostatic rebound of consolidated Tertiary strata along the margins of continental shelf troughs. The presence of mass movement (slump or debris flow) deposits overlying lithified Tertiary strata along the flanks of Moresby Trough provides the only evidence of seismic activity in the study area. The lack of a mud drape over these deposits implies a late Holocene age for the timing of their emplacement. The Quaternary troughs are incised into Tertiary-aged sedimentary fill of the Queen Charlotte basin. Previous workers had interpreted seafloor escarpments paralleling the trough margins to indicate that the location of Moresby Trough was controlled by renewed or continued activity on Tertiary-aged faults. A multi-channel seismic line across Moresby Trough shows that such an escarpment on the seafloor does not correlate to faults either in the Tertiary basin fill or the underlying basement. Tertiary reflectors are continuous underneath Moresby Trough; the seafloor escarpment is an erosional feature and was not created by reactivation of Tertiary structures. Trough erosion and subsequent fill (up to 175 m thick) are entirely of Quaternary age.

Predicting Risk from Radon in Source Waters from Water Quality Parameters

EPA Science Inventory

Overall, 47 groundwater samples were collected from 45 small community water systems (CWSs) and analyzed for radon and other water quality constituents. In general, groundwater from unconsolidated deposits and sedimentary rocks had lower average radon levels (ranging from 223 to...

Geology and ground water in the Platte-Republican Rivers watershed and the Little Blue River basin above Angus, Nebraska, with a section on chemical quality of the ground water

USGS Publications Warehouse

Johnson, C.R.; Brennan, Robert

1960-01-01

This report describes an area of about 7,300 square miles in south-central Nebraska. Approximately one-fourth of the area, largely at its east end, consists of an undissected southeastward-sloping upland plain and is almost wholly irrigable; the remainder is in various stages of dissection and only parts of it are suitable for irrigation. Although some of the deeper lying bedrock formations are potential sources of water supply, they are not likely to be tapped in the near future because abundant supplies are available at shallower depth from semiconsolidated and unconsolidated deposits. The Ogallala formation of Tertiary (Pliocene) age consists of gravel, sand, silt, and volcanic ash, some layers of which are partly cemented. It was deposited by eastward-flowing streams, which formed a constructional plain above a surface into which the streams had previously eroded broad valleys. In turn, valleys were cut into the surface of the Ogallala before the overlying deposits of gravel, sand, silt, and clay of Quaternary (Pleistocene) age were laid down, also forming a constructional plain. During Recent time, streams have dissected the older deposits and have deposited thin alluvium in their valleys; also, several parts of the area have become mantled by wind-deposited sand. Because during Tertiary and Quaternary time the area repeatedly was the site of deposition and erosion, the thickness of all the stratigraphic units differs markedly from place to place. In general, however, the Ogallala formation thins eastward and in the central and eastern parts of the area is overlain by the eastward-thickening deposits of Pleistocene age. The maximum thickness of the Ogallala formation is about 500 feet, and the maximum thickness of the Pleistocene deposits is a little more than 300 feet. Each thins to a featheredge and is completely absent in parts of the area. The water-bearing part of the combined Tertiary and Pleistocene deposits is considered to be a single zone of saturation because the ground water, as it percolates southeastward beneath the area, moves out of the Tertiary and into the Quaternary deposits without apparent hindrance. The water that enters the area as underflow from the west is augmented within the area by water that infiltrates from the land surface. The principal sources of irrigating water are precipitation, seepage from canals and reservoirs, and applied irrigation water. Except for the water withdrawn through wells or discharged by natural processes where valleys have been cut into the zone of saturation, ground water leaves the area as underflow into the Platte River valley on the north, the Blue River drainage basin on the east, or the Republican River valley on the south. Part of the water used for irrigation and watering livestock and all the water used in rural and urban homes, in public buildings, and for industrial purposes is obtained from wells, To date (1952) there is no indication that the supply of ground water is being depleted faster than it is being replenished; instead, studies indicate that greater quantities can be withdrawn without causing an excessive decline of the water table. An increase of ground-water withdrawals to a sustainable maximum, however, will be possible only if the points of withdrawal are scattered fairly uniformly. It is estimated that annual withdrawals per township should not exceed 2,100 acre-feet where infiltrating precipitation is the only source of recharge, or 3,000 acre-feet where other sources of recharge are significant. Although perennial withdrawals of this amount could be sustained indefinitely, they would cause some lowering of the water table and eventually a decrease in the amount of water discharged from the area by natural means. The ground water is of the calcium bicarbonate type. In much of the area it is hard or very hard, and in places it contains excessive amounts of iron. In all other respects the water is chemically suitable for domesti

Luminescence dating of quaternary deposits in geology in Brazil.

PubMed

Tatumi, Sonia Hatsue; Gozzi, Giuliano; Yee, Márcio; de Oliveira, Victor Inácio; Sallun, Alethéa Ernandes Martins; Suguio, Kenitiro

2006-01-01

In the present work, systematic dating by luminescence methods has been done on 50 Quaternary geological samples within the study area of São Paulo State, Brazil. Bleaching experiments showed that residual TL intensity of 375 degrees C peak, of the quartz, was obtained after 10 h of sunlight exposition. Intensities decays of the 325 and 375 degrees C TL peaks can be fitted using second order exponential equation. Paleodose values were evaluated using regeneration methods with multiple aliquots. Samples dated indicate preliminary ages varying from 9 +/- 1 to 935 +/- 130 ka for colluvio-elluvial deposits, and from 17 +/- 2 to 215 +/- 30 ka for alluvial deposits of the study area. They cover four peneplained surfaces shaped during the Quaternary: I (1000-400 ka), II (400-120 ka), III (120-10 ka) and IV (10 ka until today), in decreasing order.

Local recharge processes in glacial and alluvial deposits of a temperate catchment

NASA Astrophysics Data System (ADS)

Fragalà, Federico A.; Parkin, Geoff

2010-07-01

SummaryThis study demonstrates that the composition and structure of Quaternary deposits and topography significantly influence rates of recharge and distribution of diffuse agricultural pollution at the hillslope scale. Analyses were made of vertical profiles of naturally-occurring chloride and nitrate, and artificially introduced bromide, in unsaturated and saturated sections of borehole cores of glacial till and alluvium under different land uses in the Upper Eden valley (UK). Estimates of local potential recharge were made based on chloride mass balance and nitrate peak methods. Persistent chloride bulges below the root zone were observed, and are interpreted to result from filtration processes at lithological boundaries. Changes in the shape of chloride profiles downslope, corroborated by nitrate profiles, indicate the roles of surface or near-surface runoff and runon, and the existence of lateral subsurface flows at depth. These findings have implications for estimation of recharge rates through unsaturated zones in Quaternary deposits, and the interpretation of potential 'hot-spots' of diffuse agrochemicals, particularly nitrates, moving through Quaternary deposits into groundwater.

Cenozoic stratigraphy and geologic history of the Tucson Basin, Pima County, Arizona

USGS Publications Warehouse

Anderson, S.R.

1987-01-01

This report was prepared as part of a geohydrologic study of the Tucson basin conducted by the U.S. Geological Survey in cooperation with the city of Tucson. Geologic data from more than 500 water supply and test wells were analyzed to define characteristics of the basin sediments that may affect the potential for land subsidence induced by groundwater withdrawal. The Tucson basin is a structural depression within the Basin and Range physiographic province. The basin is 1,000 sq mi in units area and trends north to northwest. Three Cenozoic stratigraphic unit--the Pantano Formation of Oligocene age, the Tinaja beds (informal usage) of Miocene and Pliocene age, and the Fort Lowell Formation of Pleistocene age--fill the basin. The Tinaja beds include lower, middle, and upper unconformable units. A thin veneer of stream alluvium of late Quaternary age overlies the Fort Lowell Formation. The Pantano Formation and the lower Tinaja beds accumulated during a time of widespread continental sedimentation, volcanism, plutonism, uplift, and complex faulting and tilting of rock units that began during the Oligocene and continued until the middle Miocene. Overlying sediments of the middle and upper Tinaja beds were deposited in response to two subsequent episodes of post-12-million-year block faulting, the latter of which was accompanied by renewed uplift. The Fort Lowell Formation accumulated during the Quaternary development of modern through-flowing the maturation of the drainage. The composite Cenozoic stratigraphic section of the Tucson basin is at least 20,000 ft thick. The steeply tilted to flat-lying section is composed of indurated to unconsolidated clastic sediments, evaporites, and volcanic rocks that are lithologically and structurally complex. The lithology and structures of the section was greatly affected by the uplift and exhumation of adjacent metamorphic core-complex rocks. Similar Cenozoic geologic relations have been identified in other parts of southern Arizona. (Author 's abstract)

Neotectonic reactivation of shear zones and implications for faulting style and geometry in the continental margin of NE Brazil

NASA Astrophysics Data System (ADS)

Bezerra, F. H. R.; Rossetti, D. F.; Oliveira, R. G.; Medeiros, W. E.; Neves, B. B. Brito; Balsamo, F.; Nogueira, F. C. C.; Dantas, E. L.; Andrades Filho, C.; Góes, A. M.

2014-02-01

The eastern continental margin of South America comprises a series of rift basins developed during the breakup of Pangea in the Jurassic-Cretaceous. We integrated high resolution aeromagnetic, structural and stratigraphic data in order to evaluate the role of reactivation of ductile, Neoproterozoic shear zones in the deposition and deformation of post-rift sedimentary deposits in one of these basins, the Paraíba Basin in northeastern Brazil. This basin corresponds to the last part of the South American continent to be separated from Africa during the Pangea breakup. Sediment deposition in this basin occurred in the Albian-Maastrichtian, Eocene-Miocene, and in the late Quaternary. However, our investigation concentrates on the Miocene-Quaternary, which we consider the neotectonic period because it encompasses the last stress field. This consisted of an E-W-oriented compression and a N-S-oriented extension. The basement of the basin forms a slightly seaward-tilted ramp capped by a late Cretaceous to Quaternary sedimentary cover ~ 100-400 m thick. Aeromagnetic lineaments mark the major steeply-dipping, ductile E-W- to NE-striking shear zones in this basement. The ductile shear zones mainly reactivated as strike-slip, normal and oblique-slip faults, resulting in a series of Miocene-Quaternary depocenters controlled by NE-, E-W-, and a few NW-striking faults. Faulting produced subsidence and uplift that are largely responsible for the present-day morphology of the valleys and tablelands in this margin. We conclude that Precambrian shear zone reactivation controlled geometry and orientation, as well as deformation of sedimentary deposits, until the Neogene-Quaternary.

Chemistry of runoff and shallow ground water at the Cattlemans Detention basin site, South Lake Tahoe, California, August 2000-November 2001

USGS Publications Warehouse

Prudic, David E.; Sager, Sienna J.; Wood, James L.; Henkelman, Katherine K.; Caskey, Rachel M.

2005-01-01

A study at the Cattlemans detention basin site began in November 2000. The site is adjacent to Cold Creek in South Lake Tahoe, California. The purpose of the study is to evaluate the effects of the detention basin on ground-water discharge and changes in nutrient loads to Cold Creek, a tributary to Trout Creek and Lake Tahoe. The study is being done in cooperation with the Tahoe Engineering Division of the El Dorado County Department of Transportation. This report summarizes data collected prior to and during construction of the detention basin and includes: (1) nutrient and total suspended solid concentrations of urban runoff; (2) distribution of unconsolidated deposits; (3) direction of ground-water flow; and (4) chemistry of shallow ground water and Cold Creek. Unconsolidated deposits in the area of the detention basin were categorized into three classes: fill material consisting of a red-brown loamy sand with some gravel and an occasional cobble that was placed on top of the meadow; meadow deposits consisting of gray silt and sand with stringers of coarse sand and fine gravel; and a deeper brown to yellow-brown sand and gravel with lenses of silt and sand. Prior to construction of the detention basin, ground water flowed west-northwest across the area of the detention basin toward Cold Creek. The direction of ground-water flow did not change during construction of the detention basin. Median concentrations of dissolved iron and chloride were 500 and 30 times higher, respectively, in ground water from the meadow deposits than dissolved concentrations in Cold Creek. Median concentration of sulfate in ground water from the meadow deposits was 0.4 milligrams per liter and dissolved oxygen was below the detection level of 0.3 milligrams per liter. The relatively high concentrations of iron and the lack of sulfate in the shallow ground water likely are caused by chemical reactions and biological microbial oxidation of organic matter in the unconsolidated deposits that result in little to no dissolved oxygen in the ground water. The higher chloride concentrations in ground water compared with Cold Creek likely are caused from the application of salt on Pioneer Trail and streets in Montgomery Estates subdivision during the winter. Runoff from these roads contributes to the recharge of the shallow ground water. The range of dissolved constituents generally was greater in the meadow deposits than in the deeper sand and gravel. Ammonia plus organic nitrogen were the dominant forms of dissolved nitrogen and concentrations ranged from 0.04 to 18 milligrams per liter as nitrogen. Highest concentration was beneath the middle of the detention basin. Nitrate plus nitrite concentrations were low (<0.33 milligrams per liter as nitrogen) throughout the area and dissolved phosphorus concentrations ranged from 0.001 to 0.34 milligrams per liter. Nitrogen and dissolved organic carbon showed no consistent pattern in the direction of ground-water flow, which suggests that, similar to iron and sulfate, local variations in the chemical and biological reactions within the meadow deposits controlled the variation in nitrogen concentrations. The gradual increase in dissolved phosphorus along the direction of ground-water flow suggest that phosphorus may be slowly dissolving into ground water. Dissolved phosphorus was consistently low in July, which may be the result of greater microbial activity in the unconsolidated deposits or from uptake by roots during the summer.

Process interpretation of laminated lacustrine sediments from the valley of the river Alf, Quaternary West Eifel Volcanic Field, Germany

NASA Astrophysics Data System (ADS)

Eichhorn, Luise; Pirrung, Michael; Zolitschka, Bernd; Büchel, Georg

2016-04-01

High-resolution annually laminated sediment archives from lakes Holzmaar and Meerfelder Maar located in the Quaternary West Eifel Volcanic Field are in the focus of many investigations (e.g. Brauer et al. 2001, Zolitschka 1991). These publications are related to predominantly biogenic varves covering the last ca. 14 ka years, i.e. the Lateglacial and the Holocene. In our study, laminated sediments consisting of clay-silt couplets are presented from paleolake Alf. This paleolake formed in a valley dammed by volcanic products, and covers the Pleniglacial between 31 and 24 ka BP (Pirrung et al. 2007). The focus of our study is the characterization of the structure of clay-silt couplets and the determination of their origin. The applied granulometry revealed mean grain sizes of 10 μm for the light laminae (colors refer to core scan photo) and 14 μm for the dark laminae (both middle silt). X-ray diffraction confirms identical mineral phases for light and dark laminae, with light laminae being clay-enriched containing a higher amount of sericite and chlorite while dark laminae are enriched in quartz. X-ray fluorescence and detrital microfacies analysis on thin sections indicate that calcite dominates in the dark laminae. Microscopically, three different types of silt layers are present. Type I are laminae with homogeneous sublayers, Type II are graded laminae and Type III are laminae with graded sublayers. Processes causing the formation of these silt lamination types can be attributed to repeatedly occurring snow melting, permafrost thawing or rain events linked with sediment delivery from the catchment into the lake. The amount of precipitation and melt water, sediment discharge and density stratification lead to gravity suspension fall out, partial erosion of previously deposited unconsolidated sediments and resuspension in the lake. Brauer, A., et al. (2001). Lateglacial varve chronology and biostratigraphy of lakes Holzmaar and Meerfelder Maar, Germany. Boreas 30(1): 83-88. Pirrung, M., et al. (2007). Hochauflösende fluviolakustrine Sedimente des jüngeren Pleistozän aus dem Alfbachtal bei Gillenfeld (Westeifel) - erste Ergebnisse. Mainzer geowissenschaftliche Mitteilungen 35: 51-80. Zolitschka, B. (1991). Absolute dating of late-Quaternary lacustrine sediments by high resolution varve chronology. Hydrobiologia 214: 59-61.

Mössbauer and XRD study of novel quaternary Sn-Fe-Co-Ni electroplated alloy

NASA Astrophysics Data System (ADS)

Kuzmann, E.; Sziráki, L.; Stichleutner, S.; Homonnay, Z.; Lak, G. B.; El-Sharif, M.; Chisholm, C. U.

2017-11-01

Constant current electrochemical deposition technique was used to obtain quaternary alloys of Sn-Fe-Co-Ni from a gluconate electrolyte, which to date have not been reported in the literature. For the characterization of electroplated alloys, 57Fe and 119Sn Conversion Electron Mössbauer Spectroscopy (CEMS), XRD and SEM/EDAX were used. XRD revealed the amorphous character of the novel Sn-Fe-Co-Ni electrodeposited alloys. 57Fe Mössbauer spectrum of quaternary deposit with composition of 37.0 at% Sn, 38.8 at% Fe, 16.8 at% Co and 7.4 at% Ni displayed a magnetically split sextet (B = 28.9T) with broad lines typical of iron bearing ferromagnetic amorphous alloys. Magnetically split 119Sn spectra reflecting a transferred hyperfine field (B = 2.3T) were also observed. New quaternary Sn-Fe-Co-Ni alloys were successfully prepared.

The source of naturally occurring arsenic in a coastal sand aquifer of eastern Australia.

PubMed

O'Shea, Bethany; Jankowski, Jerzy; Sammut, Jesmond

2007-07-01

The discovery of dissolved arsenic in a coastal aquifer used extensively for human consumption has led to widespread concern for its potential occurrence in other sandy coastal environments in eastern Australia. The development of an aquifer specific geomorphic model (herein) suggests that arsenic is regionally derived from erosion of arsenic-rich stibnite (Sb(2)S(3)) mineralisation present in the hinterland. Fluvial processes have transported the eroded material over time to deposit an aquifer lithology elevated in arsenic. Minor arsenic contribution to groundwater is derived from mineralised bedrock below the unconsolidated aquifer. An association with arsenic and pyrite has been observed in the aquifer in small discrete arsenian pyrite clusters rather than actual acid sulfate soil horizons. This association is likely to influence arsenic distribution in the aquifer, but is not the dominant control on arsenic occurrence. Arsenic association with marine clays is considered a function of their increased adsorptive capacity for arsenic and not solely on the influence of sea level inundation of the aquifer sediments during the Quaternary Period. These findings have implications for, but are not limited to, coastal aquifers. Rather, any aquifer containing sediments derived from mineralised provenances may be at risk of natural arsenic contamination. Groundwater resource surveys should thus incorporate a review of the aquifer source provenance when assessing the likely risk of natural arsenic occurrence in an aquifer.

Depth of the base of the Jackson aquifer, based on geophysical exploration, southern Jackson Hole, Wyoming, USA

USGS Publications Warehouse

Nolan, B.T.; Campbell, D.L.; Senterfit, R.M.

1998-01-01

A geophysical survey was conducted to determine the depth of the base of the water-table aquifer in the southern part of Jackson Hole, Wyoming, USA. Audio-magnetotellurics (AMT) measurements at 77 sites in the study area yielded electrical-resistivity logs of the subsurface, and these were used to infer lithologic changes with depth. A 100-600 ohm-m geoelectric layer, designated the Jackson aquifer, was used to represent surficial saturated, unconsolidated deposits of Quaternary age. The median depth of the base of the Jackson aquifer is estimated to be 200 ft (61 m), based on 62 sites that had sufficient resistivity data. AMT-measured values were kriged to predict the depth to the base of the aquifer throughout the southern part of Jackson Hole. Contour maps of the kriging predictions indicate that the depth of the base of the Jackson aquifer is shallow in the central part of the study area near the East and West Gros Ventre Buttes, deeper in the west near the Teton fault system, and shallow at the southern edge of Jackson Hole. Predicted, contoured depths range from 100 ft (30 m) in the south, near the confluences of Spring Creek and Flat Creek with the Snake River, to 700 ft (210 m) in the west, near the town of Wilson, Wyoming.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2010

USGS Publications Warehouse

Beman, Joseph E.

2011-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and about a 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2010), the network consists of 124 wells and piezometers (a piezometer is a small-diameter subwell usually nested within a larger well). To better help the Albuquerque Bernalillo County Water Utility Authority manage water use, this report presents water-level data collected by U.S. Geological Survey personnel at those 124 sites through water year 2010.

The mass balance of soil evolution on late Quaternary marine terraces, northern California

NASA Technical Reports Server (NTRS)

Merritts, Dorothy J.; Chadwick, Oliver A.; Hendricks, David M.; Brimhall, George H.; Lewis, Christopher J.

1992-01-01

Mass-balance interpretation of a soil chronosequence provides a means of quantifying elemental addition, removal, and transformation that occur in soils from a flight of marine terraces in northern California. Six soil profiles that range in age from several to 240,000 yr are developed in unconsolidated, sandy-marine, and eolian parent material deposited on bedrock marine platforms. Soil evolution is dominated by (1) open-system depletion of Si, Ca, Mg, K, and Na; (2) open-system enrichment of P in surface soil horizons; (3) relative immobility of Fe and Al; and (4) transformation of Fe, Si, and Al in the parent material to secondary clay minerals and sesquioxides. Net mass losses of bases and Si are generally uniform with depth and substantial, in some cases approaching 100 percent; however, the rate of loss of each element differs markedly, causing the ranking of each by relative abundance to shift with time. Loss of Si from the sand fraction by dissolution and particle-size diminution, from about 100 percent to less than 35 percent over 240 ky, mirrors a similar gain in the silt and clay size fractions. The Fe originally present in the sand fraction decreases from greater than 80 percent to less than 10 percent, whereas the amount of Fe present in the clay and crystalline oxyhydroxide fractions increases to 25 percent and 70 percent, respectively.

Native gold and gold-rich sulfide deposits in a submarine basaltic caldera, Higashi-Aogashima hydrothermal field, Izu-Ogasawara frontal arc, Japan

NASA Astrophysics Data System (ADS)

Iizasa, Kokichi; Asada, Akira; Mizuno, Katsunori; Katase, Fuyuki; Lee, Sangkyun; Kojima, Mitsuhiro; Ogawa, Nobuhiro

2018-04-01

Sulfide deposits with extremely high Au concentrations (up to 275 ppm; avg. 102 ppm, n = 15), high Au/Ag ratios (0.24, n = 15), and low Cu/(Cu + Zn) ratios (0.03, n = 15) were discovered in 2015 in active hydrothermal fields at a water depth of 760 m in a basalt-dominated submarine caldera in the Izu-Ogasawara frontal arc, Japan. Native gold grains occur in massive sulfide fragments, concretions, and metalliferous sediments from a sulfide mound (40 m across and 20 m high) with up to 30-m-high black smoker chimneys. Tiny native gold grains up to 14 μm in diameter are mainly present in sulfide fallouts from chimney orifices and plumes. Larger native gold grains up to 150 μm long occur mostly as discrete particles and/or with amorphous silica and sulfides. The larger gold grains are interpreted to represent direct precipitation from Au-bearing hydrothermal fluids circulating in and/or beneath the unconsolidated sulfide mound deposits. Sulfur isotope compositions from a limited number of sulfide separates (n = 4) range from 4.3 to 5.8‰ δ34S, similar to the quaternary volcanic rocks of the arc. Barite separates have values of 22.2 and 23.1‰, close to modern seawater values, and indicate probable seawater sulfate origin. The Cu, Zn, and Pb concentrations in bulk samples of sulfide-rich rocks are similar to those of volcanogenic massive sulfides formed in continental crustal environments. The gold is interpreted to have formed by low-temperature hydrothermal activity, perhaps genetically different from systems with documented magmatic contributions or from seafloor hydrothermal systems in other island arc settings. Its presence suggests that basalt-dominated submarine calderas situated on relatively thick continental crust in an intraoceanic arc setting such as the Higashi-Aogashima knoll caldera may be perspective for gold mineralization.

Loess and its geomorphic, stratigraphic and paleoclimatic significance in the Quaternary

USGS Publications Warehouse

Muhs, Daniel R.

2013-01-01

Loess is aeolian silt visible in the field as a sedimentary body. It covers a significant portion of the land surface of the Earth. Loess thickness, particle size, and carbonate content decrease downwind from sources, useful trends for paleowinds. Many loess sections consist of relatively thick deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition slowed significantly. Loess in most regions was deposited during glacial periods and paleosols formed during interglacial periods. Loess has the potential to record the timing and environment of glacial–interglacial cycles of the Quaternary on many continents.

Electrical and well log study of the Plio-Quaternary deposits of the southern part of the Rharb Basin, northern Morocco

NASA Astrophysics Data System (ADS)

El Bouhaddioui, Mohamed; Mridekh, Abdelaziz; Kili, Malika; El Mansouri, Bouabid; El Gasmi, El Houssine; Magrane, Bouchaib

2016-11-01

The Rharb Basin is located in the NW of Morocco. It is the onshore extension of a lager offshore basin between Kenitra and Moulay Bousselham. The Rharb plain (properly called) extends over an area of 4200 Km2 between two very different structural entities: the unstable Rif domain in the NE and the East and the ''relatively stable'' Meseta domain in the south. The distribution of Pliocene-Quaternary deposits under this plain is complex and was controlled by both tectonics and climatic factors. The main objective of the present work is to define the spatiotemporal evolution of these deposits in the onshore part of the basin and to make a comparison with a sequence analysis defined, for equivalent deposits in the offshore basin, by a previous work. The proposed model allows thus to characterize the geometry of these deposits in the extension of continental shelf under the present day onshore basin, and to explain there is genesis in terms of interactions between eustatic sea level fluctuations, tectonics and sedimentary rates at the mouths of paleo-rivers that had drained the Rharb plain during Pliocene to Quaternary Times.

The 1959 MW 7.3 Hebgen Lake earthquake revisited: morphology and mechanics from lidar

NASA Astrophysics Data System (ADS)

Johnson, K. L.; Nissen, E.; Lajoie, L. J.

2016-12-01

This study demonstrates how we can glean new information by revisiting an early instrumental earthquake with high-resolution topography and modern thinking about the mechanics of surface rupturing. The 1959 MW 7.3 Hebgen Lake earthquake is among the largest and most deadly historic earthquakes within the conterminous United States outside of California, and one of the largest normal faulting earthquakes on record globally. The earthquake ruptured the subparallel Hebgen and Red Canyon faults within the slowly extending ( 3 mm/yr) Centennial Mountain Belt, and is one of the first to be field mapped in detail, modeled from global seismograms, and surveyed geodetically. Here, we augment these early studies with an investigation of the surface rupture in its current state. We use a 50 cm-resolution airborne lidar digital terrain model collected by the National Center for Airborne Laser Mapping (NCALM) in 2014 to document the fault scarp morphology, constrain its evolution, and speculate on the mechanical rupture properties. Using a dense set of scarp profiles, we add >400 displacement measurements to the 143 published data points from early field work, allowing more rigorous quantification of along-strike slip variability and strain gradients. Evidence of off-fault deformation is sparse along most of the scarp, though damage zone width increases where the earthquake ruptured closely spaced sedimentary contacts rather than unconsolidated Quaternary deposits. In a few places, we can identify composite scarps from which we estimate the number of earthquakes that have offset Holocene surfaces. We assess the scarp's degraded state, including some sites that were surveyed in 1980 and 2009 and others that have not been revisited since the initial investigation. Where the rupture crosses unconsolidated surfaces, we compute local sediment diffusion coefficients and analyze their variability along strike. Lastly, we model subsurface fault geometry by fitting dipping planes to its surface trace, testing our best-fit fault dips against those recovered in seismic analyses; this reaffirms that both main rupture strands correspond to primary faulting rather than induced landsliding.

The Hei River Basin in northwestern China - tectonics, sedimentary processes and pathways

NASA Astrophysics Data System (ADS)

Rudersdorf, Andreas; Nottebaum, Veit; Schimpf, Stefan; Yu, Kaifeng; Hartmann, Kai; Stauch, Georg; Wünnemann, Bernd; Reicherter, Klaus; Diekmann, Bernhard; Lehmkuhl, Frank

2014-05-01

The Hei River Basin (catchment area of c. 130,000 km²) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper catchment is represented by the Qilian Shan mountain range and its immediate foreland. Here, a tripartite altitudinal distribution of terrestrial sediment archives is evident, which is representative of catchment-wide sedimentological processes. Insights into their formation mechanisms, therefore, add valuable perspective regarding the reconstruction of sedimentological and paleoenvironmental conditions in the depositional area of the Hei River Basin. For the characterization of provenance and dispersal of Quaternary sediments in relation to the modern depositional environment, over 200 surface samples from the whole catchment were analyzed using XRD and XRF measurements on the clay fractions, heavy minerals and bulk sediments. The clay mineral results in-particular show that it is possible to discriminate between the chlorite rich metamorphic sediments originating from greenschist bearing rocks in the Qilian Shan Mountain Range in the south, and the more intrusive rocks from the Bei Shan Mountain Range west of the Hei River Basin. Additionally, these two main sources reflect different transportation processes; the Qilian Shan sediments are mainly transported by the rivers Heihe and Beida He, and the deposition of the Bei Shan sediments is mainly driven by wind or local runoff. Grain size results of primary loess deposits indicate different eolian transport pathways, i.e., far-travelled dust input (medium silty) vs. local deflation from active fluvial channels (fine sandy). Along the altitudinal transect, the varying geomorphological settings exert a significant influence on the grain size composition showing an increased contribution of far-travelled dust at higher altitudes.

Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

USGS Publications Warehouse

Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

2011-01-01

To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing through time of Quaternary sediments reflects the eastward progradational geometry of the continental shelf.The preservation potential of marginal marine deposits (barrier island, shoreface, backbarrier deposits) is not high, except in topographic lows associated with late Pleistocene paleovalleys and inlets because the current interglacial highstand has not yet reached its highest level. Given the documented increase in rate of relative sea-level rise in this region, shallow marine conditions are likely to return to the central Albemarle Embayment in the near future. ?? 2011 Elsevier B.V.

Quaternary tephrochronology and deposition in the subsurface Sacramento-San Joaquin Delta, California, U.S.A.

USGS Publications Warehouse

Maier, Katherine L.; Gatti, Emma; Wan, Elmira; Ponti, Daniel J.; Pagenkopp, Mark; Starratt, Scott W.; Olson, Holly A.; Tinsley, John

2015-01-01

We document characteristics of tephra, including facies and geochemistry, from 27 subsurface sites in the Sacramento-San Joaquin Delta, California, to obtain stratigraphic constraints in a complex setting. Analyzed discrete tephra deposits are correlative with: 1) an unnamed tephra from the Carlotta Formation near Ferndale, California, herein informally named the ash of Wildcat Grade (<~1.450 - >~0.780 Ma), 2) the Rockland ash bed (~0.575 Ma), 3) the Loleta ash bed (~0.390 Ma), and 4) a middle Pleistocene tephra resembling volcanic ash deposits at Tulelake, California, and Pringle Falls, Bend, and Summer Lake, Oregon, herein informally named the dacitic ash of Hood (<~0.211 to >~0.180 Ma, correlated age). All four tephra are derived from Cascades volcanic sources. The Rockland ash bed erupted from the southern Cascades near Lassen Peak, California, and occurs in deposits up to >7 m thick as observed in core samples taken from ~40 m depth below land surface. Tephra facies and tephra age constraints suggest rapid tephra deposition within fluvial channel and overbank settings, likely related to flood events shortly following the volcanic eruption. Such rapidly deposited tephra are important chronostratigraphic markers that suggest varying sediment accumulation rates (~0.07-0.29 m/1000 yr) in Quaternary deposits below the modern Sacramento-San Joaquin Delta. This study provides the first steps in developing a subsurface Quaternary stratigraphic framework necessary for future hazard assessment.

Znaczenie analizy minerałów ciężkich w badaniach osadów czwartorzędowych Polski

NASA Astrophysics Data System (ADS)

Racinowski, Roman

2008-01-01

In most regions of Poland the composition of heavy minerals assemblage permits to distinguish the Quaternary deposits from the older ones. The pre-Quaternary deposits are characterized by high content of glauconite, carbonate-ferruginous-manganese concretions, muscovite and chlorites. In their transparent heavy minerals spectrum the following minerals predominate: zircon, tourmaline, rutile, staurolite, disthene. However, the Tertiary deposits in the Carpathians and their foreland contain a significant amount of garnet, and sometimes also amphiboles, pyroxenes and biotite. Pyroxenes and sillimanite are found in the Sudetes foreland. In many Tertiary deposits of the northwestern and western Poland there are rather high contents of amphiboles, biotite, pyroxenes, garnets, rutile. In all Quaternary deposits in Poland the qualitative composition of heavy minerals assemblage is similar but the contents of particular minerals are different depending on the examined grain fraction. In tills (Table 1) and glaciofluvial deposits (Table 2), with the decreasing grain diameter the contents of zircon, rutile, and partly epidote increase, and those of amphiboles and garnets decrease. In rubble of coastal zone in the Polish Baltic Sea, with the decreasing grain diameter the contents of zircon, rutile and epidote increase, and those of amphibole, biotite and pyroxenes decrease (Tables 3-7). In Poland, glacial, glaciofluvial and glaciolacustrine deposits are characterized by quantitatively similar composition of heavy minerals assemblage. Amphiboles, biotite, epidotes, garnets and pyroxenes are typical transparent minerals (Tables 8 and 9). Young Pleistocene and Holocene sands of river terraces and dune fields in the upland zone of Poland differ from glacial deposits in low contents of amphiboles, biotite and pyroxenes, and higher contents of garnets and epidotes (Tables 8 and 9). Fossil river and lacustrine deposits of Polish Lowlands have very similar assemblage of heavy minerals to that found in glacial deposits. Both glacial and glaciofluvial deposits have similar composition of heavy minerals assemblage irrespective of their age (Tables 10, 11 and 12). This principle concerns also loesses (Table 13a, b) but the youngest ones are characterized by higher contents of amphiboles and epidotes. The composition of heavy minerals assemblage is useful for determining the source of material forming the Quaternary deposits. In the case of glacial deposits, the enrichment in glauconite, chlorites, and even zircon, rutile, tourmaline, staurolite indicates that material from local older substratum was supplied to the Quaternary deposits. Heavy minerals spectrum of non-glacial deposits can directly indicate the source material that formed a deposit. Conversely, it is difficult to draw the conclusions about fossil and modern weathering-soil horizons in loesses from the composition of heavy minerals assemblage (Tables 14 and 15). The results of heavy minerals analysis are useful for lithodynamic and lithofacial interpretation of flowing water environments, e.g. river (Table 16), glaciofluvial (Table 17) and sea coastal (Table 18).

Rock avalanche deposits in Alai Valley, Central Asia: misinterpretation of glacial record

NASA Astrophysics Data System (ADS)

Reznichenko, Natalya; Davies, Tim; Robinson, Tom; De Pascale, Gregory

2013-04-01

The reconstruction of Quaternary glaciations has been restricted by conventional approaches with resulting contradictions in interpretation of the regional glacial record, that recently have been subjected to critical re-evaluation. Along with uncertainties in dating techniques and their applicability to particular landforms (Kirkbride and Winkler, 2012), it has recently been demonstrated that the presence of rock avalanche debris in a landform can be unequivocally detected; this allows for the first time definitive identification of and distinction between glacial moraines and landslide deposits. It also identifies moraines that have formed due to rock avalanche deposition on glaciers, possibly with no associated climatic signal (Reznichenko et al., 2012). Confusion between landslide deposits and moraines is evident for ranges in Central Asia (e.g., Hewitt, 1999) where the least-studied glacial record is selectively correlated with established glacial chronologies in Alpine ranges, which in turn masks the actual glacial extent and their responses to climate change, tectonics and landsliding activity. We describe examples in the glaciated Alai Valley, large intermountain depression between the Zaalay Range of the Northern Pamir and the Alay Range of the Southern Tien-Shan, showing that some large Quaternary deposits classically interpreted as moraines are of rock avalanche origin. Sediment from these deposits has been tested for the presence of agglomerates that are only produced under high stress conditions during rock avalanche motion, and are absent from glacial sediments (Reznichenko et al., 2012). This reveals that morphologically-similar deposits have radically different geneses: rock avalanche origin for a deposit in the Komansu river catchment and glacial origin for deposits in the Ashiktash and Kyzylart catchments. The enormous Komansu rock avalanche deposit, probably triggered by a rupture of the Main Pamir thrust, currently covers about 100 km2 with a minimum estimated volume more than 1 x 109 m3. Another smaller rock avalanche deposit rests on the Lenin Glacial sediment in the neighbour Ashiktash river catchment, which was previously suggested to originate from Mt. Lenin (7134 m). The revised origin of these deposits highlights the role of rock avalanches in glacial activity and in the resulting glacial record in this valley and other actively tectonic areas of Central Asia. Although further investigation is required to detail the geneses, magnitudes and ages for these and other landforms in the valley, this study contributes explicit evidence for contamination of palaeoclimate proxies with data from non-climatic events, and reinforces the urgent need for revised interpretation of the glacial chronologies. Hewitt, K., 1999. Quaternary moraines vs. catastrophic rock avalanches in the Karakoram Himalaya, Northern Pakistan. Quaternary Research, v. 51, p. 220-237. Kirkbride, M.P., and Winkler, S., 2012. Correlation of Late Quaternary moraines: impact of climate variability, glacier response, and chronological resolution: Quaternary Science Reviews, v. 46, p. 1-29. Reznichenko, N.V., Davies, T.R.H., Shulmeister, J. and Larsen S.H, 2012. A new technique for identifying rock-avalanche-sourced sediment in moraines and some paleoclimatic implications. Geology, v. 40, p. 319-322.

California State Waters Map Series: offshore of Refugio Beach, California

USGS Publications Warehouse

Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Krigsman, Lisa M.; Dieter, Bryan E.; Conrad, James E.; Greene, H. Gary; Seitz, Gordon G.; Endris, Charles A.; Sliter, Ray W.; Wong, Florence L.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Yoklavich, Mary M.; East, Amy E.; Hart, Patrick E.; Johnson, Samuel Y.; Cochran, Susan A.

2015-01-01

Seafloor habitats in the broad Santa Barbara Channel region consist of significant amounts of soft, unconsolidated sediment interspersed with isolated areas of rocky habitat that support kelp-forest communities nearshore and rocky-reef communities in deep water. The potential marine benthic habitat types mapped in the Offshore of Refugio Beach map area are directly related to its Quaternary geologic history, geomorphology, and active sedimentary processes. These potential habitats, which lie primarily within the Shelf (continental shelf) but also partly within the Flank (basin flank or continental slope) megahabitats, primarily are composed of soft sediment interrupted by a few carbonate mounds. This homogeneous seafloor of sediment and low-relief bedrock provides promising habitat for groundfish, crabs, shrimp, and other marine benthic organisms.

Geohydrology and water utilization in the Willcox Basin, Graham and Cochise Counties, Arizona

USGS Publications Warehouse

Brown, S.G.; Schumann, Herbert H.

1969-01-01

The Willcox basin is an area of interior drainage in the northern part of Sulphur Springs Valley, Cochise and Graham Counties, Ariz. The basin comprises about 1,500 square miles, of which the valley floor occupies about 950 square miles. The basin probably formed during middle and late Tertiary time, when the area was subjected to large-scale faulting accompanied by the uplift of the mountain ranges that presently border it. During and after faulting, large quantities of alluvium were deposited in the closed basin. The rocks in the basin are divided into two broad groups--the rocks of the mountain blocks, of Precambrian through Tertiary age, and the rocks of the basin, of Tertiary and Quaternary age. The mountain blocks consist of igneous, metamorphic, and sedimentary rocks; the water-bearing characteristics of these rocks depend primarily on their degree of weathering and fracturing. Even in areas where these rocks are fractured and jointed, only small amounts of water have been developed. The rocks of the basin consist of moderately consolidated alluvium, poorly consolidated alluvium, and unconsolidated alluvium. The water-bearing characteristics of the moderately and poorly consolidated alluvium are not well known. The unconsolidated alluvium underlies most of the valley floor and consists of two facies, stream deposits and lake beds associated with the old playa. The lenticular sand and gravel layers interbedded in silt- and clay-size material of the unconsolidated alluvium constitute the principal aquifer in the basin. The other aquifers, which yield less water, consist of beds of poorly to moderately consolidated sand- and gravel-size material; these beds occur in both the poorly consolidated and moderately consolidated alluvium. In the Stewart area the median specific capacity of wells per 100 feet of saturated unconsolidated alluvium was 20 gallons per minute, and in the Kansas Settlement area the specific capacity of wells penetrating the poorly and moderately consolidated alluvium, undifferentiated, was only 7.4 gallons per minute per 100 feet of saturated material penetrated. The aquifer in the Kansas Settlement area is much less permeable but more homogeneous than the aquifer in the Stewart area. The coefficient of transmissibility of the aquifers, which was estimated from the specific-capacity data, ranged from 58,000 to 160,000 gal. tons per day per foot. Prior to extensive ground-water pumpage, the ground-water system probably was in equilibrium, with discharge equaling recharge. At that time, ground water moved toward the playa, where it was discharged by transpiration and evaporation. The estimate of the evapotranspiration in the playa area before large-scale development was about 75,000 acre-feet per year. On the basis of estimates of coefficients of transmissibility of the aquifer and on the basis of the water-table configuration, underflow toward the playa was computed to be about 54,000 acre-feet per year. By 1963, large-scale pumping had caused marked changes in the shape of the piezometric surface; large cones of depression had developed, and ground-water movement was toward the centers of pumping. The cones of depression caused by large-scale pumping have since expanded, and water-level declines have been measured in the recharge areas along the mountain fronts. Ground water has been used for irrigation since 1910. In 1928, about 4,000 acre-feet of ground water was pumped, and by 1963 180,000 acre-feet per year was being pumped. An estimated 1,860,000 acre-feet of water has been pumped for irrigation in the Willcox basin through 1963; 680,000 acre-feet from the Stewart area, 990,000 acre-feet from the Kansas Settlement area, and 190,000 acre-feet from the Pearce-Cochise area. In the Sierra Bonita Ranch area and the north playa area, ground-water withdrawal for irrigation through 1963 was small. From the spring of 1952 to the spring of 1964 water-level declines resulting from the

Quaternary geology and sapphire deposits from the BO PHLOI gem field, Kanchanaburi Province, Western Thailand

NASA Astrophysics Data System (ADS)

Choowong, Montri

2002-01-01

One of the most famous blue sapphire deposits in Thailand and SE Asia is from the Bo Phloi District, Kanchanaburi Province, Western Thailand. This paper presents the results of our gemstone investigation as well as establishing the Bo Phloi depositional sequence as one of the Quaternary Type Sections in the region. Relationships among the sedimentology, depositional sequences and geomorphology were investigated in order to understand the gemstone depositional features. Sedimentary structures and textures of the sequences show that the deposition of gemstones is related genetically to fluvial processes. Gemstones are recognized in floodplain and low terrace deposits where gemstone paystreaks concentrate mostly inside layers of gravel beds and foreset-bedded gravels lithofacies. C-14 dating of wood and peat within gemstone-bearing layers indicated that the deposit formed during the middle to late Pleistocene. The gemstone-bearing gravel bed defines a north-south trend along the incised palaeo-channel of an ancient braided river system in the middle part of the basin.

Evaluating the reliability of Late Quaternary landform ages: Integrating 10Be cosmogenic surface exposure dating with U-series dating of pedogenic carbonate on alluvial and fluvial deposits, Sonoran desert, California

NASA Astrophysics Data System (ADS)

Blisniuk, K.; Sharp, W. D.

2015-12-01

To assess the reliability of Quaternary age determinations of alluvial and fluvial deposits across the Sonoran Desert (Coachella Valley and Anza Borrego) in southern California, we applied both 10Be exposure age dating of surface clasts and U-series dating of pedogenic carbonate from subsurface clast-coatings to the same deposits. We consider agreement between dates from the two techniques to indicate reliable age estimates because each technique is subject to distinct assumptions and therefore their systematic uncertainties are largely independent. 10Be exposure dates should yield maximum ages when no correction is made for inheritance and post-depositional erosion is negligible. U-series dating, in contrast, provides minimum dates because pedogenic carbonate forms after deposition. Our results show that: (1) For deposits ca. 70 ka or younger, 10Be and U-series dates were generally concordant. We note, however, that in most cases U-series soil dates exceed 10Be exposure dates that are corrected for inheritance when using 10Be in modern alluvium. This suggests that 10Be concentrations of modern alluvium may exceed the 10Be acquired by late Pleistocene deposits during fluvial transport and hillslope residence (i.e., Pleistocene inherited 10Be). (2) For deposits older than ~70 ka, U-series dates are significantly younger than the 10Be dates. This implies that U-series dates in this region may significantly underestimate the depositional age of older alluvium, probably because of delayed onset of deposition, slow accumulation, or poor preservation of secondary carbonate in response to climatic controls. Thus, whenever possible, multiple dating methods should be applied to obtain reliable ages for late Quaternary deposits.

A potential archive of Pleistocene uplift and erosion in the eastern Nete basin, Campine area, north-eastern Belgium

NASA Astrophysics Data System (ADS)

Beerten, Koen; Leterme, Bertrand

2013-04-01

From a geodynamic point of view, the Campine area is situated on the crossroads between distinctive tectonic settings: the subsiding North Sea basin and Roer Valley Graben in the north, and the uplifting Brabant Massif and Ardennes in the south. In general, this has led to overall Cenozoic subsidence of the area and sedimentation of unconsolidated marine sands. However, the morphology of the present-day Nete basin, which is situated in the central and eastern part of the Campine area, is a clear example of an erosional feature and shows evidence of up to 30 m of Quaternary erosion. However, the drivers, timing and rate of landscape development in the Nete basin are poorly constrained. Here, we present and describe geological and geomorphological remnants testifying to past landscape development in the Nete basin, that will help understanding the Quaternary geodynamic evolution (uplift) of the Campine area. The Nete basin is located in northern Belgium and is drained by two small rivers, the Kleine Nete and Grote Nete, that merge into the larger Nete river several km before entering the Lower Scheldt basin. The Nete basin can clearly be identified on topographical maps as a depression, ca. 40 km x 40 km, with valley floors ranging between 10-20 m above sea level (a.s.l.). It is bounded in the north, east and south by erosion resistant geological formations at altitudes between 30 m (north) and 60 m (south). The major direction of drainage is from ENE to WSW and the basin thus opens towards the west. The start of basin development is situated after deposition of Rhine sediments (~ 1 Ma) which form the erosion resistant eastern watershed with the Meuse basin at an altitude of ~ 50 m a.s.l. on top of the Campine Plateau. GIS-based landscape analysis of the topography and the contour map of the Quaternary base confirm the observation that the lowering of the relief from the Campine Plateau down to the floodplain of the Kleine Nete and Grote Nete shows a stepwise appearance. Hitherto, 7 levels have been identified, at ~ 42 m, ~ 37 m, ~ 33 m, ~ 28 m, ~ 24 m, ~ 19 m and ~ 17 m (a.s.l.). These surfaces are sometimes very well preserved and may represent erosional terraces (of an old S-N flowing river) or pediment remnants, according to the very thin Quaternary deposits preserved there. In other cases, substantially thick Quaternary deposits (2-3 m) are associated with such surfaces. For example, the level at ~ 33 m is associated with sediments which are indicated as 'Pleistocene of the river valleys' on the geological map, suggesting a fluvial origin for these deposits at an intermediate altitude between the Campine Plateau and the Nete valley. The upper three levels are believed to have been formed in a drainage basin with consequent flow in northern direction, while the lower levels very likely correspond to a drainage network that already adapted to the underlying geological structure. The upper three levels are tentatively assigned to the period during which the Campine Plateau experienced significant uplift and tilting together with the northern Ardennes (van Balen et al., 2000; Westaway, 2001), i.e. between 0.4-0.8 Ma. The lower levels are believed to have been formed primarily in response to base level lowering following major sea level lowstand basin changes in the southern North Sea and the English Channel in the time period after ~ 0.4 Ma (Toucanne et al., 2009; Hijma et al., 2012). In future work, cosmogenic nuclide dating and optically stimulated luminescence dating of exposed and/or buried sediments will be applied in order to verify this hypothesis. Acknowledgments This work is performed in close cooperation with, and with the financial support of ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Fissile Materials, as part of the programme on geological disposal of high-level/long-lived radioactive waste that is carried out by ONDRAF/NIRAS. The views expressed in the abstract do not necessarily correspond to those of ONDRAF/NIRAS. References Hijma, M.P., Cohen, K.M., Roebroeks, W., Westerhoff, W.E., Busschers, F.S., 2012. Pleistocene Rhine-Thames landscapes: geological background for hominin occupation of the southern North Sea region. Journal of Quaternary Science, 27, 17-39. Toucanne, S., Zaragosi, S., Bourillet, J.F., Gibbard, P.L., Eynaud, F., Giraudeau, J., Turon, J.L., Cremer, M., Cortijo, E., Martinez, P., Rossignol, L., 2009. A 1.2 Ma record of glaciation and fluvial discharge from the Western European Atlantic margin. Quaternary Science Reviews, 28, 2974-2981. van Balen, R.T., Houtgast, R.F., Van der Wateren, F.M., Vandenberghe, J., Bogaart, P.W., 2000. Sediment budget and tectonic evolution of the Meuse catchment in the Ardennes and the Roer Valley Rift System. Global and Planetary Change, 27, 113-129. Westaway, 2001. Flow in the lower continental crust as a mechanism for the Quaternary uplift of the Rhenish Massif, north-west Europe. In: Maddy, D., Macklin, M.G. & Woodward, J.C. (eds) River Basin Sediment Systems: Archives of Environmental Change. Balkema (Rotterdam), 87-167.

Late Quaternary stratigraphy and depositional history of the Long Island Sound basin

USGS Publications Warehouse

Lewis, Ralph S.; Stone, Janet R.

1991-01-01

Where quiet waters prevail, marine mud generally less than 15 m thick blankets the older deposits of the Basin. Elsewhere, especially in eastern LIS, tidal currents are actively reworking and transporting glacial and postglacial deposits.

Quaternary and pre-Quaternary( ) materials and processes of southeast Ohio: Overview, speculations, and recommendations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berg, T.M.

1992-01-01

Investigations and mapping of surficial deposits in Ohio have focused largely on the glacial deposits which cover nearly two-thirds of the state. Research on Quaternary deposits beyond the glacial border has been done by Foster, Hildreth, Andrews, Leverett, Tight, Stout, Goldthwait, Forsyth, Lessig, White, Totten, Hoyer, and Noltimier. However, growing human interaction with surficial materials of southeast Ohio now requires much more detailed mapping and characterization of these deposits. Recognition of periglacial, proglacial, and preglacial processes and materials in eastern and southern states has led to the search for similar processes and materials in southeast Ohio. Evidence for gelifraction, gelifluction,more » cryoturbation, and considerable periglacial colluviation is more extensive than previously thought. Proglacial deposits are also much more extensive, outwash and glaciolacustrine deposits cover large areas in southeast Ohio and are poorly mapped and characterized, or not mapped at all. Preglacial processes including a long span of profound weathering and formation of saprolite have been given little or no attention in southeast Ohio. The signature of protracted preglacial weathering still remains in this part of the state, and should change prevailing views of the terrain upon which periglacial processes worked. Mapping and characterization of these materials are urgently needed as citizens make important land-use decisions such as locating landfills and new developments.« less

Appraisal of water resources in the Hackensack River basin, New Jersey

USGS Publications Warehouse

Carswell, L.D.

1976-01-01

The Hackensack River basin, in the northern part of the New Jersey-New York metropolitan area, includes some of the most highly urbanized areas in the United States as well as a largely undeveloped 23.4 square mile area of tidal marsh referred to as the Hackensack Meadows. Bedrock in the Hackensack River basin, consisting of the Newark Group of Triassic age, is composed of diabase dikes and sills and gently westward dipping sandstone, conglomerate, and shale. The Brunswick Formation of the Newark Group is the only important bedrock aquifer in the basin. Water occurs in this aquifer in joints and fractures. The zone of most abundant and largest water-bearing joints and fractures occurs generally within 200 feet of land surface in lowland areas of major streams and within 400 to 500 feet of land surface in upland areas. Reported yields of industrial and public-supply wells tapping the Brunswick are as much as 600 gpm (gallons per minute): the median yield is 100 gpm. The formation is anisotropic; the greatest permeability and thus the movement of water in response to pumping are parallel to the strike of bedding. Therefore, wells in well fields alined perpendicular to strike have minimum interference. The Newark Group is overlain by unconsolidated deposits of till, varved silt and clay, alluvium, and sand and gravel of Quaternary age. Sand and gravel aquifers consist of (1) deltaic deposits formed at the mouths of streams that entered ancient Lake Hackensack in the western part of the basin and (2) valley-fill deposits along the eastern side of the basin. These aquifers locally yield large quantities of water (greater than 300 gpm) to wells. The chemical quality of water in the Brunswick Formation is generally good, and the water is relatively low in dissolved mineral matter in the upper area of the Hackensack River basin. In the lower area of the basin, water in the Brunswick is highly mineralized: specific conductance ranges from 579 to 3,480 micromhos per centimeter at 25 °C; chloride content ranges from 19 to 755 mg/L (milligrams per liter); and sufate content ranges from 87 to 966 mg/L. Chemical quality in both the Brunswick Formation and the unconsolidated deposits in the lower area is affected by induced recharge of poor quality surface water from the Hackensack River and Newark Bay. Water quality in these surface water bodies is influenced by tidal flooding and by the disposal of an average of 57 mgd (million gallons per day) of sewage and industrial wastes in the Hackensack Meadows. Future development of ground-water supplies in the upper area of the basin is restricted, because such development would decrease surface-water supplies which are almost entirely utilized for water supply. Additional development of ground water in the lower area of the basin is limited by the small amount of ground water in the basin and by the intrusion of highly mineralized surface water into the aquifers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Opdyke, B.N.; Walker, J.C.G.

Differences in the rate of coral reef carbonate deposition from the Pleistocene to the Holocene may account for the Quaternary variation of atmospheric CO[sub 2]. Volumes of carbonate associated with Holocene reefs require an average deposition rate of 2.0 [times] 10[sup 13] mol/yr for the past 5 ka. In light of combined riverine, mid-ocean ridge, and ground-water fluxes of calcium to the oceans of 2.3 [times] 10[sub 13] mol/yr, the current flux of calcium carbonate to pelagic sediments must be far below the Pleistocene average of 1.2 [times] 10[sub 13] mol/yr. The authors suggest that sea-level change shifts the locusmore » of carbonate deposition from the deep sea to the shelves as the normal glacial-interglacial pattern of deposition of Quaternary global carbonates. To assess the impact of these changes on atmospheric CO[sub 2], a simple numerical simulation of the global carbon cycle was developed. Atmospheric CO[sub 2] as well as calcite saturation depth and sediment responses to these carbonate deposition changes are examined. Atmospheric CO[sub 2] changes close to those observed in the Vostok ice core, [approximately] 80 ppm CO[sub 2], for the Quaternary are observed as well as the approximate depth changes in percent carbonate of sediments measured in the Pacific Ocean over the same time interval.« less

Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

USGS Publications Warehouse

McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

2013-01-01

Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

Pulsed laser deposited BexZn1-xO1-ySy quaternary alloy films: structure, composition, and band gap bowing

NASA Astrophysics Data System (ADS)

Zhang, Wuzhong; Xu, Maji; Zhang, Mi; Cheng, Hailing; Li, Mingkai; Zhang, Qingfeng; Lu, Yinmei; Chen, Jingwen; Chen, Changqing; He, Yunbin

2018-03-01

In this work, c-axis preferentially oriented BexZn1-xO1-ySy (BeZnOS) quaternary alloy films were prepared successfully on c-plane sapphire by pulsed laser deposition for the first time. By appropriate adjustment of O2 pressure during the deposition, the grown films exhibited a single-phase hexagonal structure and good crystalline quality. The solid solubility of S in BexZn1-xO1-ySy quaternary alloy was significantly expanded (y ≤ 0.17 or y ≥ 0.35) as a result of simultaneous substitution of cation Zn2+ by smaller Be2+ and anion O2- by bigger S2-. Besides, due to the introduction of BeO with a wide band gap, BeZnOS quaternary films exhibited wider band gaps than the ternary ZnOS films with similar S contents. As the O2 pressure increased from 0.05 Pa to 6 Pa, the band gap of BeZnOS displayed an interesting bowing behavior. The variation range of the band gap was between 3.55 eV and 3.10 eV. The BeZnOS films with a wide band gap show potential applications in fabricating optoelectronic devices such as UV-detectors.

Geophysical Characterization of the Quaternary-Cretaceous Contact Using Surface Resistivity Methods in Franklin and Webster Counties, South-Central Nebraska

USGS Publications Warehouse

Teeple, Andrew; Kress, Wade H.; Cannia, James C.; Ball, Lyndsay B.

2009-01-01

To help manage and understand the Platte River system in Nebraska, the Platte River Cooperative Hydrology Study (COHYST), a group of state and local governmental agencies, developed a regional ground-water model. The southern boundary of this model lies along the Republican River, where an area with insufficient geologic data immediately north of the Republican River led to problems in the conceptualization of the simulated flow system and to potential problems with calibration of the simulation. Geologic descriptions from a group of test holes drilled in south-central Nebraska during 2001 and 2002 indicated a possible hydrologic disconnection between the Quaternary-age alluvial deposits in the uplands and those in the Republican River lowland. This disconnection was observed near a topographic high in the Cretaceous-age Niobrara Formation, which is the local bedrock. In 2003, the U.S. Geological Survey, in cooperation with the COHYST, collected surface geophysical data near these test holes to better define this discontinuity. Two-dimensional imaging methods for direct-current resistivity and capacitively coupled resistivity were used to define the subsurface distribution of resistivity along several county roads near Riverton and Inavale, Nebraska. The relation between the subsurface distribution of resistivity and geology was defined by comparing existing geologic descriptions of test holes to surface-geophysical resistivity data along two profiles and using the information gained from these comparisons to interpret the remaining four profiles. In all of the resistivity profile sections, there was generally a three-layer subsurface interpretation, with a resistor located between two conductors. Further comparison of geologic data with the geophysical data and with surficial features was used to identify a topographic high in the Niobrara Formation near the Franklin Canal which was coincident with a resistivity high. Electrical properties of the Niobrara Formation made accurate interpretation of the resistivity profile sections difficult and less confident because of similar resistivity of this formation and that of the coarser-grained sediment of the Quaternary-age deposits. However, distinct conductive features were identified within the resistivity profile sections that aided in delineating the contact between the resistive Quaternary-age deposits and the resistive Niobrara Formation. Using this information, an interpretive boundary was drawn on the resistivity profile sections to represent the contact between the Quaternary-age alluvial deposits and the Cretaceous-age Niobrara Formation. A digital elevation model (DEM) of the top of the Niobrara Formation was constructed using the altitudes from the interpreted contact lines. This DEM showed that the general trend of top of the Niobrara Formation dips to the southeast. At the north edge of the study site, the Niobrara Formation topographic high trends east-west with an altitude range of 559 meters in the west to 543 meters in the east. Based on the land-surface elevation and the Niobrara Formation DEM, the estimated thickness of the Quaternary-age alluvial deposits throughout the study area was mapped and showed a thinning of the Quaternary-age alluvial deposits to the north, approximately where the topographic high of the Niobrara Formation is located. This topographic high in the Niobrara Formation has the potential to act as a barrier to ground-water flow from the uplands alluvial aquifer to the Republican River alluvial aquifer as shown in the resistivity profile sections. The Quaternary-age alluvial deposits in the uplands and those in the Republican River Valley are not fully represented as disconnected because it is possible that there are ground-water flow paths that were not mapped during this study.

Reconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Hults, Chad P.; Mohadjer, Solmaz; Coonrad, Warren L.

2013-01-01

The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950s to 1990s. Pioneering work in the map area by J.M. Hoare and W.L. Coonrad forms the basis for much of this map, either directly or as the stepping off point for later studies compiled here. Physiographically, the map area ranges from glaciated mountains, as much as 1,500 m high, in the Ahklun Mountains to the coastal lowlands of northern Bristol Bay and the Kuskokwim River delta. The mountains and the finger lakes (drowned fiords) on the east have been strongly affected by Pleistocene and Holocene glaciation. Within the map area are a number of major faults. The Togiak-Tikchik Fault and its extension to the northeast, the Holitna Fault, are considered extensions of the Denali fault system of central Alaska. Other sub-parallel faults include the Golden Gate, Sawpit, Goodnews, and East Kulukak Faults. Northwest-trending strike-slip faults crosscut and offset northeast-trending fault systems. Rocks of the area are assigned to a number of distinctive lithologic packages. Most distinctive among these packages are the high-grade metamorphic rocks of the Kanektok metamorphic complex or Kilbuck terrane, composed of a high-grade metamorphic orthogneiss core surrounded by greenschist and amphibolite facies schist, gneiss, and rare marble and quartzite. These rocks have yielded radiometric ages strongly suggestive of a 2.05 Ga emplacement age. Poorly known Paleozoic rocks, including Ordovician to Devonian and Permian limestone, are found east of the Kanektok metamorphic complex. A Triassic(?) ophiolite complex is on the southeast side of Kuskokwim Bay; otherwise only minor Triassic rock units are known. The most widespread rocks of the area are Jurassic and Early Cretaceous(?) volcanic and volcaniclastic rocks. The Kuskokwim Group flysch is restricted largely to the northeast part of the map area. It consists primarily of shelf and minor nearshore facies rocks. Primarily exposed in the lowlands west of the Ahklun Mountains, extensive latest Tertiary and Quaternary alkalic basalt flows and lesser pyroclastic rocks form much of the bedrock of the remaining area. On Saint Matthew Island, Cretaceous volcanic and pyroclastic rocks occur that are not found elsewhere within the map area. The Kuskokwim Group and older rocks, including on Saint Matthew Island, but not the Kanektok metamorphic complex, are intruded by widely dispersed Late Cretaceous and (or) Early Tertiary granitic rocks. Much of the lowland area is mantled by unconsolidated deposits that include glacial, alluvial and fluvial, marine, estuarine, and eolian deposits. These formed during several episodes of Quaternary glaciation.

Correlation of generation interval and scale of large-scale submarine landslides using 3D seismic data off Shimokita Peninsula, Northeast Japan

NASA Astrophysics Data System (ADS)

Nakamura, Yuki; Ashi, Juichiro; Morita, Sumito

2016-04-01

To clarify timing and scale of past submarine landslides is important to understand formation processes of the landslides. The study area is in a part of continental slope of the Japan Trench, where a number of large-scale submarine landslide (slump) deposits have been identified in Pliocene and Quaternary formations by analysing METI's 3D seismic data "Sanrikuoki 3D" off Shimokita Peninsula (Morita et al., 2011). As structural features, swarm of parallel dikes which are likely dewatering paths formed accompanying the slumping deformation, and slip directions are basically perpendicular to the parallel dikes. Therefore, parallel dikes are good indicator for estimation of slip directions. Slip direction of each slide was determined one kilometre grid in the survey area of 40 km x 20 km. The remarkable slip direction varies from Pliocene to Quaternary in the survey area. Parallel dike structure is also available for the distinguishment of the slump deposit and normal deposit on time slice images. By tracing outline of slump deposits at each depth, we identified general morphology of the overall slump deposits, and calculated the volume of the extracted slump deposits so as to estimate the scale of each event. We investigated temporal and spatial variation of depositional pattern of the slump deposits. Calculating the generation interval of the slumps, some periodicity is likely recognized, especially large slump do not occur in succession. Additionally, examining the relationship of the cumulative volume and the generation interval, certain correlation is observed in Pliocene and Quaternary. Key words: submarine landslides, 3D seismic data, Shimokita Peninsula

Surficial Geologic Map of the Evansville, Indiana, and Henderson, Kentucky, Area

USGS Publications Warehouse

Moore, David W.; Lundstrom, Scott C.; Counts, Ronald C.; Martin, Steven L.; Andrews, William M.; Newell, Wayne L.; Murphy, Michael L.; Thompson, Mark F.; Taylor, Emily M.; Kvale, Erik P.; Brandt, Theodore R.

2009-01-01

The geologic map of the Evansville, Indiana, and Henderson, Kentucky, area depicts and describes surficial deposits according to their origin and age. Unconsolidated alluvium and outwash fill the Ohio River bedrock valley and attain maximum thickness of 33-39 m under Diamond Island, Kentucky, and Griffith Slough, south of Newburgh, Indiana. The fill is chiefly unconsolidated, fine- to medium-grained, lithic quartz sand, interbedded with clay, clayey silt, silt, coarse sand, granules, and gravel. Generally, the valley fill fines upward from the buried bedrock surface: a lower part being gravelly sand to sandy gravel, a middle part mostly of sand, and a surficial veneer of silt and clay interspersed with sandy, natural levee deposits at river's edge. Beneath the unconsolidated fill are buried and discontinuous, lesser amounts of consolidated fill unconformably overlying the buried bedrock surface. Most of the glaciofluvial valley fill accumulated during the Wisconsin Episode (late Pleistocene). Other units depicted on the map include creek alluvium, slackwater lake (lacustrine) deposits, colluvium, dune sand, loess, and sparse bedrock outcrops. Creek alluvium underlies creek floodplains and consists of silt, clayey silt, and subordinate interbedded fine sand, granules, and pebbles. Lenses and beds of clay are present locally. Silty and clayey slackwater lake (lacustrine) deposits extensively underlie broad flats northeast of Evansville and around Henderson and are as thick as 28 m. Fossil wood collected from an auger hole in the lake and alluvial deposits of Little Creek, at depths of 10.6 m and 6.4 m, are dated 16,650+-50 and 11,120+-40 radiocarbon years, respectively. Fossil wood collected from lake sediment 16 m below the surface in lake sediment was dated 33,100+-590 radiocarbon years. Covering the hilly bedrock upland is loess (Qel), 3-7.5 m thick in Indiana and 9-15 m thick in Kentucky, deposited about 22,000-12,000 years before present. Most mapped surficial deposits in the quadrangle are probably no older than about 55,000 years. Lithologic logs, shear-wave velocities, and other cone penetrometer data are used to interpret depositional environments and geologic history of the surficial deposits. This map, which includes an area of slightly more than seven 7.5-minute quadrangles, serves several purposes. It is a tool for assessing seismic and flood hazards of a major urban area; aids urban planning; conveys geologic history; and locates aggregate resources. The map was produced concurrently with research by seismologists to determine places where the surficial deposits may tend to liquefy and (or) to amplify ground motions during strong earthquakes. Such hazardous responses to shaking are related to the characteristics of the geologic materials and topographic position, which the geologic map depicts. The geologic map is an element in the cooperative seismic hazard assessment program among the States of Indiana, Kentucky, and Illinois and the U.S. Geological Survey, funded by the National Earthquake Hazards Reduction Program and National Cooperative Geologic Mapping Program of the U.S. Geological Survey.

Impregnating unconsolidated pyroclastic sequences: A tool for detailed facies analysis

NASA Astrophysics Data System (ADS)

Klapper, Daniel; Kueppers, Ulrich; Castro, Jon M.; Pacheco, Jose M. R.; Dingwell, Donald B.

2010-05-01

The interpretation of volcanic eruptions is usually derived from direct observation and the thorough analysis of the deposits. Processes in vent-proximal areas are usually not directly accessible or likely to be obscured. Hence, our understanding of proximal deposits is often limited as they were produced by the simultaneous events stemming from primary eruptive, transportative, and meteorological conditions. Here we present a method that permits for a direct and detailed quasi in-situ investigation of loose pyroclastic units that are usually analysed in the laboratory for their 1) grain-size distribution, 2) componentry, and 3) grain morphology. As the clast assembly is altered during sampling, the genesis of a stratigraphic unit and the relative importance of the above mentioned deposit characteristics is hard to achieve. In an attempt to overcome the possible loss of information during conventional sampling techniques, we impregnated the cleaned surfaces of proximal, unconsolidated units of the 1957-58 Capelinhos eruption on Faial, Azores. During this basaltic, emergent eruption, fluxes in magma rise rate led to a repeated build-up and collapse of tuff cones and consequently to a shift between phreatomagmatic and magmatic eruptive style. The deposits are a succession of generally parallel bedded, cm- to dm-thick layers with a predominantly ashy matrix. The lapilli content is varying gradually; the content of bombs is enriched in discrete layers without clear bomb sags. The sample areas have been cleaned and impregnated with two-component glue (EPOTEK 301). For approx. 10 * 10 cm, a volume of mixed glue of 20 ml was required. Using a syringe, this low-viscosity, transparent glue could be easily applied on the target area. We found that the glue permeated the deposit as deep as 5 mm. After > 24 h, the glue was sufficiently dry to enable the sample to be laid open. This impregnation method renders it possible to cut and polish the sample and investigate grain-size distribution, componentry, and grain morphology in situ in a 2D-plane. In a first step, the sample surface has been scanned and analysed by means of image analysis software (Image J). After that, selected areas were investigated through thin section analysis. We were able to define depositional units in the (sub)-mm scale and the show the varying relative importance of 1) eruptive style, 2) transportation mode, and 3) the influence of wind and (air) humidity. The presented method is an easy and efficient tool for a detailed stratigraphic investigation of unconsolidated pyroclastic units.

Application of Landsat imagery to problems of petroleum exploration in Qaidam Basin, China

USGS Publications Warehouse

Bailey, G.B.; Anderson, P.D.

1982-01-01

Tertiary and Quaternary nonmarine, petroleum-bearing sedimentary rocks have been extensively deformed by compressive forces. These forces created many folds which are current targets of Chinese exploration programs. Image-derived interpretations of folds, strike-slip faults, thrust faults, normal or reverse faults, and fractures compared very favorably, in terms of locations and numbers mapped, with Chinese data compiled from years of extensive field mapping. Many potential hydrocarbon trapping structures were precisely located. Orientations of major structural trends defined from Landsat imagery correlate well with those predicted for the area based on global tectonic theory. These correlations suggest that similar orientations exist in the eastern half of the basin where folded rocks are mostly obscured by unconsolidated surface sediments and where limited exploration has occurred.--Modified journal abstract.

Quaternary geologic map of the Glasgow 1° x 2° quadrangle, Montana

USGS Publications Warehouse

Fullerton, David S.; Colton, Roger B.; Bush, Charles A.

2012-01-01

The Glasgow quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S./Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes the Boundary Plateau, Peerless Plateau, and Larb Hills. The primary river is the Milk River. The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (for example, ground-moraine deposits, end-moraine deposits, and stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 23 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in pedology or agronomy. Rather, it is a generalized map of soils recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. The surficial deposits are glacial, ice-contact, glaciofluvial, alluvial, lacustrine, eolian, colluvial, and mass-movement deposits. Residuum, a surficial material, also is mapped. Till of late Wisconsin age is represented by three map units. Till of Illinoian age is also represented locally but is widespread in the subsurface. This map was prepared to serve as a database for compilation of a Quaternary geologic map of the United States and Canada (scale 1:1,000,000). Letter symbols for the map units are those used for the same units in the Quaternary Geologic Atlas of the United States map series.

Quaternary stratigraphy of Bermuda: A high-resolution pre-Sangamonian rock record

NASA Astrophysics Data System (ADS)

Hearty, Paul J.; Vacher, H. Leonard

Carbonate islands such as Bermuda are created by climatic change. Warm climates and high sea levels stimulate carbonate sediment production that may ultimately result in island growth, while cold glacials expose the platforms to weathering, dissolution and soil formation. Of great importance in Quaternary studies is the ability to decipher this climatic history. Mapping and geochronologic studies have established that Bermuda may have one of the most continuous and detailed Quaternary interglacial depositional records on a carbonate platform. Advances in racemization dating (AAR) have offered a means of deciphering this climatic history and generating a high-resolution stratigraphic and age framework for the Quaternary. Bermudian interglacial units consist predominantly of eolianites, with less voluminous occurrences of beach deposits and calcarenite protosols (Entisols). Glacial or stadial-age terra rossa (aluminous laterite) paleosols, whose degree of development is a function of time of exposure, form boundaries between interglacial units. D-alloiso-leucine/ L-isoleucine ( {A}/{I}) ratios have been determined on marine pelecypods, land snails and whole-rock samples from mapped sections; aminozones have been defined for two Sangamonian and at least five pre-Sangamonian depositional intervals. From kinetic models based on calibration with previously published U-series coral dates, estimated ages of middle Pleistocene and older aminozones are: F = 190,000-265,000 years; G = 300,000-400,000 years; H = 400,000-500,000 years; J = >700,000 years; and K = > 900,000 years. Aminozone G, which is correlated with the upper Town Hill Formation and Isotope Stage 9, is volumetrically the most important depositional event of the middle Pleistocene. The great mass of sediment deposited during this period suggests an interglacial of significant duration and prolonged shelf submergence, during which the island grew to over half its present size. Only the Sangamonian ( sensu lato) rivals Stage 9 in volume of eolianite deposited on the island. Sea-level amplitude, as determined from dated outcrops, appears to correlate well with amplitudinal variations in the oxygen isotope record.

Climatic, eustatic, and tectonic controls on Quaternary deposits and landforms, Red Sea coast, Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arvidson, R.; Becker, R.; Shanabrook, A.

1994-06-10

The degree to which local climatic variations, eustatic sea level fluctuations, and tectonic uplift have influenced the development of Quaternary marine and fluvial landforms and deposits along the Red Sea coast, Eastern Desert, Egypt was investigated using a combination of remote sensing and field data, age determinations of corals, and numerical simulations. False color composites generated from Landsat Thematic Mapper and SPOT image data, digital elevation models derived from stereophotogrammetric analysis of SPOT data, and field observations document that a {approximately}10-km-wide swath inland from the coast is covered in many places with coalescing alluvial fans of Quaternary age. Wadis cuttingmore » through the fans exhibit several pairs of fluvial terraces, and wadi walls expose alluvium interbedded with coralline limestone deposits. Further, three distinct coral terraces are evident along the coastline. Climatic, eustatic, and tectonic uplift controls on the overall system were simulated using a cellular automata algorithm with the following characteristics: (1) uplift as a function of position and time, as defined by the elevations and ages of corals; (2) climatic variations driven by insolation changes associated with Milankovitch cycles; (3) sea level fluctuations based on U/Th ages of coral terraces and eustatic data; and (4) parameterized fluvial erosion and deposition. Results imply that the fans and coralline limestones were generated in a setting in which the tectonic uplift rate decreased over the Quaternary to negligible values at present. During lowstands, wadis cut into sedimentary deposits; coupled with continuing uplift, fans were dissected, leaving remnant surfaces, and wadi-related terraces were generated by down cutting. Only landforms from the past three to four eustatic sea level cycles (i.e., {approximately} 300 to 400 kyr) are likely to have survived erosion and deposition associated with fluvial processes. 33 refs., 18 figs., 2 tabs.« less

Near-Surface Shear Wave Velocity Versus Depth Profiles, VS30, and NEHRP Classifications for 27 Sites in Puerto Rico

USGS Publications Warehouse

Odum, Jack K.; Williams, Robert A.; Stephenson, William J.; Worley, David M.; von Hillebrandt-Andrade, Christa; Asencio, Eugenio; Irizarry, Harold; Cameron, Antonio

2007-01-01

In 2004 and 2005 the Puerto Rico Seismic Network (PRSN), Puerto Rico Strong Motion Program (PRSMP) and the Geology Department at the University of Puerto Rico-Mayaguez (UPRM) collaborated with the U.S. Geological Survey to study near-surface shear-wave (Vs) and compressional-wave (Vp) velocities in and around major urban areas of Puerto Rico. Using noninvasive seismic refraction-reflection profiling techniques, we acquired velocities at 27 locations. Surveyed sites were predominantly selected on the premise that they were generally representative of near-surface materials associated with the primary geologic units located within the urbanized areas of Puerto Rico. Geologic units surveyed included Cretaceous intrusive and volcaniclastic bedrock, Tertiary sedimentary and volcanic units, and Quaternary unconsolidated eolian, fluvial, beach, and lagoon deposits. From the data we developed Vs and Vp depth versus velocity columns, calculated average Vs to 30-m depth (VS30), and derived NEHRP (National Earthquake Hazards Reduction Program) site classifications for all sites except one where results did not reach 30-m depth. The distribution of estimated NEHRP classes is as follows: three class 'E' (VS30 below 180 m/s), nine class 'D' (VS30 between 180 and 360 m/s), ten class 'C' (VS30 between 360 and 760 m/s), and four class 'B' (VS30 greater than 760 m/s). Results are being used to calibrate site response at seismograph stations and in the development of regional and local shakemap models for Puerto Rico.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2011

USGS Publications Warehouse

Beman, Joseph E.

2012-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and of about 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2011), the network consists of 126 wells and piezometers (a piezometer is a specialized well open to a specific depth in the aquifer and is often of small diameter and nested with other piezometers open to different depths). This report presents water-level data collected by U.S. Geological Survey personnel at those 126 sites through water year 2011 to better help the Albuquerque Bernalillo County Water Utility Authority manage water use.

Geology and ground-water resources of southeastern New Hampshire

USGS Publications Warehouse

Bradley, Edward

1964-01-01

The continued growth and development of southeastern New Hampshire, an area of about 390 square miles adjacent to the Atlantic Ocean, will depend partly on effectively satisfying the demand for water, which has increased rapidly since World War II. The report identifies and describes the principal geologic units with respect to the occurrence of ground water. These units include bedrock and the various unconsolidated deposits that mantle the bedrock surface discontinuously throughout the area. The bedrock formations, consisting of igneous and metamorphic rocks, chiefly of Paleozoic age, form a single water-bearing unit. Ground water is in joints and fractures. The fractures are small and scattered and therefore impart only a low permeability to the rocks. Wells in the bedrock commonly produce small but reliable supplies of ground water at depths of less than 150 feet. The yields of about 80 wells inventoried for this report ranged from 1? to 100 gpm (gallons per minute) and the median was 912 gpm. Depths ranged from 45 to 600 feet. The unconsolidated deposits consist of glacial drift of Pleistocene age; swamp deposits, alluvium, and beach deposits of Recent age; and eolian deposits of Pleistocene -and Recent age. For this report the glacial drift is divided into till, ice-contact deposits, marine deposits, and outwash and shore deposits. Glacial till forms a discontinuous blanket, commonly less than 15 but in some hills (drumlins) as much as about 200 feet thick. It has a low permeability but, because of its widespread outcrop area, it has been utilized as a source of water for numerous domestic supplies. Because most wells in till are shallow, many fail to meet modern demands during dry summers. Ice-contact deposits locally form kames, kame terraces, kame plains, and ice-channel fillings throughout the area. They overlie bedrock and till and range in thickness from less than 1 foot to as much as 190 feet. In general, the ice-contact deposits are coarse textured and permeable, but variations in- the physical and hydrologic properties of a single deposit and from deposit to deposit are common. Ice-contact deposits are the source of the larger ground-water supplies in southeastern New Hampshire. Marine deposits underlie lowlands and valleys to a distance of about 20 miles inland from the present coastline. They commonly overlie bedrock and till and at places overlie or are interbedded with ice-contact deposits. Marine deposits range in thickness from less than 1 foot to possibly 75 feet. They are fine textured and impermeable; they do not yield water to wells in southeastern New Hampshire but generally act as a barrier to ground-water movement. Outwash and shore deposits form broad sand plains or gently sloping terraces of small extent. At most places the outwash and shore deposits, which range in thickness from less than 1 foot to about 50 feet, overlie marine deposits, but at some places they overlie bedrock, till, or ice-contact deposits. The outwash and shore deposits are fine textured and moderately permeable. They commonly yield enough ground water to meet the needs of farms, homes, and small industries. Alluvium underlies the flood plains and channels of the principal streams and overlies bedrock and older unconsolidated deposits wherever streams cross the older units. The alluvium generally is not tapped by wells. Beach deposits occupy areas along the Atlantic Ocean between promontories of bedrock or till. In general beach deposits are permeable and are a source of water supplies for domestic use. Yields of wells are limited, however, by the danger of drawing in salty water. Recharge in southeastern New Hampshire is derived principally from precipitation on outcrop areas of ice-contact deposits and outwash and shore deposits during the nongrowing season. Ground water is discharged naturally by springs, by effluent seepage to streams and other bodies of surface water, and by evapotranspiration. It

Sedimentation in small reservoirs on the San Rafael Swell, Utah

USGS Publications Warehouse

King, Norman Julius; Mace, Mervyn M.

1953-01-01

Movement of sediment from upland areas and eventually into main drainages and rivers is by no means through continuous transportation of material from the source to the delta. Instead it consists of a series of intermittent erosional and depositional phases that present a pulsating movement. Hence, sediment carried off upland areas may be deposited in lower reaches or along main drainages if an existing combination of factors tend to effect deposition. During this period actual sediment movement out of the basin may be relatively small. Following any change in existing conditions, however, these unconsolidated alluvial fills may be subjected to rapid removal; thus, for a limited time, abnormally high sediment production rates occur until the deposits are either removed or another cycle of deposition is started.

Hydrogeology and Hydrologic Landscape Regions of Nevada

USGS Publications Warehouse

Maurer, Douglas K.; Lopes, Thomas J.; Medina, Rose L.; Smith, J. LaRue

2004-01-01

In 1999, the U.S. Environmental Protection Agency initiated a rule to protect ground water in areas other than source-water protection areas. These other sensitive ground water areas (OSGWAs) are aquifers that are not currently but could eventually be used as a source of drinking water. The OSGWA program specifically addresses existing wells that are used for underground injection of motor vehicle waste. If the injection well is in a ground-water protection area or an OSGWA, well owners must either close the well or apply for a permit. The Nevada Division of Environmental Protection will evaluate site-specific information and determine if the aquifer associated with a permit application is susceptible to contamination. A basic part of evaluating OSGWAs is characterizing the hydrogeology of aquifer systems including the lithology, hydrologic properties, soil permeability, and faulting, which partly control the susceptibility of ground water to contamination. Detailed studies that evaluate ground-water susceptibility are not practical in a largely unpopulated State like Nevada. However, existing and new information could be extrapolated to other areas of the State if there is an objective framework to transfer the information. The concept of hydrologic landscape regions, which identify areas with similar hydrologic characteristics, provides this framework. This report describes the hydrogeology and hydrologic landscape regions of Nevada. Consolidated rocks that form mountain ranges and unconsolidated sediments that fill the basins between the ranges are grouped into hydrogeologic units having similar lithology and assumed to have similar hydrologic properties. Consolidated rocks and unconsolidated sediments are the two major hydrogeologic units and comprise 51 and 49 percent of the State, respectively. Consolidated rocks are subdivided into 8 hydrogeologic units. In approximate order of decreasing horizontal hydraulic conductivity, consolidated-rock hydrogeologic units consist of: (1) carbonate rocks, Quaternary to Tertiary age; (2) basaltic, (3) rhyolitic, and (4) andesitic volcanic flows; (5) volcanic breccias, tuffs, and volcanic rocks older than Tertiary age; (6) intrusive and metamorphic rocks; (7) consolidated and semi-consolidated tuffaceous rocks and sediments; and (8) clastic rocks consisting of sandstone and siltstone. Unconsolidated sediments are subdivided into four hydrogeologic units on the basis of flow regime, topographic slope, and mapped stream channels. The four units are (1) alluvial slopes, (2) valley floors, (3) fluvial deposits, and (4) playas. Soil permeability was grouped into five descriptive categories ranging from very high to very low, which generally correspond to mapped geomorphic features such as playas and alluvial slopes. In general, soil permeability is low to moderate in northern, northeastern, and eastern Nevada and high to very high in western, southwestern, and southern Nevada. Within a particular basin, soil permeability decreases downslope from the bedrock contact. The type of parent rock, climate, and streamflow velocities are factors that likely cause these spatial patterns. Faults in unconsolidated sediments usually are barriers to ground-water flow. In consolidated rocks, permeability and ground-water flow is reduced in directions normal to the fault zone and increased in directions parallel to the fault zone. With time, mineral precipitation may seal fractures in consolidated rocks, reducing the permeability. However, continued movement along the fault may form new fractures, resulting in a fault alternating from a zone of preferred flow to a flow barrier during geologic time. The effect of faults on ground-water flow at a particular location is difficult to determine without a site- specific investigation. Hydrologic landscape regions were delineated by overlaying a grid of 100-foot (30-meter) cells over the State, estimating the value of five variables for each cell, an

Return of the coral reef hypothesis: basin to shelf partitioning of CaCO3 and its effect on atmospheric CO2.

PubMed

Opdyke, B N; Walker, J C

1992-08-01

Differences in the rate of coral reef carbonate deposition from the Pleistocene to the Holocene may account for the Quaternary variation of atmospheric CO2. Volumes of carbonate associated with Holocene reefs require an average deposition rate of 2.0 x 10(13) mol/yr for the past 5 ka. In light of combined riverine, midocean ridge, and ground-water fluxes of calcium to the oceans of 2.3 x 10(13) mol/yr, the current flux of calcium carbonate to pelagic sediments must be far below the Pleistocene average of 1.2 x 10(13) mol/yr. We suggest that sea-level change shifts the locus of carbonate deposition from the deep sea to the shelves as the normal glacial-interglacial pattern of deposition for Quaternary global carbonates. To assess the impact of these changes on atmospheric CO2, a simple numerical simulation of the global carbon cycle was developed. Atmospheric CO2 as well as calcite saturation depth and sediment responses to these carbonate deposition changes are examined. Atmospheric CO2 changes close to those observed in the Vostok ice core, approximately 80 ppm CO2, for the Quaternary are observed as well as the approximate depth changes in percent carbonate of sediments measured in the Pacific Ocean over the same time interval.

Quaternary Geologic Map of the Regina 4 Degrees x 6 Degrees Quadrangle, United States and Canada

USGS Publications Warehouse

Fullerton, David S.; Christiansen, Earl A.; Schreiner, Bryan T.; Colton, Roger B.; Clayton, Lee; Bush, Charles A.; Fullerton, David S.

2007-01-01

For scientific purposes, the map differentiates Quaternary surficial deposits and materials on the basis of clast lithology or composition, matrix texture or particle size, structure, genesis, stratigraphic relations, engineering geologic properties, and relative age, as shown on the correlation diagram and indicated in the 'Description of Map Units'. Deposits of some constructional landforms, such as end moraines, are distinguished as map units. Deposits of erosional landforms, such as outwash terraces, are not distinguished, although glaciofluvial, ice-contact, fluvial, and lacustrine deposits that are mapped may be terraced. Differentiation of sequences of fluvial and glaciofluvial deposits at this scale is not possible. For practical purposes, the map is a surficial materials map. Materials are distinguished on the basis of lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized and classified in pedology or agronomy. Rather, it is a generalized map of soils as recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. As a materials map, it serves as a base from which a variety of maps for use in planning engineering, land-use planning, or land-management projects can be derived and from which a variety of maps relating to earth surface processes and Quaternary geologic history can be derived.

Pollen preservation and Quaternary environmental history in the southeastern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delcourt, P.A.; Delcourt, H.R.

Reconstructions of Quaternary environmental history based upon modern pollen/vegetation/climate calibrations are more tenable if the factors responsible for variation in pollen assemblages are evaluated. Examination of the state of preservation of Quaternary palynomorphs provides quantitative data concerning the degree of information loss due to alteration of pollen assemblages by syndepositional and post-depositional deterioration. The percentage, concentration, and influx values for total indeterminable pollen are useful criteria in providing an objective and quantitative basis for evaluating the comparability of pollen spectra within and between sites. Supporting data concerning sediment particle-size distribution, organic matter content, and concentration, influx, and taxonomic composition ofmore » both determinable pollen and plant macrofossils aid in reconstructing past depositional environments. The potential is high for deterioration of pollen in sediments from the southeastern United States, although considerable variation is found in both kind and degree of deterioration between lacustrine and alluvial sites of different ages and in different latitudes. Modern analogs are a basis for late Quaternary environmental reconstructions when pollen deterioration has not significantly biased the information content of fossil pollen assemblages.« less

Atomic layer deposition of quaternary chalcogenides

DOEpatents

Thimsen, Elijah J; Riha, Shannon C; Martinson, Alex B.F.; Elam, Jeffrey W; Pellin, Michael J

2014-06-03

Methods and systems are provided for synthesis and deposition of chalcogenides (including Cu.sub.2ZnSnS.sub.4). Binary compounds, such as metal sulfides, can be deposited by alternating exposures of the substrate to a metal cation precursor and a chalcogen anion precursor with purge steps between.

Geology and ground-water resources of the San Carlos Indian Reservation, Gila, Graham, and Pinal counties, Arizona

USGS Publications Warehouse

Brown, J.G.

1989-01-01

The San Carlos Indian Reservation includes about 2,900 sq mi in east- central Arizona. Relatively impermeable pre-Tertiary rocks are exposed in about 23% of the reservation and underlie water-bearing Tertiary and quaternary basin fill and Quaternary stream alluvium in much of the southern part of the reservation. About 9,000 members of the San Carlos Apache Tribe live on the reservation and rely on groundwater to meet public supply, irrigation, and other needs. Basin fill is widespread in the valley of the San Carlos and Gila Rivers and consists of fine sand, silt, limestone, clay, and pyroclastic volcanics that may attain a total maximum thickness of more than 3,200 ft in the reservation. Quaternary stream alluvium overlies the basin fill along many streams and washes. Stream alluvium consists of poorly sorted, unconsolidated, gravelly, muddy, sand; and sandy gravel and reaches a maximum thickness of 100 ft along the San Carlos and Gila Rivers. The volume of recoverable water stored in the basin fill to a depth of 1,200 ft is estimated to be about 20 million acre-ft. The volume of recoverable water stored in the stream alluvium on the reservation is estimated to be more than 100,000 acre-ft. The stream alluvium along the San Carlos River supplies most of the water used for drinking. Water throughout much of the reservation is suitable for most uses except for that in the alluvium along the Gila River, which contains large concentrations of dissolved solids. (USGS)

Environmental Assessment: Implementation of the Tyndall Air Force Base Integrated Natural Resources Management Plan

DTIC Science & Technology

2006-04-01

3-21 TPA060050033/TYNDALLINRMPEAFINAL.DOC VI Acronyms and Abbreviations ACM asbestos-containing materials ...Inventory FONPA Finding of No Practicable Alternative FONSI Finding of No Significant Impact HAZMO Hazardous Materials Management Office ICRMP...land surface (bls) by unconsolidated sands and clayey sands deposited since the Pliocene age. This material is relatively permeable and is underlain

A ground-water reconnaissance of the Republic of Ghana, with a description of geohydrologic provinces

USGS Publications Warehouse

Gill, H.E.

1969-01-01

This report gives a general summary of the availability and use of ground water and describes the occurrence of ground water in five major geohydrologic provinces lying in the eight administrative regions of Ghana. The identification and delineation of the geohydrologic provinces are based on their distinctive characteristics with respect to the occurrence and availability of ground water. The Precambrian province occupies the southern, western, and northern parts of Ghana and is underlain largely by intrusive crystalline and metasedimentary rocks. The Voltaian province includes that part of the Voltaian sedimentary basin in central Ghana and is underlain chiefly by consolidated sandstone, mudstone, and shale. Narrow discontinuous bands of consolidated Devonian and Jurassic sedimentary rocks near the coast constitute the Coastal Block Fault province. The Coastal Plain province includes semiconsolidated to unconsolidated sediments of Cretaceous to Holocene age that underlie coastal plain areas in southwestern and southeastern Ghana. The Alluvial province includes the Quaternary alluvial deposits in the principal river valleys and on the delta of the Volta River. Because of the widespread distribution of crystalline and consolidated sedimentary rocks of low permeability in the Precambrian, Voltaian, and Coastal Block Fault provinces, it is difficult to develop large or event adequate groundwater supplies in much of Ghana. On the other hand, small (1 to 50 gallons per minute) supplies of water of usable quality are available from carefully sited boreholes in most parts of the country. Also, moderate (50 to 200 gpm) supplies of water are currently (1964) obtained from small-diameter screened boreholes tapping sand and limestone aquifers in the Coastal Plain province in southwestern and southeastern Ghana, but larger supplies could be obtained through properly constructed boreholes. In the Alluvial province, unconsolidated deposits in the larger stream valleys that are now largely undeveloped offer desirable locations for shallow vertical or horizontal wells, which can induce infiltration from streams and yield moderate to large water supplies. The principal factors that limit development of ground-water supplies in Ghana are (1) prevailing low permeability and water-yielding potential of the crystalline and consolidated sedimentary rocks that underlie most of the country, (2) highly mineralized ground water which appears to be widely distributed in the northern part of the Voltaian province, and (3) potential problems of salt-water encroachment in the Coastal Plain province in the Western Region and in the Keta area. On the other hand, weathering has increased porosity and has thus substantially increased the water-yielding potential of the crystalline and consolidated sedimentary rocks in much of central and northern Ghana. Also, with proper construction and development, much larger yields than those now (1964) prevalent could be obtained from boreholes tapping sand and limestone aquifers in the Coastal Plain province.

Late Quaternary glaciation of the Upper Soca River Region (Southern Julian Alps, NW Slovenia)

USGS Publications Warehouse

Bavec, Milos; Tulaczyk, Slawek M.; Mahan, Shannon; Stock, Gregory M.

2004-01-01

Extent of Late Quaternary glaciers in the Upper Soc??a River Region (Southern Julian Alps, SE Europe) has been analyzed using a combination of geological mapping, glaciological modeling, and sediment dating (radiocarbon, U/Th series and Infrared Stimulated Luminescence-IRSL). Field investigations focused mainly on relatively well preserved Quaternary sequences in the Bovec Basin, an intramontane basin located SW of the Mediterranean/Black Sea divide and surrounded by mountain peaks reaching from approximately 2100 up to 2587 m a.s.l. Within the Basin we recognized two Late Quaternary sedimentary assemblages, which consist of the same facies association of diamictons, laminated lacustrine deposits and sorted fluvial sediments. Radiocarbon dating of the upper part of the lake sediments sequence (between 12790??85 and 5885??60 14C years b.p.) indicates that the younger sedimentary assemblage was deposited during the last glacial maximum and through early Holocene (Marine Isotope Stage 21, MIS 2-1). Sediment ages obtained for the older assemblage with U/Th and IRSL techniques (between 154.74??22.88 and 129.93??7.90 ka b.p. for selected samples) have large errors but both methods yield results consistent with deposition during the penultimate glacial-interglacial transition (MIS 6-5). Based on analyses of field data combined with glaciological modeling, we argue that both sediment complexes formed due to high sediment productivity spurred by paraglacial conditions with glaciers present in the uplands around the Bovec Basin but not extending down to the basin floor. Our study shows that the extent and intensity of direct glacial sedimentation by Late Quaternary glaciers in the region was previously significantly overestimated. ?? 2004 Elsevier B.V. All rights reserved.

Permeability profiles in granular aquifers using flowmeters in direct-push wells

USGS Publications Warehouse

Paradis, D.; Lefebvre, R.; Morin, R.H.; Gloaguen, E.

2010-01-01

Numerical hydrogeological models should ideally be based on the spatial distribution of hydraulic conductivity (K), a property rarely defined on the basis of sufficient data due to the lack of efficient characterization methods. Electromagnetic borehole flowmeter measurements during pumping in uncased wells can effectively provide a continuous vertical distribution of K in consolidated rocks. However, relatively few studies have used the flowmeter in screened wells penetrating unconsolidated aquifers, and tests conducted in gravel-packed wells have shown that flowmeter data may yield misleading results. This paper describes the practical application of flowmeter profiles in direct-push wells to measure K and delineate hydrofacies in heterogeneous unconsolidated aquifers having low-to-moderate K (10−6 to 10−4 m/s). The effect of direct-push well installation on K measurements in unconsolidated deposits is first assessed based on the previous work indicating that such installations minimize disturbance to the aquifer fabric. The installation and development of long-screen wells are then used in a case study validating Kprofiles from flowmeter tests at high-resolution intervals (15 cm) with K profiles derived from multilevel slug tests between packers at identical intervals. For 119 intervals tested in five different wells, the difference in log K values obtained from the two methods is consistently below 10%. Finally, a graphical approach to the interpretation of flowmeter profiles is proposed to delineate intervals corresponding to distinct hydrofacies, thus providing a method whereby both the scale and magnitude of K contrasts in heterogeneous unconsolidated aquifers may be represented.

Permeability profiles in granular aquifers using flowmeters in direct-push wells.

PubMed

Paradis, Daniel; Lefebvre, René; Morin, Roger H; Gloaguen, Erwan

2011-01-01

Numerical hydrogeological models should ideally be based on the spatial distribution of hydraulic conductivity (K), a property rarely defined on the basis of sufficient data due to the lack of efficient characterization methods. Electromagnetic borehole flowmeter measurements during pumping in uncased wells can effectively provide a continuous vertical distribution of K in consolidated rocks. However, relatively few studies have used the flowmeter in screened wells penetrating unconsolidated aquifers, and tests conducted in gravel-packed wells have shown that flowmeter data may yield misleading results. This paper describes the practical application of flowmeter profiles in direct-push wells to measure K and delineate hydrofacies in heterogeneous unconsolidated aquifers having low-to-moderate K (10(-6) to 10(-4) m/s). The effect of direct-push well installation on K measurements in unconsolidated deposits is first assessed based on the previous work indicating that such installations minimize disturbance to the aquifer fabric. The installation and development of long-screen wells are then used in a case study validating K profiles from flowmeter tests at high-resolution intervals (15 cm) with K profiles derived from multilevel slug tests between packers at identical intervals. For 119 intervals tested in five different wells, the difference in log K values obtained from the two methods is consistently below 10%. Finally, a graphical approach to the interpretation of flowmeter profiles is proposed to delineate intervals corresponding to distinct hydrofacies, thus providing a method whereby both the scale and magnitude of K contrasts in heterogeneous unconsolidated aquifers may be represented. Journal compilation © 2010 National Ground Water Association. No claim to original US government works.

Simultaneous acquisition of Sparker and airgun seismic data - a key to understanding the interaction of deep structures and the Quaternary in the Kattegat area

NASA Astrophysics Data System (ADS)

Nørmark, Egon; Jensen, Jørn B.; Bendixen, Carina; Clausen, Ole R.; Trinhammer, Per L.; Boldreel, Lars O.; Seidenkrantz, Marit S.; Fanget, Anne-Sophie

2014-05-01

The geological evolution of the Kattegat and Baltic Sea area during the last 130,000 years encompasses a complex series of glacial advances with highly oscillating ice margins interrupted by marine inundations and significant glacial lake deposition. One of the most significant lacustrine episodes is related to the build-up and drainage of the Baltic Glacial Lake during the last deglaciation. The link of these major depositional events to global climate as well as their impact on local and regional environment is, however, still poorly understood. The relation between the deep structures and Quaternary deposition is also not well resolved. In order to improve this understanding we aim at acquiring an understanding of the 3-dimensional evolution of the Quaternary sediments in the Kattegat and Baltic Sea areas using seismic studies. We relate these seismic data to the palaeoclimatic and sedimentological information obtained through the sedimentological and micropalaeontological analyses of both short sediment gravity cores and of samples from IODP Expedition 347 drilled in the fall of 2013. Different types of seismic data are needed for studying the relationship between the crustal structure, pre-Quaternary topography, and Quaternary deposition than seismic data needed for studying the detailed depositional dynamics within the Quaternary deposits. This is because when using airguns with a deep penetration needed for studying deep-laying structures the resulting seismic data has too poor resolution for studying the very shallow parts. In contrast the very high resolution sparker data has a poor penetration depth. Traditionally, these two different types of seismic data are for practical reasons not been collected simultaneously, or even on the same cruise. As a result, these two (complementary) dataset are difficult to compare, especially when they are acquired under different conditions (changes in positioning, noise levels, etc.). In this study, we have solved the problem by acquiring both seismic datasets simultaneously during the same leg. Both the sparker and airgun energy sources are towed behind the vessel, and the common streamer is placed in the middle behind the energy sources. In order to optimize the acquisition hydrophones are spaced with 3.125m for the uppermost 125m of the layout, where the main part of the reflections for the Sparker data is acquired, whereas the spacing is 6.25m at the remaining 400m of the streamer. The energy release of the different sources is timed in order to minimize the interference between the two systems. The resulting seismic sections are excellent examples of different data from the same area that is resolved at different depth intervals and vertical resolution. This allows us to directly compare the data and gives a hitherto unseen differentiation of seismic resolution in different parts of the succession. A preliminary geological analysis of the data shows that deposition in a number of the Quaternary mini-basins is controlled by the underlying structures, which can be related to the Sorgenfrei-Tornquist fault Zone. This infers that deep structures in some areas may still control the present bathymetry, even within smaller basins. The dating of the events and the relation to global climatic changes awaits the biostratigraphical analysis of the IODP boreholes.

Hydrology and simulation of ground-water flow in Juab Valley, Juab County, Utah.

USGS Publications Warehouse

Thiros, Susan A.; Stolp, Bernard J.; Hadley, Heidi K.; Steiger, Judy I.

1996-01-01

Plans to import water to Juab Valley, Utah, primarily for irrigation, are part of the Central Utah Project. A better understanding of the hydrology of the valley is needed to help manage the water resources and to develop conjunctive-use plans.The saturated unconsolidated basin-fill deposits form the ground-water system in Juab Valley. Recharge is by seepage from streams, unconsumed irrigation water, and distribution systems; infiltration of precipitation; and subsurface inflow from consolidated rocks that surround the valley. Discharge is by wells, springs, seeps, evapotranspiration, and subsurface outflow to consolidated rocks. Ground-water pumpage is used to supplement surface water for irrigation in most of the valley and has altered the direction of groundwater flow from that of pre-ground-water development time in areas near and in Nephi and Levan.Greater-than-average precipitation during 1980-87 corresponds with a rise in water levels measured in most wells in the valley and the highest water level measured in some wells. Less-than average precipitation during 1988-91 corresponds with a decline in water levels measured during 1988-93 in most wells. Geochemical analyses indicate that the sources of dissolved ions in water sampled from the southern part of the valley are the Arapien Shale, evaporite deposits that occur in the unconsolidated basin-fill deposits, and possibly residual sea water that has undergone evaporation in unconsolidated basin-fill deposits in selected areas. Water discharging from a spring at Burriston Ponds is a mixture of about 70 percent ground water from a hypothesized flow path that extends downgradient from where Salt Creek enters Juab Valley and 30 percent from a hypothesized flow path from the base of the southern Wasatch Range.The ground-water system of Juab Valley was simulated by using the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model. The numerical model was calibrated to simulate the steady-state conditions of 1949, multi-year transient-state conditions during 1949-92, and seasonal transient-state conditions during 1992-94. Calibration parameters were adjusted until model-computed water levels reasonably matched measured water levels. Parameters important to the calibration process include horizontal hydraulic conductivity, transmissivity, and the spatial distribution and amount of recharge from subsurface inflow and seepage from ephemeral streams to the east side of Juab Valley.

Evaluation of the Location and Recency of Faulting Near Prospective Surface Facilities in Midway Valley, Nye County, Nevada

USGS Publications Warehouse

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2001-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern zone of fractures is within Quaternary alluvial sediments, but no bedrock was encountered in trenches and soil pits in this part of the prospective surface facilities site; thus, the direct association of this zone with one or more bedrock faults is uncertain. No displacement of lithologic contacts and soil horizons could be detected in the fractured Quaternary deposits. The results of these investigations imply the absence of any appreciable late Quaternary faulting activity at the prospective surface-facilities site.

Geological and mechanical properties on the 3-D fault patch of the rapid creeping Chihshang Fault: a plate suture between Luzon arc and Eurasia in eastern Taiwan

NASA Astrophysics Data System (ADS)

Lee, J. C.; Mu, C. H.; Huang, W. J.; Liu, Z. Y. C.; Shirzaei, M.

2017-12-01

The 35-km-long Chihshang Fault is a rapidly creeping thrust at plate suture between the converging Philippine and Eurasian plates in eastern Taiwan. We combined geological investigation, geodetic data, seismological information, and a rate-dependant friction model, to illustrate the mechanical frictional properties and their variations along the strike and the depth (30-km-deep) of the fault. During the interseismic period, the Chihshang Fault is characterized by three different slip behaviours at different depths: 1) abundant micro-seismicity and semi-continuous rapid slip at the depth of 10-20 km seismogenic zone; 2) visco-elastic aseismic slip zone beneath 25 km; 3) seasonal locked/creep switch at depth of 0-2 km. Using elastic dislocation model, 1-D diffusion model, Coulomb stress criterion, and rate-dependent frictional law, we simulate the surface creep curves from the creep meters data. The result shows a rate-strengthening zone with positive frictional property (a-b) in the upper 500 meters of fault, which appears to be locked during the dry season. We tend to interpret it as a result of 300-500 m thick of unconsolidated gravels layers in the footwall of the Chihshang Fault. We also implement an inverse dynamic modeling scheme to estimate the frictional parameter () in depths by taking into account pre-seismic stress and coulomb stress changes associated with co- and post-seismic deformation of the 2003 Mw 6.5 Chengkung earthquake. Model parameters are determined from fitting the transient post-seismic geodetic signal measured at 12 continuous GPS stations. We apply a non-linear optimization algorithm, Genetic Algorithm (GA), to search for the optimum parameters. The optimum is 1.4 ×10-2 along the shallow part of the fault (0-10 km depth) and 1.2 × 10-2 in 22-28 km depth. The inferred frictional parameters are consistent with the laboratory measurements on clay rich fault zone gouges comparable to the Lichi mélange, considering the main rock composition of the Chihshang fault. Our results indicate a possibly strong influence from the surface cover of a few hundreds meter thick unconsolidated deposits (i.e., late Quaternary gravel) and the clay rich fault gouge (i.e. the Lichi Melange) on frictional properties.

Compilation of Stratigraphic Thicknesses for Caldera-Related Tertiary Volcanic Rocks, East-Central Nevada and West-Central Utah

USGS Publications Warehouse

Sweetkind, D.S.; Du Bray, E.A.

2008-01-01

The U.S. Geological Survey (USGS), the Desert Research Institute (DRI), and a designee from the State of Utah are currently conducting a water-resources study of aquifers in White Pine County, Nevada, and adjacent areas in Nevada and Utah, in response to concerns about water availability and limited geohydrologic information relevant to ground-water flow in the region. Production of ground water in this region could impact water accumulations in three general types of aquifer materials: consolidated Paleozoic carbonate bedrock, and basin-filling Cenozoic volcanic rocks and unconsolidated Quaternary sediments. At present, the full impact of extracting ground water from any or all of these potential valley-graben reservoirs is not fully understood. A thorough understanding of intermontane basin stratigraphy, mostly concealed by the youngest unconsolidated deposits that blanket the surface in these valleys, is critical to an understanding of the regional hydrology in this area. This report presents a literature-based compilation of geologic data, especially thicknesses and lithologic characteristics, for Tertiary volcanic rocks that are presumably present in the subsurface of the intermontane valleys, which are prominent features of this area. Two methods are used to estimate volcanic-rock thickness beneath valleys: (1) published geologic maps and accompanying descriptions of map units were used to compile the aggregate thicknesses of Tertiary stratigraphic units present in each mountain range within the study areas, and then interpolated to infer volcanic-rock thickness in the intervening valley, and (2) published isopach maps for individual out-flow ash-flow tuff were converted to digital spatial data and thickness was added together to produce a regional thickness map that aggregates thickness of the individual units. The two methods yield generally similar results and are similar to volcanic-rock thickness observed in a limited number of oil and gas exploration drill holes in the region, although local geologic complexity and the inherent assumptions in both methods allow only general comparison. These methods serve the needs of regional ground-water studies that require a three-dimensional depiction of the extent and thickness of subsurface geologic units. The compilation of geologic data from published maps and reports provides a general understanding of the distribution and thickness of tuffs that are presumably present in the subsurface of the intermontane valleys and are critical to understanding the ground-water hydrology of this area.

Geology and biology of Oceanographer submarine canyon.

USGS Publications Warehouse

Valentine, P.C.; Uzmann, J.R.; Cooper, R.A.

1980-01-01

Santonian beds more than 100 m thick are the oldest rocks collected from the canyon. Quaternary silty clay veneers the canyon walls in many places and is commonly burrowed by benthic organisms that cause extensive erosion of the canyon walls, especially in the depth zone (100-1300 m) inhabited by the crabs Geryon and Cancer. Bioerosion is minimal on high, near-vertical cliffs of sedimentary rock, in areas of continual sediment movement, and where the sea floor is paved by gravel. A thin layer of rippled, unconsolidated silt and sand is commonly present on the canyon walls and in the axis. Shelf sediments are transported from Georges Bank over the E rim and in the Canyon by the SW drift and storm currents; tidal currents and internal waves move the sediment downcanyon along the walls and axis.- from Authors

Reconnaissance geology of the Manjamah Quadrangle, sheet 18/41 A, Kingdom of Saudi Arabia

USGS Publications Warehouse

Hadley, D.G.

1982-01-01

The Manjamah quadrangle (sheet 18/41 A) lies between lat 18?30' and 19?00' N. and long 41?00' and 41?30' E. and encompasses an area of 2,932 km2, of which about half is land and the remainder covered by the Red Sea. The geologic formations exposed in the quadrangle comprise Precambrian layered and intrusive rocks,. Tertiary layered rocks and gabbro dikes, and. Quaternary basaltic lavas, pyroclastic rocks, and surficial deposits. The Precambrian rocks are layered metasedimentary and metavolcanic rocks that have been assigned to the Baish and Bahah groups. These rocks are cut by Precambrian biotite quartz monzonite and by Miocene gabbro dikes that were intruded during the initial stages of the opening of the Red Sea rift. Tuffaceous siltstone of the Baid formation was also deposited during the Miocene, followed in the Pliocene by the polymict conglomerate of the Bathan formation. The Quaternary rocks include basalt that was extruded during a continuation of the opening of the Red Sea rift, after uplift of the escarpment parallel with the Red Sea but before the Holocene erosional cycle. The greater part of the land area of the quadrangle is covered by Quaternary coastal, pediment, and alluvial deposits of various kinds associated with the deltaic mouths of Wadi Hall and Wadi Yiba and their tributaries and with the development of fringing reefs and islands. The area also contains extensive Quaternary eolian deposits. The economic potential of the quadrangle lies essentially in the agricultural value .of its flood-plain deposits, which are frequently refreshed during flooding with the products of weathering and erosion of the Precambrian rocks in the valleys of Wadi Hal i and Wadi Yiba; coral reefs could possibly provide raw material for use in a cement industry, if any such industry were ever required in this area.

Giant landslide deposits in northwest Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fauque, L.; Strecker, M.R.; Bloom, A.L.

1985-01-01

Giant Quaternary landslide deposits occur along mountain fronts in the structural transition zone between the high-angle reverse-fault-bounded Sierras Pampeanas and the low-angle thrust belt of the Sierras Subandinas. There are two modes of occurrence: (1) chaotic masses without distinct geometry, and (2) masses with distinct lobate geometry similar to glacial moraines. Type (1) deposits occur where the moving rock mass followed a narrow valley and blocked the drainage. Many of these caused subsequent formation of lakes and changed the sedimentation processes on pediments at the mountain fronts. In type (2) deposits, lateral and frontal ridges are up to 10 mmore » higher than the interior parts; in some places pressure ridges within the lobes are well preserved. Type (2) deposits show reverse grading and were deposited on relatively smooth pediments or alluvial fans. The lobate geometry strongly suggests that type (2) deposits are a product of flowage and are debris stream or sturzstrom deposits (sense of Heim, 1932 and Hsu, 1975). All investigated deposits occur in areas of demonstrated Quaternary faulting and are interpreted as the result of tectonic movements, although structural inhomogeneities in the source area may have been a significant factor for some of the landslides. No datable materials have yet been found associated with the deposits.« less

Reconnaissance geology of the Jabal Hashahish Quadrangle, sheet 17/41 B, Kingdom of Saudi Arabia

USGS Publications Warehouse

Hadley, D.G.

1982-01-01

The Jabal Hashahish quadrangle (sheet 17/41 B) lies between lat 17?30' and 18?00' N. and long 41?30' and 42?00' E. and encompasses an area of 2,950 km2, of which only about 600 km2 is land; the remainder is covered by the Red Sea. The geologic formations exposed in the quadrangle include Precambrian layered and intrusive rocks, Tertiary gabbro dikes, Quaternary basaltic lavas and pyroclastic rocks, and Quaternary surficial deposits. The Precambrian rocks include layered sedimentary and volcanic rocks that have been assigned to the Baish, Bahah, and Ablah groups. These rocks have been folded, metamorphosed, and invaded by intrusions. They are cut by Miocene gabbro dikes that were intruded during the initial stages of the opening of the Red Sea rift. The Quaternary rocks also include basalt that was extruded during a continuation of that opening, after the uplift that formed the escarpment that parallels the eastern shore of the Red Sea, but before the Holocene erosional cycle. Coastal, pediment, and alluvial, and eolian deposits of various kinds are also of Quaternary age. The economic potential of the quadrangle lies essentially in the agricultural value of its flood-plain deposits, though these are not so widely used as those in Wadi Hali and Wadi Yiba, which are located in the Manjamah quadrangle. The coral reefs possibly could provide raw materials for use in a cement industry, if any such industry were ever required in this area.

Predictions of Bedforms in Tidal Inlets and River Mouths

DTIC Science & Technology

2016-07-31

that community modeling environment. APPROACH Bedforms are ubiquitous in unconsolidated sediments . They act as roughness elements, altering the...flow and creating feedback between the bed and the flow and, in doing so, they are intimately tied to erosion, transport and deposition of sediments ...With this approach, grain-scale sediment transport is parameterized with simple rules to drive bedform-scale dynamics. Gallagher (2011) developed a

Sand Waves That Impede Navigation of Coastal Inlet Navigation Channels

DTIC Science & Technology

2006-08-01

Merrymeeting Bay. The bay collects coarse-grained sediment from unconsolidated ice-contact and periglacial deposits (Fenster and FitzGerald 1996). During...bed, which is a layer of denser or larger sized sediment left after finer material has been winnowed by a strong current, can inhibit bed form...Order Descriptors (important) • Superposition: simple or compound. • Sediment Characteristics (size, sorting). Third Order Descriptors (useful

Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California: Chapter E in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

USGS Publications Warehouse

Bloss, Benjamin R.; Bedrosian, Paul A.; Buesch, David C.

2015-01-01

Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include plutonic and metamorphic (basement) rocks, lava flows, consolidated sedimentary rocks, and unconsolidated sedimentary deposits that formed in a series of intermountain basins. Basement rocks, lava flows, and some lithified tuffs are generally resistive (≥100 ohm-meters [Ω·m]) when saturated. Saturated unconsolidated samples are moderately conductive to conductive, with resistivities generally less than 100 Ω·m, and many of these samples are less than 50 Ω·m. The unconsolidated samples can further be separated into two broad groups: (1) younger sediments that are moderately conductive, owing to their limited clay content, and (2) older, more conductive sediments with a higher clay content that reflects substantial amounts of originally glassy volcanic ash subsequently altered to clay. The older sediments are believed to be Tertiary. Time-domain electromagnetic (TEM) data were acquired near most of the boreholes, and, on the whole, close agreements between laboratory measurements and resistivity models were found. 

Geology and hydrogeology of the Caribbean islands aquifer system of the Commonwealth of Puerto Rico and the U.S. Virgin Islands

USGS Publications Warehouse

Renken, Robert A.; Ward, W. C.; Gill, I.P.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús; ,

2002-01-01

Poorly lithified to unconsolidated carbonate and clastic sedimentary rocks of Tertiary (Oligocene to Pliocene) and Quaternary (Pleistocene to Holocene) age compose the South Coast aquifer and the North Coast limestone aquifer system of Puerto Rico; poorly lithified to unlithified carbonate rocks of late Tertiary (early Miocene to Pliocene) age make up the Kingshill aquifer of St. Croix, U.S. Virgin Islands. The South Coast aquifer, North Coast limestone aquifer system, and Kingshill aquifer are the most areally extensive and function as the major sources of ground water in the U.S. Caribbean Islands Regional Aquifer-System Analysis (CI-RASA) study area. In Puerto Rico's South Coast ground-water province, more than 1,000 meters of clastic and carbonate rocks of Oligocene to Pliocene age infill the South Coast Tertiary Basin. The pattern of lithofacies within this basin appears to have been controlled by changes in base level that were, at times, dominated by tectonic movement (uplift and subsidence), but were also influenced by eustasy. Deposition of the 70-kilometer long and 3- to 8-kilometer wide fan-delta plain that covers much of the South Coast ground-water province occurred largely in response to glacially-induced changes in sea level and climate during the Quaternary period. Tectonic movement played a much less important role during the Quaternary. The North Coast ground-water province of Puerto Rico is underlain by homoclinal coastal plain wedge of carbonate and siliciclastic rocks that infill the North Coast Tertiary Basin and thicken to more than 1,700 meters. A thin basal siliciclastic sequence of late Oligocene age is overlain by a thick section of mostly carbonate rocks of Oligocene to middle Miocene age. Globigerinid limestone of late Miocene to Pliocene age crops out and lies in the shallow subsurface areas of northwestern Puerto Rico. Oligocene to middle Miocene age rocks tentatively can be divided into five depositional sequences and associated systems tracts; these rocks record carbonate and minor siliciclastic deposition that occurred in response to changes in relative sea level. The Cibao Formation represents the most complex of these sequences and contains a varied facies of carbonate, mixed carbonate-siliciclastic, and siliciclastic rocks that reflect differential uplift, subsidence, and transgression of the sea. Uplift, graben formation, and gradual shallowing of the sea are reflected within the bathyal-dominated sedimentary facies of the Kingshill Limestone in St. Croix, U.S. Virgin Islands. Reef-tract limestone beds of Pliocene age were subject to exposure, resubmergence, and meteoric leaching of aragonitic skeletal debris; these beds contain patchy lenses of dolomite that are restricted to a small, structurally-controlled embayment. The South Coast aquifer, the principal water-bearing unit of Puerto Rico's South Coast ground-water province, consists of boulder- to silt-size detritus formed by large and small coalescing fan deltas of Pleistocene to Holocene age. Deep well data indicates that it is possible to vertically separate and group a highly complex and irregular-bedded detrital sequence that underlies distal parts of the fan-delta plain into discrete water-bearing units if correlated with 30- to 40-meter thick, eustatically-controlled depositional cycles. Lithofacies maps show that greatest hydraulic conductivity within the fan-delta plain is generally associated with proximal fan and midfan areas. Distal and interfan areas are least permeable. Alluvial valley aquifers located in the western part of the South Coast ground-water province are important local sources of water supply and appear to contain some of the same physical and hydraulic characteristics as the South Coast aquifer. Older sedimentary rocks within the basin are poor aquifers; conglomeratic beds are well-cemented, and carbonate beds do not contain well-developed solution features, except locally where the beds are over

Hydrology of Park County, Wyoming, exclusive of Yellowstone National Park

USGS Publications Warehouse

Lowry, M.E.; Smalley, M.L.; Mora, K.L.; Stockdale, R.G.; Martin, M.W.

1993-01-01

The climate of Park County, Wyoming, ranges from desert to alpine tundra. Average annual precipitation ranges from 6 to 40 inches. Ground water is present throughout most of the county, but supplies adequate for stock or domestic use are not readily available in areas of greatest need. The chemical quality of most of the water sampled was of suitable quality for livestock, but most of the water was not suitable for drinking, and the water from bedrock aquifers generally was not suitable for irrigation. Unconsolidated deposits are a principal source of ground water in the county. However, ground water is found in deposits topographically higher than stream level only where surface water has been applied for irrigation; those unconsolidated deposits beneath areas that are not irrigated, such as Polecat Bench, are dry. The conversion of irrigated land to urban development poses problems in some areas because yields of water-supply wells will be adversely affected by reduced recharge. The trend toward urban development also increases the risk of contamination of the ground water by septic tanks, petroleum products, and toxic and hazardous wastes. Perennial streams originate in the mountains and in areas where drainage from irrigated land is adequate to sustain flow. The average annual runoff from streams originating in the mountains is as large as 598 acre-feet per square mile, and the average annual runoff from streams originating in badlands and plains is as low as 14.8 acre-feet per square mile.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2013

USGS Publications Warehouse

Beman, Joseph E.

2014-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when treatment and distribution of surface water from the Rio Grande began. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22-percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2013), the network consists of 123 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority, currently (2013) measures and reports water levels from the 123 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 123 sites through water year 2013.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2012

USGS Publications Warehouse

Beman, Joseph E.

2013-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22 percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2012), the network consists of 126 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (ABCWUA), currently (2012) measures and reports water levels from the 126 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 126 sites through water year 2012.

Micropaleontologic record of late Pliocene and Quaternary paleoenvironments in the northern Albemarle Embayment, North Carolina, U.S.A.

USGS Publications Warehouse

Culver, S.J.; Farrell, K.M.; Mallinson, D.J.; Horton, B.P.; Willard, D.A.; Thieler, E.R.; Riggs, S.R.; Snyder, S.W.; Wehmiller, J.F.; Bernhardt, C.E.; Hillier, C.

2008-01-01

Micropaleontological data provide a strong actualistic basis for detailed interpretations of Quaternary paleoenvironmental change. The 90??m-thick Quaternary record of the Albemarle Embayment in the mid-Atlantic coastal plain of the USA provides an excellent opportunity to use such an approach in a region where the details of Quaternary environmental change are poorly known. The foraminiferal record in nine cores from the northern Outer Banks, east of Albemarle Sound, North Carolina, indicates the deposition of subhorizontal, mostly open-marine early to late Pleistocene units unconformably upon a basement of late Pliocene reduced-oxygen, fine-grained, shelf-basin deposits. Pollen data record several warm-cool fluctuations within the early to mid-Pleistocene deposits. Diatom data indicate that some fresh and brackish-water units occur within the generally open-marine Pleistocene succession. A channel cut by the paleo-Roanoke River during the last glacial sea-level lowstand occurs in the northern part of the study area. Pollen indicates that the basal fluvial valley fill accumulated in cooler than modern climate conditions in the latest Pleistocene. Overlying silts and muds accumulated under cool climatic, estuarine conditions according to diatom and pollen data. Radiocarbon ages from the estuarine deposits indicate that the bulk of these sediments accumulated during the latest Pleistocene. The estuarine channel-fill deposits are overlain by Holocene open-marine sands deposited as the rising sea transgressed into the estuary approximately 8.5 to 9.0??kyr BP. Within the barrier island drill cores of this study, fully marine sedimentation occurred throughout the Holocene. However, immediately west of the present barrier island, mid- to late Holocene estuarine deposits underlie the modern Albemarle Sound. The islands that currently form a continuous barrier across the mouth of Albemarle Sound have a complex history of Holocene construction and destruction and large portions of them may be less than 3??kyr old. The barrier island sands overlie open-marine sands of Colington Shoal in the north and to the south overlie fluvial and marine sand filling paleo-Roanoke tributary valleys. The Pleistocene sediments underlying the northern Outer Banks study area are mainly of open inner to mid-shelf origin. If, as is likely, sea level continues to rise, a return to such environmental conditions is likely in the near future. ?? 2008 Elsevier B.V.

Sedimentary development and correlation of Late Quaternary terraces in the Kyrenia Range, northern Cyprus, using a combination of sedimentology and optical luminescence data

NASA Astrophysics Data System (ADS)

Palamakumbura, Romesh N.; Robertson, Alastair H. F.; Kinnaird, Tim C.; Sanderson, David C. W.

2016-01-01

This study focuses on the younger of a series of Quaternary terraces along the flanks of the Kyrenia Range in northern Cyprus, specifically the Kyrenia (Girne) and the Koupia terraces. The Kyrenia (Girne) terrace is tentatively correlated with oxygen isotope stage 5 (125 Ka), and the Koupia terrace with oxygen isotope stage 3 (<50 Ka). Along the northern flank of the range, the Kyrenia (Girne) terrace deposits (5-20 m above modern sea level) typically begin with a basal lag conglomerate and then pass upwards into shallow-marine calcarenites and then into variable aeolianites, paleosols and fluvial deposits (up to 20 m thick). In contrast, the Koupia terrace (<2 m above modern sea level) consists of aeolianites and shallow-marine calcarenites (up to 8 m thick). The equivalent deposits along the southern flank of the range are entirely non-marine fluvial mud, sands and conglomerates. The marine to continental terrace systems can be tentatively correlated based on mapping, height above modern sea level and sedimentary facies. However, variable preservation and patchy exposure require such correlations to be independently tested. To achieve this, a portable optically stimulated luminescence (OSL) reader was used to determine the luminescence characteristics of the two terrace systems. Luminescence profiles show major differences in luminescence characteristics between the two terrace depositional systems, which can be related to sedimentary processes, provenance and age. These features allow sections in different areas to be effectively correlated. Individual sections show luminescence properties that are generally consistent with an expected up-sequence decrease in age. However, the younger Koupia terrace deposits show higher luminescence intensities compared with the older Kyrenia (Girne) terrace deposits. This can be explained by multiple phases of reworking of the Kyrenia (Girne) terrace deposits, which changed the luminescence characteristics of the sediment. The use of the portable OSL reader is therefore an effective means of correlating Late Quaternary terrace deposits in northern Cyprus and probably also elsewhere.

Geologic map of the Bailey 30' x 60' quadrangle, North-Central Colorado

USGS Publications Warehouse

Ruleman, Chester A.; Bohannon, Robert G.; Bryant, Bruce; Shroba, Ralph R.; Premo, Wayne R.

2011-01-01

The Bailey, Colo. 1:100,000-scale quadrangle lies within two physiographic and geologic provinces in central Colorado: 1) the Front Range and 2) South Park. Most of the Front Range is composed of Proterozoic rocks ranging in age from 1,790 Ma to 1,074 Ma. Along the eastern flanks and within the Denver Basin, sedimentary rocks ranging from Pennsylvanian to Cretaceous are deformed and steeply tilted to the east. Upper Cretaceous through Paleocene rocks were deposited in the foreland (that is, the Front Range eastern flank) and hinterland (that is, South Park) of this thrust and reverse fault system developed during the Late Cretaceous to Paleocene Laramide orogeny. Within South Park, rocks range in age from Pennsylvanian to Miocene with Quaternary deposits indicating tectonic subsidence of the basin. These rocks record five major geologic episodes: 1) the Paleozoic Anasazi uplift that formed the Ancestral Rockies, 2) the Late Cretaceous to Paleocene Laramide orogeny, 3) widespread Eocene to Oligocene volcanism, 4) Oligocene-Quaternary tectonics, and 5) Quaternary glacial episodes.

High resolution seismic stratigraphy and sedimentological signature of the Late Quaternary deposits in the northern Western Basin (Ross Sea, Antarctica)

NASA Astrophysics Data System (ADS)

Corradi, N.; Finocchiaro, F.; Ivaldi, R.; Melis, R.; Pittà, A.

2003-04-01

The northern Western Basin is a sector of the continental shelf of the Western Ross Sea that is considered to be the natural northward extension of the Drygalski Basin by many authors. The literature provides a general model of the evolution of the basin and the recent papers propose a seismic stratigraphy for the post-Miocene sedimentation. However, the sedimentary processes during the Late Quaternary and, in particular, the Last Glacial Maximum (LGM) are still little understood (Brambati et al., 2001). In this paper we present the preliminary results of the very high-resolution seismic surveys (Sub Bottom Profiler, Huntec Deep Tow Boomer and Sparker) and their calibration with the sediment samples collected during the three Marine Geology Campaigns of the PNRA (XIII, XIV and XVII), with the scientific objective of the research to investigate the role of the East Antarctic Ice Sheet (EAIS) in the morphogenesis and deposition of the Late Quaternary sedimentary series.

Fluvial deposits of Yellowstone tephras: Implications for late Cenozoic history of the Bighorn basin area, Wyoming and Montana

USGS Publications Warehouse

Reheis, M.C.

1992-01-01

Several deposits of tephra derived from eruptions in Yellowstone National Park occur in the northern Bighorn basin area of Wyoming and Montana. These tephra deposits are mixed and interbedded with fluvial gravel and sand deposited by several different rivers. The fluvial tephra deposits are used to calculate stream incision rates, to provide insight into drainage histories and Quaternary tectonics, to infer the timing of alluvial erosion-deposition cycles, and to calibrate rates of soil development. ?? 1992.

Hydrogeologic and geochemical characterization and evaluation of two arroyos for managed aquifer recharge by surface infiltration in the Pojoaque River Basin, Santa Fe County, New Mexico, 2014–15

USGS Publications Warehouse

Robertson, Andrew J.; Cordova, Jeffrey; Teeple, Andrew; Payne, Jason; Carruth, Rob

2017-02-22

In order to provide long-term storage of diverted surface water from the Rio Grande as part of the Aamodt water rights settlement, managed aquifer recharge by surface infiltration in Pojoaque River Basin arroyos was proposed as an option. The initial hydrogeologic and geochemical characterization of two arroyos located within the Pojoaque River Basin was performed in 2014 and 2015 in cooperation with the Bureau of Reclamation to evaluate the potential suitability of these two arroyos as sites for managed aquifer recharge through surface infiltration.The selected reaches were high-gradient (average 3.0–3.5 percent) braided channels filled with unconsolidated sand and gravel-sized deposits that were generally 30–50 feet thick. Saturation was not observed in the unconsolidated channel sands in four subsurface borings but was found at 7–60 feet below the contact between the unconsolidated channel sands and the bedrock. The poorly to well-cemented alluvial deposits that make up the bedrock underlying the unconsolidated channel material is the Tesuque Formation. The individual beds of the Tesuque Formation are reported to be highly heterogeneous and anisotropic, and the bedrock at the site was observed to have variable moisture and large changes in lithology. Surface electrical-resistivity geophysical survey methods showed a sharp contrast between the electrically resistive unconsolidated channel sands and the highly conductive bedrock; however, because of the high conductivity, the resistivity methods were not able to image the water table or preferential flow paths (if they existed) in the bedrock.Infiltration rates measured by double-ring and bulk infiltration tests on a variety of channel morphologies in the study reaches were extremely large (9.7–94.5 feet per day), indicating that the channels could potentially accommodate as much as 6.6 cubic feet per second of applied water without generating surface runoff out of the reach; however, the small volume available for storage in the unconsolidated channel sands (about 410 acre-feet in the east arroyo and about 190 acre-feet in the west arroyo) and the potential for the infiltrating water to preferentially flow over the bedrock contact and out of the reach present a challenge for storing water. Although a detailed assessment of the infiltration rate of the Tesuque Formation is beyond the scope of this investigation, one double-ring infiltrometer test was conducted on an outcrop, resulting in an estimated infiltration rate of about 4 feet per day.The shallow groundwater observed in this investigation was determined to be recharged locally on the basis of groundwater elevations and geochemical and isotopic signatures. The channel sands and shallow bedrock were observed to be weathered, indicating contact with oxic groundwater following deposition. This observation was supported by whole-rock elemental analysis and mineralogy of several core samples. The downward groundwater gradient between the shallow wells and those wells screened at greater depths suggests that the shallow groundwater is recharged by local precipitation and has the potential to migrate to the deeper aquifer units. The two age-dating tracers measured in this investigation, however, demonstrate that the shallow groundwater flow paths are very slow and that the deeper flow paths are likely part of a larger regional system.The composition of the shallow, native groundwater suggests that storing water diverted from the Rio Grande is not likely to leach constituents of concern that would cause the stored water to exceed health-based U.S. Environmental Protection Agency Maximum Contaminant Levels.

Preliminary Surficial Geologic Map of the Mesquite Lake 30' X 60' Quadrangle, California and Nevada

USGS Publications Warehouse

Schmidt, Kevin M.; McMackin, Matthew

2006-01-01

The Quaternary surficial geologic map of the Mesquite Lake, California-Nevada 30'X60' quadrangle depicts deposit age and geomorphic processes of erosion and deposition, as identified by a composite of remote sensing investigations, laboratory analyses, and field work, in the arid to semi-arid Mojave Desert area, straddling the California-Nevada border. Mapping was motivated by the need to address pressing scientific and social issues such as understanding and predicting the effects of climate and associated hydrologic changes, human impacts on landscapes, ecosystem function, and natural hazards at a regional scale. As the map area lies just to the south of Las Vegas, Nevada, a rapidly expanding urban center, land use pressures and the need for additional construction materials are forecasted for the region. The map contains information on the temporal and spatial patterns of surface processes and hazards that can be used to model specific landscape applications. Key features of the geologic map include: (1) spatially extensive Holocene alluvial deposits that compose the bulk of Quaternary units (~25%), (2) remote sensing and field studies that identified fault scarps or queried faults in the Kingston Wash area, Shadow Mountains, southern Pahrump Valley, Bird Spring Range, Lucy Gray Mountains and Piute Valley, (3) a lineament indicative of potential fault offset is located in Mesquite Valley, (4) active eolian dunes and sand ramps located on the east side of Mesquite, Ivanpah, and Hidden Valleys adjacent to playas, (4) groundwater discharge deposits in southern Pahrump Valley, Spring Mountains, and Lucy Gray Mountains and (5) debris-flow deposits spanning almost the entire Quaternary period in age.

Quaternary geology of the Rhode Island inner shelf

USGS Publications Warehouse

Needell, S. W.; O'Hara, C. J.; Knebel, H.J.

1983-01-01

Five sedimentary units and three erosional unconformities identified in high-resolution seismic-reflection profiles reveal the stratigraphic framework and Quaternary history of the inner continental shelf south of Narragansett Bay, Rhode Island. Late Tertiary to early Pleistocene rivers eroded the pre-Mesozoic bedrock and the Upper Cretaceous to lower Tertiary coastal plain and continental shelf strata to form a lowland and cuesta having a north-facing escarpment. The lowland and landward flanks of the cuesta were modified by glaciers during Pleistocene time and subsequently were overlain by drift and end moraine deposits of the late Wisconsinan ice advance. During deglaciation, freshwater lakes formed between the retreating ice and end moraines. Prior to sea-level rise, the drift and older deposits were cut by streams flowing south and southwestward toward Block Island Sound. As sea level rose, postglacial valleys were partly filled by fluvial, freshwater-peat, estuarine and salt-marsh deposits. Transgressing seas eroded the sea floor, exposing bedrock and coastal plain outcrops, and deposited marine sediments. ?? 1983.

Surficial and bedrock geologic map database of the Kelso 7.5 Minute quadrangle, San Bernardino County, California

USGS Publications Warehouse

Bedford, David R.

2003-01-01

This geologic map database describes geologic materials for the Kelso 7.5 Minute Quadrangle, San Bernardino County, California. The area lies in eastern Mojave Desert of California, within the Mojave National Preserve (a unit of the National Parks system). Geologic deposits in the area consist of Proterozoic metamorphic rocks, Cambrian-Neoproterozoic sedimentary rocks, Mesozoic plutonic and hypabyssal rocks, Tertiary basin fill, and Quaternary surficial deposits. Bedrock deposits are described by composition, texture, and stratigraphic relationships. Quaternary surficial deposits are classified into soil-geomorphic surfaces based on soil characteristics, inset relationships, and geomorphic expression. The surficial geology presented in this report is especially useful to understand, and extrapolate, physical properties that influence surface conditions, and surface- and soil-water dynamics. Physical characteristics such as pavement development, soil horizonation, and hydraulic characteristics have shown to be some of the primary drivers of ecologic dynamics, including recovery of those ecosystems to anthropogenic disturbance, in the eastern Mojave Desert and other arid and semi-arid environments.

Multiple geophysical methods examining neotectonic blind structures in the Maradona valley, Central Precordillera (Argentina)

NASA Astrophysics Data System (ADS)

Lara, Gabriela; Klinger, Federico Lince; Perucca, Laura; Rojo, Guillermo; Vargas, Nicolás; Leiva, Flavia

2017-08-01

A high-resolution superficial geophysical study was carried out in an area of the retroarc region of the Andes mountains, located in the southwest of San Juan Province (31°45‧ S, 68°50‧ W), Central Precordillera of Argentina. The main objectives of this study were to confirm the presence of blind neotectonic structures and characterize them by observing variations in magnetic susceptibility, density and p-wave velocities. Geological evidence demonstrates the existence of a neotectonic fault scarps affecting Quaternary alluvial deposits in eastern piedmont of de Las Osamentas range, in addition to direct observation of the cinematic of this feature in several natural exposures. The Maradona valley is characterized by the imbricated eastern-vergence Maradona Fault System that uplifts Neogene sedimentary rocks (Albarracín Formation) over Quaternary (Late Pleistocene-Holocene) alluvial deposits. The combined application of different geophysical methods has allowed the characterization of a blind fault geometry also identified on a natural exposure. The magnetic data added to the gravimetric model, and its integration with a seismic profile clearly shows the existence of an anomalous zone, interpreted as uplifted blocks of Miocene sedimentary rocks of Formation Albarracín displaced over Quaternary deposits. The application and development of different geophysical methods, together with geological studies allow to significantly improving the knowledge of an area affected by Quaternary tectonic activity. Finally, this multidisciplinary study, applied in active blind structures is very relevant for future seismic hazard analysis on areas located very close to populated centers.

Estimation of the tectonic slip-rate from Quaternary lacustrine facies within the intraplate Albacete province (SE of Spain)

USGS Publications Warehouse

Rodriguez-Pascua, M. A.; Bischoff, J.; Garduno-Monroy, Victor H.; Pérez-López, R.; Giner-Robles, J.L.; Israde-Alcántara, I.; Calvo, J.P.; Williams, Ross W.

2009-01-01

The Quaternary lacustrine basin of Cordovilla (CB) represents one of the most active tectonic areas of the Prebetic Zone (Albacete, SE of Spain). The Quaternary sedimentary deposits of this basin are mainly endoreic lacustrine carbonate and alluvial deposits, developed in a semi-arid climate (Pleistocene-present). The basin is a NW-SE-elongated graben bounded by a major right-lateral oblique-fault, the Pozohondo Fault. This fault trends NW-SE, with an approximate trace of 55 km, and is composed of various segments which are identified by fault scarps. In order to establish the slip-rate of the most active segment of the Pozohondo Fault, called the Cordovilla segment, we carried out a detailed study of the affected Quaternary lacustrine deposits. We found that the lacustrine facies could be related to episodic moderate paleoearthquakes. The slip-rate is calculated to be 0.05 and 0.09 mm/yr, using radiometric dating for the vertical offsets of the lacustrine facies. A trenching study at the northern part of the Cordovilla segment revealed two events caused by paleoearthquakes, with the most recent expressed as an oblique-fault off-setting a poorly-developed soil. The magnitude of the last event was greater than 6, using various empirical relationships for the fault displacement and the surface-length rupture. We estimate episodic activity across the Cordovilla segment, to be characterized by moderate-sized paleoearthquakes (M6), which is in agreement with the tectonic context of an intraplate zone of the Iberian plate. ?? 2009 Elsevier B.V.

Late Quaternary landscape evolution, climate, and neotectonism along the eastern margin of the Puna Plateau: Pucará Valley, NW Argentina

NASA Astrophysics Data System (ADS)

McCarthy, J. A.; Schoenbohm, L. M.; Bierman, P. R.; Rood, D. H.

2013-12-01

The eastern margin of the Puna Plateau has been the focus of many studies seeking to link climatically-moderated surface processes and tectonism through dynamic feedbacks. However, evaluating any theories regarding climatic-tectonic feedbacks requires the determination of tectonic, climatic, and geomorphic chronologies across a wide region, from plateau to wedge-top to foreland. In this study, we contribute to that effort by examining Quaternary landscape evolution of a single intermontane basin of spatially uniform climate, adjacent to the plateau margin. The semi-arid Pucará Valley contains eight abandoned and incised geomorphic surfaces, most of which are deformed by active structures. These geomorphic surfaces - thin alluvial fans and strath terraces - dominate the landscape and record multiple pulses of incision in the late Quaternary. We find no evidence for significant depositional intervals and valley incision continues currently. Substantial accumulations of pedogenic carbonate and pedogenic gypsum within abandoned surfaces indicate that arid or semi-arid conditions are long lived in this valley. Conversely, relict periglacial morphology in adjacent ranges supports cooler temperatures in the past. River incision is enhanced across active structures, but preliminary observations suggest that the magnitude of deformation cannot fully explain the magnitude of incision. As a result, we argue that extrabasinal base-level lowering is the primary driver of incision in the Pucará Valley, but Quaternary deformation is significant enough to spatially influence erosion. Cooler climatic intervals may influence the sedimentology of alluvial and fluvial deposits, but we find no evidence for significant climatic changes that could change rates or styles of landscape evolution over this time frame. Pending cosmogenic nuclide analysis of fan deposits and river sediments will permit the derivation of fault slip rates, surface ages, modern and paleo-erosion rates, and sediment transport histories. These results will further refine our understanding of tectonic and climatic forcing of surface processes in the Quaternary.

Late Quaternary Compression Revealed By Surface Faults At The Western Margin of Corsica Basin (corse, France)

NASA Astrophysics Data System (ADS)

Fellin, M. G.; Picotti, V.; Zattin, M.

Corsica is a continental block located between the Ligurian-Balearic and the North Tyrrhenian Seas (Corsica basin). Recent studies indicate that from Eocene to Pliocene the structural evolution of Corsica was controlled by extensional tectonics which prob- ably continued till Holocene (Jolivet et al., 1998). New field data have been collected in the the Marana plain (Eastern Corsica), which is a subsiding area covered by allu- vial deposits. These deposits have been dated as late Quaternary by Conchon (1978) through outcrop analyses, wells, paleosoils and weathering rinds. The master fault, separating the Marana plain from the mountain range to the west, shows an extensional tectonics and a later compressional reactivation. The river network in the Marana plain area is characterized by incised meanders formed at the intersection between the rivers and the master fault. This feature is related to a river profile convexity and not to a lithological change of the bedrock. Therefore the incised meanders may be due to a recent activity of the master fault. Reverse faults cutting Wuermian deposits of the Marana plain have been observed for the first time and they indicate a late Quaternary NW-SE directed compression. This regime is in good agreement with the present day compressional stress field determined on the basis of earthquakes focal mechanism in the Ligurian Sea (Baroux et al., 2001) and it may be responsible for the reactivation of the master fault of the Marana plain. Conchon O., 1978: Quaternary studies in Corsica (France). Quaternary Research, v. 9, pp. 41-53. Jolivet L. et al., 1998: Midcrustal shear zones in postorogenic extension: ex- ample from the North Tyrrhenian Sea. J. Geoph. Res., v. 103 (B6), pp.12,123-12,160. Baroux E. et al., 2001: Analyses of the stress field in southern France from earthquakes focal mechanisms. Geophys. J. Int., v. 145, pp. 336-348.

Summary of Quaternary geology of the Municipality of Anchorage, Alaska

USGS Publications Warehouse

Schmoll, H.R.; Yehle, L.A.; Updike, R.G.

1999-01-01

Quaternary geology of the Upper Cook Inlet region is dominated by deposits of glacier retreats that followed repeated advances from both adjacent and more distant mountains. At several levels high on the mountains, there are remnant glacial deposits and other features of middle or older Pleistocene age. Late Pleistocene lateral moraines along the Chugach Mountain front represent successively younger positions of ice retreat from the last glacial maximum. As the trunk glacier retreated northeastward up the Anchorage lowland, Cook Inlet transgressed the area, depositing the Bootlegger Cove Formation and Tudor Road deposits. The glacier then readvanced to form the latest Pleistocene Elmendorf Moraine, a prominent feature that trends across the Anchorage lowland. Extensive alluvium was deposited both concurrently and somewhat later as Cook Inlet regressed. Mountain valleys contain (1) locally preserved moraines possibly of early Holocene age; (2) poorly preserved moraine remnants of older late Holocene age; and (3) well-preserved moraines formed mainly during the Little Ice Age. Glaciers still occupy large parts of the mountains, the upper ends of some mountain valleys, and small cirques. Holocene landslide deposits, including those formed during the great Alaska earthquake of 1964, occur throughout the area, especially along bluffs containing the Bootlegger Cove Formation.

The Great Acceleration and the disappearing surficial geologic record

USGS Publications Warehouse

Rech, Jason A.; Springer, Kathleen; Pigati, Jeffrey S.

2017-01-01

The surficial geologic record is the relatively thin veneer of young (<~1 Ma) and mostly unconsolidated sediments that cover portions of Earth’s terrestrial surface (Fig. 1). Once largely ignored as “overburden” by geologists, surficial deposits are now studied to address a wide range of issues related to the sustainability of human societies. Geologists use surficial deposits to determine the frequency and severity of past climatic changes, quantify natural and anthropogenic erosion rates, identify hazards, and calculate recurrence intervals associated with earthquakes, landslides, tsunamis, and volcanic eruptions. Increasingly, however, humans are eradicating the surficial geologic record in many key areas through progressive modification of Earth’s surface.

Evaluation of ERTS-1 imagery for mapping Quaternary deposits and landforms in the Great Plains and Midwest

NASA Technical Reports Server (NTRS)

Morrison, R. B. (Principal Investigator); Hallberg, G. R.

1973-01-01

The author has identified the following significant results. The main landform associations and larger landforms are readily identifiable on the better images and commonly the gross associations of surficial Quaternary deposits also can be differentiated, primarily by information on landforms and soils. Maps showing the Quaternary geologic-terrain units that can be differentiated from the ERTS-1 images are being prepared for 20-odd potential study areas in Illinois, Iowa, Missouri, Kansas, Nebraska, and South Dakota. Among the more distinct features are the major moraines and outwash channels of the last (Wisconsin) glaciation. Analysis of dissection/drainage patterns from the synoptic imagery is proving useful for detecting anomalies that may be caused by stream diversions and moraines of pre-Wisconsin glaciations, by variable loess deposition, by tectonism, and other factors. Numerous abandoned river valleys have been mapped. Trend-lines of several known pre-Wisconsin moraine systems have been identified in Iowa, Nebraska, and Kansas, and also several similar trend-lines, that may indicate previously unknown moraine systems of middle and possibly early Pleistocene age, have been found in Iowa and Missouri. The area inundated by a major flood in southwestern Iowa also has been delineated from ERTS-1 imagery.

Geology and ground-water resources of the upper Lodgepole Creek drainage basin, Wyoming, with a section on chemical quality of the water

USGS Publications Warehouse

Bjorklund, Louis Jay; Krieger, R.A.; Jochens, E.R.

1959-01-01

The principal sources of ground-water supply in the upper Lodgepole Creek drainage basin-the part of the basin west of the Wyoming-Nebraska State line-are the Brule formation of Oligocene age, the Arikaree formation of Miocene age, the Ogallala formation of Pliocene age, and the unconsolidated deposits of Quaternary age. The Brule formation is a moderately hard siltstone that generally is not a good aquifer. However, where it is fractured or where the upper part consists of pebbles of reworked siltstone, it will yield large quantities of water to wells. Many wells in the Pine Bluffs lowland, at the east end of the area, derive water from the Brule. The Arikaree formation, which consists of loosely to moderately cemented fine sand, will yield small quantities of water to wells but is not thick enough or permeable enough to supply sufficient water for irrigation. Only a few wells derive water from it. The Ogallala formation consists of lenticular beds of clay, silt, sand, and gravel which, in part, are cemented with calcium carbonate. Only the lower part of the formation is saturated. Nearly all the wells in the upland part of the area tap the Ogallala, but they supply water in amounts sufficient for domestic and stock use only. Two of the wells have a moderately large discharge, and other wells of comparable discharge probably could be drilled in those parts of the upland where the saturated part of the Ogallala is fairly thick. Most of the unconsolidated deposits of Quaternary age are very permeable and, where a sufficient thickness is saturated, will yield large quantities of water to wells. These deposits are a significant source of water supply in the southeastern part of the area. The Chadron formation of Oligocene age, which underlies the Brule formation, is a medium- to coarse-grained sandstone where it crops out in the Islay lowland. No wells tap the Chadron, but it probably would yield small quantities of water to wells. It lies at a relatively shallow depth beneath most of the Islay lowland, near the west end of the area, and at a depth of about 800 feet beneath the Pine Bluffs lowland. In the latter area it probably is finer grained and may not be permeable enough to yield water to wells. All the ground water in the area is derived from precipitation. It is estimated that about 5 percent of the precipitation infiltrates directly to the zone of saturation. The remainder either is evaporated immediately; is retained by the soil, later to be evaporated or transpired; or is discharged by overland flow to the surface drainage courses. Most of the water that reaches the surface drainage courses eventually sinks to the zone of saturation or is evaporated. The slope of the water table and the movement of ground water are generally eastward. The depth to water ranges from less than 10 feet in parts of the valley to about 300 feet in the upland areas. In much of the Pine Bluffs lowland, the depth to water is less than 50 feet. Ground water not pumped from wells within the area is discharged by evapotranspiration where the water table is close to the land surface, by outflow into streams, or by underflow eastward beneath the State line. The chemical quality of ground water from the principal sources is remarkably uniform, and the range in concentration of dissolved constituents is narrow. In general, the water is of the calcium bicarbonate type, is hard (hardness as CaC03 is as high as 246 ppm), and contains less than about 400 parts per million of dissolved solids, which is a moderate mineralization. Silica constitutes a large proportion of the dissolved solids. The water is suitable for irrigation and, except for iron in water from some wells that tap the Ogallala formation, meets the drinking water standards of the U.S. Public Health Service for chemical constituents. Because the water is siliceous, alkaline, and hard, it is unsuitable for many industrial uses unless treated.

Loess as a Quaternary paleoenvironmental indicator

USGS Publications Warehouse

Muhs, Daniel R.; Prins, M.A.; Machalett, B.

2014-01-01

Loess is aeolian sediment that is dominated by silt-sized particles. Unlike either coarser dune sand or finer-grained, long-range-transported dust, loess is relatively poorly sorted, reflecting a combination of transport processes, including saltation, low suspension, and high suspension. Loess can be readily identified in the field; deposits range in thickness from a few centimeters to many tens of meters, and are found over large areas of Eurasia, South and North America (Fig. 1), and smaller areas of New Zealand, Australia, Africa and the Middle East. Loess covers approximately 10% of the Earth’s land surface and is therefore one of the most important terrestrial archives of paleoenvironmental change during the Quaternary. In many regions, loess sections consist of deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition ceased altogether, or at least slowed significantly. Loess can be dated directly using luminescence, radiocarbon, and amino acid geochronology methods.

Mapping the North Sea base-Quaternary: using 3D seismic to fill a gap in the geological record

NASA Astrophysics Data System (ADS)

Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

2014-05-01

The identification and mapping of the base-Quaternary boundary in the central parts of the North Sea is problematic due to the change from an unconformable transition between Pliocene and Pleistocene deltaic deposits in the southern North Sea to a conformable one further north (Sejrup et al 1991; Gatliff et al 1994). The best estimates of the transition use seismic reflection data to identify a 'crenulated reflector' (Buckley 2012), or rely on correlating sparse biostratigraphy (Cameron et al 1987). Recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) allows greater confidence in the correlation to a regional 3D seismic dataset and show that the base-Quaternary can be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The mapped horizon is presented here alongside the difference between this new interpretation and the previously interpreted base-Quaternary (Buckley 2012). The revised base-Quaternary surface reaches a depth of 1248 ms TWT or approximately 1120 m (assuming average velocity of 1800 m/s) showing an elongate basin shape that follows the underlying structure of the Central Graben. The difference between the revised base-Quaternary and the traditional base-Quaternary reaches a maximum of over 600 ms TWT or approximately 540 m in the south-west with over 300 ms TWT or approximately 270 m at the Josephine well (56° 36.11'N, 2° 27.09'E) in the centre of the basin. Mapping this new base-Quaternary allows for the interpretation of the paleo-envionrment during the earliest Quaternary. Seismic attribute analysis indicates a deep water basin with sediment deposition from multiple deltas and redistribution by deep water currents. This has strong implications for both the Quaternary climate archive and petroleum systems in the North Sea. Key Words: base-Quaternary; chronostratigraphy: seismic interpretation; paleoenvironments References Buckley, F.A., (2012) 'An Early Pleistocene grounded ice sheet in the Central North Sea' From: Huuse, M., Redfern, J., Le Heron, D.P., Dixon, R.J., Moscariello, A., Craig, J. (eds) 'Glaciogenic reservoirs and Hydrocarbon Systems' Geological Society, London, Special Publications, 368 Cameron, T.D.J., Stoker, M.S., Long, D., (1987) 'The history of Quaternary sedimentation in the UK sector of the North Sea Basin' Journal of the Geological Society, 144, 43-58 Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional report: the geology of the central North Sea.' London: HMSO for the British Geological Survey Kulhmann, G., Langereis C.G., Munsterman, D., van Leeuwen, R.-J., Verreussel, R., Meulenkamp, J.E., Wong, Th.E., 2006 'Intergrated chronostratigraphy of the Pliocene-Pliestocene interval and its relation to the regional stratigraphical stages in the Southern North Sea region' Netherlands Journal of Geosciences 85(1), 29-45 Rasmussen, E.A., Vejb?k O.V., Bidstrup, T., Piasecki, S., Dybkj?r, K., 2005 'Late Cenozoic depositional history of the Danish North Sea Basin: implications for the petroleum systems in the Kraka, Halfdan, Siri and Nini fields', Petroleum Geology Conference series 6, 1347-1358 Sejrup, H.P., Aareseth, I., Haflidason, H., 1991 'The Quaternary succession in the northern North Sea' Marine Geology 101 103-111

Climatic implications of the Quaternary fluvial tufa record in the NE Iberian Peninsula over the last 500 ka

NASA Astrophysics Data System (ADS)

Sancho, Carlos; Arenas, Concha; Vázquez-Urbez, Marta; Pardo, Gonzalo; Lozano, María Victoria; Peña-Monné, José Luis; Hellstrom, John; Ortiz, José Eugenio; Osácar, María Cinta; Auqué, Luis; Torres, Trinidad

2015-11-01

The drainage area of the Iberian Ranges (NE Spain) houses one of the most extensive Quaternary fluvial tufaceous records in Europe. In this study, tufa deposits in the Añamaza, Mesa, Piedra and Ebrón river valleys were mapped, stratigraphically described and chronologically referenced from U/Th disequilibrium series, amino acid racemization and radiocarbon methods. Tufa deposits accumulated in cascades, barrage-cascades and related damming areas developed in stepped fluvial systems. The maximum frequency of tufa deposition was identified at 120 ka (Marine Oxygen Isotope Stage [MIS] 5e), 102 ka (MIS 5c), 85 ka ( MIS 5a) and 7 ka (MIS 1), probably under warmer and wetter conditions than today. Additional phases of tufa deposition appear at 353 ka ( end of MIS 11), 258-180 ka (MIS 7) and 171-154 ka (MIS 6). Although most tufa deposition episodes are clearly correlated with interstadial periods, the occurrence of tufa deposits during the penultimate glaciation (MIS 6) is remarkable, indicating that the onset of this stage was climatically favourable in the Iberian Peninsula. Biostatic conditions and the dynamics of karstic systems regulating tufa deposition seem to be sensitive to the precipitation regime, controlled by shifts in the position of North Atlantic atmospheric belts, and summer insolation, regulated by orbital forcing.

MX Siting Investigation Geotechnical Siting Status Report. Volume I.

DTIC Science & Technology

1978-06-21

and have moderate shear strength. GNU. HAl SUNAL, INC ENGINEERING AND GEOPHYSICAL PROPERTIES Int rrniatd.an. ungur . Aluvial Lacustrine /oNan gdotlS t...an unvarnished, active surface of sediment transport gra A53 stream channel and floodplain deposits. A52 - Unconsolidated to poorly consolidated sand...silt, and sandy gravel, with va c.0 A52 surface gravels forming isolated areas of desert pavement. This fan is in vario Cc surface of sediment

Hydrogeology of Cibola County, New Mexico

USGS Publications Warehouse

Baldwin, J.A.; Rankin, D.R.

1995-01-01

The hydrogeology of Cibola County, New Mexico, was evaluated to determine the occurrence, availability, and quality of ground-water resources. Rocks of Precambrian through Quaternary age are present in Cibola County. Most rocks are sedimentary in origin except for Precambrian igneous and metamorphic rocks exposed in the Zuni Uplift and Tertiary and Quaternary basalts in northern and central parts of the county. The most productive aquifers in the county include (youngest to oldest) Quaternary deposits, sandstones in the Mesaverde Group, the Dakota-Zuni-Bluff aquifer, the Westwater Canyon aquifer, the Todilto- Entrada aquifer, sandstone beds in the Chinle Formation, and the San Andres-Glorieta aquifer. Unconsolidated sand, silt, and gravel form a mantle ranging from a few inches to 150 to 200 feet over much of the bedrock in Cibola County. Well yields range from 5 to 1,110 gallons per minute. Dissolved-solids concentrations of ground water range from 200 to more than 5,200 milligrams per liter. Calcium, magnesium, bicarbonate, and sulfate are the predominant ions in ground water in alluvial material. The Mesaverde Group mainly occurs in three areas of the county. Well yields range from less than 1 to 12 gallons per minute. The predominant ions in water from wells in the Mesaverde Group are calcium, sodium, and bicarbonate. The transition from calcium-predominant to sodium-predominant water in the southwestern part of the county likely is a result of ion exchange. Wells completed in the Dakota-Zuni-Bluff aquifer yield from 1 to 30 gallons per minute. Dissolved-solids concentrations range from 220 to 2,000 milligrams per liter in water from 34 wells in the western part of the county. Predominant ions in the ground water include calcium, sodium, sulfate, and bicarbonate. Calcium predominates in areas where the aquifer is exposed at the surface or is overlain with alluvium. Sandstones in the Chinle Formation yield from 10 to 300 gallons per minute to wells in the Grants-Bluewater area. In the western part of the county, sodium and bicarbonate predominate in water from the Chinle Formation. In the eastern part of the county, water quality is more variable than elsewhere and the predominant constituents include calcium, sodium, sulfate, and chloride. Well yields from the San Andres-Glorieta aquifer in the Grants- Bluewater area are as much as 2,830 gallons per minute, whereas the maximum recorded pumping rate from the aquifer in other areas of the county is 88 gallons per minute. Dissolved-solids concentrations of ground-water range from about 130 to 4,200 milligrams per liter, and the water generally is a calcium bicarbonate sulfate type.

Stratigraphy of a proposed wind farm site southeast of Block Island: Utilization of borehole samples, downhole logging, and seismic profiles

NASA Astrophysics Data System (ADS)

Sheldon, Dane P. H.

Seismic stratigraphy, sedimentology, lithostratigraphy, downhole geophysical logging, mineralogy, and palynology were used to study and interpret the upper 70 meters of the inner continental shelf sediments within a proposed wind farm site located approximately two to three nautical miles to the southeast of Block Island, Rhode Island. Core samples and downhole logging collected from borings drilled for geotechnical purposes at proposed wind turbine sites along with seismic surveys in the surrounding area provide the data for this study. Cretaceous coastal plain sediments that consist of non-marine to marine sand, silt, and clay are found overlying bedrock at a contact depth beyond the sampling depth of this study. The upper Cretaceous sediments sampled in borings are correlated with the Magothy/Matawan formations described regionally from New Jersey to Nantucket. An unconformity formed through sub-aerial, fluvial, marine, and glacial erosion marks the upper strata of the Cretaceous sediments separating them from the overlying deposits. The majority of Quaternary deposits overlying the unconformity represent the advance, pulsing, and retreat of the Laurentide ice sheet that reached its southern terminus in the area of Block Island approximately 25,000 to 21,000 years before present. The sequence consists of a basal glacial till overlain by sediments deposited by meltwater environments ranging from deltaic to proglacial lakefloor. A late Pleistocene to early Holocene unconformity marks the top of the glacial sequence and was formed after glacial retreat through fluvial and subaerial erosion/deposition. Overlying the glacial sequence are sediments deposited during the late Pleistocene and Holocene consisting of interbedded gravel, sand, silt, and clay. Sampling of these sediments was limited and surficial reflectors in seismic profiles were masked due to a hard bottom return. However, two depositional periods are interpreted as representing fluvial and estuarine/marine environments respectively. One sample recovered at five meters contained shell fragments within a gray fine to coarse sand possibly representing a shallow estuarine to marine environment. A coarse near surface deposit described but not recovered in all borings may represent a transgressive unconformity and resulting lag deposit however due to lack of sampling and seismic resolution in the upper 5 meters, the nature of this deposit is merely speculation. In areas where depth to the glacial surface increased, sediments ranging from sand to fine-grained silt and clay were encountered in borings. In summary, the upper 70 meters of the inner continental shelf section within the study site consists of unconsolidated sediments spanning three major depositional periods. Sediments derived from glacial activity represent the bulk of samples collected. The glacial sequences represent various depositional environments, although most samples are interpreted to be the product of glacial meltwater deposition with distribution determined by source as well as highs and lows present in the antecedent topography. Finely laminated (varved) sediment to the south of Block Island indicates the presence of proglacial lakes in the area during the time of glacial retreat. Overlying sediments represent environments ranging from fluvial to marine.

Geologic effects of the March 1964 earthquake and associated seismic sea waves on Kodiak and nearby islands, Alaska: Chapter D in The Alaska earthquake, March 27, 1964: regional effects

USGS Publications Warehouse

Plafker, George; Kachadoorian, Reuben

1966-01-01

Kodiak Island and the nearby islands constitute a mountainous landmass with an aggregate area of 4,900 square miles that lies at the western border of the Gulf of Alaska and from 20 to 40 miles off the Alaskan mainland. Igneous and metamorphic rocks underlie most of the area except for a narrow belt of moderately to poorly indurated rocks bordering the Gulf of Alaska coast and local accumulations of unconsolidated alluvial and marine deposits along the streams and coast. The area is relatively undeveloped and is sparsely inhabited. About 4,800 of the 5,700 permanent residents in the area live in the city of Kodiak or at the Kodiak Naval Station. The great earthquake, which occurred on March 27, 1964, at 5:36 p.m. Alaska standard time (March 28,1964, 0336 Greenwich mean time), and had a Richter magnitude of 8.4-8.5, was the most severe earthquake felt on Kodiak Island and its nearby islands in modern times. Although the epicenter lies in Prince William Sound 250 miles northeast of Kodiak—the principal city of the area—the areal distribution of the thousands of aftershocks that followed it, the local tectonic deformation, and the estimated source area of the subsequent seismic sea wave, all suggest that the Kodiak group of islands lay immediately adjacent to, and northwest of, the focal region from which the elastic seismic energy was radiated. The duration of strong ground motion in the area was estimated at 2½ minutes. Locally, the tremors were preceded by sounds audible to the human ear and were reportedly accompanied in several places by visible ground waves. Intensity and felt duration of the shocks during the main earthquake and aftershock sequence varied markedly within the area and were strongly influenced by the local geologic environment. Estimated Mercalli intensities in most areas underlain by unconsolidated Quaternary deposits ranged from VIII to as high as IX. In contrast, intensities in areas of upper Tertiary rock ranged from VII to VIII, and in areas of relatively well indurated lower Tertiary and Mesozoic rocks, from VI to VII. Local subsidence of as much as 10 feet was widespread in noncohesive granular deposits through compaction, flow, and sliding that resulted from vibratory loading during the earthquake. This phenomenon, which was largely restricted to saturated beach and alluvial deposits or artificial fill, was locally accompanied by extensive cracking of the ground and attendant ejection of water and water-sediment mixtures. Numerous landslides, including a wide variety of rockfalls, rockslides, and flows along steep slopes, were triggered by the long-duration horizontal and vertical accelerations during the earthquake. The landslides are most numerous in a narrow belt along the southeast coast of Kodiak Island and the nearby offshore islands. Their abundance appears to be related to an area underlain predominantly by Tertiary rocks. Temporary and permanent changes of level occurred after the earthquake in some wells, lakes, and streams throughout the area; ice was cracked, and the salinity of a few wells increased. Permanent change of water level at some localities appears to be related to readjustments of fracture porosity by earthquake-induced movements of bedrock blocks. Increased salinity of wells in coastal areas resulted from encroachment of seawater into aquifiers after subsidence during the earthquake, and to flooding of watersheds by seismic sea waves. Vertical displacements, both downward and upward, occurred throughout the area as a result of crustal warping along a northeast-trending axis. Most of Kodiak and all of Afognak, Shuyak, and adjacent islands are within a regional zone of subsidence whose trough plunges gently northeastward and approximately coincides with the mountainous backbone of Kodiak Island. Subsidence in excess of 6 feet occurred throughout the northern part of the zone-a maximum subsidence of 6½ feet having occurred on Marmot and, eastern Afognak Islands. Southeast of the axis of tectonic tilting, uplift of at least 2lh feet occurred in a narrow zone that includes most of the southeasterly capes of Kodiak Island, the southeastern half of Sitkalidak Island, and Sitkinak Island. The uplift is inferred to extend offshore over much or all of the continental shelf adjacent to the Kodiak group of islands. Within the affected area, tectonic subsidence, which was locally augmented by surficial subsidence of unconsolidated. deposits, caused widespread inundation of shorelines and attendant damage to intertidal organisms, nearshore terrestrial vegetation, and salmon-spawning areas. The most devastating effect of the earthquake on Kodiak Island and nearby islands resulted from seismic sea waves that probably originated along a linear zone of differential uplift in the Gulf of Alaska. A train of at least seven seismic sea waves, having initial periods of 50–55 minutes, struck along all the southeast coast of the island group from 38 to 63 minutes after the earthquake. The southeast shores were repeatedly washed by destructive waves having runup heights along exposed coasts of perhaps as much as 40 feet above existing tide level, and of 8–20 feet along protected shores. Runup heights of the waves were much less on the northwest and southwest sides of the islands, and no wave damage was incurred there. Locally, high-velocity currents that accompanied the waves caused intense erosion and redistribution of unconsolidated natural and artificial shore deposits and of shallow sea-floor deposits. The Alaska earthquake was the greatest natural catastrophe to befall the Kodiak Island area in historic time. The combination of seismic shock and the earthquake-related tectonic deformation and seismic sea waves took 18 lives, destroyed property worth about $45 million, and resulted in estimated losses of income to the fishing industry of an additional $5 million. Most of the damage and all of the loss of life were directly attributable to the seismic sea waves that crippled the city of Kodiak, wiped out the village of Kaguyak, and destroyed most of the village of Old Harbor and parts of the villages of Afognak and Uzinki. Bridges and segments of the highways in the vicinity of the city of Kodiak were washed out, and parts of the Kodiak Naval Station were inundated and damaged. Especially serious to all the damaged communities was the loss of fishing boats, seafood processing plants, and other waterfront installations, which had been the mainstay of the economy. Additional heavy losses resulted from the combined regional tectonic and local surficial subsidence that occurred during the earthquake. Widespread shoreline flooding by high tides necessitated raising, protecting, or removing many installations otherwise undamaged by the earthquake or waves. Structural damage attributable to seismic shock during the earthquake was relatively light and was restricted to areas underlain by saturated unconsolidated deposits. The chief structural failure in the area as a result of shaking was the collapse of part of a cannery built on saturated beach deposits that were partially liquefied during the earthquake. Minor structural damage resulted from differential settlement and cracking of the ground on natural granular deposits and artificial fills. The overwhelming majority of structures are constructed on indurated bedrock; none of these sustained damage other than small losses resulting from shifting about and breakage of their contents.

Poly(3,4-ethylenedioxythiophene)-Poly(styrenesulfonate) Interlayer Insertion Enables Organic Quaternary Memory.

PubMed

Cheng, Xue-Feng; Hou, Xiang; Qian, Wen-Hu; He, Jing-Hui; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei

2017-08-23

Herein, for the first time, quaternary resistive memory based on an organic molecule is achieved via surface engineering. A layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was inserted between the indium tin oxide (ITO) electrode and the organic layer (squaraine, SA-Bu) to form an ITO/PEDOT-PSS/SA-Bu/Al architecture. The modified resistive random-access memory (RRAM) devices achieve quaternary memory switching with the highest yield (∼41%) to date. Surface morphology, crystallinity, and mosaicity of the deposited organic grains are greatly improved after insertion of a PEDOT-PSS interlayer, which provides better contacts at the grain boundaries as well as the electrode/active layer interface. The PEDOT-PSS interlayer also reduces the hole injection barrier from the electrode to the active layer. Thus, the threshold voltage of each switching is greatly reduced, allowing for more quaternary switching in a certain voltage window. Our results provide a simple yet powerful strategy as an alternative to molecular design to achieve organic quaternary resistive memory.

A conceptual model for groundwater - surface water interactions in the Darling River Floodplain, N.S.W., Australia

NASA Astrophysics Data System (ADS)

Brodie, R. S.; Lawrie, K.; Somerville, P.; Hostetler, S.; Magee, J.; Tan, K. P.; Clarke, J.

2013-12-01

Multiple lines of evidence were used to develop a conceptual model for interaction between the Darling River and associated floodplain aquifers in western New South Wales, Australia. Hydrostratigraphy and groundwater salinities were mapped using airborne electromagnetics (AEM), validated by sonic-core drilling. The AEM was highly effective in mapping groundwater freshening due to river leakage in discrete zones along the river corridor. These fresh resources occurred in both the unconfined Quaternary aquifers and the underlying, largely semi-confined Pliocene aquifers. The AEM was also fundamental to mapping the Blanchetown Clay aquitard which separates these two aquifer systems. Major-ion chemistry highlighted a mixing signature between river waters and groundwaters in both the Quaternary and Pliocene aquifers. Stable isotope data indicates that recharge to the key Pliocene aquifers is episodic and linked to high-flow flood events rather than river leakage being continuous. This was also evident when groundwater chemistry was compared with river chemistry under different flow conditions. Mapping of borehole levels showed groundwater mounding near the river, emphasising the regional significance of losing river conditions for both aquifer systems. Critically, rapid and significant groundwater level responses were measured during large flood events. In the Pliocene aquifers, continuation of rising trends after the flood peak receded confirms that this is an actual recharge response rather than hydraulic loading. The flow dependency of river leakage can be explained by the presence of mud veneers and mineral precipitates along the Darling River channel bank when river flows are low. During low flow conditions these act as impediments to river leakage. During floods, high flow velocities scour these deposits, revealing lateral-accretion surfaces in the shallow scroll plain sediments. This scouring allows lateral bank recharge to the shallow aquifer. During flood recession, mud veneers are re-deposited while transient return flows from bank storage results in carbonate precipitation in river banks. Active recharge of the Pliocene aquifers requires leakage pathways through the overlying Blanchetown Clay. Neogene-to-Present tectonic modification of the alluvial sequence, including discrete fault offsets in the Blanchetown Clay, was identified in the AEM data. Mapped faults are coincident with structures mapped in LiDAR, airborne magnetics, regional gravity, and seismic data.The study highlighted the utility of AEM in mapping the critical geological controls on groundwater-surface interaction, including the previously unrecognised tectonic influences on the largely unconsolidated alluvial sequence. Flow-dependent recharge due to changing river bed conductance has implications for groundwater assessment and management. An analysis of historic river flows suggests that active recharge would only occur for about 17% of the time when flow exceeds about 9,000 ML/d. Recharge would be negligible with groundwater extraction during low-flow conditions.

Qal'eh Hasan Ali maars, central Iran.

USGS Publications Warehouse

Milton, D.J.

1976-01-01

This group of some 15 Late Quaternary explosion craters are typical maars, with rims of bedded pyroclastics. In all but the largest crater, the deposits consist entirely of clasts of country rock (granodiorite and Eocene volcanics). The maars were formed by phreatomagmatic explosions, possibly caused by groundwater originating from a major river. The deposits of the largest maar contain up to 20% juvenile fragments of two types. Tephrite clasts have phenocrysts of phlogopite, clinopyroxene, olivine and anorthoclase; the presence of hauyne as a groundmass phase is notable. Cumulate blocks of phlogopite-clinopyroxene rock also occur. The maar field is part of a distinct province of Quaternary alkaline volcanism, related to a major crustal fracture - the N-S-trending Nayband fault.-R.J.S.

Late Quaternary transgressive large dunes on the sediment-starved Adriatic shelf

USGS Publications Warehouse

Correggiari, A.; Field, M.E.; Trincardi, F.

1996-01-01

The Adriatic epicontinental basin is a low-gradient shelf where the late-Quaternary transgressive systems tract (TST) is composed of thin parasequences of backbarrier, shoreface and offshore deposits. The facies and internal architecture of the late-Quaternary TST in the Adriatic epicontinental basin changed consistently from early transgression to late transgression reflecting: (1) fluctuations in the balance between sediment supply and accommodation increase, and (2) a progressive intensification of the oceanographic regime, driven by the transgressive widening of the basin to as much as seven times its lowstand extent. One of the consequences of this trend is that high-energy marine bedforms such as sand ridges and sand waves characterize only areas that were flooded close to the end of the late-Quaternary sea-level rise, when the wind fetch was maximum and bigger waves and stronger storm currents could form. We studied the morphology, sediment composition and sequence-stratigraphical setting of a field of asymmetric bedforms (typically 3 m high and 600 m in wavelength) in 20-24 m water depth offshore the Venice Lagoon in the sediment-starved North Adriatic shelf. The sand that forms these large dunes derived from a drowned transgressive coastal deposit reworked by marine processes. Early cementation took place over most of the dune crests limiting their activity and preventing their destruction. Both the formation and deactivation of this field of sand dunes occurred over a short time interval close to the turn-around point that separates the late-Quaternary sea-level rise and the following highstand and reflect rapid changes in the oceanographic regime of the basin.

Holocene Indian Ocean Cosmic Impacts: The Megatsunami Chevron Evidence From Madagascar

NASA Astrophysics Data System (ADS)

Masse, W.; Bryant, E.; Gusiakov, V.; Abbott, D.; Rambolamana, G.; Raza, H.; Courty, M.; Breger, D.; Gerard-Little, P.; Burckle, L.

2006-12-01

The 2.6 million year Quaternary period terrestrial physical record lacks definitive crater evidence for major regional catastrophic impacts by asteroids and comets other than the 10.5-km diameter Botsumtwi structure in Ghana and the 14.0-km diameter Zhamanshin structure in Kazakhstan [1] dating between about 900 and 1100 kya. Current cosmic impact rate models suggest that an average of between 3-6 globally catastrophic impacts should have occurred on the Earth during the Quaternary, along with several additional significant regional impacts in addition to Zhamanshin and Botsumtwi. These models and data indicate that the great majority of the "missing" major impact locations would likely have occurred in poorly studied oceanic settings. Only recently have Late Quaternary and Holocene period coastal paleo-megatsunami chevron deposits been defined in the Caribbean and along the western coasts of Australia, along with the suggestion that some may have been created by oceanic cosmic impacts in distinction to those caused by landslips, eruptions, and seismic events. We investigate the possibility that many or most megatsunami chevrons occurring along the southern coast of Madagascar were caused by two or more major Holocene Indian Ocean cosmic impacts. This hypothesis is based on an initial study of the worldwide archaeological and anthropological record, and the preliminary study of satellite images of the chevrons, selected Indian Ocean deep-sea cores, sea-floor bathymetry, and physical examination of the Madagascar deposits themselves. Candidate Indian Ocean impact structures are identified and correlated with the southern Madagascar megatsunami chevron deposits. [1] Masse, W.B. 2007 The Archaeology and Anthropology of Quaternary Period Cosmic Impact. In Bobrowsky, P.T. & Rickman, H. (eds.)Comets/Asteroid Impacts and Human Society. Springer, Berlin (in press).

Amplification of earthquake ground motions in Washington, DC, and implications for hazard assessments in central and eastern North America

USGS Publications Warehouse

Pratt, Thomas L.; Horton, J. Wright; Munoz, Jessica; Hough, Susan E.; Chapman, Martin C.; Olgun, C. Guney

2017-01-01

The extent of damage in Washington, DC, from the 2011 Mw 5.8 Mineral, VA, earthquake was surprising for an epicenter 130 km away; U.S. Geological Survey “Did-You-Feel-It” reports suggest that Atlantic Coastal Plain and other unconsolidated sediments amplified ground motions in the city. We measure this amplification relative to bedrock sites using earthquake signals recorded on a temporary seismometer array. The spectral ratios show strong amplification in the 0.7 to 4 Hz frequency range for sites on sediments. This range overlaps with resonant frequencies of buildings in the city as inferred from their heights, suggesting amplification at frequencies to which many buildings are vulnerable to damage. Our results emphasize that local amplification can raise moderate ground motions to damaging levels in stable continental regions, where low attenuation extends shaking levels over wide areas and unconsolidated deposits on crystalline metamorphic or igneous bedrock can result in strong contrasts in near-surface material properties.

Reconnaissance geology, mineral occurrences, and geochemical anomalies of the Yentna district, Alaska

USGS Publications Warehouse

Clark, Allen L.; Hawley, C.C.

1968-01-01

The Yentna district, in south-central Alaska, is underlain by slightly metamorphosed Mesozoic sedimentary rocks, and by sandstones, conglomerates and coaly minerals of the Tertiary Kenai Formation. The bedrock is locally covered by extensive surficial deposits of Quaternary and Recent (Holocene) age. The Mesozoic strata are cut by a quartz monzonite batholith in the Tokositna Mountains and by alaskitic dikes and plugs in the Peters and Dutch Hills. A silica-carbonate dike, which formed by alteration of a mafic or ultramafic dike, was noted in the Peters Hills. The major ore deposits are gold placer deposits of several types, including stream and bench deposits of Recent (Holocene) age, glacial-fluviatile deposits of Quaternary age, and conglomerates of Tertiary age. Quartz-rich conglomerates and breccias have also been productive and are interesting and controversial genetically. The present study indicates that they are closely related to shear zones containing quartz veins and highly altered rocks; previously the origin of the associated altered rocks had been ascribed to deep weathering. The report also contains descriptions of a few gold lode prospects and of geochemically anomalous areas such as those at Bunco Creek and near Mount Goldie.

Epiguruk: a late Quaternary environmental record from northwestern Alaska

USGS Publications Warehouse

Hamilton, T.D.; Ashley, G.M.

1993-01-01

Epiguruk, a prominent bluff along the Kobuk River in northwestern Alaska, exposes a rich depositional record of Quaternary eolian and fluvial sand, with associated loess, paleosols, and periglacial features. Three major complexes of alluvial and eolian deposits are separated by two conspicuous organic-rich paleosols which formed during cool-moist interstadial intervals. Sediments between the two paleosols include eolian, channel, and floodplain deposits that formed during alluviation of the Kobuk River to a height of about 12m above the present level. The youngest depositional complex, which overlies the upper paleosol, is divisible into late Wisconsinan and Holocene components and into fluvial-channel, flood-plain, eolian-dune, sand-sheet, loess, and pond facies. Eolian sand from the active Kobuk sand sea overloaded the river during late Wisconsinan time, causing it to alluviate to about 13m above its modern level. The Holocene record reflects erosion and deposition by a small southern Tributary to the Kobuk River, downcutting by the Kobuk River toward its modern level, and subsequent erosion across a meander belt nearly 8km wide. 66 radiocarbon ages, many from rooted shrubs, provide a firm chronology for the past 35 k.y. at Epiguruk. -from Authors

Aminostratigraphy of surface and subsurface Quaternary sediments, North Carolina coastal plain, USA

USGS Publications Warehouse

Wehmiller, John F.; Thieler, E. Robert; Miller, D.; Pellerito, V.; Bakeman, Keeney V.; Riggs, S.R.; Culver, S.; Mallinson, D.; Farrell, K.M.; York, L.L.; Pierson, J.; Parham, P.R.

2010-01-01

The Quaternary stratigraphy and geochronology of the Albemarle Embayment of the North Carolina (NC) Coastal Plain is examined using amino acid racemization (AAR) in marine mollusks, in combination with geophysical, lithologic, and biostratigraphic analysis of 28 rotasonic cores drilled between 2002 and 2006. The Albemarle Embayment is bounded by structural highs to the north and south, and Quaternary strata thin westward toward the Suffolk paleoshoreline, frequently referred to as the Suffolk Scarp. The Quaternary section is up to ∼90 m thick, consists of a variety of estuarine, shelf, back-barrier, and lagoonal deposits, and has been influenced by multiple sea-level cycles. The temporal resolution of the amino acid racemization method is tested statistically and with the stratigraphic control provided by this geologic framework, and it is then applied to the correlation and age estimation of subsurface units throughout the region. Over 500 specimens (primarily Mercenaria and Mulinia) from the subsurface section have been analyzed using either gas chromatographic (GC) or reverse-phase liquid chromatographic (RPLC) techniques. The subsurface stratigraphic data are compared with AAR results from numerous natural or excavated exposures from the surrounding region, as well as results from NC beach collections, to develop a comprehensive aminostratigraphic database for the entire Quaternary record within the NC coastal system. Age mixing, recognized in the beach collections, is also seen in subsurface sections, usually where major seismic reflections or core lithology indicate the presence of stratigraphic discontinuities. Kinetic models for racemization are tested within the regional stratigraphic framework, using either radiocarbon or U-series calibrations or comparison with regional biostratigraphy. Three major Pleistocene aminozones [AZ2, AZ3, and AZ4] are found throughout the region, all being found in superposition in several cores. Each can be subdivided, yielding a total of at least eight stratigraphically and statistically distinct aminozones. Kinetic modeling, supplemented with local calibration, indicates that these aminozones represent depositional events ranging from ∼80 ka to nearly 2 Ma. Three prominent seismic reflections are interpreted to represent the base of the early, middle, and late Pleistocene, respectively, roughly 2 Ma, 800 ka, and 130 ka. The large number of samples and the available stratigraphic control provide new insights into the capabilities and limitations of aminostratigraphic methods in assessing relative and numerical ages of Atlantic Coastal Plain Quaternary deposits.

Quaternary sea level high-stand deposits of the southeast U.S. Atlantic Coastal Plain: Age, distribution, and implications.

NASA Astrophysics Data System (ADS)

Poirier, R. K.; Cronin, T. M.; Ghaleb, B.; Portell, R.; Hillaire-Marcel, C.; Wehmiller, J. F.; Thompson, W. G.; Oches, E. A.; Willard, D. A.; Katz, M. E.

2015-12-01

Emerged Quaternary paleo-shorelines and marine deposits provide a more direct way to reconstruct and analyze sea-level variability than methods using oxygen isotope analyses of deep ocean benthic foraminifera. New Uranium-series dates on fossil corals (primarily Astrangia spp. and Septastrea spp.) combined with previously published dates have allowed us to constrain the age, elevation, and geographical distribution of marine sediments deposited in the United States Atlantic Coastal Plain (ACP) from Virginia to Florida during periods of past high relative sea level (SL). We present new dates from deposits (VA/NC: Tabb/Norfolk, Nassawadox, & Omar Formations; SC: Wando, Socastee, & Canepatch Formations; FL: Anastasia, Ft. Thompson, & Bermont Formations) representing interglacial high-stands during Marine Isotope Stages (MIS) 5, 7, 9, and 11. In addition, we incorporate stratigraphic, marine micropaleontologic, and palynologic records with our SL chronology to reconstruct a more complete history of middle-to-late Pleistocene interglacial climates of the ACP. Ultimately, these results will test modeled sea-level fingerprint studies based on various melting scenarios of the Greenland and/or Antarctic ice sheets.

Three-Dimensional Grain Shape-Fabric from Unconsolidated Pyroclastic Density Current Deposits: Implications for Extracting Flow Direction and Insights on Rheology

NASA Astrophysics Data System (ADS)

Hawkins, T. T.; Brand, B. D.; Sarrochi, D.; Pollock, N.

2016-12-01

One of the greatest challenges volcanologists face is the ability to extrapolate information about eruption dynamics and emplacement conditions from deposits. Pyroclastic density current (PDC) deposits are particularly challenging given the wide range of initial current conditions, (e.g., granular, fluidized, concentrated, dilute), and rapid flow transformations due to interaction with evolving topography. Analysis of particle shape-fabric can be used to determine flow direction, and may help to understand the rheological characteristics of the flows. However, extracting shape-fabric information from outcrop (2D) apparent fabric is limited, especially when outcrop exposure is incomplete or lacks context. To better understand and quantify the complex flow dynamics reflected in PDC deposits, we study the complete shape-fabric data in 3D using oriented samples. In the field, the prospective sample is carved from the unconsolidated deposit in blocks, the dimensions of which depend on the average clast size in the sample. The sample is saturated in situ with a water-based sodium silicate solution, then wrapped in plaster-soaked gauze to form a protective cast. The orientation of the sample is recorded on the block faces. The samples dry for five days and are then extracted in intact blocks. In the lab, the sample is vacuum impregnated with sodium silicate and cured in an oven. The fully lithified sample is first cut along the plan view to identify orientations of the long axes of the grains (flow direction), and then cut in the two plains perpendicular to grain elongation. 3D fabric analysis is performed using high resolution images of the cut-faces using computer assisted image analysis software devoted to shape-fabric analysis. Here we present the results of samples taken from the 18 May 1980 PDC deposit facies, including massive, diffuse-stratified and cross-stratified lapilli tuff. We show a relationship between the strength of iso-orientation of the elongated particles and different facies architectures, which is used to interpret rheological conditions of the flow. We chose the 18 May PDC deposits because their well-exposed and well-studied outcrops provide context, which allow us to test the method and extract information useful for interpreting ancient deposits that lack context.

Origin of Bermuda's clay-rich Quaternary paleosols and their paleoclimatic significance

USGS Publications Warehouse

Herwitz, S.R.; Muhs, D.R.; Prospero, J.M.; Mahan, S.; Vaughn, B.

1996-01-01

Red clayey paleosols that are chiefly the product of aerosolic dust deposition are interbedded in the Quaternary carbonate formations of the Bermuda oceanic island system. These paleosols provide a basis for reconstructing Quaternary atmospheric circulation patterns in the northwestern Atlantic. Geochemical analyses were performed on representative paleosol samples to identify their parent dust source. Fine-grained fractions were analyzed by energy-dispersive X ray fluorescence to determine trace element (Zr, Y, La, Ti, and Nb) concentrations and to derive geochemical signatures based on immobile element ratios. These ratios were compared with geochemical signatures determined for three possible sources of airborne dust: (1) Great Plains loess, (2) Mississippi River Valley loess, and (3) Saharan dust. The Zr/Y and Zr/La ratios provided the clearest distinction between the hypothesized dust sources. The low ratios in the paleosol B horizons most closely resemble Saharan dust in the <2-??m size class fraction. Contributions from the two North American loessial source areas could not be clearly detected. Thus Bermuda paleosols have a predominantly Saharan aerosolic dust signature. Saharan dust deposition on Bermuda during successive Quaternary glacial periods is consistent with patterns of general circulation models, which indicate that during glacial maxima the northeast summer trade winds were stronger than at present and reached latitudes higher than 30 ?? N despite lower-than-present sea surface temperatures in the North Atlantic.

Quaternary extensional growth folding beneath Reno, Nevada, imaged by urban seismic profiling

USGS Publications Warehouse

Stephenson, William J.; Frary, Roxy N.; Louie, John; Odum, Jackson K.

2013-01-01

We characterize shallow subsurface faulting and basin structure along a transect through heavily urbanized Reno, Nevada, with high‐resolution seismic reflection imaging. The 6.8 km of P‐wave data image the subsurface to approximately 800 m depth and delineate two subbasins and basin uplift that are consistent with structure previously inferred from gravity modeling in this region of the northern Walker Lane. We interpret two primary faults that bound the uplift and deform Quaternary deposits. The dip of Quaternary and Tertiary strata in the western subbasin increases with greater depth to the east, suggesting recurrent fault motion across the westernmost of these faults. Deformation in the Quaternary section of the western subbasin is likely evidence of extensional growth folding at the edge of the Truckee River through Reno. This deformation is north of, and on trend with, previously mapped Quaternary fault strands of the Mt. Rose fault zone. In addition to corroborating the existence of previously inferred intrabasin structure, these data provide evidence for an active extensional Quaternary fault at a previously unknown location within the Truckee Meadows basin that furthers our understanding of both the seismotectonic framework and earthquake hazards in this urbanized region.

Quaternary Sea-Level History from the US Atlantic Coastal Plain

NASA Astrophysics Data System (ADS)

Poirier, R. K.; Cronin, T. M.; Katz, M. E.; Browning, J. V.; Miller, K. G.; Willard, D. A.

2014-12-01

Analyses of emerged Quaternary paleo-shorelines and marine deposits aid in the reconstruction of environmental conditions and variability surrounding recent ice volume and sea-level histories derived from oxygen isotope records. We present preliminary results from a project designed to analyze the age, elevation, and paleoclimate history of Quaternary sediments deposited during sea level highstands along the United States Atlantic Coastal Plain (ACP) from Maryland to Florida. Prior studies have shown that, depending on the region, ACP sediments correlate with past interglacial periods corresponding to Marine Isotope Stages (MIS) 5, 7, possibly 9, and 11. Stratigraphy, marine micropaleontology, and palynology indicate at least two major marine transgressive sequences on the Delmarva Peninsula in Virginia corresponding to MIS 5a and 11, the Nassawadox Formation and Accomack beds of the Omar Formation, respectively. These depositional sequences represent sea-level positions of approximately +10m and +15m, relative to today. Despite generally corresponding to glacio-eustatic sea levels of +5-9m for MIS 5a-e (Potter & Lambeck, 2003; Kopp et al., 2009), and of +6-13m for MIS 11 (Raymo & Mitrovica, 2012), the relative sea-level positions during both interglacial periods were likely affected by glacio-isostatic adjustment in the region. Corresponding marine units and paleo-shorelines, identified by pronounced inland scarps separated by intermittent terraces on the western side of the Chesapeake Bay, are likely from MIS 5, 7, and 11. Ostracode and foraminifera assemblages identify significant environmental variability within these transgressive interglacial deposits, likely driven by relatively minor, suborbital climatic and sea-level oscillations.

A solution-processed quaternary oxide system obtained at low-temperature using a vertical diffusion technique

PubMed Central

Yoon, Seokhyun; Kim, Si Joon; Tak, Young Jun; Kim, Hyun Jae

2017-01-01

We report a method for fabricating solution-processed quaternary In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) at low annealing temperatures using a vertical diffusion technique (VDT). The VDT is a deposition process for spin-coating binary and ternary oxide layers consecutively and annealing at once. With the VDT, uniform and dense quaternary oxide layers were fabricated at lower temperatures (280 °C). Compared to conventional IGZO and ternary In-Zn-O (IZO) thin films, VDT IGZO thin film had higher density of the metal-oxide bonds and lower density of the oxygen vacancies. The field-effect mobility of VDT IGZO TFT increased three times with an improved stability under positive bias stress than IZO TFT due to the reduction in oxygen vacancies. Therefore, the VDT process is a simple method that reduces the processing temperature without any additional treatment for quaternary oxide semiconductors with uniform layers. PMID:28230088

A solution-processed quaternary oxide system obtained at low-temperature using a vertical diffusion technique

NASA Astrophysics Data System (ADS)

Yoon, Seokhyun; Kim, Si Joon; Tak, Young Jun; Kim, Hyun Jae

2017-02-01

We report a method for fabricating solution-processed quaternary In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) at low annealing temperatures using a vertical diffusion technique (VDT). The VDT is a deposition process for spin-coating binary and ternary oxide layers consecutively and annealing at once. With the VDT, uniform and dense quaternary oxide layers were fabricated at lower temperatures (280 °C). Compared to conventional IGZO and ternary In-Zn-O (IZO) thin films, VDT IGZO thin film had higher density of the metal-oxide bonds and lower density of the oxygen vacancies. The field-effect mobility of VDT IGZO TFT increased three times with an improved stability under positive bias stress than IZO TFT due to the reduction in oxygen vacancies. Therefore, the VDT process is a simple method that reduces the processing temperature without any additional treatment for quaternary oxide semiconductors with uniform layers.

A solution-processed quaternary oxide system obtained at low-temperature using a vertical diffusion technique.

PubMed

Yoon, Seokhyun; Kim, Si Joon; Tak, Young Jun; Kim, Hyun Jae

2017-02-23

We report a method for fabricating solution-processed quaternary In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) at low annealing temperatures using a vertical diffusion technique (VDT). The VDT is a deposition process for spin-coating binary and ternary oxide layers consecutively and annealing at once. With the VDT, uniform and dense quaternary oxide layers were fabricated at lower temperatures (280 °C). Compared to conventional IGZO and ternary In-Zn-O (IZO) thin films, VDT IGZO thin film had higher density of the metal-oxide bonds and lower density of the oxygen vacancies. The field-effect mobility of VDT IGZO TFT increased three times with an improved stability under positive bias stress than IZO TFT due to the reduction in oxygen vacancies. Therefore, the VDT process is a simple method that reduces the processing temperature without any additional treatment for quaternary oxide semiconductors with uniform layers.

Climatic, geomorphic, and archaeological implications of a late Quaternary alluvial chronology for the lower Salt River, Arizona, USA

NASA Astrophysics Data System (ADS)

Huckleberry, Gary; Onken, Jill; Graves, William M.; Wegener, Robert

2013-03-01

Recent archaeological excavations along the lower Salt River, Arizona resulted in the unexpected discovery of buried late Pleistocene soils and cultural features dating 5800-7100 cal YBP (Early Archaic), the latter representing the earliest evidence of human activity in the lower Salt River floodplain thus far identified. Because the lower Salt River floodplain has been heavily impacted by recent agriculture and urbanization and contains few stratigraphic exposures, our understanding of the river's geological history is limited. Here we present a late Quaternary alluvial chronology for a segment of the lower Salt River based on 19 accelerator mass spectrometry 14C and four optically stimulated luminescence ages obtained during two previous geoarchaeological investigations. Deposits are organized into allostratigraphic units and reveal a buried late Pleistocene terrace inset into middle-to-late Pleistocene terrace deposits. Holocene terrace fill deposits unconformably cap the late Pleistocene terrace tread in the site area, and the lower portion of this fill contains the Early Archaic archaeological features. Channel entrenchment and widening ~ 900 cal YBP eroded much of the older terrace deposits, leaving only a remnant of fill containing the buried latest Pleistocene and middle-to-late Holocene deposits preserved in the site area. Subsequent overbank deposition and channel filling associated with a braided channel system resulted in the burial of the site by a thin layer of flood sediments. Our study confirms that the lower Salt River is a complex mosaic of late Quaternary alluvium formed through vertical and lateral accretion, with isolated patches of buried soils preserved through channel avulsion. Although channel avulsion is linked to changes in sediment load and discharge and may have climatic linkages, intrinsic geomorphic and local base level controls limit direct correlations of lower Salt River stratigraphy to other large rivers in the North American Southwest.

Quaternary sedimentation of the Alaskan Beaufort shelf: Influence of regional tectonics, fluctuating sea levels, and glacial sediment sources

USGS Publications Warehouse

Dinter, D.A.

1985-01-01

The offshore stratigraphy of the Quaternary Gubik Formation of Arctic Alaska has been studied on high-resolution seismic profiles with a maximum sub-seafloor penetration of about 100 m. In general, marine transgressive subunits of the Gubik Formation are wedge-shaped on the shelf, thickening slightly seaward to the shelf break, beyond which they are offset by landslides and slumps. Beneath the eastern third of the Alaskan Beaufort shelf, active folding has created two persistent structural depressions, the Eastern and Western Wedge Terranes, in which the wedge morphology is especially well developed. The youngest transgressive marine wedge, which was deposited in such a way as to fill these depressions, leaving a generally flat present-day shelf surface, is inferred to be late Wisconsin or younger in age because it overlies a prominent disconformity interpreted to have been formed during the late Wisconsin glacial sea-level minimum. The thickness of this youngest wedge, Unit A, locally exceeds 40 m on the outer shelf, yet apparently relict gravel deposits collected from its seabed surface indicate that the depositional rate is presently quite low on the middle and outer shelf. Lithologies of the gravels are exotic to Alaska, but similar to suites exposed in the Canadian Arctic Islands. These observations suggest a depositional scenario in which the retreating Laurentide Ice Sheet shed sediment-laden icebergs from the Canadian Arctic Islands into the Arctic Ocean following the late Wisconsin glacial maximum. These bergs were then rafted westward by the Beaufort Gyre and grounded on the Alaskan shelf by northeasterly prevailing winds. Especially large numbers of bergs accumulated in the wedge terrane embayments-created as sea level rose-and melted there, filling the embayments with their sedimentary cargo. As glacial retreat slowed, depositional rates on the shelf dwindled. This mode of deposition in the Alaskan Beaufort wedge terranes may be typical of early post-glacial transgressive phases throughout Quaternary time. It has resulted in the preservation of disconformities that apparently formed during glacioeustatic lowstands, and whose seaward termination depths, appropriately corrected, may yield estimates of lowstand magnitudes. Knowledge of global sea-level fluctuations back through the Sangamon Interglacial (oxygen isotope stage 5e) and possible correlations with dated onshore deposits have facilitated a tentative correlation of major disconformities in the Beaufort Sea record with major 18O enrichment maxima in the oxygen isotope curve back through stage 8. In this tentative scheme, close similarities between the two data sets occur both in magnitudes and in numbers of fluctuations intervening between major correlation points. Further testing of the Quaternary depositional model suggested here and of the resulting sea level curve awaits the collection and dating of core samples from the Beaufort wedge terranes. ?? 1985.

Effects of the earthquake of March 27, 1964, on various communities: Chapter G in The Alaska earthquake, March 27, 1964: effects on communities

USGS Publications Warehouse

Plafker, George; Kachadoorian, Reuben; Eckel, Edwin B.; Mayo, Lawrence R.

1969-01-01

The 1964 earthquake caused wide-spread damage to inhabited places throughout more than 60,000 square miles of south-central Alaska. This report describes damage to all communities in the area except Anchorage, Whittier, Homer, Valdez, Seward, the communities of the Kodiak group of islands, and communities in the Copper River Basin; these were discussed in previous chapters of the Geological Survey's series of reports on the earthquake. At the communities discussed herein, damage resulted primarily from sea waves of diverse origins, displacements of the land relative to sea level, and seismic shaking. Waves took all of the 31 lives lost at those communities; physical damage was primarily from the waves and vertical displacements of the land relative to sea level. Destructive waves of local origin struck during or immediately after the earthquake throughout much of Prince William Sound, the southern Kenai Peninsula, and the shores of Kenai Lake. In Prince William Sound, waves demolished all but one home at the native village of Chenega, destroyed homesites at Point Nowell and Anderson Bay, and caused varying amounts of damage to waterfront facilities at Sawmill Bay, Latouche, Port Oceanic, Port Nellie Juan, Perry Island, and western Port Valdez. The local waves, which ran up as high as 70 feet above tide level at Chenega and more than 170 feet in several uninhabited parts of the Sound, took nearly all of the lives lost by drowning at these communities. Destructive local waves that devastated shores of Anderson Bay and adjacent parts of western Port Valdez probably were generated primarily by massive submarine slides of glacial and fluvioglacial deposits ; the origin of the waves that caused damage at most of the other communities and at extensive uninhabited segments of shoreline is not known. At these places the most probable generative mechanisms are: unidentified submarine slides of unconsolidated deposits, and (or) the horizontal tectonic displacements, of 20 to more than 60 feet, that occurred in the Prince William Sound region during the earthquake. A train of long-period seismic sea waves that began about 20 minutes after the start of the earthquake inundated shores along the Gulf of Alaska coast to a maximum height of 35 feet above tide level. At the communities described, they virtually destroyed two logging camps at Whidbey Bay and Puget Bay on the south coast of the Kenai Peninsula, caused moderate damage to boat harbors and docks at Seldovia and Cordova, floated away some beach cabins in the Cordova area, and drowned two people, one at Point Whitshed near Cordora and one at the Cape Saint Elias Light Station. The seismic sea waves were generated by regional tectonic uplift of the sea floor on the Continental Shelf. Vertical tectonic displacements of the land relative to sea level that accompanied the earthquake affected virtually all the coastal communities. Tectonic subsidence of 5 to 6 feet, augmented locally by surficial subsidence of unconsolidated deposits required either the relocation or raising of structures at Portage, Girdwood, and Hope on Turnagain Arm. Shoreline submergence resulting from about 3½ feet of tectonic subsidence at Seldovia necessitated raising all waterfront facilities and the airstrip above the level of high tides. On the other hand, tectonic uplift of the land in the Prince Williams Sound region required deepening of the small-boat harbors at Cordora and Tatitlek, dredging of the waterways in the Cordova area, and lengthening of some docks or piers at Cordova, the Cape Hinchinbrook Light Station, and in Sawmill Bay. Significant structural damage from direct seismic shaking was largely confined to fluid containers and a pier facility near Kenai. Indirect damage from fissuring and differential settling of foundation mterials in the vicinity of the Cordova airfield mused damage to a building, underground utilities, an airfield fill, and the highway. Minor amounts of direct and indirect damage from seismic vibrations were sustained by most of the communities situated on unconsolidated deposits as far east as Yakutat, north to Fairbanks, and west to King Salmon. Except for a few cracked or toppled chimney, all the damage from shaking was confined to areas of thick, unconsolidated deposits. Foundation damage was almost entirely restricted to water-saturated unconsolidated deposits which, when liquefied by seismic shaking, could spread laterally toward free faces and (or) settle differentially through compaction.

Characteristics of a young lava-hyaloclastite sheet, Snaebylisheidi, Iceland

NASA Astrophysics Data System (ADS)

White, J. D.; Gorny, C. F.; Gudmundsson, M. T.

2009-12-01

Extensive sheets of hyaloclastite volcaniclastic debris, coupled with and intruded by largely underlying layers of coherent basalt, are common in the Sida area of southeastern Iceland. They were initially interpreted as submarine deposits, but have recently been re-interpreted as nonmarine deposits formed in the presence of glaciers. Detailed interpretation of the units has been challenging, because their source areas are not preserved. A younger deposit of the same type forms an elongate flat-topped ridge in the Snaebylisheidi area. Its volume of ca. 35 cubic km is similar to that of the larger Sida units, its source area is preserved, and parts of the deposit remain unlithified. Our initial investigation reveals that the source area is dominated by clastic deposits. There is no evidence for a source edifice of pillow or sheet lavas, but there are extensive low-level intrusions near the base, and a plexus of smaller high-level intrusions showing evidence of high viscosities during emplacement. Isolated pillows and other fluidal juvenile clasts near the source lie within matrices of highly vesicular ash and lapilli, or of mixed vesicular and dense glassy fragments. Downstream in the unit, deposits are dominated by dense clasts, and these can in places be demonstrated to have been derived locally from the underlying to intruding basalt sheet. Larger dense clasts are commonly highly irregular, vuggy, and composite; in places many are rolled into subspherical forms enclosing matrix material comprising dense angular glass fragments. The clastic part of the unit has an upper subunit dominated by well-developed bedding in complex geometries with multiple internal truncation surfaces. Lower subunits include thick structureless to alignment-bedded layers, along with intrusion-dominated zones. Soft-sediment deformation is ubiquitous along the edges of the deposit, with many layers broken and tilted to subvertical inclinations. Taken together, these features indicate that little or no lava accumulated at the source area during eruption, but that much basalt was intruded into unconsolidated volcaniclastic deposits. Coherent basalt sheets extended downslope from the source, perhaps largely as intrusions into earlier-deposited tephra, and produced much of the downstream clastic material by local fragmentation of the advancing sheet. Thick beds reflecting high accumulation rates are intercalated with groups of thinner beds formed by multiple depositional pulses. Deformation along deposit tops and edges records pervasive slumping of the unconsolidated deposits. The characteristics overall are suggestive of an initially explosive subglacial origin, with much of the unit emplaced subglacially. More work is underway to better understand the source eruption, and the way in which the basalt sheet was emplaced and associated volcaniclastic deposits produced and deposited.

Hydrogeologic reconnaissance of part of the headwaters area of the Price River, Utah

USGS Publications Warehouse

Cordova, Robert M.

1963-01-01

The area investigated comprises 33 square miles in the Price River drainage basin ad is in the High Plateaus section of Utah. Precipitation on most of the area ranges from about 20 to 23 inches per year, and the average annual precipitation for the entire area was assumed to be 22 inches, of which approximately 65 percent is lost by evapotranspiration. The geologic formations underlying the area are the Blackhawk and Price River Formations of Cretaceous age, the North Horn Formation of Cretaceous and Tertiary age, the Flagstaff Limestone and Colton Formation of tertiary age, and unconsolidated deposits of probable Quaternary age.Some ground water issues from springs and seeps and is used by stock and the cities of Price and Helper. The annual discharge from the springs and seeps in the area averages about 3,000 acre-feet. Two deep wells supply about 400 acre-feet per year for use at a steam-generating plant. The aquifers penetrated by the wells are in the Flagstaff Limestone and the North Horn formation, the deepest aquifer being about 1,500 feet below the land surface. Most of the ground water in the area is suitable for municipal and industrial use.The surface discharge from the area is approximately 6,000 acre-feet per year. By means of a water budget, it is calculated that approximately 4,000 acre-feet per year leaves the area by subsurface flow. Further development of ground water on a large scale can be accomplished only by the use of wells. It is possible, however, that part of any newly developed supply from wells may be drawn from existing spring discharge or streamflow.

Environmental setting of the Yellowstone River basin, Montana, North Dakota, and Wyoming

USGS Publications Warehouse

Zelt, Ronald B.; Boughton, G.K.; Miller, K.A.; Mason, J.P.; Gianakos, L.M.

1999-01-01

Natural and anthropogenic factors influence water-quality conditions in the Yellowstone River Basin. Physiography parallels the structural geologic setting that is generally composed of several uplifts and structural basins. Contrasts in climate and vegetation reflect topographic controls and the midcontinental location of the study unit. Surface-water hydrology reflects water surpluses in mountainous areas that are dominated by snowmelt runoff, and arid to semiarid conditions in the plains that are dissected by typically irrigated valleys in the remainder of the study unit. Principal shallow aquifers are Tertiary sandstones and unconsolidated Quaternary deposits. Human population, though sparsely distributed in general, is growing most rapidly in a few urban centers and resort areas, mostly in the northwestern part of the basin. Land use is areally dominated by grazing in the basins and plains and economically dominated by mineral-extraction activities. Forests are the dominant land cover in mountainous areas. Cropland is a major land use in principal stream valleys. Water use is dominated by irrigated agriculture overall, but mining and public-supply facilities are major users of ground water. Coal and hydrocarbon production and reserves distinguish the Yellowstone River Basin as a principal energy-minerals resources region. Current metallic ore production or reserves are nationally significant for platinum-group elements and chromium.The study unit was subdivided as an initial environmental stratification for use in designing the National Water-Quality Assessment Program investigation that began in 1997. Ecoregions, geologic groups, mineral-resource areas, and general land-cover and land-use categories were used in combination to define 18 environmental settings in the Yellowstone River Basin. It is expected that these different settings will be reflected in differing water-quality or aquatic-ecological characteristics.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2015

USGS Publications Warehouse

Beman, Joseph E.; Bryant, Christina F.

2016-10-27

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is hydrologically defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift between San Acacia to the south and Cochiti Lake to the north. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began treatment and distribution of surface water from the Rio Grande through the San Juan-Chama Drinking Water Project. A 20-percent population increase in the basin from 1990 to 2000 and a 22-percent population increase from 2000 to 2010 may have resulted in an increased demand for water in areas within the basin.An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the Albuquerque Basin. In 1983, this network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. The network currently (2015) consists of 124 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the ABCWUA, currently (2015) measures and reports water levels from the 124 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 124 sites through water year 2015 (October 1, 2014, through September 30, 2015).

Modeling saltwater intrusion in highly heterogeneous coastal aquifers

NASA Astrophysics Data System (ADS)

Safi, Amir; El-Fadel, Mutasem; Doummar, Joanna; Abou Najm, Majdi; Alameddine, Ibrahim

2016-04-01

In this study, a 3D variable-density flow and solute transport model SEAWAT was used to examine the impact of macroscopic variation in a soil matrix on widening or narrowing the thickness of the saltwater-freshwater mixing zone. Located along the Eastern Mediterranean (Beirut), the pilot aquifer consists of karstified limestone of Cretaceous age overlain by Upper Tertiary and Quaternary unconsolidated deposits. The model used the advanced pilot-points parameterization coupled with PEST to characterize spatial heterogeneity. Historically simulated water levels were relied upon to reduce potential numerical instabilities induced by insensitive parameters in transient calibration. The latter demonstrated a high degree of heterogeneity in the middle parts of the aquifer and along western coastlines with specification of a high hydraulic conductivity and low storativity in fault networks. The response of the aquifer to seasonal stresses such as climate cycles, pumping rates and recharge rates was manifested as high fluctuations in potentiometric surface due to potential fast flow pathways along faults. The final distribution of saltwater intrusion supports two mechanisms 1) lateral encroachment of recent seawater into the western zone of the aquifer which is of most concern due to high horizontal hydraulic conductivity in the wave direction and 2) upconing in the northwest and southwest of the aquifer due to large vertical hydraulic conductivities that tend to exacerbate the vertical movement of salinity. Acknowledgments This study is part of a program on climate change and seawater intrusion along the Eastern Mediterranean funded by the International Development Research Center (IDRC) of Canada at the American University of Beirut (AUB). Special thanks are extended to Dr. Charlotte Macalister at IDRC for her support and feedback in implementing this program.

Gigantic landslides versus glacial deposits: on origin of large hummock deposits in Alai Valley, Northern Pamir

NASA Astrophysics Data System (ADS)

Reznichenko, Natalya

2015-04-01

As glaciers are sensitive to local climate, their moraines position and ages are used to infer past climates and glacier dynamics. These chronologies are only valid if all dated moraines are formed as the result of climatically driven advance and subsequent retreat. Hence, any accurate palaeoenvironmental reconstruction requires thorough identification of the landform genesis by complex approach including geomorphological, sedimentological and structural landform investigation. Here are presented the implication of such approach for the reconstruction of the mega-hummocky deposits formation both of glacial and landslide origin in the glaciated Alai Valley of the Northern Pamir with further discussion on these and similar deposits validity for palaeoclimatic reconstructions. The Tibetan Plateau valleys are the largest glaciated regions beyond the ice sheets with high potential to provide the best geological record of glacial chronologies and, however, with higher probabilities of the numerous rock avalanche deposits including those that were initially considered of glacial origin (Hewitt, 1999). The Alai Valley is the largest intermountain depression in the upper reaches of the Amudarja River basin that has captured numerous unidentified extensive hummocky deposits descending from the Zaalai Range of Northern Pamir, covering area in more than 800 km2. Such vast hummocky deposits are usually could be formed either: 1) glacially by rapid glacial retreat due to the climate signal or triggered a-climatically glacial changes, such as glacial surge or landslide impact, or 2) during the landslide emplacement. Combination of sediment tests on agglomerates forming only in rock avalanche material (Reznichenko et al., 2012) and detailed geomorphological and sedimentological descriptions of these deposits allowed reconstructing the glacial deposition in the Koman and Lenin glacial catchments with identification of two gigantic rock avalanches and their relation to this glacial deposits. Here are presented a new data on: parameters, extent and probable source for Lenin rock avalanche, travelled 24 km from the back wall of the Lenin Glacier over the glacial Achiktash hummock deposit covering more than 35 km2; updated data on Koman rock avalanche deposit, such as its extend and source; the first reconstruction of the Achiktash glacial material deposition with proposed landscape evolution during recent Quaternary in respect to the large landslide in the catchment. Hewitt, K., 1999. Quaternary moraines vs. catastrophic rock avalanches in the Karakoram Himalaya, Northern Pakistan. Quaternary Research, v. 51, p. 220-237. Reznichenko, N.V., Davies, T.R.H., Shulmeister, J. and Larsen S.H, 2012. A new technique for identifying rock-avalanche-sourced sediment in moraines and some paleoclimatic implications. Geology, v. 40, p. 319-322.

Analysis and characterization of Cu2CdSnS4 quaternary alloy nanostructures deposited on GaN

NASA Astrophysics Data System (ADS)

Odeh, Ali Abu; Al-Douri, Y.; Ameri, M.; Bouhemadou, A.

2018-06-01

Through using spin coating technique, Cu2CdSnS4 (CCTS) quaternary alloy nanostructures were successfully deposited on GaN substrate using a wide range of spin coating speeds; 1500, 2000, 2500, 3000 and 3500 RPM at annealing temperature 300 °C. The optical properties were investigated through UV-vis which revealed the changing of energy band gap as the spin coating speed increases, in addition, to verify specific models of refractive index and optical dielectric constant. The structural properties were studied by X-ray diffraction which indicated that the number and intensity of the peaks were changed as the spin coating speed changes. The morphological and topographical studies of CCTS were elaborated by field emission-scanning electron microscopy and atomic force microscopy. The obtained results suggest that CCTS nanostructures deposited on GaN substrate are very suitable for optoelectronic applications, that are in accordance with the available theoretical and experimental data.

Fossil organic matter characteristics in permafrost deposits of the northeast Siberian Arctic

Treesearch

Lutz Schirrmeister; Guido Grosse; Sebastian Wetterich; Pier Paul Overduin; Jens Straub; Edward A.G. Schuur; Hans-Wolfgang Hubberton

2011-01-01

Permafrost deposits constitute a large organic carbon pool highly vulnerable to degradation and potential carbon release due to global warming. Permafrost sections along coastal and river bank exposures in NE Siberia were studied for organic matter (OM) characteristics and ice content. OM stored in Quaternary permafrost grew, accumulated, froze, partly decomposed, and...

A study of Quaternary structures in the Qom region, West Central Iran

NASA Astrophysics Data System (ADS)

Babaahmadi, A.; Safaei, H.; Yassaghi, A.; Vafa, H.; Naeimi, A.; Madanipour, S.; Ahmadi, M.

2010-12-01

West Central Iran comprises numerous Quaternary faults. Having either strike-slip or thrust mechanisms, these faults are potentially active and therefore capable of creating destructive earthquakes. In this paper, we use satellite images as well as field trips to identify these active faults in the Qom region. The Qom and Indes faults are the main NW-trending faults along which a Quaternary restraining step-over zone has formed. Kamarkuh, Mohsen Abad, and Ferdows anticlines are potentially active structures that formed in this restraining step-over zone. There are some thrusts and anticlines, such as the Alborz anticline and Alborz fault, which are parallel to strike-slip faults such as the Qom fault, indicating deformation partitioning in the area. In addition to NW-trending structures, there is an important NE-trending fault known as the Qomrud fault that has deformed Quaternary deposits and affected Kushk-e-Nosrat fault, Alborz anticline, and Qomrud River. The results of this study imply that the major Quaternary faults of West Central Iran and their restraining step-over zones are potentially active.

Ancient dna from pleistocene fossils: Preservation, recovery, and utility of ancient genetic information for quaternary research

NASA Astrophysics Data System (ADS)

Yang, Hong

Until recently, recovery and analysis of genetic information encoded in ancient DNA sequences from Pleistocene fossils were impossible. Recent advances in molecular biology offered technical tools to obtain ancient DNA sequences from well-preserved Quaternary fossils and opened the possibilities to directly study genetic changes in fossil species to address various biological and paleontological questions. Ancient DNA studies involving Pleistocene fossil material and ancient DNA degradation and preservation in Quaternary deposits are reviewed. The molecular technology applied to isolate, amplify, and sequence ancient DNA is also presented. Authentication of ancient DNA sequences and technical problems associated with modern and ancient DNA contamination are discussed. As illustrated in recent studies on ancient DNA from proboscideans, it is apparent that fossil DNA sequence data can shed light on many aspects of Quaternary research such as systematics and phylogeny. conservation biology, evolutionary theory, molecular taphonomy, and forensic sciences. Improvement of molecular techniques and a better understanding of DNA degradation during fossilization are likely to build on current strengths and to overcome existing problems, making fossil DNA data a unique source of information for Quaternary scientists.

Peralkaline Rhyolite Achneliths with Evidence of Post-Emplacement Vesiculation at Aluto Volcano, Main Ethiopian Rift: What can these unusual pyroclasts tell us?

NASA Astrophysics Data System (ADS)

Calder, E.; Clarke, B. A.; Cortes, J. A.; Butler, I. B.; Yirgu, G.

2016-12-01

In peralkaline rhyolitic melts, Na+ and K+ combined with halogens act to disrupt silicate polymers reducing melt viscosity in comparison to other melts of equivalent silica content. As a result, such magmas are often associated with somewhat unusual deposits for which the associated eruptive behaviours are relatively poorly understood. We have discovered unusual globule-shaped clasts within an unconsolidated pyroclastic succession associated with a pumice cone at Aluto volcano in the Main Ethiopian Rift. The clasts are lapilli to ash sized, often have a droplet-like morphology and are characterised by a distinctive obsidian skin indicative of having been shaped by surface tension. We adopt Walker's term achneliths for these clasts. These achneliths however, unlike their mafic counterparts, are highly vesicular ( 78 vol %), and the glassy skin often shows a bread-crusted texture. Importantly, there is strong evidence for post-depositional, in-situ, inflation, including expanding against other clasts and in some cases fusing together. The unconsolidated nature of the deposit at Aluto means that these peralkaline achneliths are easily separated and investigated in 3D, providing an unprecedented opportunity to study their features in detail through the use of µCT, SEM and EPMA. Textural observations and preliminary 3D vesicle size distribution data suggest that surface tension is an important factor in shaping these clasts, and that vesiculation and degassing occurs over a prolonged period post-emplacement. MELTS model calculations on the EPMA analyses assuming dry conditions, suggest maximum liquidus temperatures of 1030 °C and minimum viscosities of 6 Log(poise). These observations have important implications for understanding the nature of late stage degassing, fragmentation and eruption style in peralkaline rhyolite systems as well as incipient welding in peralkaline pyroclastic units.

Geology and ground-water resources of Dane County, Wisconsin

USGS Publications Warehouse

Cline, Denzel R.

1965-01-01

The purpose of the ground-water investigation of Dane County, Wis., was to determine the occurrence, movement, quantity, quality, and availability of ground water in the unconsolidated deposits and the underlying bedrock. The relationships between ground water and surface water were studied in general in Dane County and in detail in the Madison metropolitan area. An analysis was made of the hydrologic system of the Yahara River valley and of the effects of ground-water pumpage on that system.

Distribution of surface deposits in the Gijón urban subsurface (NW Spain)

NASA Astrophysics Data System (ADS)

López-Fernández, Carlos; Pando, Luis; María Díaz-Díaz, Luis; Arias, Daniel; Flor-Blanco, Germán

2016-04-01

Gijón is the second most populous city (278.285 inhabitants in 2015) of the Spanish north coast. The urban subsurface is mostly formed (≈80%) by Quaternary sediments which exceeds 20 meters of thickness when cover the Jurassic carbonate basement (Gijón Formation). This work has allowed to know the spatial distribution of the different types of sediments in urban area. To do this, a GIS database was developed that contains data from more than 450 geotechnical reports. Information provided by fieldwork and the exploration of excavation works in progress throughout the city was also incorporated. Currently, the geodatabase developed comprises more than 1,400 site investigation points: boreholes, dynamic probing and trial pits. This has been supplemented with hundreds on-site and laboratory tests carried out on core samples of soils and rocks, performed following renowned testing standards. Quaternary formations, largely concealed below man-made fills, set up two main areas composed by granular and cohesive soils: the littoral zone at the northern urban perimeter and the continental zone at the southern sector. The first one, fluvial-marine deposits, consist of sandy sediments related to beach/dune systems and marsh deposits, with gravels, organogenic mud and layers of Holocene peat. The southern area is composed by residual clays -silt and coarse-grained soils to a lesser extent- linked to the dissolution of the Mesozoic substrate. Associated with these two types of deposits, two main aquifers can be differentiated. The thickness of the man-made deposits, fluvial-marine sediments and residual deposits was determined in this work. Thus, a 3-d model of Gijón subsurface at urban scale was obtained. A map of the Jurassic bedrock bedrock was also produced. Building construction works may be affected by the geotechnical behavior of the Quaternary deposits and the saturation of granular sediments., This is because the shallowness of the water table, the usual low bearing capacity and other issues such as clays consolidation or swelling phenomena. The use of concrete slabs, deep foundations and piled/anchored retaining walls is very common when projecting underground floors under these conditions.

Sedimentary and tectonic evolution of Plio Pleistocene alluvial and lacustrine deposits of Fucino Basin (central Italy)

NASA Astrophysics Data System (ADS)

Cavinato, Gian Paolo; Carusi, Claudio; Dall'Asta, Massimo; Miccadei, Enrico; Piacentini, Tommaso

2002-04-01

The Fucino Basin was the greatest lake of the central Italy, which was completely drained at the end of 19th century. The basin is an intramontane half-graben filled by Plio-Quaternary alluvial and lacustrine deposits located in the central part of the Apennines chain, which was formed in Upper Pliocene and in Quaternary time by the extensional tectonic activity. The analysis of the geological surface data allows the definition of several stratigraphic units grouped in Lower Units and Upper Units. The Lower Units (Upper Pliocene) are exposed along the northern and north-eastern basin margins. They consist of open to marginal lacustrine deposits, breccia deposits and fluvial deposits. The Upper Units (Lower Pliocene-Holocene) consist of interbedded marginal lacustrine deposits and fluvial deposits; thick coarse-grained fan-delta deposits are interfingered at the foot of the main relief with fluvial-lacustrine deposits. Most of the thickness of the lacustrine sequences (more than 1000-m thick) is buried below the central part of the Fucino Plain. The basin is bounded by E-W, WSW-ENE and NW-SE fault systems: Velino-Magnola Fault (E-W) and Tremonti-Celano-Aielli Fault (WSW-ENE) and S. Potito-Celano Fault (NW-SE) in the north; the Trasacco Fault, the Pescina-Celano Fault and the Serrone Fault (NW-SE) in the south-east. The geometry and kinematic indicators of these faults indicate normal or oblique movements. The study of industrial seismic profiles across the Fucino Basin gives a clear picture of the subsurface basin geometry; the basin shows triangular-shaped basin-fill geometry, with the maximum deposits thickness toward the main east boundary fault zones that dip south-westward (Serrone Fault, Trasacco Fault, Pescina-Celano Fault). On the basis of geological surface data, borehole stratigraphy and seismic data analysis, it is possible to recognize and to correlate sedimentary and seismic facies. The bottom of the basin is well recognized in the seismic lines available from the good and continuous signals of the top of Meso-Cenozoic carbonate rocks. The shape of sedimentary bodies indicates that the filling of the basin was mainly controlled by normal slip along the NW-SE boundary faults. In fact, the continental deposits are frequently in on-lap contact over the carbonate substratum; several disconformable contacts occurred during the sedimentary evolution of the basin. The main faults (with antithetic and synthetic fault planes) displace the whole sedimentary sequence up to the surface indicating a recent faults' activity (1915 Avezzano earthquake, Ms=7.0). The stratigraphic and tectonic setting of the Fucino Basin and neighboring areas indicates that the extensional tectonic events have had an important role in driving the structural-sedimentary evolution of the Plio-Quaternary deposits. The geometry of the depositional bodies, of the fault planes and their relationships indicate that the Fucino Basin was formed as a half-graben type structure during Plio-Quaternary extensional events. Some internal complexities are probably related to the fold-and-thrust structures of the Apenninic orogeny formed in Messinian time, in this area, and to a different activity timing of the E-W and WSW-ENE fault systems and the NW-SE fault systems. We believe, based on the similarity of the surface characteristics, that the structural setting of the Fucino Basin can be extrapolated to the other great intramontane basins in Central Italy (e.g. Rieti, L'Aquila, Sulmona, Sora, Isernia basins).

Water Resources of the Ground-Water System in the Unconsolidated Deposits of the Colville River Watershed, Stevens County, Washington

USGS Publications Warehouse

Kahle, Sue C.; Longpre, Claire I.; Smith, Raymond R.; Sumioka, Steve S.; Watkins, Anni M.; Kresch, David L.

2003-01-01

A study of the water resources of the ground-water system in the unconsolidated deposits of the Colville River Watershed provided the Colville River Watershed Planning Team with an assessment of the hydrogeologic framework, preliminary determinations of how the shallow and deeper parts of the ground-water system interact with each other and the surface-water system, descriptions of water-quantity characteristics including water-use estimates and an estimated water budget for the watershed, and an assessment of further data needs. The 1,007-square-mile watershed, located in Stevens County in northeastern Washington, is closed to further surface-water appropriations throughout most of the basin during most seasons. The information provided by this study will assist local watershed planners in assessing the status of water resources within the Colville River Watershed (Water Resources Inventory Area 59). The hydrogeologic framework consists of glacial and alluvial deposits that overlie bedrock and are more than 700 feet thick in places. Twenty-six hydrogeologic sections were constructed, using a map of the surficial geology and drillers' logs for more than 350 wells. Seven hydrogeologic units were delineated: the Upper outwash aquifer, the Till confining unit, the Older outwash aquifer, the Colville Valley confining unit, the Lower aquifer, the Lower confining unit, and Bedrock. Synoptic stream discharge measurements made in September 2001 identified gaining and losing reaches over the unconsolidated valley deposits. During the September measurement period, the Colville River gained flow from the shallow ground-water system near its headwaters to the town of Valley and lost flow to the shallow ground-water system from Valley to Chewelah. Downstream from Chewelah, the river generally lost flow, but the amounts lost were small and within measurement error. Ground-water levels indicate that the Lower aquifer and the shallow ground-water system may act as fairly independent systems. The presence of flowing wells completed in the Lower aquifer indicates upward head gradients along much of the Colville Valley floor. Total surface- and ground-water withdrawals during 2001 were estimated to be 9,340 million gallons. Water use for 2001, as a percentage of the total, was 75.3 percent for irrigation, 16.3 percent for public supply, 6.5 percent for private wells, and about 1 percent each for industrial and livestock use. An approximate water budget for a typical year in the Colville River Watershed shows that 27 inches of precipitation are balanced by 4.2 inches of streamflow discharge from the basin, 0.3 inch of ground-water discharge from the basin, and 22.5 inches of evapotranspiration.

Interplay of late Cenozoic siliciclastic supply and carbonate response on the southeast Florida platform

USGS Publications Warehouse

Cunningham, K.J.; Locker, S.D.; Hine, A.C.; Bukry, D.; Barron, J.A.; Guertin, L.A.

2003-01-01

High-resolution seismic-reflection data collected along the length of the Caloosahatchee River in southwestern Florida have been correlated to nannofossil biostratigraphy and strontium-isotope chemostratigraphy at six continuously cored boreholes. These data are interpreted to show a major Late Miocene(?) to Early Pliocene fluvial-deltaic depositional system that prograded southward across the carbonate Florida Platform, interrupting nearly continuous carbonate deposition since early in the Cretaceous. Connection of the platform top to a continental source of siliciclastics and significant paleotopography combined to focus accumulation of an immense supply of siliciclastics on the southeastern part of the Florida Platform. The remarkably thick (> 100 m), sand-rich depositional system, which is characterized by clinoformal progradation, filled in deep accommodation, while antecedent paleotopography directed deltaic progradation southward within the middle of the present-day Florida Peninsula. The deltaic depositional system may have prograded about 200 km southward to the middle and upper Florida Keys, where Late Miocene to Pliocene siliciclastic form the foundation of the Quaternary carbonate shelf and shelf margin of the Florida Keys. These far-traveled siliciclastic deposits filled accommodation on the southeastern part of the Florida Platform so that paleobathymetry was sufficiently shallow to allow Quaternary recovery of carbonate sedimentation in the area of southern peninsular Florida and the Florida Keys.

Geologic control of mineral composition of stream waters of the eastern slope of the Southern Coast Ranges, California

USGS Publications Warehouse

Davis, G.H.

1961-01-01

Chemical analyses of waters of streams that drain the semiarid eastern slope of the southern Coast Ranges in California demonstrate that differences in the anion composition, especially in the ratio of bicarbonate to sulfate, are related chiefly to the lithologic character of the rocks exposed in the tributary drainage area. Where more than hall the drainage area of a typical eastern-slope stream is underlain by clastic marine sedimentary rocks of Jurassic and Cretaceous age, bicarbonate generally predominates over sulfate; the ratio of bicarbonate to sullate, both expressed in equivalents per million, in samples of the streams at low-flow stage ranges from 0.8 to 6. Conversely, where more than hall the drainage area is underlain by marine and continental deposits of Tertiary age and continental deposits of Quaternary age, sulfate predominates over bicarbonate, and the ratio of bicarbonate to sulfate in samples taken during the low-flow stage ranges from 0.02 to 0.7. Organic siliceous marine shale of Tertiary age deposited in a reducing environment is probably the primary source of sullate in the region. Secondary deposits of sulfate minerals, chiefly gypsum, which are abundant in the continental deposits of late Tertiary and Quaternary age, also contribute sullate to the stream waters.

Heteroepitaxial growth of 3-5 semiconductor compounds by metal-organic chemical vapor deposition for device applications

NASA Technical Reports Server (NTRS)

Collis, Ward J.; Abul-Fadl, Ali

1988-01-01

The purpose of this research is to design, install and operate a metal-organic chemical vapor deposition system which is to be used for the epitaxial growth of 3-5 semiconductor binary compounds, and ternary and quaternary alloys. The long-term goal is to utilize this vapor phase deposition in conjunction with existing current controlled liquid phase epitaxy facilities to perform hybrid growth sequences for fabricating integrated optoelectronic devices.

Evaluation of ERTS-1 imagery for mapping Quaternary deposits and landforms in the Great Plains and Midwest

NASA Technical Reports Server (NTRS)

Morrison, R. B. (Principal Investigator); Hallberg, G. R.

1973-01-01

The author has identified the following significant results. The main landform associations and larger landforms are readily identifiable on the better images and commonly the gross associations of surficial Quaternary deposits also can be determined primarily by information on landforms and soils (obtained by analysis of stream dissection and drainage and stream-divide patterns, land use patterns, etc.). Maps showing the Quaternary geologic-terrain units that can be distinguished on the ERTS-1 images are being prepared for study areas in Illinois, Iowa, Missouri, Kansas, Nebraska, and South Dakota. Preliminary maps of 1:1,000,000 scale are included for three of the study areas: the Grand Island and Fremont, Nebraska, and the Davenport, Iowa-Illinois, 1 deg x 2 deg quadrangles. These maps exemplify the first phase of investigations, which consists of identifying and mapping landform and land use characteristics and geologic-surficial materials directly from the ERTS-1 images alone, with no additional information. These maps show that commonly the boundaries of geologic-terrain units can be delineated more accurately on ERTS-1 images than on topographic maps at 1:250,000 scale.

Role of Growth Faulting in the Quaternary Development of Mississippi-River Delta

NASA Astrophysics Data System (ADS)

Mohrig, D.; George, T. J.; Straub, K. M.

2008-12-01

We use an industry grade seismic volume and observations of present-day surface topography to resolve the influence of growth faulting on evolution of Mississippi delta in southeastern Louisiana from the Pleistocene to Recent. The volume of seismic data covers an area roughly 1400 square kilometers in size and it resolves many normal faults with displacements that can be tied to movement of Jurassic Louann Salt in the subsurface. We have defined the Quaternary activity associated with 6 of these normal faults by measuring the progressive offset of strata deposited on the delta surface over time. These measurements of fault displacement were restricted to the sedimentary section positioned 150 to 1500 m beneath the delta surface. Total vertical offsets measured within this Quaternary section range from 60 to 150 m. These fault displacements represent abrupt spatial variations in subsidence rate that are between 4 and 8 percent of the regional, long-term deposition rate. Our best estimates for the Quaternary rates of fault displacement vary between 0.1 and 1 mm/yr. Five faults can be connected to deformation of the modern delta surface. Wetland on the footwall is replaced by open water on the hanging wall of these structures. In spite of this evidence for modern surface deformation, the orientations of buried, seismically resolved channel bodies do not appear to be affected by the positions of active growth faults. We will evaluate the competition between subsidence and sedimentation patterns that leads to this style of channelized stratigraphy.

Deconvolving the process-origin of sediments on volcanic mountains and implications for paleoclimatic reconstruction: Mt Ruapehu area, New Zealand

NASA Astrophysics Data System (ADS)

Brook, Martin; Winkler, Stefan

2016-04-01

Glaciation on the central North Island of New Zealand is limited to the volcanoes of Tongariro National Park, including Mt Ruapehu, the largest and most active andesitic stratovolcano on the North Island. At 2797 m asl, Mt Ruapehu represents the only peak in the North Island to currently intercept the permanent snowline, with small cirque glaciers descending to an altitude of ~2300 m. During the last glacial maximum (LGM), small ice-caps existed on Mt Ruapehu and the Tongariro Massif (15 km to the NNE of Ruapehu), with a series of small (<10 km-long) valley glaciers radiating out from domes centered on the summit areas to altitudes of ~1200 m. Holocene glacier advances have left smaller deposits inboard of some of the LGM moraines. However, understanding of moraine deposition and reconstructing former glacier extent is limited by: (1) the fragmentary nature of glacier moraines in this high precipitation environment; and (2) the broad range of possible process-origins for unconsolidated debris ridges on active volcanoes. Here, we describe the clast roundness, clast shape and textural characteristics associated with active and former glaciers on Mt Ruaephu and the Tongariro Massif, in order to assist in classifying the process-origin of sediments on glaciated volcanic mountains. Supraglacial inputs include rockfall, tephra, and avalanche material delivered to the surface of glaciers. Basal debris, where observed at the terminus of active cirque glaciers, consists mainly of incorporated fluvial material. Following deposition, reworking is mainly by proglacial streams, debris flows and lahars. Within the vicinity of glaciers, the dominant facies appear to be: (i) bouldery gravel with angular clasts on steep slopes surrounding glaciers, (ii) silty-sandy boulder gravel, with mainly subangular clasts, forming lateral moraines, (iii) boulder/cobble gravel with mainly subrounded clasts and associated laminated sediments representing fluvially-reworked material; and (iv) debris-avalanche deposits including fragmental rock clasts with an unsorted inter-clast matrix. As some of these deposits appear to include unambiguous indicators of glacial transport, interpretation of unconsolidated debris ridges on volcanic mountains should not necessarily exclude the contribution of glacial processes.

Review: groundwater in Alaska (USA)

USGS Publications Warehouse

Callegary, J.B.; Kikuchi, C.P.; Koch, Joshua C.; Lilly, M.R.; Leake, S.A.

2013-01-01

Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of groundwater use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding groundwater/surface-water interactions and the effects of climate change is critical for understanding groundwater availability and the movement of natural and anthropogenic contaminants.

High-resolution shear-wave reflection profiling to image offset in unconsolidated near-surface sediments

NASA Astrophysics Data System (ADS)

Bailey, Bevin L.

S-wave reflection profiling has many theoretical advantages, when compared to P-wave profiling, such as high-resolution potential, greater sensitivities to lithologic changes and insensitivity to the water table and pore fluids, and could be particularly useful in near-surface settings. However, S-wave surveys can be plagued by processing pitfalls unique to near-surface studies such as interference of Love waves with reflections, and the stacking of Love waves as coherent noise, leading to possible misinterpretations of the subsurface. Two lines of S-wave data are processed and used to locate previously unknown faults in Quaternary sediments in a region where earthquake activity poses a threat to surface structures. This study provides clear examples of processing pitfalls such as Love waves with hyperbolic appearances on shot gathers, and a CMP section with coherent noise that is easily misinterpreted as reflections. This study demonstrates pros and cons of using SH reflection data in the near surface.

Paleomagnetic investigation of late Quaternary sediments of south San Francisco Bay, California

USGS Publications Warehouse

Hillhouse, John W.

1977-01-01

Paleomagnetic inclinations of the Late Quaternary sediments of South San Francisco Bay were determined from bore hole samples collected near Dumbarton Bridge. The sediments consist of estuarine muds and nonmarine sand deposits, floored by bedrock of the Mesozoic Franciscan Formation. - Beneath Dumbarton Bridge the entire sedimentary fill is normally polarized; therefore, the fill postdates the Brunhes-Matayama polarity reversal (700,000 y. B.P.). Magnetic time lines such as the Mono Lake excursion (24,000 y. B.P.) and the reversed Blake event (110,000 y B.P.) were not found in this bore hole. In addition to Holocene and modern deposits of San Francisco Bay, an older estuarine unit occurs in the stratigraphic section. The older unit was deposited during a period of high sea level, tentatively correlated with the Sangamon interglacial period. Because evidence of the Blake event is not present in the older estuarine unit, the proposed age of this unit could not be confirmed. Although the Holocene estuarine deposits of South San Francisco Bay carry stable remanent magnetization, a reliable record of geomagnetic secular variation could not be recovered because the water-saturated sdiment was deformed by drilling.

Regional deformation of late Quaternary fluvial sediments in the Apennines foreland basin (Emilia, Italy)

NASA Astrophysics Data System (ADS)

Stefani, Marco; Minarelli, Luca; Fontana, Alessandro; Hajdas, Irka

2018-04-01

Our research is aimed at estimating the vertical deformation affecting late Quaternary units accumulated into the foreland basin of the Northern Apennines chain. Beneath the study alluvial plain, compressive fault-fold structures are seismically active. We reconstructed the stratigraphic architecture and the depositional evolution of the alluvial deposits, which accumulated in the first 40 m of subsurface, through the last 45,000 years, from before the Last Glacial Maximum to the present. A 58 km-long stratigraphic profile was correlated from the foothill belt near Bologna to the vicinity of the Po River. The analysis of the profile documents subsidence movements through the last 12,000 years, exceeding - 18 m in syncline areas, with subsidence rates of at least 1.5 m/ka. Anticlines areas experienced a much lower subsidence than the syncline ones.

Quaternary geology of the Boston area: Glacial events from Lake Charles to Lake Aberjona

USGS Publications Warehouse

Stone, Byron D.; Lane, John W.

2014-01-01

The multiple-glacial and glaciomarine Quaternary history of the Boston, Massachusetts area has been known generally since the earliest studies of the then newly recognized glacial deposits described by Prof. Louis Agassiz in the late1840’s and fossil marine shells in the drift in the 1850’s. Attention then turned to possible glacial erosional effects on the preglacial bedrock physiography, as related to rock units and structure, and to the challenges of defining useful physical and lithic characteristics of the drift by Prof. W.O. Crosby and others, 1880-1900. The problems of deducing the relative stratigraphic order among such small, fossil-barren surficial sedimentary deposits, and extending knowledge gained from studies of postulated ancient glacial lakes to a regional understanding of the history of many lakes during the retreat of the ice sheet required field work and use of geologic maps. With the advent of modern topographic maps in the 1880’s, the early period of discovery included field studies of glacial lake deposits in local river basins in the Boston region, basins that drain northward, thereby creating glacial lake basins dammed by the ice margin as it retreated to the north. Guided by M.I.T. and Harvard professors W.O. Crosby, N.S. Shaler, J.B. Woodworth, W.M. Davis, and others in the 1880-1920 period, the first Quaternary glacial stratigraphers were students (e.g. Crosby and Grabau, 1896, Clapp, 1905, Fuller 1905, Goldthwaite 1906, Grabau, 1906, Taylor, Tight).

Fine-grained rutile in the Gulf of Maine: Diagenetic origin, source rocks, and sedimentary environment of deposition

USGS Publications Warehouse

Valentine, P.C.; Commeau, J.A.

1990-01-01

The Gulf of Maine, an embayment of the New England margin, is floored by shallow, glacially scoured basins that are partly filled with late Pleistocene and Holocene silt and clay containing 0.7 to 1.0 wt percent TiO2 chiefly in the form of silt-size rutile. Much of the rutile in the Gulf of Maine mud probably formed diagenetically in poorly cemented Carboniferous and Triassic coarse-grained sedimentary rocks of Nova Scotia and New Brunswick after the dissolution of titanium-rich detrital minerals (ilmenite, ilmenomagnetite). The diagenesis of rutile in coarse sedimentary rocks (especially arkose and graywacke) followed by erosion, segregation, and deposition (and including recycling of fine-grained rutile from shales) can serve as a model for predicting and prospecting for unconsolidated deposits of fine-grained TiO2. -from Authors

High-resolution and high-precision correlation of dark and light layers in the Quaternary hemipelagic sediments of the Japan Sea recovered during IODP Expedition 346

NASA Astrophysics Data System (ADS)

Tada, Ryuji; Irino, Tomohisa; Ikehara, Ken; Karasuda, Akinori; Sugisaki, Saiko; Xuan, Chuang; Sagawa, Takuya; Itaki, Takuya; Kubota, Yoshimi; Lu, Song; Seki, Arisa; Murray, Richard W.; Alvarez-Zarikian, Carlos; Anderson, William T.; Bassetti, Maria-Angela; Brace, Bobbi J.; Clemens, Steven C.; da Costa Gurgel, Marcio H.; Dickens, Gerald R.; Dunlea, Ann G.; Gallagher, Stephen J.; Giosan, Liviu; Henderson, Andrew C. G.; Holbourn, Ann E.; Kinsley, Christopher W.; Lee, Gwang Soo; Lee, Kyung Eun; Lofi, Johanna; Lopes, Christina I. C. D.; Saavedra-Pellitero, Mariem; Peterson, Larry C.; Singh, Raj K.; Toucanne, Samuel; Wan, Shiming; Zheng, Hongbo; Ziegler, Martin

2018-12-01

The Quaternary hemipelagic sediments of the Japan Sea are characterized by centimeter- to decimeter-scale alternation of dark and light clay to silty clay, which are bio-siliceous and/or bio-calcareous to a various degree. Each of the dark and light layers are considered as deposited synchronously throughout the deeper (> 500 m) part of the sea. However, attempts for correlation and age estimation of individual layers are limited to the upper few tens of meters. In addition, the exact timing of the depositional onset of these dark and light layers and its synchronicity throughout the deeper part of the sea have not been explored previously, although the onset timing was roughly estimated as 1.5 Ma based on the result of Ocean Drilling Program legs 127/128. Consequently, it is not certain exactly when their deposition started, whether deposition of dark and light layers was synchronous and whether they are correlatable also in the earlier part of their depositional history. The Quaternary hemipelagic sediments of the Japan Sea were drilled at seven sites during Integrated Ocean Drilling Program Expedition 346 in 2013. Alternation of dark and light layers was recovered at six sites whose water depths are > 900 m, and continuous composite columns were constructed at each site. Here, we report our effort to correlate individual dark layers and estimate their ages based on a newly constructed age model at Site U1424 using the best available paleomagnetic datum and marker tephras. The age model is further tuned to LR04 δ18O curve using gamma ray attenuation density (GRA) since it reflects diatom contents that are higher during interglacial high-stands. The constructed age model for Site U1424 is projected to other sites using correlation of dark layers to form a high-resolution and high-precision paleo-observatory network that allows to reconstruct changes in material fluxes with high spatio-temporal resolutions.

Regional seismic stratigraphy and controls on the Quaternary evolution of the Cape Hatteras region of the Atlantic passive margin, USA

USGS Publications Warehouse

Mallinson, D.J.; Culver, S.J.; Riggs, S.R.; Thieler, E.R.; Foster, D.; Wehmiller, J.; Farrell, K.M.; Pierson, J.

2010-01-01

Seismic and core data, combined with amino acid racemization and strontium-isotope age data, enable the definition of the Quaternary stratigraphic framework and recognition of geologic controls on the development of the modern coastal system of North Carolina, U.S.A. Seven regionally continuous high amplitude reflections are defined which bound six seismic stratigraphic units consisting of multiple regionally discontinuous depositional sequences and parasequence sets, and enable an understanding of the evolution of this margin. Data reveal the progressive eastward progradation and aggradation of the Quaternary shelf. The early Pleistocene inner shelf occurs at a depth of ca. 20-40 m beneath the western part of the modern estuarine system (Pamlico Sound). A mid- to outer shelf lowstand terrace (also early Pleistocene) with shelf sand ridge deposits comprising parasequence sets within a transgressive systems tract, occurs at a deeper level (ca. 45-70 m) beneath the modern barrier island system (the Outer Banks) and northern Pamlico Sound. Seismic and foraminiferal paleoenvironmental data from cores indicate the occurrence of lowstand strandplain shoreline deposits on the early to middle Pleistocene shelf. Middle to late Pleistocene deposits occur above a prominent unconformity and marine flooding surface that truncates underlying units, and contain numerous filled fluvial valleys that are incised into the early and middle Pleistocene deposits. The stratigraphic framework suggests margin progradation and aggradation modified by an increase in the magnitude of sea-level fluctuations during the middle to late Pleistocene, expressed as falling stage, lowstand, transgressive and highstand systems tracts. Thick stratigraphic sequences occur within the middle Pleistocene section, suggesting the occurrence of high capacity fluvial point sources debouching into the area from the west and north. Furthermore, the antecedent topography plays a significant role in the evolution of the geomorphology and stratigraphy of this marginal system. ?? 2009 Elsevier B.V.

Mohawk Lake or Mohawk meadow Sedimentary facies and stratigraphy of Quaternary deposits in Mohawk Valley, upper Middle Fork of the Feather River, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yount, J.C.; Harwood, D.S.; Bradbury, J.P.

1993-04-01

Mohawk Valley (MV) contain thick, well-exposed sections of Quaternary basin-fill sediments, with abundant interbedded tephra and a diverse assemblage of sedimentary facies. The eastern arm of MV, extending from Clio to Portola, contains as much as 100 m of trough cross-bedded cobble to pebble gravel and planar and trough cross-bedded coarse and medium sand, interpreted as braided stream deposits. Sections exposed in the western arm of MV consist in their lower parts of massive organic-rich silt and clay interbedded with blocky to fissile peat beds up to 1 m thick. Diatom assemblages are dominated by benthic species indicating fresh marshmore » environments with very shallow water depths of one meter or less. Proglacial lacustrine deposits of limited lateral extent are present within the outwash complexes as evidenced by varved fine sand and silt couplets, poorly sorted quartz-rich silt beds containing dropstones, and contorted beds of diamict grading laterally into slump blocks surrounded by wood-bearing silt and silty sand. The Rockland Ash (400 ka) is a prominent marker in the middle or lower part of many sections throughout MV, indicating that at least half of the basin-fill sequence is Late Quaternary in age. A log buried in diamict slumped into a proglacial lake lying approximately 3 km downstream from the Tioga Stage ice termini in Jamison and Gray Eagle Creeks yields an age of 18,715 [+-]235 C[sup 14] years BP. Previous interpretations of MV deposits originating in a large, deep lake with water depths in excess of 150 m are untenable given the sedimentary facies and diatom floras that dominate the valley. Unexhumed valleys such as Sierra Valley to the east and Long Valley to the northwest which contain large meadows traversed by braided streams are probably good analogs for the conditions that existed during the accumulation of the Mohawk Valley deposits.« less

Surficial geologic map of the southwest Memphis Quadrangle, Shelby County, Tennessee, and Crittenden County, Arkansas

USGS Publications Warehouse

Moore, David W.; Diehl, Sharon F.

2004-01-01

This map is one of seven 1:24,000-scale (7.5-minute) quadrangle maps of the surficial geology of the Memphis, Tennessee, area--part of a series of urban hazard maps. Wind-deposited silt and clayey silt (loess) is the predominant surficial deposit in this quadrangle. The loess was deposited as dust during the last major continental glaciation of the region and it covers the upland to depths of 4.5-16 m. River alluvium (unit Qal), which is chiefly a sandy and gravelly sand deposit about 30 m thick, underlies the Mississippi River floodplain. This unit supports extensive artificial fill and infrastructure used for shipping storage and petroleum processing and storage. Based on paleoliquefaction structures (sand boils) documented in Mississippi River alluvium elsewhere, this unit probably has the potential to liquefy during strong earthquake shaking. No paleoliquefaction structures were observed within the Southwest Memphis quadrangle. Another deposit in the quadrangle is silty alluvium of the Nonconnah Creek floodplain, and is 1-10 m thick. Sparse, unconsolidated pebbly sand deposits are 0.5-3 m thick and make up point bars and channel deposits of Nonconnah Creek.

Hydrogeology of the Lloyd Aquifer on Long Island, New York-A Brief Summary of USGS Investigations

USGS Publications Warehouse

Chu, Anthony

2006-01-01

The four counties of Long Island (fig. 1) are underlain by a wedge-shaped sequence of unconsolidated deposits of Late Cretaceous and Pleistocene age that lie unconformably on crystalline bedrock (fig. 2). A saprolitic (weathered bedrock) zone 20 to 100 ft thick overlies the bedrock in most areas. The sequence of unconsolidated deposits thickens to the south and southeast by about 65 to 100 feet per mile and contains Long Island's fresh ground water. Long Island's ground-water system consists of four main aquifers-the upper glacial, the Jameco, the Magothy, and the Lloyd. The Lloyd aquifer underlies nearly all of Long Island (fig. 3), but pumpage from the Lloyd has been limited to the northern and southern coastal areas of the island by the New York State Department of Environmental Conservation since about 1955 (Garber, 1986). Coastal areas are exempt where the Lloyd is the only source of potable water. The former Jamaica Water Supply Corporation (now owned by New York City) is a noted exception withdrawing as much as 6 million gallons per day (Mgal/d) since the mid-1930s from the Lloyd in central Queens County. This paper: (1) provides a brief history of U.S. Geological Survey (USGS) studies that provided significant data on the Lloyd, (2) summarizes the hydraulic characteristics of the Lloyd as reported in those studies, and (3) describes present-day monitoring of the Lloyd by the USGS.

Preliminary assessment of water chemistry related to groundwater flooding in Wawarsing, New York, 2009-11

USGS Publications Warehouse

Brown, Craig J.; Eckhardt, David A.; Stumm, Frederick; Chu, Anthony

2012-01-01

Water-quality samples collected in an area prone to groundwater flooding in Wawarsing, New York, were analyzed and assessed to better understand the hydrologic system and to aid in the assessment of contributing water sources. Above average rainfall over the past decade, and the presence of a pressurized water tunnel that passes about 700 feet beneath Wawarsing, could both contribute to groundwater flooding. Water samples were collected from surface-water bodies, springs, and wells and analyzed for major and trace inorganic constituents, dissolved gases, age tracers, and stable isotopes. Distinct differences in chemistry exist between tunnel water and groundwater in unconsolidated deposits and in bedrock, and among groundwater samples collected from some bedrock wells during high head pressure and low head pressure of the Rondout-West Branch Tunnel. Samples from bedrock wells generally had relatively higher concentrations of sulfate (SO42-), strontium (Sr), barium (Ba), and lower concentrations of calcium (Ca) and bicarbonate (HCO3-), as compared to unconsolidated wells. Differences in stable-isotope ratios among oxygen-18 to oxygen-16 (δ18O), hydrogen-2 to hydrogen-1 (δ2H), sulfur-34 to sulfur-32(δ34S) of SO42-, Sr-87 to Sr-86 (87Sr/86Sr), and C-13 to C-12 (δ13C) of dissolved inorganic carbon (DIC) indicate a potential for distinguishing water in the Delaware-West Branch Tunnel from native groundwater. For example, 87Sr/86Sr ratios were more depleted in groundwater samples from most bedrock wells, as compared to samples from surface-water sources, springs, and wells screened in unconsolidated deposits in the study area. Age-tracer data provided useful information on pathways of the groundwater-flow system, but were limited by inherent problems with dissolved gases in bedrock wells. The sulfur hexafluoride (SF6) and (or) chlorofluorocarbons (CFCs) apparent recharge years of most water samples from wells screened in unconsolidated deposits and springs ranged from 2003 to 2010 (current) and indicate short flow paths from the point of groundwater recharge. All but three of the samples from bedrock wells had interference problems with dissolved gases, mainly caused by excess air from degassing of hydrogen sulfide and methane. The SF6 and (or) CFC apparent recharge years of samples from three of the bedrock wells ranged from the 1940s to the early 2000s; the sample with the early 2000s recharge year was from a flowing artesian well that was chemically similar to water samples collected at the influent to the tunnel at Rondout Reservoir and the most hydraulically responsive to water tunnel pressure compared to other bedrock wells. Data described in this report can be used, together with hydrogeologic data, to improve the understanding of source waters and groundwater-flow patterns and pathways, and to help assess the mixing of different source waters in water samples. Differences in stable isotope ratios, major and trace constituent concentrations, saturation indexes, tritium concentrations, and apparent groundwater ages will be used to estimate the proportion of water that originates from Rondout-West Branch Tunnel leakage.

A statistical evaluation of formation disturbance produced by well- casing installation methods

USGS Publications Warehouse

Morin, R.H.; LeBlanc, D.R.; Teasdale, W.E.

1988-01-01

Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed sediments produced by the casing-installation method. In an attempt to quantify this disturbance and recognize its impact on the characterization of unconsolidated deposits, three installation methods were examined and compared in a sand-and-gravel outwash at a test site on Cape Cod, Massachusetts. These installation methods were: 1) casing installed in a mud-rotary hole; 2) casing installed in an augered hole; and 3) flush-joint steel casing hammer-driven from land surface. Fifteen wells were logged with epithermal neutron and natural gamma tools. Concludes that augering is the most disruptive of the three casing-installation methods and that driving casing directly, though typically a more time-consuming operation, transmits the least amount of disturbance into the surrounding formation. -from Authors

Mapping process and age of Quaternary deposits on Santa Rosa Island, Channel Islands National Park, California

NASA Astrophysics Data System (ADS)

Schmidt, K. M.; Minor, S. A.; Bedford, D.

2016-12-01

Employing a geomorphic process-age classification scheme, we mapped the Quaternary surficial geology of Santa Rosa (SRI) within the Channel Islands National Park. This detailed (1:12,000 scale) map represents upland erosional transport processes and alluvial, fluvial, eolian, beach, marine terrace, mass wasting, and mixed depositional processes. Mapping was motivated through an agreement with the National Park Service and is intended to aid natural resource assessments, including post-grazing disturbance recovery and identification of mass wasting and tectonic hazards. We obtained numerous detailed geologic field observations, fossils for faunal identification as age control, and materials for numeric dating. This GPS-located field information provides ground truth for delineating map units and faults using GIS-based datasets- high-resolution (sub-meter) aerial imagery, LiDAR-based DEMs and derivative raster products. Mapped geologic units denote surface processes and Quaternary faults constrain deformation kinematics and rates, which inform models of landscape change. Significant findings include: 1) Flights of older Pleistocene (>120 ka) and possibly Pliocene marine terraces were identified beneath younger alluvial and eolian deposits at elevations as much as 275 m above modern sea level. Such elevated terraces suggest that SRI was a smaller, more submerged island in the late Neogene and (or) early Pleistocene prior to tectonic uplift. 2) Structural and geomorphic observations made along the potentially seismogenic SRI fault indicate a protracted slip history during the late Neogene and Quaternary involving early normal slip, later strike slip, and recent reverse slip. These changes in slip mode explain a marked contrast in island physiography across the fault. 3) Many of the steeper slopes are dramatically stripped of regolith, with exposed bedrock and deeply incised gullies, presumably due effects related to past grazing practices. 4) Surface water presence is spatially discontinuous and correlated with major fault traces and geologic unit boundaries.

Transgressive systems tract development and incised-valley fills within a quaternary estuary-shelf system: Virginia inner shelf, USA

USGS Publications Warehouse

Foyle, A.M.; Oertel, G.F.

1997-01-01

High-frequency Quaternary glacioeustasy resulted in the incision of six moderate- to high-relief fluvial erosion surfaces beneath the Virginia inner shelf and coastal zone along the updip edges of the Atlantic continental margin. Fluvial valleys up to 5 km wide, with up to 37 m of relief and thalweg depths of up to 72 m below modern mean sea level, cut through underlying Pleistocene and Mio-Pliocene strata in response to drops in baselevel on the order of 100 m. Fluvially incised valleys were significantly modified during subsequent marine transgressions as fluvial drainage basins evolved into estuarine embayments (ancestral generations of the Chesapeake Bay). Complex incised-valley fill successions are bounded by, or contain, up to four stacked erosional surfaces (basal fluvial erosion surface, bay ravinement, tidal ravinement, and ebb-flood channel-base diastem) in vertical succession. These surfaces, combined with the transgressive oceanic ravinement that generally caps incised-valley fills, control the lateral and vertical development of intervening seismic facies (depositional systems). Transgressive stratigraphy characterizes the Quaternary section beneath the Virginia inner shelf where six depositional sequences (Sequences I-VI) are identified. Depositional sequences consist primarily of estuarine depositional systems (subjacent to the transgressive oceanic ravinement) and shoreface-shelf depositional systems; highstand systems tract coastal systems are thinly developed. The Quaternary section can be broadly subdivided into two parts. The upper part contains sequences consisting predominantly of inner shelf facies, whereas sequences in the lower part of the section consist predominantly of estuarine facies. Three styles of sequence preservation are identified. Style 1, represented by Sequences VI and V, is characterized by large estuarine systems (ancestral generations of the Chesapeake Bay) that are up to 40 m thick, have hemicylindrical wedge geometries, and occur within large, coast-oblique trending depressions (paleo-estuaries). Style 1 is dominated by fluvial through estuary-mouth depositional systems (Seismic Facies 1-4). Style 2 sequence preservation, represented by Sequences III and II, is dominantly an inner shelf and shoreface succession with a seaward-thickening tabular wedge geometry that does not exceed 15 m in thickness. These shoreface and inner shelf depositional systems of the upper transgressive systems tract (Seismic Facies 9) and highstand systems tract (Seismic Facies 7 and 11) are not associated with paleo-estuaries. Style 3 sequence preservation is represented by Sequence 1, the Holocene Sequence. It consists of lower transgressive systems tract fluvial-estuarine, lagoonal, and tidal-inlet fill deposits (Seismic Facies 1-6, and 8) overlain by upper transgressive systems tract shelf and shoreface sands (Seismic Facies 9). Style 3 has a crenulated wedge geometry, and is thickest beneath and seaward of the modern Chesapeake Bay mouth. It thins northward and landward onto Late Pleistocene interfluvial highs on the basinward side of the southern Delmarva Peninsula.

Description and analysis of the geohydrologic system in western Pinal County, Arizona

USGS Publications Warehouse

Hardt, W.F.; Cattany, R.E.

1965-01-01

Western Pinal County is between Phoenix and Tucson in the Basin and Range physiographic province of southern Arizona and consists of about 2,000 square miles of valley floor with low relief surrounded by mountains. It is the second largest agricultural area in the State, and about 25 percent of the ground water pumped in the State is from this area. The study area has been divided into four parts. Three of these--the Casa Grande-Florence area, the Eloy area, and the Stanfield-Maricopa area--are in the lower Santa Cruz basin; the fourth--the Gila River area--is a long narrow strip along the Gila River from the Ashurst-Hayden Dam to the confluence of the Gila and Santa Cruz Rivers. The project was undertaken to provide a better understanding of the ground-water supply in relation to the present and potential water use in this area of extensive ground-water development. The arid climate of western Pinal County--combining high temperatures and low humidity--causes most of the precipitation to be returned to the atmosphere by evapotranspiration, which leaves only a very small part for recharge to the ground-water reservoir. The computed potential evapotranspiration--44. 97 inches--is five times greater than the average precipitation. In general, the subsurface materials in western Pinal County are unconsolidated alluvial deposits underlain by consolidated alluvium and crystalline rocks and bounded by mountains consisting of crystalline and minor sedimentary rocks. The crystalline and sedimentary rocks of the mountains are not known to be water bearing in western Pinal County. The impermeable rocks underlying the basin are called the hydrologic bedrock unit in this report. Although the unit may consist of several different rock types, the distinction between them is relatively unimportant in this study because none of them yield appreciable amounts of water. The lower Santa Cruz basin in western Pinal County is divided into two sections by a buried ridge of the hydrologic bedrock unit, referred to in this report as the Casa Grande ridge. The ridge trends in a north-south direction from the Sacaton to the Silver Reef Mountains. The unconsolidated deposits constitute the main storage reservoir for ground water in western Pins/ County. The deposits are divided into four units---the local gravel unit, the lower sand and gravel unit, the silt and clay unit, and the upper sand and gravel unit--all of which are major water-yielding units except the silt and clay unit. The local gravel unit, which is present only in the western section of the lower Santa Cruz basin, ranges in thickness from 0 to nearly 1,000 feet and is generally a productive aquifer. The lower sand and gravel unit, Which is a heterogeneous mixture of sand, gravel, and clay, ranges in thickness from 0 to about 500 feet. Where the lower sand and gravel unit is overlain by the silt and clay unit, it generally contains water under artesian conditions; where it is not overlain by the silt and clay unit, it is indistinguishable from the upper sand and gravel unit, and the water is under water-table conditions. The silt and clay unit is the least permeable deposit of the unconsolidated alluvium, and ranges in thickness from 0 to about 2, 000 feet. Generally it is less productive than the other units of the unconsolidated alluvium, although it yields moderate amounts of water from numerous thin stringers and lenses of highly permeable sand and gravel. The upper sand and gravel unit is at the land surface in most of the area; it ranges in thickness from less than 50 to about 600 feet. The unit has the highest average permeability of all the unconsolidated alluvial units; however, the permeability of the unit varies vertically and laterally, which results in a wide range of well yields. As of 1964, the static water levels in most wells in the basin were still in the upper sand and gravel unit. However, the unit is being dewatered in most of the basin, and water levels in

Quaternary geology of the Channeled Scabland and adjacent areas

NASA Technical Reports Server (NTRS)

Baker, V. R.

1978-01-01

The quaternary history of the channeled scabland is characterized by discrete episodes of catastrophic flooding and prolonged periods of loess accumulation and soil formation. The loess sequence was correlated with Richmond's Rocky Mountain glacial chronology. At least five major catastrophic flood events occurred in the general vicinity of the channeled scabland. The earliest episode occurred prior to the extensive deposition of the Palouse formation. The last major episode of flooding occurred between about 18,000 and 13,000 years ago. It probably consisted of two outbursts from glacial Lake Missoula.

Quaternary geology of the Kenai Lowland and glacial history of the Cook Inlet region, Alaska

USGS Publications Warehouse

Karlstrom, Thor N.V.

1964-01-01

The Kenai Lowland is part of the Cook Inlet Lowland physiographic subprovince that borders Cook Inlet, a major marine reentrant along the Pacific Ocean coastline of south-central Alaska. The Cook Inlet Lowland occupies a structural trough underlain by rocks of Tertiary age and mantled by Quaternary deposits of varying thicknesses. The bordering high alpine mountains—the Aleutian and Alaska Ranges to the northwest and north and the Talkeetna, Chugach, and Kenai Mountains to the northeast and southeast—are underlain by rocks of Mesozoic and older ages.

Use of surface and borehole geophysics to delineate the glacial-drift stratigraphy of northeastern St. Joseph County, Indiana

USGS Publications Warehouse

Bayless, E. Randall; Westjohn, David B.; Watson, Lee R.

1995-01-01

Inverse models of direct current electrical- resistivity sounding data and normal-resistivity and natural-gamma logs were used to assist delineation of the glacial-drift stratigraphy in a 580-square- kilometer area of northeastern St. Joseph County, Indiana. Unconsolidated deposits in the study area are composed of glacial-drift, including outwash, till, and lacustrine sediments; thicknesses range from about 15 to more than 70 meters. The glacial outwash deposits are mostly composed of sand and gravel and are the primary source of drinking water to northeastern St. Joseph County. The glacial till and glacio-lacustrine deposits contain a larger fraction of clay than the outwash deposits and may retard ground-water flow between shallow and deeper sand and gravel aquifers. Results of the geophysical measurements collected during this study indicate that glacial-drift deposits in the area north and east of the St. Joseph River are mostly composed of sand and gravel with inter-layered clay-rich deposits that are laterally discontinuous. In the area south of the St. Joseph River, the thickness of sand and gravel deposits diminishes, and clay-rich deposits dominate the stratigraphy. The presence of an electrically conductive bedrock, the Ellsworth Shale, beneath the glacial-drift deposits is identified in inverse models of direct current electrical-resistivity sounding data.

Late-Pleistocene evolution of the East Mediterranean shallow continental shelf of north-central Israel

NASA Astrophysics Data System (ADS)

Shtienberg, Gilad; Dix, Justin; Waldmann, Nicolas; Makovsky, Yizhaq; Bookman, Revital; Roskin, Joel; Bialik, Or; Golan, Arik; Sivan, Dorit

2016-04-01

Sea-level fluctuations are a dominant and dynamic mechanism that control coastal environmental through time. This is especially the case for the successive regressions and transgressions over the last interglacial cycle, which have shaped the deposition, preservation and erosion patterns of unconsolidated sediments currently submerged on continental shelves. The current study focuses on an integrated high-resolution marine and terrestrial litho-stratigraphic and geophysical framework of the north-central Mediterranean coastal zone of Israel. The interpretation enabled the reconstruction of the coastal evolution over the last ˜130 ka. A multi-disciplinary approach was applied by compiling existing elevation raster grids, bathymetric charts, detailed lithological borehole data-sets, a dense 110 km long sub-bottom geophysical survey and seven continuous boreholes sediment records. Based on seismic stratigraphic analysis, observed geometries, and reflective appearances, six bounding surfaces and seven seismic units were identified and characterized. Meanwhile, the chronostratigraphy of the terrestrial side was constructed through integration of magnetic susceptibility, sedimentological and geochemical analysis with 17 new OSL ages. The seismic units were correlated with the available terrestrial borehole data and then associated to the retrieved terrestrial chronostratigraphy to produce a 4D reconstruction model of the paleo-landscape. The entire unconsolidated sequence overlies a calcareous aeolianite (locally named Kurkar unit) dated from ˜131 - ˜104 ka, which represents the top of the last interglacial cycle dune sediments. The lower unconsolidated unit consists of a red silty loam dated to ˜71 ka. This Red-Paleosol unit is overlaid by a dark brown clayey silty loam This Brown-Paleosol unit dates to ˜58 - ˜36 ka and is overlaid by a dark silty clay wetland deposit dated to ˜21 - ˜10 ka. The wetland unit is topped by a quartz sand dated to ˜6.6 - 0.1 ka. This approach allowed us to investigate the relationship between the lithological units and sea-level change and thus enable the reconstruction of the coastal evolution over the last ˜130 ka. This reconstruction suggests that the stratigraphy is dominated by a sea level lowstand during which aeolian, fluvial and paleosol sediments were deposited in a terrestrial environment. The coastal-terrestrial landscape was flooded by the early to middle Holocene transgression. The results of this study provide a valuable framework for future national strategic shallow-water infrastructure construction and also for the possible locations of past human settlements in relation to coastal evolution through time.

Changes in landscape evolution patterns during the Mid-Pleistocene Revolution

NASA Astrophysics Data System (ADS)

Claude, A.; Akçar, N.; Ivy-Ochs, S.; Schlunegger, F.; Kubik, P.; Christl, M.; Vockenhuber, C.; Dehnert, A.; Kuhlemann, J.; Rahn, M. K. W.; Schluechter, C.

2016-12-01

River terraces in the Alpine Foreland are sedimentary archives that have recorded paleoenvironmental changes during the Quaternary. In the Swiss Alpine Foreland, Quaternary terraces represent a succession of proximal glaciofluvial gravels deposited by meltwater during repeated glaciations of the Alps and the foreland and lying unconformably on Tertiary molasse or Mesozoic carbonate bedrock. The morphostratigraphy of the terrace gravels has a reversed stratigraphic relationship such that older deposits occur at higher elevations than younger deposits. The aim of this study is to reconstruct the landscape evolution of the northern Alpine Foreland since the early and middle Pleistocene. We focus on seven different sites where we establish their chronology by applying cosmogenic depth-profile and isochron burial dating with 10Be, 26Al and 36Cl. Additionally we perform detailed investigations of clast fabrics, petrographic compositions and clast morphometries to identify the sediment source areas and interpret their transport mechanisms and depositional environments. Finally, coupling the reconstructed chronologies with interpolated height differences between the bedrock underlying the Quaternary deposits and the bedrock beneath the modern river allows estimating post-depositional bedrock incision rates. Analyses show that a first gravel accumulation occurred at around 2 Ma, with most of the sediments originating from the northern Central Alps or being reworked from the Miocene Molasse conglomerates. At that time, the Alpine Rhine was draining through Lake Constance into the Danube River and eastwards into the Black Sea. Long-term incision rates into bedrock are ≤ 100 m/Ma. A second phase of gravel accumulation was observed at around 1 Ma, coinciding with the Mid-Pleistocene Revolution. Results from provenance studies showed that these sediments were derived either from the northern central and eastern Alps or were reworked from the Molasse in the Alpine Foreland. During the second accumulation phase, the Alpine Rhine was already redirected westwards into the Upper Rhine Valley from where it drained northwards into the North Sea. The reorganisation of the drainage network in the foreland probably led to an acceleration in bedrock incision rates with estimated values between 100 and 350 m/Ma.

Geomorphology of submerged river channels indicates Late Quaternary tectonic activity in the Gulf of Trieste, Northern Adriatic

NASA Astrophysics Data System (ADS)

Vrabec, M.; Slavec, P.; Poglajen, S.; Busetti, M.

2012-04-01

We use multibeam and parametric subbottom sonar data, complemented with multichannel and high-resolution single-channel seismic profiles, to investigate sea-bottom morphology and subbottom sediment structure in the south-eastern half of the Gulf of Trieste, northern Adriatic Sea. The study area comprises 180 km2 of predominantly flat seabed with the water depth from 20 to 25 m. Pre-Quaternary basement consists of Mesozoic-Paleogene carbonate platform unit, overlain by Eocene marls and sandstones, covered by up to 300 m thick Quaternary sediments of predominantly continental origin. The uppermost few meters of sediment consist of Holocene fine-grained marine deposits. Structurally, the investigated area belongs to the imbricated rim of the Adriatic microplate and is dissected by several NE-dipping low-angle thrusts with up to several kms of displacement. The thrusts are cut by younger NE-SW-trending steeply dipping faults with sinistral and/or normal offset, mapped onshore. The continuation of those faults into the offshore area is suggested by mismatch of thrust structures between parallel seismic profiles. Geodetic data on present-day tectonic activity is controversial. Whereas the Adriatic microplate is currently moving northwards towards Eurasia at the rate of 2-4 mm/yr, the GNSS data show no measurable deformation in the Gulf of Trieste. On the other hand, onshore precise-levelling data suggest localized vertical motions in the range of 1 mm/yr, interpreted as an indication of thrust activity. High-resolution swath bathymetry revealed several current-related erosional and depositional features such as gullies and megadunes with up to 5 m of relief. The most conspicuous seabed morphological features are pre-Holocene river channels preserved in low-erosion submarine environment, which make excellent markers for studying the long-term geomorphological evolution of the area. The WNW-ESE-trending paleo-Rižana river is characterized by highly sinuous meandering channels. Sequential profiles perpendicular to the river course suggest consistent ~NE-ward lateral shifting of channels, parallel with inclination of the present-day seabed and with the present-day lateral gradient in channel depth. A longitudinal profile of the Rižana river plain revealed downstream increase in elevation of the stream bed, visible both from seabed bathymetry and from vertical position of channel lag deposits in subbottom sonar profiles. These observations suggest post-depositional tectonic tilting of the fluvial sediments that could be related either to activation of NE-dipping thrusts in the pre-Quaternary basement, or to minor anticlinal folding associated with Quaternary transpressional faulting along NW-SE-trending zones, implied from seismic profiles NW-ward of our study area. An enigmatic low-sinuosity channel feature runs along the coastline in the NE-SW direction and crosses the paleo-Rižana channel. Subbottom sonar profiles show asymmetric channel geometry and strong reflectors (channel lag deposits?) at the channel bottom, typical of other documented river channels in the area. This feature is vertically offset by a NE-SW-trending linear morphological flexure that corresponds in location and orientation to the onshore Monte Spaccato fault. Subbottom profiling revealed in several places an abrupt truncation of horizontal reflectors that could be manifestation of faulting. These indications of Late Quaternary - Holocene tectonic activity may have important implications for seismic hazard in the heavily populated coastal area of the Gulf of Trieste.

An alluvial record of El Niño events from northern coastal Peru

NASA Astrophysics Data System (ADS)

Wells, Lisa E.

1987-12-01

Overbank flood deposits of northern coastal Peru provide the potential for the development of a late Quaternary chronology of El Niño events. Alluvial deposits from the 1982-1983 El Niño event are the basis for establishing a type El Niño deposit. Sedimentary structures suggesting depositional processes range from sheet flows to debris flows, with sheet flood deposits being the most common. The 1982-1983 deposits are characterized by a 50- to 100-cm- thick basal gravel, overlain by a 10- to 100-cm-thick sand bed, grading into a 1- to 10-cm-thick silty sand bed and capped by a very thin layer of silt or clay. The surface of the deposit commonly displays the original shear flow lines crosscut by postdepositional mud cracks and footprints (human and animal). Stacked sequences of flood deposits are present in Pleistocene and Holocene alluvial fill, suggesting that El Niño type events likely occurred throughout the late Quaternary. A relative chronology of the deposits is developed based on terrace and soil stratigraphy and on the degree of preservation of surficial features. A minimum of 15 El Niño events occurred during the Holocene; a minimum of 21 events occurred during the late Pleistocene. Timing of the Holocene events is bracketed by isochrons derived from the archaeologic stratigraphy. Corrected radiocarbon ages from included detrital wood provide the following absolute dates for El Niño events: 1720 ± 60 A.D., 1460 ± 20 A.D., 1380 ± 140 A.D. (error overlaps with the A.D. 1460 event; these may represent a single event), and 1230 ± 60 B.C.

Characteristics of newly found Quaternary fault, southern Korea, and its tectonic implication

NASA Astrophysics Data System (ADS)

Lee, Y.; Kim, M. C.; Cheon, Y.; Ha, S.; Kang, H. C.; Choi, J. H.; Son, M.

2017-12-01

This study introduces the detailed geometry and kinematics of recently found Quaternary fault in southern Korea, named Seooe Fault, and discusses its tectonic implication through a synthetic analysis with previous studies. The N-S striking Seooe Fault shows a top-to-the-east thrust geometry and cuts the Cretaceous Goseong Formation and overlying Quaternary deposits, and its slip senses and associated minor folds in the hanging wall indicate an E-W compressional stress. The age of the lower part of the Quaternary deposits obtained by OSL dating indicates that the last movement of the fault occurred after 61 60 ka. Arcuate geometry of the main fault showing an upward decreasing dip-angle, reverse offset of the fault breccias, and reverse-sense indicators observed on neighboring N-S striking high-angle fractures indicate that this Quaternary fault was produced by the reactivation of pre-existing fault under E-W compressional stress field. Using the apparent vertical displacement of the fault and the attitudes of cutting slope and main fault surface, its minimum net displacement is calculated as 2.17 m. When the value is applied to the empirical equation of maximum displacement - moment earthquake magnitude (Mw), the magnitude is estimated to reach about 6.7, assuming that this displacement was due to one seismic event. Most of the Quaternary faults in southern Korea are observed along major inherited fault zones, and their geometry and kinematics indicate that they were reactivated under ENE-WSW or E-W compressional stress field, which is concordant with the characteristics of the Seooe Fault. In addition, focal mechanism solutions and geotechnical in-situ stress data in and around the Korean peninsula also support the current ENE-WSW or E-W regional compression. On the basis of the regional stress trajectories in and around East Asia, the current stress field in Korean peninsula is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate doesn't contribute to the crustal contraction due to its high-angle subduction that results in the crustal extension of back-arc region.

Eolian intracrater deposits on Mars - Physical properties and global distribution

NASA Technical Reports Server (NTRS)

Christensen, P. R.

1983-01-01

It is noted that more than one-fourth of all craters larger than 25 km in diameter between -50 deg S and 50 deg N have localized deposits of coarse material on the floor which are associated with the dark 'splotches' that are seen visually. If homogeneous, unconsolidated materials are assumed, the measured thermal inertias of these deposits imply effective grain sizes that range from 0.1 mm to 1 cm, with a modal value of 0.9 mm. Even though these deposits are coarser and darker than the surrounding terrains and the greater part of the Martian surface, they are not compositionally distinct from materials with similar albedos. It is thought most likely that these features were formed by entrapment of marginally mobile material that can be transported into, but not out of, crater depressions by the wind. Most of the 'splotch' deposits are coarser than the dune-forming materials occurring in the north polar region and inside extreme southern latitude craters; they probably form low, broad zibar dunes or lag deposits. The distribution of intracrater deposits is seen as suggesting that the intracrater features have been buried in the interior of Arabia and that the dust deposit is less extensive at the margins and may currently be expanding.

Late quaternary history and uranium isotopic compositions of ground water discharge deposits, Crater Flat, Nevada

USGS Publications Warehouse

Paces, James B.; Taylor, Emily M.; Bush, Charles

1993-01-01

Three carbonate-rich spring deposits are present near the southern end of Crater Flat, NV, approximately 18 km southwest of the potential high-level waste repository at Yucca Mountain. We have analyzed five samples of carbonate-rich material from two of the deposits for U and Th isotopic compositions. Resulting U-series disequilibrium ages indicate that springs were active at 18 ?? 1, 30 ?? 3, 45 ?? 4 and >70 ka. These ages are consistent with a crude internal stratigraphy at one site. Identical ages for two samples at two separate sites suggest that springs were contemporaneous, at least in part, and were most likely part of the same hydrodynamic system. In addition, initial U isotopic compositions range from 2.8 to 3.8 and strongly suggest that ground water from the regional Tertiary-volcanic aquifer provided the source for these hydrogenic deposits. This interpretation, along with water level data from near-by wells suggest that the water table rose approximately 80 to 115 m above present levels during the late Quaternary and may have fluctuated repeatedly. Current data are insufficient to allow reconstruction of a detailed depositional history, however geochronological data are in good agreement with other paleoclimatic proxy records preserved throughout the region. Since these deposits are down gradient from the potential repository site, the possibility of higher ground water levels in the future dramatically shortens both vertical and lateral ground water pathways and reduces travel times of transported radionuclides to potential discharge sites.

Soil-landscape development and late Quaternary environmental change in coastal Estremadura, Portugal

NASA Astrophysics Data System (ADS)

Daniels, Michael; Haws, Jonathan; Benedetti, Michael; Bicho, Nuno

2015-04-01

This poster integrates soil-landscape analysis with archaeological survey and paleoenvironmental reconstruction. Soils in surface and buried contexts in Estremadura, Portugal, provide evidence of landscape stability and instability, relative age relationships between landforms, and general paleoenvironmental conditions during the late Quaternary. These factors provide insight into the distribution and condition of Paleolithic archaeological sites and help understand the record of human settlement in the region. Late Pleistocene and Holocene dunes extend inland approximately 10 km from coastal source regions. Surface soils in Holocene dunes under maritime pine (Pinus pinaster) forest exhibit A, E, C/Bh and A, C horizon sequences and classify as Quartzipsamments. Surface soils in late Pleistocene dunes exhibit A, E, Bh, Bhs, Bs horizon sequences and classify as Haplorthods. Both Pleistocene and Holocene dunes commonly bury a heavily weathered soil formed in calcareous sandstone. The boundary between underlying buried soils and overlying surface soils is characterized by a lag deposit of medium to coarse, moderately-rounded gravels, underlain immediately by subsurface Bt and Bss horizons. The lag deposit and absence of buried A horizons both indicate intense and/or prolonged surface erosion prior to burial by late Quaternary dunes. Soil-geomorphic relationships therefore suggest at least two distinct episodes of dune emplacement and subsequent landscape stability following an extensive episode late Pleistocene landscape instability and soil erosion. A conceptual model of soil-landscape evolution through the late Quaternary and Holocene results from the integration of soil profile data, proxy paleoenvironmental data, and the partial record of human settled as revealed in the archaeological record.

Land subsidence threats and its management in the North Coast of Java

NASA Astrophysics Data System (ADS)

Sarah, D.; Soebowo, E.

2018-02-01

Cities on the north coast of Java such as Jakarta, Semarang, Pekalongan, and Surabaya are vulnerable to environmental pressures such as sea level change and land subsidence. Land subsidence can be caused by natural and anthropogenic processes. Geologically, the north coastal plain of Java consists of unconsolidated Holocene alluvial deposit. The recent alluvial deposit is prone to compaction, and further aggravated by anthropogenic forces such as groundwater extraction and land development. Understanding the complex interaction of natural and manmade factors is essential to establish mitigation strategy. Although the impacts of land subsidence are widely felt, many do not realize that land subsidence is taking place. This paper presents a brief review of the land subsidence threats in the North coast of Java and proposes a recommendation for suitable management response.

Late Quaternary alluviation and offset along the eastern Big Pine fault, southern California

USGS Publications Warehouse

DeLong, S.B.; Minor, S.A.; Arnold, L.J.

2007-01-01

Determining late Quaternary offset rates on specific faults within active mountain belts is not only a key component of seismic hazard analysis, but sheds light on regional tectonic development over geologic timescales. Here we report an estimate of dip-slip rate on the eastern Big Pine oblique-reverse fault in the upper Cuyama Valley within the western Transverse Ranges of southern California, and its relation to local landscape development. Optically stimulated luminescence (OSL) dating of sandy beds within coarse-grained alluvial deposits indicates that deposition of alluvium shed from the Pine Mountain massif occurred near the southern margin of the Cuyama structural basin at the elevation of the Cuyama River between 25 and 14??ka. This alluvial deposit has been offset ??? 10??m vertically by the eastern Big Pine fault, providing a latest Quaternary dip-slip rate estimate of ??? 0.9??m/ky based on a 50?? fault dip. Incision of the adjacent Cuyama River has exposed a section of older Cuyama River sediments beneath the Pine Mountain alluvium that accumulated between 45 and 30??ka on the down-thrown footwall block of the eastern Big Pine fault. Corroborative evidence for Holocene reverse-slip on the eastern Big Pine fault is ??? 1??m of incised bedrock that is characteristically exposed beneath 2-3.5??ka fill terraces in tributaries south of the fault. The eastern Big Pine fault in the Cuyama Valley area has no confirmed record of historic rupture; however, based on our results, we suggest the likelihood of multiple reverse-slip rupture events since 14??ka. ?? 2007 Elsevier B.V. All rights reserved.

Evaluation of ERTS-1 imagery for mapping Quaternary deposits and landforms in the Great Plains and Midwest

NASA Technical Reports Server (NTRS)

Morrison, R. B. (Principal Investigator); Hallberg, G. R.

1973-01-01

The author has identified the following significant results. The main landform associations and larger landforms are readily identifiable on the better images and commonly the gross associations of surficial Quaternary deposits also can be differentiated, primarily by information on landforms and soils. Maps showing the Quaternary geologic-terrain units that can be differentiated from the ERTS-1 images are being prepared for study areas in Illinois, Iowa, Missouri, Kansas, Nebraska, and South Dakota. Preliminary maps at 1:1 million scale are given of two of the study areas, the Peoria and Decatur, Illinois, 1 deg x 2 quadrangles. These maps exemplify the first phase of investigations, which consists of identifying and mapping landform and land use characteristics and geologic-surficial materials directly from ERTS-1 images alone, without input of additional data. These maps shown that commonly the boundaries of geologic-terrain units can be identified more accurately on ERTS-1 images than on topographic maps of 1:250,000 scale. From analysis of drainage patterns, stream-divide relations, and tone and textural variations on the ERTS-1 images, the trends of numerous moraines of Wisconsinan and possibly some of Illinoian age were mapped. In the Peoria study area the trend of a buried valley of the Mississippi River is revealed.

Quaternary geology and geologic hazards of the West Desert Hazardous Industry Area, Tooele County, Utah

USGS Publications Warehouse

Solomon, Barry J.; Black, Bill D.; ,

1990-01-01

The study of Quaternary geology provides information to evaluate geologic conditions and identify geologic constraints on construction in the West Desert Hazardous Industry Area (WDHIA). The WDHIA includes portions of the Great Salt Lake Desert to the west, underlain by several thousand feet of sediments capped by saline mudflats, and Ripple Valley to the east, separated from the Desert by the Grayback Hills and underlain by several hundred feet of sediments in the Cedar Mountains piedmont zone. Quaternary surficial units include marginal, shore-zone, and deep-water lacustrine sediments deposited in Pleistocene Lake Bonneville; eolian deposits; and alluvial sediments. The level of Lake Bonneville underwent major oscillations resulting in the creation of four basin-wide shorelines, three of which are recognized in the WDHIA. Geologic hazards in the WDHIA include the possible contamination of ground water in basin-fill aquifers, debris flows and flash floods in the piedmont zone, and earthquakes and related hazards. Numerous factors contribute to unsafe foundation conditions. Silty and sandy sediments may be subject to liquefaction or hydrocompaction, clayey sediments and mud flats of the Great Salt Lake Desert may be subject to shrinking or swelling, and gypsiferous dunes and salt flats are subject to subsidence due to dissolution.

The enigma of the Australian Alps, young landscapes and missing cryogenic features.

NASA Astrophysics Data System (ADS)

Slee, Adrian; Shulmeister, James; Clark, Doug

2014-05-01

Widespread evidence for pre last glacial cycle glaciation of late Quaternary ages has been documented from mid-latitude southern hemisphere mountain environments in New Zealand, southern South America and the Tasmanian Highlands. On mainland Australia however cirque and small valley glaciation in the Australian Alps is limited to OIS 4-3 and the last glacial maximum (OIS 2) (Barrows et al. 2001). This contrasts with the other southern hemisphere glacial records that indicate significantly more extensive glaciations preceding the last glacial cycle. In both the Southern Andes and Tasmania the maximum glaciations occurred prior to 783 kya (Glasser et al. 2008, Colhoun et al. 2010) while in tectonically active New Zealand it is at least clear that the scale of glaciation has been diminishing over the last 3 glacial cycles (Shulmeister et al. 2010). In all these locations early workers argued for extensive ice coverage, but subsequent investigations limited the extent and number of glacial advances before more recent work has locally re-extended the glacial limits and greatly increased the number of glacial advances. Similarly, in the highlands of SE Australia the possibility of more pervasive ice coverage was initially entertained; but since the 1960s and especially the 1980s the general consensus is that the lack of glacial evidence is a result of cold dry conditions prevailing for much of the Quaternary on the Australian Alps (Reeves et al. 2013) Recent work by the authors on the extent of relict periglacial block deposits in Australia have identified these block deposits as far north as 29°30'S on the Great Dividing Range, confirming strong freeze-thaw conditions well into the sub-tropics at moderate (900-1200 m) elevations. Curiously, however, the same mapping work has also highlighted the limited development of block deposits and other freeze-thaw landforms, such as tors, in the highest regions of the Australian Alps, in areas beyond the known limits of glaciation. It is also noteworthy that the periglacial features on mainland SE Australia that have absolute ages relate primarily to the last glacial maximum (Barrows et al. 2004). This again contrasts with Tasmania were the periglacial features are both associated with multiple ice ages and are often polygenetic. This presentation reviews geomorphic evidence from two of the highest regions of SE Australia (Bogong High Plains and the Kosciuszko Massif) to determine the extent and nature of cryogenic landscape features in these areas. It will attempt to resolve questions both about the nature of processes operating in these landscapes and add to the debate about the curious paucity of pre-last glacial landscapes at high elevations in SE Australia. References: Barrows, T.T., Stone, J.O., Fifield, L.K. and Cresswell, R.G., 2001. Late Pleistocene glaciation of the Kosciuszko Massif, Snowy Mountains, Australia. Quaternary Research, 55: 179-189 Barrows, T.T., Stone, J. O. and Fifield. L.K, 2004. Exposure ages for Plestocene periglacial deposits in Australia. Quaternary Science Reviews, Vol. 23 (5-6): 697-708 Colhoun, E.A., Kiernan, K., Barrows, T.T. and Geode, A., 2010, Advances in Quaternary studies in Tasmania. Geological Society, London, Special Publications 346:121-139 Glasser, N.F., Jansson, K.N., Harrison, S. and Klenman, J., 2008. The glacial geomorphology and Pleistocene history of South America between 38°S and 56°S. Quaternary Science Reviews 27 (3-4): 365-390 Reeves, J.M., Barrows, T.T., Cohen, T.J., Kiem, A.S., Bostock, H.C., Fitzsimmons, K.E., Jansen, J.D., Kemp, J., Krause, C., Petherick, L. and Phipps, S.J., Climate variability over the last 35,000 years recorded in marine and terrestrial archives in the Australian region: an OZ-INTIMATE compilation. Quaternary Science Reviews 74: 21-34 Shulmeister, J, Thackray, G.D., Rieser, U, Hyatt, O.M, Rother, H., C.C. Smart, and D.J.A. Evans 2010. The stratigraphy, timing and climatic implications of glacilacustrine deposits in the middle Rakaia Valley, South Island, New Zealand. Quaternary Science Reviews 29:2362-2381.

Classification of the LCVF AVIRIS test site with a Kohonen artificial neural network

NASA Technical Reports Server (NTRS)

Merenyi, Erzsebet; Singer, Robert B.; Farrand, William H.

1993-01-01

We present a classification of an AVIRIS spectral image of the Lunar Crater Volcanic Field (LCVF). Geologic mapping from such data is made possible by distinctive mineral signatures: absorption features and the shape of the spectral continuum. The subtle spectral shape differences between some of the geological units in this scene along with the high dimensionality of the spectral presents a challenging pattern recognition task. We found an artificial neural network powerful in separating 13 geological units based on the full spectral resolution. The LCVF, in northern Nye County, Nevada, was the primary focus of the NASA-sponsored Geologic Remote Sensing Field Experiment in the summer of 1989. It consists of over 100 square miles of Quaternary basaltic pyroclastic and flow deposits. These deposits lie atop ignimbrites and silicic lava flows of Tertiary age and in turn are overlain by Quaternary alluvial and playa deposits. This AVIRIS image was collected on September 29, 1989 at 11:44 at 11:44 PDT. The 256-by-256 pixel subsection in this study contains oxidized basaltic cinder deposits, the southern half of the Lunar Lake playa, and outcrops of the Rhyollite of Big Sand Spring Valley. Vegetation in LCVF is sparse, but locally abundant within washes and near springs.

Imaging Quaternary glacial deposits and basement topography using the transient electromagnetic method for modeling aquifer environments

NASA Astrophysics Data System (ADS)

Simard, Patrick Tremblay; Chesnaux, Romain; Rouleau, Alain; Daigneault, Réal; Cousineau, Pierre A.; Roy, Denis W.; Lambert, Mélanie; Poirier, Brigitte; Poignant-Molina, Léo

2015-08-01

Aquifer formations along the northern shore of the Saint-Lawrence River in Quebec (Canada) mainly consist of glacial and coastal deposits of variable thickness overlying Precambrian bedrock. These deposits are important because they provide the main water supply for many communities. As part of a continuing project aimed at developing an inventory of the groundwater resources in the Charlevoix and Haute-Côte-Nord (CHCN) regions of the province of Quebec in Canada, the central loop transient electromagnetic (TEM) method was used to map the principal hydrogeological environments in these regions. One-dimensional smooth inversion models of the TEM soundings have been used to construct two-dimensional electrical resistivity sections, which provided images for hydrogeological validation. Electrical contour lines of aquifer environments were compared against available well logs and Quaternary surface maps in order to interpret TEM soundings. A calibration table was achieved to represent common deposits and basements. The calibration table was then exported throughout the CHCN region. This paper presents three case studies; one in the Forestville site, another in the Les Escoumins site and the other in the Saint-Urbain site. These sites were selected as targets for geophysical surveys because of the general lack of local direct hydrogeological data related to them.

Differentiation of debris-flow and flash-flood deposits: implications for paleoflood investigations

USGS Publications Warehouse

Waythomas, Christopher F.; Jarrett, Robert D.; ,

1993-01-01

Debris flows and flash floods are common geomorphic processes in the Colorado Rocky Mountain Front Range and foothills. Usually, debris flows and flash floods are associated with excess summer rainfall or snowmelt, in areas were unconsolidated surficial deposits are relatively thick and slopes are steep. In the Front Range and foothills, flash flooding is limited to areas below about 2300m whereas, debris flow activity is common throughout the foothill and alpine zones and is not necessarily elevation limited. Because flash floods and debris flows transport large quantities of bouldery sediment, the resulting deposits appear somewhat similar even though such deposits were produced by different processes. Discharge estimates based on debris-flow deposits interpreted as flash-flood deposits have large errors because techniques for discharge retrodiction were developed for water floods with negligible sediment concentrations. Criteria for differentiating between debris-flow and flash-flood deposits are most useful for deposits that are fresh and well-exposed. However, with the passage of time, both debris-flow and flash-flood deposits become modified by the combined effects of weathering, colluviation, changes in surface morphology, and in some instances removal of interstitial sediment. As a result, some of the physical characteristics of the deposits become more alike. Criteria especially applicable to older deposits are needed. We differentiate flash-flood from debris-flow and other deposits using clast fabric measurements and other morphologic and sedimentologic techniques (e.g., deposit morphology, clast lithology, particle size and shape, geomorphic setting).

Quaternary geologic map of the Shelby 1° x 2° quadrangle, Montana

USGS Publications Warehouse

Fullerton, David S.; Colton, Roger B.; Bush, Charles A.

2013-01-01

The Shelby quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S./Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes the Sweet Grass Hills. The primary river is the Marias River. The ancestral Missouri River was diverted south of the Bearpaw Mountains by a Laurentide ice sheet. The fill in the buried ancestral valleys of the Missouri River and Marias River in the southeast quarter of the quadrangle contains a complex stratigraphy of fluvial, glaciofluvial, ice-contact, glacial, lacustrine, and eolian deposits. The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (for example, ground-moraine deposits, end-moraine deposits, stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 21 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in pedology or agronomy. Rather, it is a generalized map of soils recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. On the glaciated plains, the surficial deposits are glacial, ice-contact, glaciofluvial, alluvial, lacustrine, eolian, colluvial, and mass-movement deposits. In the Sweet Grass Hills, beyond the limit of Quaternary glaciation they are fluvial, colluvial, and mass-movement deposits. Till of late Wisconsin age is represented by three map units. Tills of Illinoian and pre-Illinoian glaciations are not mapped, but are widespread in the subsurface. Linear ice-molded landforms (primarily drumlins) indicate directions of ice flow during late Wisconsin glaciation.

Aquifer characteristics, water availability, and water quality of the Quaternary aquifer, Osage County, northeastern Oklahoma, 2001-2002

USGS Publications Warehouse

Mashburn, Shana L.; Cope, Caleb C.; Abbott, Marvin M.

2003-01-01

Additional sources of water are needed on the Osage Reservation for future growth and development. The Quaternary aquifer along the Arkansas River in the Osage Reservation may represent a substantial water resource, but limited amounts of hydrogeologic data were available for the aquifer. The study area is about 116 square miles of the Quaternary aquifer in the Arkansas River valley and the nearby upland areas along the Osage Reservation. The study area included the Arkansas River reach downstream from Kaw Lake near Ponca City, Oklahoma to upstream from Keystone Lake near Cleveland, Oklahoma. Electrical conductivity logs were produced for 103 test holes. Water levels were determined for 49 test holes, and 105 water samples were collected for water-quality field analyses at 46 test holes. Water-quality data included field measurements of specific conductance, pH, water temperature, dissolved oxygen, and nitrate (nitrite plus nitrate as nitrogen). Sediment cores were extracted from 20 of the 103 test holes. The Quaternary aquifer consists of alluvial and terrace deposits of sand, silt, clay, and gravel. The measured thickness of the alluvium ranged from 13.7 to 49.8 feet. The measured thickness of the terrace sediments ranged from 7 to 93.8 feet. The saturated thickness of all sediments ranged from 0 to 38.2 feet with a median of 24.8 feet. The weighted-mean grain size for cores from the alluvium ranged from 3.69 to 0.64 f, (0.08- 0.64 millimeter), and ranged from 4.02 to 2.01 f (0.06-0.25 millimeter) for the cores from terrace deposits. The mean of the weighted-mean grain sizes for cores from the alluvium was 1.67 f (0.31 millimeter), and the terrace deposits was 2.73 f (0.15 millimeter). The hydraulic conductivity calculated from grain size of the alluvium ranged from 2.9 to 6,000 feet per day and of the terrace deposits ranged from 2.9 to 430 feet per day. The calculated transmissivity of the alluvium ranged from 2,000 to 26,000 feet squared per day with a median of 5,100 feet squared per day. Water in storage in the alluvium was estimated to be approximately 200,000 acre-feet. The amount of water annually recharging the aquifer was estimated to be approximately 4,800 acre-feet. Specific conductance for all water samples ranged from 161 to 6,650 microsiemens per centimeter. Median specific conductance for the alluvium was 683 microsiemens per centimeter and for the terrace deposits was 263 microsiemens per centimeter. Dissolved-solids concentrations, estimated from specific conductance, for water samples from the aquifer ranged from 88 to 3,658 milligrams per liter. Estimated median dissolved- solids concentration for the alluvium was 376 milligrams per liter and for the terrace deposits was 145 milligrams per liter. More than half of the samples from the Quaternary aquifer were estimated to contain less than 500 milligrams per liter dissolved solids. Field-screened nitrate concentrations for the sampling in December 2001-August 2002 ranged from 0 to 15 milligrams per liter. The field-screened nitrate concentrations for the second sampling in September 2002 were less than corresponding laboratory reported values.

Debris-flow deposits and watershed erosion rates near southern Death Valley, CA, United States

USGS Publications Warehouse

Schmidt, K.M.; Menges, C.M.; ,

2003-01-01

Debris flows from the steep, granitic hillslopes of the Kingston Range, CA are commensurate in age with nearby fluvial deposits. Quaternary chronostratigraphic differentiation of debris-flow deposits is based upon time-dependent characteristics such as relative boulder strength, derived from Schmidt Hammer measurements, degree of surface desert varnish, pedogenesis, and vertical separation. Rock strength is highest for Holocene-aged boulders and decreases for Pleistocene-aged boulders weathering to grus. Volumes of age-stratified debris-flow deposits, constrained by deposit thickness above bedrock, GPS surveys, and geologic mapping, are greatest for Pleistocene deposits. Shallow landslide susceptibility, derived from a topographically based GIS model, in conjunction with deposit volumes produces watershed-scale erosion rates of ???2-47 mm ka-1, with time-averaged Holocene rates exceeding Pleistocene rates. ?? 2003 Millpress.

Results of Radiocarbon Dating of Holocene Deposits from the Sea of Azov

NASA Astrophysics Data System (ADS)

Matishov, G. G.; Kovaleva, G. V.; Arslanov, Kh. A.; Dyuzhova, K. V.; Polshin, V. V.; Zolotareva, A. E.

2018-04-01

New data on the absolute age of Quaternary bottom deposits from the Sea of Azov based on the results of radiocarbon analysis (14C) are presented. Overall, 67 radiocarbon dating of bottom deposits of New and Ancient Azov Ages were obtained. The thickness of sediments of the New Azov Age and their distribution over different areas of the Sea of Azov was determined during the study; the results obtained were compared with the reference data available. An integrated approach to the study of deposits, based on the combination of the biostratigraphy methods and the results of absolute age dating, was applied.

Quaternary Geochronology, Paleontology, and Archaeology of the Upper San Pedro River Valley, Sonora, Mexico

NASA Astrophysics Data System (ADS)

Gaines, E. P.

2013-12-01

This poster presents the results of multi-disciplinary investigations of the preservation and extent of Quaternary fossil-bearing strata in the San Pedro River Valley in Sonora, Mexico. Geologic deposits in the portions of the San Pedro Valley in southern Arizona contain one of the best late Cenozoic fossil records known in North America and the best record of early humans and extinct mammals on the continent. The basin in the U.S. is one of the type locations for the Blancan Land Mammal Age. Hemiphilian and Irvingtonian fossils are common. Rancholabrean remains are widespread. Strata in the valley adjacent to the international border with Mexico have yielded the densest concentration of archaeological mammoth-kill sites known in the western hemisphere. Despite more than 60 years of research in the U.S., however, and the fact that over one third of the San Pedro River lies south of the international boundary, little has been known about the late Cenozoic geology of the valley in Mexico. The study reported here utilized extensive field survey, archaeological documentation, paleontological excavations, stratigraphic mapping and alluvial geochronology to determine the nature and extent of Quaternary fossil-bearing deposits in the portions of the San Pedro Valley in Sonora, Mexico. The results demonstrate that the Plio-Pleistocene fossil -bearing formations known from the valley in Arizona extend into the uppermost reaches of the valley in Mexico. Several new fossil sites were discovered that yielded the remains of Camelids, Equus, Mammuthus, and other Proboscidean species. Late Pleistocene archaeological remains were found on the surface of the surrounding uplands. AMS radiocarbon dating demonstrates the widespread preservation of middle- to late- Holocene deposits. However, the late Pleistocene deposits that contain the archaeological mammoth-kill sites in Arizona are absent in the valley in Mexico, and are now known to be restricted to relatively small portions of the valley immediately north of the international border.

Outcrop-scale acoustic facies analysis and latest Quaternary development of Hueneme and Dume submarine fans, offshore California

USGS Publications Warehouse

Piper, D.J.W.; Hiscott, R.N.; Normark, W.R.

1999-01-01

The uppermost Quaternary deposits of the Hueneme and Dume submarine fans in the Santa Monica Basin have been investigated using a closed-spaced grid of boomer seismic-reflection profiles, which give vertical resolution of a few tens of centimetres with acoustic penetration to 50 m. Acoustic facies integrated with geometry define six architectural elements, some with discrete subelements that are of a scale that can be recognized in outcrops of ancient turbidite systems. In the Santa Monica Basin, the relationship of these elements to fan morphology, stratigraphy and sediment source is precisely known. The width of upper Hueneme fan valley has been reduced from 5 km since the last glacial maximum to 1 km at present by construction of laterally confined sandy levees within the main valley. The middle fan comprises three main subelements: thick sand deposits at the termination of the fan valley, low-gradient sandy lobes typically 5 km long and < 10 m thick, and scoured lobes formed of alternating sand and mud beds with many erosional depressions. The site of thickest lobe sediment accumulation shifts through time, with each sand bed deposited in a previous bathymetric low (i.e. compensation cycles). The lower fan and basin plain consists of sheet-like alternations of sand and mud with shallow channels and lenses. Variations in the rate of late Quaternary sea level rise initiated changes in sediment facies distribution. At lowstand, and during the approximately 11 ka stillstand in sea level, the Hueneme Fan was fed largely by hyperpycnal flow from the Santa Clara River delta, depositing high sediment waves on the right hand levee and thick sandy lobes on the middle fan. At highstand of sea level, most turbidity currents were generated by failure of silty prodelta muds. In contrast, the smaller Dume Fan was apparently always fed from littoral drift of sand through a single-canyon point source.

Dissolved noble gases and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany

NASA Astrophysics Data System (ADS)

Gumm, L. P.; Bense, V. F.; Dennis, P. F.; Hiscock, K. M.; Cremer, N.; Simon, S.

2016-02-01

Groundwater in shallow unconsolidated sedimentary aquifers close to the Bornheim fault in the Lower Rhine Embayment (LRE), Germany, has relatively low δ2H and δ18O values in comparison to regional modern groundwater recharge, and 4He concentrations up to 1.7 × 10-4 cm3 (STP) g-1 ± 2.2 % which is approximately four orders of magnitude higher than expected due to solubility equilibrium with the atmosphere. Groundwater age dating based on estimated in situ production and terrigenic flux of helium provides a groundwater residence time of ˜107 years. Although fluid exchange between the deep basal aquifer system and the upper aquifer layers is generally impeded by confining clay layers and lignite, this study's geochemical data suggest, for the first time, that deep circulating fluids penetrate shallow aquifers in the locality of fault zones, implying that sub-vertical fluid flow occurs along faults in the LRE. However, large hydraulic-head gradients observed across many faults suggest that they act as barriers to lateral groundwater flow. Therefore, the geochemical data reported here also substantiate a conduit-barrier model of fault-zone hydrogeology in unconsolidated sedimentary deposits, as well as corroborating the concept that faults in unconsolidated aquifer systems can act as loci for hydraulic connectivity between deep and shallow aquifers. The implications of fluid flow along faults in sedimentary basins worldwide are far reaching and of particular concern for carbon capture and storage (CCS) programmes, impacts of deep shale gas recovery for shallow groundwater aquifers, and nuclear waste storage sites where fault zones could act as potential leakage pathways for hazardous fluids.

New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

NASA Astrophysics Data System (ADS)

Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

2014-05-01

In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional report: the geology of the central North Sea.' London: HMSO for the British Geological Survey Kuhlmann, G., Langereis C.G., Munsterman, D., van Leeuwen, R.-J., Verreussel, R., Meulenkamp, J.E., Wong, Th.E., 2006 'Intergrated chronostratigraphy of the Pliocene-Pliestocene interval and its relation to the regional stratigraphical stages in the Southern North Sea region' Netherlands Journal of Geosciences 85(1), 29-45 Rasmussen, E.A., Vejb?k O.V., Bidstrup, T., Piasecki, S., Dybkj?r, K., 2005 'Late Cenozoic depositional history of the Danish North Sea Basin: implications for the petroleum systems in the Kraka, Halfdan, Siri and Nini fields', Petroleum Geology Conference series 6, 1347-1358 Sejrup, H.P., Aareseth, I., Haflidason, H., 1991 'The Quaternary succession in the northern North Sea' Marine Geology 101 103-111

Seismic stratigraphy and late Quaternary shelf history, south-central Monterey Bay, California

USGS Publications Warehouse

Chin, J.L.; Clifton, H.E.; Mullins, H.T.

1988-01-01

The south-central Monterey Bay shelf is a high-energy, wave-dominated, tectonically active coastal region on the central California continental margin. A prominent feature of this shelf is a sediment lobe off the mouth of the Salinas River that has surface expression. High-resolution seismic-reflection profiles reveal that an angular unconformity (Quaternary?) underlies the entire shelf and separates undeformed strata above it from deformed strata below it. The Salinas River lobe is a convex bulge on the shelf covering an area of approximately 72 km2 in water depths from 10 to 90 m. It reaches a maximum thickness of 35 m about 2.5 km seaward of the river mouth and thins in all directions away from this point. Adjacent shelf areas are characterized by only a thin (2 to 5 m thick) and uniform veneer of sediment. Acoustic stratigraphy of the lobe is complex and is characterized by at least three unconformity-bounded depositional sequences. Acoustically, these sequences are relatively well bedded. Acoustic foresets occur within the intermediate sequence and dip seaward at 0.7?? to 2.0??. Comparison with sedimentary sequences in uplifted onshore Pleistocene marine-terrace deposits of the Monterey Bay area, which were presumably formed in a similar setting under similar processes, suggests that a general interpretation can be formulated for seismic stratigraphic patterns. Depositional sequences are interpreted to represent shallowing-upwards progradational sequences of marine to nonmarine coastal deposits formed during interglacial highstands and/or during early stages of falling sea level. Acoustic foresets within the intermediate sequence are evidence of seaward progradation. Acoustic unconformities that separate depositional sequences are interpreted as having formed largely by shoreface planation and may be the only record of the intervening transgressions. The internal stratigraphy of the Salinas River lobe thus suggests that at least several late Quaternary regressions and transgressions may be recorded under the present shelf. This record may represent the last major eustatic cycle of sea level, an interval not observed in uplifted onshore Pleistocene marine terraces. ?? 1988.

Radiocarbon dating late Quaternary loess deposits using small terrestrial gastropod shells

USGS Publications Warehouse

Pigati, Jeff S.; McGeehin, John P.; Muhs, Daniel R.; Bettis, E. Arthur

2013-01-01

Constraining the ages and mass accumulation rates of late Quaternary loess deposits is often difficult because of the paucity of organic material typically available for 14C dating and the inherent limitations of luminescence techniques. Radiocarbon dating of small terrestrial gastropod shells may provide an alternative to these methods as fossil shells are common in loess and contain ∼12% carbon by weight. Terrestrial gastropod assemblages in loess have been used extensively to reconstruct past environmental conditions but have been largely ignored for dating purposes. Here, we present the results of a multi-faceted approach to understanding the potential for using small terrestrial gastropod shells to date loess deposits in North America. First, we compare highly resolved 14C ages of well-preserved wood and gastropod shells (Succineidae) recovered from a Holocene loess section in Alaska. Radiocarbon ages derived from the shells are nearly identical to wood and plant macrofossil ages throughout the section, which suggests that the shells behaved as closed systems with respect to carbon for at least the last 10 ka (thousands of calibrated 14C years before present). Second, we apply 14C dating of gastropod shells to late Pleistocene loess deposits in the Great Plains using stratigraphy and independent chronologies for comparison. The new shell ages require less interpretation than humic acid radiocarbon ages that are commonly used in loess studies, provide additional stratigraphic coverage to previous dating efforts, and are in correct stratigraphic order more often than their luminescence counterparts. Third, we show that Succineidae shells recovered from historic loess in the Matanuska River Valley, Alaska captured the 20th century 14C bomb spike, which suggests that the shells can be used to date late Holocene and historic-aged loess. Finally, results from Nebraska and western Iowa suggest that, similar to other materials, shell ages approaching ∼40 ka should be viewed with caution as they may reflect trace amounts of contamination. In sum, our results show that small terrestrial gastropod shells, especially from the Succineidae family, provide reliable ages for late Quaternary loess deposits in North America.

Introduction to the special issue of "Loess and Climatic Record": Memory of Professor Liu Tungsheng for his scientific contributions and his centenary birthday

NASA Astrophysics Data System (ADS)

Ding, Zhongli; Derbyshire, Edward; Sun, Jimin

2018-04-01

This special issue is to memory Professor Liu Tungsheng for his scientific contributions and his centenary birthday. Liu Tungsheng was the former President of the International Association for Quaternary Association (INQUA), and the Honorary President of the Chinese Association for Quaternary Research (CHIQUA). Liu's best known contribution to Quaternary research is his pioneering and systematic study of the extensive loess deposits of China, which has been regarded as the best terrestrial paleoclimatic archive on the Earth. He won many international awards including the Tyler Prize for Environmental Achievement in 2002 and the Alexander von Humboldt Medal in 2007. He was an inspiring leader, one of China's, and indeed one of the world's most outstanding Earth scientists. This introduction aims to explore the personal factors behind his great achievements and reviews the papers included in this special issue from his colleagues, friends, and students.

Erosional and depositional changes wrought by the flood of May 1978 in the channels of Powder River, southeastern Montana

USGS Publications Warehouse

Meade, Robert H.; Moody, John A.

2013-01-01

Powder River’s second largest flood of record (1919–2012) moved through northeastern Wyoming and southeastern Montana during May 1978. Within a ninety-kilometer reach of the channel in southeastern Montana, the most prominent planform effects of the flood were the growth of meander bends by bank erosion (this was most intense just downriver of bend apexes, causing 1–2 channel widths of lateral displacement) and the erosion of new cutoff channels through the necks of two large and two small meanders. Surveys of cross sections, made before and after the flood, show the responses of the channel to the flood waters, which ranged from minimal (bedrock control) to large (maximum channel curvature in unconsolidated bank and terrace deposits). Geomorphic work done during two weeks of extreme flooding in May 1978, as measured by cross-channel erosion and new sediment deposition, was approximately equal in magnitude to the work done during the two decades (1978–1998) that followed the flood.

Elastic stress interaction between faulting and volcanism in the Olacapato-San Antonio de Los Cobres area (Puna plateau, Argentina)

NASA Astrophysics Data System (ADS)

Bonali, F. L.; Corazzato, C.; Tibaldi, A.

2012-06-01

We describe the relationships between Plio-Quaternary tectonics, palaeoseismicity and volcanism along the NW-trending Calama-Olacapato-El Toro (COT) lineament that crosses the Andean chain and the Puna Plateau and continues within the eastern Cordillera at about 24° S. We studied in detail the area from the Chile-Argentina border to a few km east of the San Antonio del Los Cobres village. Satellite and field data revealed the presence of seven Quaternary NW-striking normal left-lateral fault segments in the southeastern part of the studied area and of a Plio-Quaternary N-S-striking graben structure in the northwestern part. The NW-striking Chorrillos fault (CF) segment shows the youngest motions, of late Pleistocene age, being marked by several fault scarps, sag ponds and offset Quaternary deposits and landforms. Offset lavas of 0.78 ± 0.1 Ma to 0.2 ± 0.08 Ma indicate fault kinematics characterised by a pitch angle of 20° to 27° SE, a total net displacement of 31 to 63.8 m, and a slip-rate of 0.16 to 0.08 mm/yr. This fault segment is 32 km long and terminates to the northwest near a set of ESE-dipping thrust faults affecting Tertiary strata, while to the southeast it terminates 10 km further from San Antonio. In the westernmost part of the examined area, in Chile at altitudes > 4000 m, recent N-S-striking normal fault scarps depict the 5-km-wide and 10-km-long graben structure. Locally, fault pitches indicate left-lateral normal kinematics. These faults affect deposits up to ignimbrites of Plio-Quaternary age. Scarp heights are from a few metres to 24 m. Despite that this area is located along the trace of the COT strike-slip fault system, which is reported as a continuous structure from Chile to Argentina in the literature, no evidence of NW-striking Plio-Quaternary strike-slip structures is present here. A series of numerical models were also developed in an elastic half-space with uniform isotropic elastic properties using the Coulomb 3.1 code. We studied the stress changes caused by slip along the various Quaternary COT fault segments, showing that the last motions occurred along the CF might promote in the future further displacement along nearby fault segments located to the northwest. Furthermore, slip along the NW-striking fault segments imparts normal stress changes on the nearby Tuzgle volcano feeding system.

Loess sedimentation in Tibet: provenance, processes, and link with Quaternary glaciations

USGS Publications Warehouse

Sun, Jielun; Li, S.-H.; Muhs, D.R.; Li, B.

2007-01-01

Well-preserved loess deposits are found on the foothills of mountains along the middle reaches of the Yarlung Zangbo River in southern Tibet. Optically stimulated luminescence (OSL) dating is used to determine loess ages by applying the single-aliquot regeneration technique. Geochemical, mineralogical, and granulometric measurements were carried out to allow a comparison between loess from Tibet and the Chinese Loess Plateau. Our results demonstrate that (i) the loess deposits have a basal age of 13-11 ka, suggesting they accumulated after the last deglaciation, (ii) loess in southern Tibet has a "glacial" origin, resulting from eolian sorting of glaciofluvial outwash deposits from braided river channels or alluvial fans by local near-surface winds, and (iii) the present loess in the interior of Tibet has accumulated since the last deglaciation when increased monsoonal circulation provided an increased vegetation cover that was sufficient for trapping eolian silt. The lack of full-glacial loess is either due to minimal vegetation cover or possibly due to the erosion of loess as glaciofluvial outwash during the beginning of each interglacial. Such processes would have been repeated during each glacial-interglacial cycle of the Quaternary. ?? 2007 Elsevier Ltd. All rights reserved.

Geomorphological characteristics of increased landslide activity in the Gudbrandsdalen valley, Norway

NASA Astrophysics Data System (ADS)

Heyerdahl, Håkon; Høydal, Øyvind

2016-04-01

The Gudbrandsdalen valley in Eastern Norway lies in a region where annual precipitation is generally low (down to 300 mm/year). The landslide activity has consequently historically been low, although the lower part of the valley sides generally is draped with thick layers of Quaternary deposits, primarily of glacial or glaciofluvial origin. The perception of natural hazards in the valley was previously primarily connected to flooding in the main river in the valley bottom during early summer, due to large discharges resulting from snowmelt in the mountainous regions west and east of the valley. However, several high-intensity events have changed the image of the region. Starting with a localized, but intense, landslide event in the Northern part of the valley in year 2008, two larger events covering almost the entire valley occurred in the years 2011 and 2013. A high number of landslides was triggered in all these events, including many flash floods and debris flows/debris slides in small and steep tributary rivers along the valley slopes. Landslide triggering covers different release mechanisms: In 2008, landslides were triggered without precipitation in not-frozen soil deposits without snow cover in the lower part of the valley. Groundwater flow through the permeable bedrock ("Otta schist") resulting from snow-melt in the elevated mountainous areas caused landslide triggering due to positive pore-water pressures forming at the bedrock surface below soil deposits, or at depressions in the terrain. Subsequent rainfall resulted in even more landslides being released. In later events (years 2011 and 2013) many landslides were caused by surface water taking new paths downslope, often due to man-made changes in existing waterways (typically poorly planned drainage solutions or new roads). Relatively small discharges in slopes with unconsolidated and easily erodible glacial deposits (typically lateral moraine) in many cases lead to small initial slides that down-slope developed into large erosional debris slides/floods of considerable size. Also along existing tributary rivers, the intense rainfall events resulted in flash-floods with heavy erosion and entrainment of deposits from the riverbed, including massive transport of trees. Also on open slopes a number of landslides were observed, assumedly triggered primarily by direct infiltration of rainfall, and possibly assisted by groundwater flow in underlying bedrock. Considerable damage to infrastructure and also dwellings has resulted from the events. A new approach has proved necessary to capture the risk elements connect to landslide and flood for this valley region when it comes to planning purposes. Among others, there is a need to consider the potential damage resulting from under-dimensioned culverts leading to complete failure of railroad or road embankments). Work is underway in order to improve the understanding of release mechanisms for typical landslides in the valley, which also will be highly relevant for other areas in Norway were similar natural hazards are encountered, and where climatic change may change the regional landslide activity.

Surficial geologic map of the Dillingham quadrangle, southwestern Alaska

USGS Publications Warehouse

Wilson, Frederic H.

2018-05-14

The geologic map of the Dillingham quadrangle in southwestern Alaska shows surficial unconsolidated deposits, many of which are alluvial or glacial in nature. The map area, part of Alaska that was largely not glaciated during the late Wisconsin glaciation, has a long history reflecting local and more distant glaciations. Late Wisconsin glacial deposits have limited extent in the eastern part of the quadrangle, but are quite extensive in the western part of the quadrangle. This map and accompanying digital files are the result of the interpretation of black and white aerial photographs from the 1950s as well as more modern imagery. Limited new field mapping in the area was conducted as part of a bedrock mapping project in the northeastern part of the quadrangle; however, extensive aerial photographic interpretation represents the bulk of the mapping effort.

Evolution of the Lian River coastal basin in response to Quaternary marine transgressions in Southeast China

NASA Astrophysics Data System (ADS)

Tang, Yongjie; Zheng, Zhuo; Chen, Cong; Wang, Mengyuan; Chen, Bishan

2018-04-01

The coastal basin deposit in the Lian River plain is among the thickest Quaternary sequences along the southeastern coast of China. The clastic sediment accumulated in a variety of environmental settings including fluvial, channel, estuary/coastal and marine conditions. Detailed investigation of lithofacies, grain-size distributions, magnetic susceptibility, microfossils and chronology of marine core CN01, compared with regional cores, and combined with offshore seismic reflection profiles, has allowed us to correlate the spatial stratigraphy in the inner and outer plain and the seismic units. Grain size distribution analysis of core CN-01 through compositional data analysis and multivariate statistics were applied to clastic sedimentary facies and sedimentary cycles. Results show that these methods are able to derive a robust proxy information for the depositional environment of the Lian River plain. We have also been able to reconstruct deltaic evolution in response to marine transgressions. On the basis of dating results and chronostratigraphy, the estimated age of the onset of deposition in the Lian River coastal plain was more than 260 kyr BP. Three transgressive sedimentary cycles revealed in many regional cores support this age model. Detailed lithological and microfossil studies confirm that three marine (M3, M2 and M1) and three terrestrial (T3, T2 and T1) units can be distinguished. Spatial correlation between the inner plain, outer plain (typical cores characterized by marine transgression cycles) and offshore seismic reflectors reveals coherent sedimentary sequences. Two major boundaries (unconformity and erosion surfaces) can be recognized in the seismic profiles, and these correspond to weathered reddish and/or variegated clay in the study core, suggesting that Quaternary sediment changes on the Lian River plain were largely controlled by sea-level variations and coastline shift during glacial/interglacial cycles.

Upper Neogene stratigraphy and tectonics of Death Valley - A review

USGS Publications Warehouse

Knott, J.R.; Sarna-Wojcicki, A. M.; Machette, M.N.; Klinger, R.E.

2005-01-01

New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to < 1.1 ka. These tephra beds and tuffs establish relations among the Upper Pliocene to Middle Pleistocene sedimentary deposits at Furnace Creek basin, Nova basin, Ubehebe-Lake Rogers basin, Copper Canyon, Artists Drive, Kit Fox Hills, and Confidence Hills. New geologic formations have been described in the Confidence Hills and at Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ???3.3 Ma the Furnace Creek basin was a northwest-southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique-normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone. Post -3.3 Ma geometric, structural, and kinematic changes in the Black Mountains and Towne Pass fault zones led to the break up of Furnace Creek basin and uplift of the Copper Canyon and Nova basins. Internal kinematics of northern Death Valley are interpreted as either rotation of blocks or normal slip along the northeast-southwest-trending Towne Pass and Tin Mountain fault zones within the Eastern California shear zone. ?? 2005 Elsevier B.V. All rights reserved.

Quaternary dinoflagellate cysts in the Arctic Ocean: Potential and limitations for stratigraphy and paleoenvironmental reconstructions

NASA Astrophysics Data System (ADS)

Matthiessen, Jens; Schreck, Michael; De Schepper, Stijn; Zorzi, Coralie; de Vernal, Anne

2018-07-01

The Arctic Ocean is a siliciclastic depositional environment which lacks any rock-forming biogenic calcareous and siliceous components during large parts of its Quaternary history. These hemipelagic sediments are nevertheless suitable for the study of organic-walled microfossils of which the fossil remains of dinoflagellates - dinoflagellate cysts - are the most important group. Dinoflagellate cysts have become an important tool in paleoceanography of the high northern latitudes, but their potential for Quaternary biostratigraphy has remained largely unexplored. Dinoflagellate cysts are the dominant marine palynomorph group which is more continuously present in the marginal seas (e.g. Barents Sea, Bering Sea) than in the Arctic Ocean itself throughout the Quaternary. Most species have long stratigraphic ranges, are temporary absent and show abundance variations on glacial-interglacial timescales. Of the more than 30 taxa recorded, only Habibacysta tectata and Filisphaera filifera became extinct in the Pleistocene. The highest persistent occurrence of H. tectata at ca. 2.0 Ma and the top of F. filifera acme at ca. 1.8 Ma can be used for supra-regional stratigraphic correlation between the Arctic Ocean and adjacent basins. These events corroborate a slow sedimentation rate model for the Quaternary section on the central Lomonosov Ridge, but a combination of different methods will have to be applied to provide a detailed chronostratigraphy. The occurrence of cysts of phototrophic dinoflagellates in certain stratigraphic intervals on Lomonosov Ridge supports published evidence of episodic opening of the multiyear Arctic sea ice cover during the Quaternary probably related to a stronger inflow of Atlantic water. This contradicts the hypothesis of a permanently ice covered central Arctic Ocean in the Quaternary.

Hydrogeologic framework and groundwater/surface-water interactions of the South Fork Nooksack River Basin, northwestern Washington

USGS Publications Warehouse

Gendaszek, Andrew S.

2014-01-01

A hydrogeologic framework of the South Fork (SF) Nooksack River Basin in northwestern Washington was developed and hydrologic data were collected to characterize the groundwater-flow system and its interaction with surface‑water features. In addition to domestic, agricultural, and commercial uses of groundwater within the SF Nooksack River Basin, groundwater has the potential to provide ecological benefits by maintaining late-summer streamflows and buffering stream temperatures. Cold-water refugia, created and maintained in part by groundwater, have been identified by water-resource managers as key elements to restore the health and viability of threatened salmonids in the SF Nooksack River. The SF Nooksack River drains a 183-square mile area of the North Cascades and the Puget Lowland underlain by unconsolidated glacial and alluvial sediments deposited over older sedimentary, metamorphic, and igneous bedrock. The primary aquifer that interacts with the SF Nooksack River was mapped within unconsolidated glacial outwash and alluvial sediment. The lower extent of this unit is bounded by bedrock and fine-grained, poorly sorted unconsolidated glaciomarine and glaciolacustrine sediments. In places, these deposits overlie and confine an aquifer within older glacial sediments. The extent and thickness of the hydrogeologic units were assembled from mapped geologic units and lithostratigraphic logs of field-inventoried wells. Generalized groundwater-flow directions within the surficial aquifer were interpreted from groundwater levels measured in August 2012; and groundwater seepage gains and losses to the SF Nooksack River were calculated from synoptic streamflow measurements made in the SF Nooksack River and its tributaries in September 2012. A subset of the field-inventoried wells was measured at a monthly interval to determine seasonal fluctuations in groundwater levels during water year 2013. Taken together, these data provide the foundation for a future groundwater-flow model of the SF Nooksack River Basin that may be used to investigate the potential effects of future climate change, land use, and groundwater pumping on water resources in the study area. Site-specific hydrologic data, including time series of longitudinal temperature profiles measured with a fiber-optic distributed temperature sensor and continuous monitoring of stream stage and water levels measured in wells in adjacent wetlands and aquifers, also were measured to characterize the interaction among the SF Nooksack River, surficial aquifers, and riparian wetlands.

Hyperspectral analysis of the ultramafic complex and adjacent lithologies at Mordor, NT, Australia

USGS Publications Warehouse

Rowan, L.C.; Simpson, C.J.; Mars, J.C.

2004-01-01

The Mordor Complex consists of a series of potassic ultramafic rocks which were intruded into Proterozoic felsic gneisses and amphibolite and are overlain by quartzite and unconsolidated deposits. In situ and laboratory 0.4 to 2.5 ??m reflectance spectra show Al-OH absorption features caused by absorption in muscovite, kaolinite, and illite/smectite in syenite, granitic gneiss, quartzite and unconsolidated sedimentary deposits, and Fe,Mg-OH features due to phlogopite, biotite, epidote, and hornblende in the mafic and ultramafic rocks. Ferrous-iron absorption positioned near 1.05 ??m is most intense in peridotite reflectance spectra. Ferric-iron absorption is intense in most of the felsic lithologies. HyMap data were recorded in 126 narrow bands from 0.43 to 2.5 ??m along a 7-km-wide swath with approximately 6-m spatial resolution. Correction of the data to spectral reflectance was accomplished by reference to in situ measurements of an extensive, alluvial plain. Spectral classes for matched filter processing were selected by using the pixel purity index procedure and analysis of in situ and laboratory spectra. Considering the spatial distribution of the resulting 14 classes, some classes were combined, which produced eight classes characterized by Al-OH absorption features, and three Fe,Mg-OH absorption-feature classes. Comparison of the distribution of these 11 spectral classes to a generalized lithologic map of the study area shows that the spectral distinction among the eight Al-OH classes is related to variations in primary lithology, weathering products, and vegetation density. Quartzite is represented in three classes, syenite corresponds to a single scattered class, quartz-muscovite-biotite schist defines a single very coherent class, and unconsolidated sediments are portrayed in four classes. The three mafic-ultramafic classes are distinguished on the basis of generally intense Fe,Mg-OH and ferrous-iron absorption features. A single class represents the main Mordor ultramafic mass. Epidote-bearing rocks define another class, which corresponds to biotite gneiss and, in the southern part of the area, to fracture zones. The third class, which exhibits Al-OH, as well as Fe,Mg-OH features, represents hornblende gneiss and other mafic gneisses. These results indicate the importance of analyzing the VNIR and SWIR spectral shape and albedo, as well as analyzing specific spectral features, for mapping lithologic units in this weathered terrain. ?? 2004 Elsevier Inc. All rights reserved.

Nature and tectonic implications of uneven sedimentary filling of the South China Sea oceanic basin

NASA Astrophysics Data System (ADS)

Yin, Shaoru; Li, Jiabiao; Ding, Weiwei; Fang, Yinxia

2017-04-01

The IODP Expedition 349 in 2014, for the first time, illustrated significant differences of sediment rate and lithology in the central South China Sea (SCS) oceanic basin. Based on seismic reflection profiles tied to IODP349 drilling data, we investigated characteristics of sedimentary filling of the whole SCS oceanic basin, and examined their implications for tectonics. Results show that sediments fill the SCS oceanic basin mainly in three depositional patterns. Firstly, during the Oligocene to middle Miocene, sediments amassed almost solely and then connected like a band parallel to the continent in a low average sediment rate (<10 m/Myr) in the northern oceanic basin. These sediments were deposited mainly in the form of submarine fans and mass transport deposits. Sediments were predominately supplied by the Red and Pearl Rivers and the Dongsha Islands. The sedimentary characteristics likely reflect the latest early Miocene end of seafloor spreading of the SCS and the first-phase rapid uplift of the Tibetan Plateau. Secondly, during the late Miocene, deposition mainly occurred in the Northwest Sub-basin and extended southeastward with a middle average sediment rate ( 30 m/Myr). Sediments were mostly transported by the Red River and Xisha Trough and deposited in the form of submarine fans. The abnormal increase of sediment rate in the Northwest Sub-basin reflects late Miocene slip reversal of the Red River Fault. Finally, since the Pliocene, sediments gradually propagated northeastward in the Southwestern Sub-basin, and accumulated rapidly in the southeastern and northeastern basin, especially in the northern Manila Trench during the Quaternary, in an average sediment rate about 60-80 m/Myr. These sediments were transported mainly by submarine canyons and settled in the form of submarine fans and canyon-overbank deposition. Sediments came from four major sources, including Taiwan, Dongsha Islands, Mekong River, and northern Palawan. The Pliocene to Quaternary explosion of uneven sedimentary filling in the SCS oceanic basin points to the combined action of local and regional tectonics, including the two-phase rapid uplift of the Tibetan Plateau, the Pliocene to Quaternary increased northwestward movement of the Philippine Sea plate and Dongsha event. This study exhibits hitherto most completed observation of sedimentary filling of the SCS oceanic basin and provides new geophysical evidences for the local and regional important tectonics.

Beatty, Nevada: A section in U.S. Geological Survey research in radioactive waste disposal - Fiscal years 1983, 1984, and 1985 (WRI 87-4009)

USGS Publications Warehouse

Fischer, Jeffrey M.; Nichols, William D.; Dinwiddie, G.A.; Trask, N.J.

1986-01-01

A commercial low-level radioactive-waste disposal site has been operating near Beatty, Nevada, about 150 km northwest of Las Vegas, since 1962. The 32-ha site is situated in a desolate region of the Amargosa River Valley, sometimes referred to as the Amargosa Desert. Average annual precipitation is only about 114 mm. The site is underlain by 175 m of unconsolidated, generally coarse-grained, alluvial-fan and flood-plain deposits. The water table is at a depth of 90 m.

California State Waters Map Series: offshore of Pacifica, California

USGS Publications Warehouse

Edwards, Brian D.; Phillips, Eleyne L.; Dartnell, Peter; Greene, H. Gary; Bretz, Carrie K.; Kvitek, Rikk G.; Hartwell, Stephen R.; Johnson, Samuel Y.; Cochrane, Guy R.; Dieter, Bryan E.; Sliter, Ray W.; Ross, Stephanie L.; Golden, Nadine E.; Watt, Janet Tilden; Chinn, John L.; Erdey, Mercedes D.; Krigsman, Lisa M.; Manson, Michael W.; Endris, Charles A.; Cochran, Susan A.; Edwards, Brian D.

2015-01-01

The continental shelf in the map area is about 40 km wide, with water depths at the shelf break that range from about 80 to 120 m. Within California’s State Waters, the midshelf to inner shelf areas are characterized by a relatively flat, shallow (water depths of as much as 44 m) seafloor that dips gently (about 0.2° to 0.3°) westward. The seafloor is composed primarily of unconsolidated Holocene sediment (marine deposits), as well as some nearshore bedrock outcrops that consist primarily of rocks of the Tertiary Purisima Formation and also Cretaceous plutonic rocks (granite or granodiorite).

Ash-flow tuffs: Their origin, geologic relations, and identification

USGS Publications Warehouse

Ross, Clarence S.; Smith, Robert L.

1961-01-01

Pyroclastic materials, which are interpreted as having been deposited by flowage as a suspension of ash in volcanic gas, are becoming widely recognized as major geologic episodes. These may be unconsolidated, indurated by partial welding, or welded into a compact rock. Many students are working on these materials and the interest in them is so widespread that need for a coordinated treatise on them has developed. This report deals with the history of the concept of their origin; gives detailed descriptions of their character and mode of occurrence; gives criteria for their recognition; and considers their distribution and consolidation.

Mapping urban geology of the city of Girona, Catalonia

NASA Astrophysics Data System (ADS)

Vilà, Miquel; Torrades, Pau; Pi, Roser; Monleon, Ona

2016-04-01

A detailed and systematic geological characterization of the urban area of Girona has been conducted under the project '1:5000 scale Urban geological map of Catalonia' of the Catalan Geological Survey (Institut Cartogràfic i Geològic de Catalunya). The results of this characterization are organized into: i) a geological information system that includes all the information acquired; ii) a stratigraphic model focused on identification, characterization and correlation of the geological materials and structures present in the area and; iii) a detailed geological map that represents a synthesis of all the collected information. The mapping project integrates in a GIS environment pre-existing cartographic documentation (geological and topographical), core data from compiled boreholes, descriptions of geological outcrops within the urban network and neighbouring areas, physico-chemical characterisation of representative samples of geological materials, detailed geological mapping of Quaternary sediments, subsurface bedrock and artificial deposits and, 3D modelling of the main geological surfaces. The stratigraphic model is structured in a system of geological units that from a chronostratigrafic point of view are structured in Palaeozoic, Paleogene, Neogene, Quaternary and Anthropocene. The description of the geological units is guided by a systematic procedure. It includes the main lithological and structural features of the units that constitute the geological substratum and represents the conceptual base of the 1:5000 urban geological map of the Girona metropolitan area, which is organized into 6 map sheets. These map sheets are composed by a principal map, geological cross sections and, several complementary maps, charts and tables. Regardless of the geological map units, the principal map also represents the main artificial deposits, features related to geohistorical processes, contours of outcrop areas, information obtained in stations, borehole data, and contour lines of the top of the pre-Quaternary basement surface. The most representative complementary maps are the quaternary map, the subsurface bedrock map and the isopach map of thickness of superficial deposits (Quaternary and anthropogenic). The map sheets also include charts and tables of relevant physic-chemical parameters of the geological materials, harmonized downhole lithological columns from selected boreholes, stratigraphic columns, and, photographs and figures illustrating the geology of the mapped area and how urbanization has changed the natural environment. The development of systematic urban geological mapping projects, such as the example of Girona's case, which provides valuable resources to address targeted studies related to urban planning, geoengineering works, soil pollution and other important environmental issues that society should deal with in the future.

Hot-spring sinter deposits in the Alvord-Pueblo Valley, Harney County, Oregon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cummings, M.L.; St. John, A.M.

1993-04-01

Silica sinter deposits occur at Borax Lake, Alvord Hot Springs, and Mickey Springs in the Alvord-Pueblo Valley. Although the sinter deposits occur in areas of active hot springs, sinter is not being deposited. Hot springs are localized along faults that have been active since the Pleistocene. The sinter deposits formed after the drying of glacial Lake Alvord, but before and during extensive wind deflation of glacial-lacustrine sediments. At Mickey Springs, sinter rests directly on unaltered, unconsolidated lithic-rich sand. At Borax Lake, sinter overlies unaltered diatomite, but some armoring, presumably by silica, of the 30 m vent has developed. Field relationsmore » suggest rapid dumping of silica from solution without alteration of the country rock at the vent. Discharge of thermal fluids and cold groundwater along the same structure may have produced colloidal silica carried in a solution stripped of dissolved silica. Sinter is composed of opal-a, traces of detrital feldspar and quartz, and evaporation-related boracite. The concentration of Sb is similar among the three sinter deposits (20 to 70 ppm); however, As, Cs, and Br are highest at Borax Lake (5 to 560 ppm; 26 to 118 ppm; 5 to 1,040 ppm) while Hg is highest at Mickey Springs (1.0 to 5.2 ppm).« less

Geomorphological palaeoenvironments of the Sneeuberg Range, Great Karoo, South Africa

NASA Astrophysics Data System (ADS)

Holmes, P. J.; Boardman, J.; Parsons, A. J.; Marker, M. E.

2003-12-01

Sedimentary sequences within headwater valleys on the landward side of the Great Escarpment of South Africa are elucidated and their significance as indicators of environmental change is assessed. This study focuses on the Sneeuberg Range, the most prominent mountain range in the semi-arid central Great Karoo. Valley fills of a hitherto unrecognised complexity and of a greater age than any previously recorded in the central Great Karoo are reported. Three phases of deposition spanning the Late Pleistocene up to the present are documented from sites where gully erosion has incised the valley fills. The earliest depositional phase is represented by deeply weathered, calcretised gravel deposits, which probably were emplaced by debris flow and fluvial processes in the form of a fan. These deposits subsequently were buried by finer grained, largely unconsolidated sediment, with much of this emplacement occurring during the Holocene. There is evidence for phases of landscape stability and instability within this facies. Finally, sheetwash has removed fine-grained sediments from valley flanks and has deposited it either on valley bottoms, or in presently active gullies. This process appears to be ongoing, and is the subject of current investigation. The sedimentary deposits are interpreted as representing a wide range of palaeoenvironmental conditions that have prevailed within the central Great Karoo since the penultimate glaciation. Copyright

Geochemical evidence for the origin of late Quaternary loess in central Alaska

USGS Publications Warehouse

Muhs, D.R.; Budahn, J.R.

2006-01-01

Loess is extensive in central Alaska, but there are uncertainties about its source and the direction of paleo-winds that deposited it. Both northerly and southerly winds have been inferred. The most likely sources of loess are the Tanana River (south), the Nenana River (southeast), and the Yukon River (north). Late Quaternary loess in central Alaska has immobile trace-element compositions (Cr/Sc, Th/Ta, Th/ Sc, Th/U, Eu/Eu*, GdN/YbN) that indicate derivation mostly from the Tanana River. However, other ratios (As/Sb, Zr/Hf, LaN/YbN) and quantitative modeling indicate that the Yukon River was also a source. During the last glacial period, there may have been a longer residence time of the Siberian and Canadian high-pressure cells, along with a strengthened Aleutian low-pressure cell. This would have generated regional-scale northeasterly winds and explains derivation of loess from the Yukon River. However, superim-posed upon this synoptic-scale circulation, there may have been strong, southerly katabatic winds from expanded glaciers on the northern flank of the Alaska Range. These winds could have provided eolian silt from the Tanana River. Yukon River and Tanana River sediments are highly calcareous, whereas Fairbanks-area loess is not. This suggests that carbonate leaching in loess kept ahead of sedimentation and that late Quaternary loess in central Alaska was deposited relatively slowly. ?? 2006 NRC Canada.

Challenges for geochronologies in permafrost environments: the case of Bol'shoy Lyakhovsky, Siberian Arctic

NASA Astrophysics Data System (ADS)

Wetterich, Sebastian; Fuchs, Margret; Schwamborn, Georg; Schirrmeister, Lutz

2015-04-01

Ice-bearing Quaternary deposits in permafrost environments comprise valuable archives of paleoenvironmental and palaeo-landscape dynamics over several glacial-interglacial cycles. Information on past conditions manifest in the mineralogical, organic and ice inventories. The characteristic ground ice abundance of permafrost evolves largely due to water supply by precipitation and surface run-off, while air, and consequently near-surface, temperatures control to which depth deposits freeze or thaw. This has several consequences on the continuity of permafrost sequences. Permafrost preservation or degradation depends basically on (1) climatic conditions during formation, (2) their decoupling from the active layer depth and (3) past relief conditions. In this context, warmer interstadial and interglacial periods promote permafrost degradation by ground ice melt and subsequent surface subsidence. Such processes are commonly named as thermokarst that forms basins and valleys within older deposits and creates new accumulation areas. Shifts between periglacial accumulation and erosion frequently cause gaps in permafrost sequences. This complicates geochronological interpretations as representatives of consecutive Quaternary periods may be found at laterally different positions and altitudes. Additionally, they may comprise differing sediment properties as a consequence of paleo-relief and related process dynamic. With this contribution, we discuss the challenges for establishing Quaternary geochronologies of arctic permafrost sequences using the example of Bol'shoy Lyakhovsky Island (New Siberian Archipelago). The island exposes sequences at its southern coast that are among the oldest dated Quaternary terrestrial permafrost deposits. Various proxies for paleo environmental reconstruction unravel at least three generations of cold- and warm-stage deposition ranging from the Holocene to the Eemian (MIS 5e) Interglacial, and potentially beyond that. However, the stratigraphic context is ambiguous due to the vertical discontinuity and potential hiatuses, especially for units older than the MIS 3 Interstadial. For example, stadial conditions of the MIS 4 and the MIS 6(?) are recorded in sediment units locally named as Kuchchugui Suite. The floodplain sediments are dated by AMS radiocarbon to < 53 ka BP and to 57 - 79 ka by IRSL. The lithostratigraphic context of other sites suggests Kuchchugui-like floodplain deposits that pre-date the Eemian Interglacial but remain without numerical ages so far. Despite the use of different dating methods to obtain permafrost formation ages there are still obvious discrepancies when comparing geochronological results from different physical methods. One main problem is that dating methods are generally not well established on frozen material and refer to differing permafrost components. Some of the challenges are related to unknown influences of freeze-thaw processes on chemical and physical parameters relevant for the chosen dating technique. Here, we cannot give the ultimate answer, but rather aim to highlight and discuss the advantages and drawbacks of the different dating techniques applied in our study area, including AMS radiocarbon, luminescence and radioisotope Th/U methods.

Hydrogeologic framework, groundwater movement, and water budget of the Kitsap Peninsula, west-central Washington

USGS Publications Warehouse

Welch, Wendy B.; Frans, Lonna M.; Olsen, Theresa D.

2014-01-01

This report presents information used to characterize the groundwater-flow system on the Kitsap Peninsula, and includes descriptions of the geology and hydrogeologic framework, groundwater recharge and discharge, groundwater levels and flow directions, seasonal groundwater-level fluctuations, interactions between aquifers and the surface‑water system, and a water budget. The Kitsap Peninsula is in the Puget Sound lowland of west-central Washington, is bounded by Puget Sound on the east and by Hood Canal on the west, and covers an area of about 575 square miles. The peninsula encompasses all of Kitsap County, the part of Mason County north of Hood Canal, and part of Pierce County west of Puget Sound. The peninsula is surrounded by saltwater and the hydrologic setting is similar to that of an island. The study area is underlain by a thick sequence of unconsolidated glacial and interglacial deposits that overlie sedimentary and volcanic bedrock units that crop out in the central part of the study area. Geologic units were grouped into 12 hydrogeologic units consisting of aquifers, confining units, and an underlying bedrock unit. A surficial hydrogeologic unit map was developed and used with well information from 2,116 drillers’ logs to construct 6 hydrogeologic sections and unit extent and thickness maps. Unconsolidated aquifers typically consist of moderately to well-sorted alluvial and glacial outwash deposits of sand, gravel, and cobbles, with minor lenses of silt and clay. These units often are discontinuous or isolated bodies and are of highly variable thickness. Unconfined conditions occur in areas where aquifer units are at land surface; however, much of the study area is mantled by glacial till, and confined aquifer conditions are common. Groundwater in the unconsolidated aquifers generally flows radially off the peninsula in the direction of Puget Sound and Hood Canal. These generalized flow patterns likely are complicated by the presence of low-permeability confining units that separate discontinuous bodies of aquifer material and act as local groundwater-flow barriers. Groundwater-level fluctuations observed during the monitoring period (2011–12) in wells completed in unconsolidated hydrogeologic units indicated seasonal variations ranging from 1 to about 20 feet. The largest fluctuation of 33 feet occurred in a well that was completed in the bedrock unit. Streamgage discharge measurements made during 2012 indicate that groundwater discharge to creeks in the area ranged from about 0.41 to 33.3 cubic feet per second. During 2012, which was an above-average year of precipitation, the groundwater system received an average of about 664,610 acre-feet of recharge from precipitation and 22,122 acre-feet of recharge from return flows. Most of this annual recharge (66 percent) discharged to streams, and only about 4 percent was withdrawn from wells. The remaining groundwater recharge (30 percent) left the groundwater system as discharge to Hood Canal and Puget Sound.

Discussion on Ubeid, K.A., 2016. Quaternary alluvial deposits of Wadi Gaza in the middle of the Gaza Strip (Palestine): Facies, granulometric characteristics, and their paleoflow direction. JAES 118: 274-283

NASA Astrophysics Data System (ADS)

Roskin, Joel

2017-10-01

The location of the Gaza Strip at the southeastern corner of the Mediterranean Sea along a transition zone between Mediterranean and arid climate zones at the meeting point between fluvial, coastal, and aeolian sediments makes the Strip an important region for Quaternary, hydrogeologic, geomorphic, and palaeoclimatic studies (Aish, 2004). Wadi Gaza, the only water course that fully crosses the Gaza Strip into the southeastern Mediterranean Sea is an important water source for the proliferating and dense population of the Gaza Strip (Zaineldeen and Aish, 2012), is an indispensable part of natural life in Gaza and has an interesting history and rich vegetation (Abd Rabou et al., 2016). As such, the hydrogeologic conditions of Wadi Gaza need to be fully resolved. This includes the study of the wadi's palaeohydrology and the current anthropogenic impact upon flow and deposition along the watercourse.

Morphostructural characterization of the Charco basin and its surrounding areas in the Chihuahua segment of north Mexican Basin and Range Province

NASA Astrophysics Data System (ADS)

Troiani, Francesco; Menichetti, Marco

2014-05-01

The Chihuahua Basin and Range (CBR) is the eastern branch of the northern Mexican Basin and Range Province that, from a morphostructural point of view, presently is one amongst the lesser-known zones of the southern portion of the North America Basin and Range Province. The study area covers an approximately 800 km2-wide portion of the CBR and encompasses the fault-bounded Charco basin and its surrounding areas. The bedrock of the area pertains to the large siliceous-igneous province of the Sierra Madre Occidental and consists of volcanoclastic rocks including Oligocene dacite, rhyolite, rhyolitic tuffs, and polimitic conglomerates. The region is characterized by a series of NW-SE oriented valleys delimited by tilted monoclinal blocks bounded by high angle, SW-dipping, normal faults. Abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins are the main morphological elements of the area. The valleys correspond to structural grabens filled with Plio-Pleistocene continental sediments. These grabens are about 10 km wide, while the extensional fault system extend over a distance of more than 15 km. The mountain ranges are in most cases continuous over distances that range from 10 to 70 km including different branches of the extensional and transfer faults. The morphogenesis is mainly erosive in character: erosional landforms (such as rocky scarps, ridges, strath-terraces, erosional pediment, reverse slopes, landslide scar zones, litho-structural flat surfaces) dominate the landscape. In contrast, Quaternary depositional landforms are mainly concentrated within the flat valleys or basins. The Quaternary deposits consist of wide alluvial fans extending to the foot of the main ridges, fluvial and debris-slope deposits. The morphostructural characterization of the area integrated different methodologies, including: i) geomorphological and structural field analyses; ii) remote sensing and geo-morphometric investigations based on aerial photos and Digital Elevation Models (a 28x28 m DEM and high-resolution LIDAR dataset in key sites), and iii) geophysical investigations (high resolution reflection seismic profiling combined with refraction seismic tomography). The main outputs of this research are as follows: i) the Charco basin master-faults and their conjugate extensional system were geometrically characterized and their main associated landforms mapped and described; ii) the morphostratigraphic correlations amongst both deformed and tectonically unaffected Quaternary deposits revealed that the Charco basin master fault has been inactive over the Holocene; iii) the main extensional fault system is associated with conjugate faults, oriented approximately SSW-NNE, that segmented the Charco basin master faults and favored the deposition of the most recent piedmont fans along the eastern margin of the basin; iv) the local morphostructures had played a dominant influence on the Quaternary evolution of both drainage network and relief landforms.

Trace metal-rich Quaternary hydrothermal manganese oxide and barite deposit, Milos Island, Greece

USGS Publications Warehouse

Hein, J.R.; Stamatakis, G.; Dowling, J.S.

2000-01-01

The Cape Vani Mn oxide and barite deposit on Milos Island offers an excellent opportunity to study the three-dimensional characteristics of a shallow-water hydrothermal system. Milos Island is part of the active Aegean volcanic arc. A 1 km long basin located between two dacitic domes in northwest Milos is filled with a 35-50 m thick section of Quaternary volcaniclastic and pyroclastic rocks capped by reef limestone that were hydrothermally mineralized by Mn oxides and barite. Manganese occurs as thin layers, as cement of sandstone and as metasomatic replacement of the limestone, including abundant fossil shells. Manganese minerals include chiefly δ-MnO2, pyrolusite and ramsdellite. The MnO contents for single beds range up to 60%. The Mn oxide deposits are rich in Pb (to 3.4%), BaO (to 3.1%), Zn (to 0.8%), As (to 0.3%), Sb (to 0.2%) and Ag (to 10 ppm). Strontium isotopic compositions of the Mn oxide deposits and sulphur isotopic compositions of the associated barite show that the mineralizing fluids were predominantly sea water. The Mn oxide deposit formed in close geographical proximity to sulphide-sulphate-Au-Ag deposits and the two deposit types probably formed from the same hydrothermal system. Precipitation of Mn oxide took place at shallow burial depths and was promoted by the mixing of modified sea water (hydrothermal fluid) from which the sulphides precipitated at depth and sea water that penetrated along faults and fractures in the Cape Vani volcaniclastic and tuff deposits. The hydrothermal fluid was formed from predominantly sea water that was enriched in metals leached from the basement and overlying volcanogenic rocks. The hydrothermal fluids were driven by convection sustained by heat from cooling magma chambers. Barite was deposited throughout the time of Mn oxide mineralization, which occurred in at least two episodes. Manganese mineralization occurred by both focused and diffuse flow, the fluids mineralizing the beds of greatest porosity and filling dilatational fractures along with barite.

Long term landscape evolution within central Apennines (Italy): Marsica and Peligna region morphotectonics and surface processes

NASA Astrophysics Data System (ADS)

Miccadei, E.; Piacentini, T.; Berti, C.

2010-12-01

The relief features of the Apennines have been developed in a complex geomorphological and geological setting from Neogene to Quaternary. Growth of topography has been driven by active tectonics (thrust-related crustal shortening and high-angle normal faulting related to crustal extension), regional rock uplift, and surface processes, starting from Late Miocene(?) - Early Pliocene. At present a high-relief landscape is dominated by morphostructures including high-standing, resistant Mesozoic and early Tertiary carbonates ridges (i.e. thrust ridges, faulted homocline ridges) and intervening, erodible Tertiary siliciclastics valleys (i.e. fault line valleys) and Quaternary continental deposits filled basins (i.e. tectonic valleys, tectonic basins). This study tries to identify paleo-uplands that may be linked to paleo-base levels and aims at the reconstruction of ancient landscapes since the incipient phases of morphogenesis. It analyzes the role of tectonics and morphogenic processes in the long term temporal scale landscape evolution (i.e. Mio?-Pliocene to Quaternary). It is focused on the marsicano-peligna region, located along the main drainage divide between Adriatic side and Tyrrhenian side of Central Apennines, one of the highest average elevation area of the whole chain. The work incorporates GIS-based geomorphologic field mapping of morphostructures and Quaternary continental deposits, and plano-altimetric analysis and morphometry (DEM-, map-based) of the drainage network (i.e. patterns, hypsometry, knick points, Ks). Field mapping give clues on the definition of paleo-landscapes related to different paleo-morpho-climatic environments (i.e. karst, glacial, slope, fluvial). Geomorphological evidence of tectonics and their cross-cutting relationships with morphostructures, continental deposits and faults, provide clues on the deciphering of the reciprocal relationship of antecedence of the paleo-landscapes and on the timing of morphotectonics. Morphotectonic features are related to Neogene thrusts, reactivated or displaced by complex kinematic strike slip and followed by extensional tectonic features (present surface evidence given by fault line scarps, fault line valleys, fault scarps, fault slopes, wind gaps, etc.). Geomorphic evidence of faults is provided also by morphometry of the drainage network: highest long slope of the main streams (knick points and Ks) are located where the streams cut across or run along recent faults. Correlation of tectonic elements, paleosurfaces, Quaternary continental deposits, by means of morphotectonic cross sections, lead to the identification, in the marsicano-peligna region, of areas in which morphotectonics acted in the same period, becoming younger moving from the West to the East. In conclusion, recognition of different morphotectonic features, identification of different paleo-landscapes, and reconstruction of their migration history, contribute to define the main phases of syn and post orogenic, Apennine chain landscape evolution: it results from the link of alternating morphotectonics and surface processes, due to migrating fault activity, rock uplift processes and alternating karst, glacial, slope, fluvial processes.

Using hydrochemical data and modelling to enhance the knowledge of groundwater flow and quality in an alluvial aquifer of Zagreb, Croatia.

PubMed

Marković, Tamara; Brkić, Željka; Larva, Ozren

2013-08-01

The Zagreb alluvial aquifer system is located in the southwest of the Pannonian Basin in the Sava Valley in Croatia. It is composed of Quaternary unconsolidated deposits and is highly utilised, primarily as a water supply for the more than one million inhabitants of the capital city of Croatia. To determine the origin and dynamics of the groundwater and to enhance the knowledge of groundwater flow and the interactions between the groundwater and surface water, extensive hydrogeological and hydrochemical investigations have been completed. The groundwater levels monitored in nested observation wells and the lithological profile indicate that the aquifer is a single hydrogeologic unit, but the geochemical characteristics of the aquifer indicate stratification. The weathering of carbonate and silicate minerals has an important role in groundwater chemistry, especially in the area where old meanders of the Sava River existed. Groundwater quality was observed to be better in the deeper parts of the aquifer than in the shallower parts. Furthermore, deterioration of the groundwater quality was observed in the area under the influence of the landfill. The stable isotopic composition of all sampled waters indicates meteoric origin. NETPATH-WIN was used to calculate the mixing proportions between initial waters (water from the Sava River and groundwater from "regional" flow) in the final water (groundwater sampled from observation wells). According to the results, the mixing proportions of "regional" flow and the river water depend on hydrological conditions, the duration of certain hydrological conditions and the vicinity of the Sava River. Moreover, although the aquifer system behaves as a single hydrogeologic unit from a hydraulic point of view, it still clearly demonstrates geochemical stratification, which could be a decisive factor in future utilisation strategies for the aquifer system. Copyright © 2013 Elsevier B.V. All rights reserved.

Spokane Valley-Rathdrum Prairie aquifer, Washington and Idaho

USGS Publications Warehouse

Drost, B.W.; Seitz, Harold R.

1977-01-01

The Spokane Valley-Rathdrum Prairie aquifer is composed of unconsolidated Quaternary glaciofluvial deposits underlying an area of about 350 square miles. Transmissivities in the aquifer range from about 0.13 million to 11 million feet squared per day and ground-water velocities exceed 60 feet per day in some areas. The water-table gradient ranges from about 2 feet per mile to more than 60 feet per mile, and during a year the water table fluctuates on the order of 5 to 10 feet. For most of the aquifer the water table is between 40 and 400 feet below land surface. The aquifer is recharged and discharged at an average rate of about 1,320 cubic feet per second. Water is presently (1976) pumped from the aquifer at an average rate of about 239 cubic feet per second for domestic, industrial, and agricultural uses. Most of this is discharged to the Spokane River, lost to evapotranspiration, or applied to the land surface with little or no change in quality. However, about 34 cubic feet per second becomes waste water generated by domestic and industrial activities and is returned to the aquifer by percolation from cesspools and drain fields. The quality of water in the aquifer is generally good. Less than one-half of 1 percent of the 3,300 analyses available exceeded the maximum contaminant levels specified in the National Interim Primary (or Proposed Secondary) Drinking Water Regulations (U.S. Environmental Protection Agency, 1975) for constituents which may be hazardous to health. Of the 6,300 analyses for constituents considered detrimental to the esthetic quality of water, about 1.4 percent have yielded values which exceeded the recommended levels. Alternative water sources for the area supplied by the aquifer are the Spokane and Little Spokane Rivers, lakes adjacent to the aquifer, and other aquifers. All of these potential sources are less desirable than the Spokane Valley-Rathdrum Prairie aquifer because of insufficient supplies, poor water quality, and (or) remoteness from the areas of need.

3D Model of the Tuscarora Geothermal Area

DOE Data Explorer

Faulds, James E.

2013-12-31

The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern portion of the model are tilted 5-30 degrees toward the Independence Mountains fault zone. Fault blocks in the western portion of the model are tilted toward steeply east-dipping normal faults. These opposing fault block dips define a shallow extensional anticline. Geothermal production is from 4 closely-spaced wells, that exploit a west-dipping, NNE-striking fault zone near the axial part of the accommodation zone.

Quaternary geologic map of the Blue Ridge 4 degrees x 6 degrees quadrangle, United States

USGS Publications Warehouse

Howard, Alan D.; Behling, Robert E.; Wheeler, Walter H.; Daniels, Raymond B.; Swadley, W.C.; Richmond, Gerald M.; Goldthwait, Richard P.; Fullerton, David S.; Sevon, William D.; Miller, Robert A.; Bush, Charles A.; Richmond, Gerald M.; Fullerton, David S.; Christiansen, Ann Coe

1991-01-01

This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1986. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Blue Ridge 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

Mathematical Simulation of the Subsidence of Ravenna

NASA Astrophysics Data System (ADS)

Gambolati, Giuseppe; Ricceri, Giuseppe; Bertoni, Werter; Brighenti, Giovanni; Vuillermin, Enzo

1991-11-01

Land subsidence at Ravenna is the result of aquitard and reservoir compaction caused, respectively, by extensive groundwater withdrawals from the unconsolidated Quaternary basin and gas production from a number of pre-Quaternary pools scattered over the area. Water pumpage paralleled the postwar industrial development of Ravenna until the middle seventies when consumption was drastically curtailed owing to the economic crisis and the activation of a new aqueduct. Gas production started in 1952. The exploitation of several reservoirs is currently under way and the search for new fields is still in progress. Geodetic records indicate that the maximum cumulative subsidence over the period 1950-1986, including a natural geologic settlement of perhaps 2 mm/yr, has been 1.30 m in the industrial zone of Ravenna. In 1980 the municipality promoted a reconnaissance study with the primary aim of providing the information base needed to reconstruct the actual occurrence, understand correctly the physical behavior and produce the essential input data to a mathematical model which realistically relates the subsidence of the city to groundwater withdrawal and gas removal with an emphasis on their respective influences. The results from the three-dimensional numerical simulations, performed with the aid of mixed finite element, finite difference and integral models, show that the primary responsibility for the regional land sinking should be placed on the subsurface water overdraft which occurred until the middle 1970s. Gas withdrawal plays a role restricted to the area overlying each reservoir with a magnitude depending on the depth of burial, thickness of mineralized rocks and overall volumetric production. A major environmental impact may be expected where the gas subsidence bowl is intersected by the Adriatic coastline.

Shear-wave splitting in Quaternary sediments: Neotectonic implications in the central New Madrid seismic zone

USGS Publications Warehouse

Harris, J.B.

1996-01-01

Determining the extent and location of surface/near-surface structural deformation in the New Madrid seismic zone (NMSZ) is very important for evaluating earthquake hazards. A shallow shear-wave splitting experiment, located near the crest of the Lake County uplift (LCU) in the central NMSZ, shows the presence of near-surface azimuthal anisotropy believed to be associated with neotectonic deformation. A shallow fourcomponent data set, recorded using a hammer and mass source, displayed abundant shallow reflection energy on records made with orthogonal source-receiver orientations, an indicator of shear-wave splitting. Following rotation of the data matrix by 40??, the S1 and S2 sections (principal components of the data matrix) were aligned with the natural coordinate system at orientations of N35??W and N55??E, respectively. A dynamic mis-tie of 8 ms at a two-way traveltime of 375 ms produced an average azimuthal anisotropy of ???2% between the target reflector (top of Quaternary gravel at a depth of 35 m) and the surface. Based on the shear-wave polarization data, two explanations for the azimuthal anisotropy in the study area are (1) fractures/cracks aligned in response to near-surface tensional stress produced by uplift of the LCU, and (2) faults/fractures oriented parallel to the Kentucky Bend scarp, a recently identified surface deformation feature believed to be associated with contemporary seismicity in the central NMSZ. In addition to increased seismic resolution by the use of shear-wave methods in unconsolidated, water-saturated sediments, measurement of near-surface directional polarizations, produced by shear-wave splitting, may provide valuable information for identifying neotectonic deformation and evaluating associated earthquake hazards.

February 2011 sensitive clay landslides in eastern Turkey

NASA Astrophysics Data System (ADS)

Akçar, N.; Yavuz, V.; Ivy-Ochs, S.; Fredin, O.; Schlunegger, F.

2016-12-01

The Çöllolar open pit mine is situated in the northwestern sector of the Elbistan basin, which is an intramontane basin located at a mean elevation of about 1200 m in the eastern Turkey. The basement rock in the basin is karstic limestone, which is overlain by a thick layer of clay (>100 m), followed by 20-50 m thick lignite series that is overlain by the 20-50 m thick gyttja sequence. These deposits are overlain by Quaternary deposits, comprising the top surfaces of the terraces of the Hurman River, which drains the surface and ground water from the surrounding hills to the northeast towards the center of the Elbistan basin. The lignite series in the basin has been excavated since early 1970's. In February 2011, two landslides in which 10 workers were killed, occurred in the Çöllolar mine. Of the two landslides, the 2nd and largest which covers an area of ca. 2.3 km2, was caused by the collapse of the northeastern wall of the open-pit mine. The failure was made of successive rearward collapses with the debris flowing into the open-pit. In this study, we focus on the sensitivity of the clays within the Quaternary deposits that seems led to instability and the trigger of the landslides based on the flow style of the movement and nature of the failure. To reveal these factors, we employed six boreholes and collected 64 undisturbed, 41 disturbed and 10 surface samples for the sedimentological and geotechnical analysis. Our results from this study show that Quaternary deposits are heterogeneous and have variable clay content. Mineralogically, most of these clays belong to the smectite group with high swelling potential. They are high plastic clays with high consolidation ratio. They have high shear and remolded shear strengths, thus low to medium sensitivity. Their sensitivity increases dramatically with increasing water content. During our analysis, we encountered a soft clay layer, which showed an over consolidation ratio of 10 and a strain softening response. This response is typical for quick clays. This indicates that the landslide was caused by the liquefaction of this layer within the thick sequence of this part of the Elbistan basin. In brief, we conclude that massive failures at the Çöllolar coalfield are unique examples of sensitive clay landslides occurred in a subtropical arid region beyond the extent of Quaternary glaciations.

Apparent late Quaternary fault slip rate increase in the southwestern Lower Rhine Graben, central Europe

USGS Publications Warehouse

Gold, Ryan D.; Friedrich, Anke M.; Kubler, Simon; Salamon, Martin

2017-01-01

In regions of low strain, long earthquake recurrence intervals (104–106  yrs) and erosive processes limit preservation of Quaternary markers suitable for distinguishing whether faults slip at uniform or secularly varying rates. The Lower Rhine graben in the border region of Germany, The Netherlands, and Belgium provides a unique opportunity to explore Quaternary slip‐rate variations in a region of low strain using the basal (2.29±0.29  Ma) and surface (700±80  ka) contacts of the regionally extensive main terrace (“Hauptterrasse”), deposited by the Rhine and Maas Rivers. These surfaces are vertically offset 3–140 m and 0–68 m, respectively, across individual fault strands within a distributed network of northwest‐trending, slow‐slipping (<0.1  mm/yr) normal faults. In this investigation, we construct Quaternary slip histories for the southern Lower Rhine graben faults using new main terrace surface vertical offset measurements made from light detection and ranging (lidar)‐derived bare‐earth digital terrain models, which we synthesize with existing constraints on the offset basal contact of this fluvial deposit (n=91 collocated sites with displacement constraints). We find that >80% of the sites record an apparent increase in slip rate for the more recent interval from 700 ka to present, which corresponds to a period of increased uplift of the nearby Rhenish Massif and regional volcanism. However, the apparent increase in slip rate could result, in part, from erosion of the footwall surface below the main terrace, leading to an apparent displacement that is smaller than the total vertical offset since the start of the Quaternary. Prior work focused on characterization of these faults as seismic sources in the Lower Rhine graben has preferentially relied on the average fault‐slip rate constrained using the base of the main terrace. We suggest that average fault‐slip rates calculated using the ∼700  ka main terrace surface are subjected to fewer uncertainties and sample a time interval that is more relevant for seismic‐hazard analysis.

Hydrogeologic and geochemical characterization of groundwater resources in Rush Valley, Tooele County, Utah

USGS Publications Warehouse

Gardner, Philip M.; Kirby, Stefan

2011-01-01

The water resources of Rush Valley were assessed during 2008–2010 with an emphasis on refining the understanding of the groundwater-flow system and updating the groundwater budget. Surface-water resources within Rush Valley are limited and are generally used for agriculture. Groundwater is the principal water source for most other uses including supplementing irrigation. Most groundwater withdrawal in Rush Valley is from the unconsolidated basin-fill aquifer where conditions are generally unconfined near the mountain front and confined at lower altitudes near the valley center. Productive aquifers also occur in fractured bedrock along the valley margins and beneath the basin-fill deposits in some areas.Drillers’ logs and geophysical gravity data were compiled and used to delineate seven hydrogeologic units important to basin-wide groundwater movement. The principal basin-fill aquifer includes the unconsolidated Quaternary-age alluvial and lacustrine deposits of (1) the upper basin-fill aquifer unit (UBFAU) and the consolidated and semiconsolidated Tertiary-age lacustrine and alluvial deposits of (2) the lower basin-fill aquifer unit (LBFAU). Bedrock hydrogeologic units include (3) the Tertiary-age volcanic unit (VU), (4) the Pennsylvanian- to Permian-age upper carbonate aquifer unit (UCAU), (5) the upper Mississippian- to lower Pennsylvanian-age upper siliciclastic confining unit (USCU), (6) the Middle Cambrian- to Mississippian-age lower carbonate aquifer unit (LCAU), and (7) the Precambrian- to Lower Cambrian-age noncarbonate confining unit (NCCU). Most productive bedrock wells in the Rush Valley groundwater basin are in the UCAU.Average annual recharge to the Rush Valley groundwater basin is estimated to be about 39,000 acre-feet. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall within the mountains with smaller amounts occurring as infiltration of streamflow and unconsumed irrigation water at or near the mountain front. Groundwater generally flows from the higher altitude recharge areas toward two distinct valley-bottom discharge areas: one in the vicinity of Rush Lake in northern Rush Valley and the other located west and north of Vernon. Average annual discharge from the Rush Valley groundwater basin is estimated to be about 43,000 acre-feet. Most discharge occurs as evapotranspiration in the valley lowlands, as discharge to springs and streams, and as withdrawal from wells. Subsurface discharge outflow to Tooele and Cedar Valleys makes up only a small fraction of natural discharge.Groundwater samples were collected from 25 sites (24 wells and one spring) for geochemical analysis. Dissolved-solids concentrations in water from these sites ranged from 181 to 1,590 milligrams per liter. Samples from seven wells contained arsenic concentrations that exceed the Environmental Protection Agency Maximum Contaminant Level of 10 micrograms per liter. The highest arsenic levels are found north of Vernon and in southeastern Rush Valley. Stable-isotope ratios of oxygen and deuterium, along with dissolved-gas recharge temperatures, indicate that nearly all modern groundwater is meteoric and derived from the infiltration of high altitude precipitation in the mountains. These data are consistent with recharge estimates made using a Basin Characterization Model of net infiltration that shows nearly all recharge occurring as infiltration of precipitation and snowmelt within the mountains surrounding Rush Valley. Tritium concentrations between 0.4 and 10 tritium units indicate the presence of modern (less than 60 years old) groundwater at 7 of the 25 sample sites. Apparent 3H/3He ages, calculated for six of these sites, range from 3 to 35 years. Adjusted minimum radiocarbon ages of premodern water samples range from about 1,600 to 42,000 years with samples from 11 of 13 sites being more than 11,000 years. These data help to identify areas where modern groundwater is circulating through the hydrologic system on time scales of decades or less and indicate that large parts of the principal basin-fill and the bedrock aquifers are much less active and receive little to no modern recharge.

Results of hydrologic research at a low-level radioactive-waste disposal site near Sheffield, Illinois

USGS Publications Warehouse

Ryan, Barbara J.

1989-01-01

Ten years of hydrologic research have been conducted by the U.S. Geological Survey at a commercial low-level radioactive-waste disposal site near Sheffield, Illinois. Research included studies of microclimate, evapotranspiration, and tritium release by plants; runoff and land modification; water movement through a trench cover; water and tritium movement in the unsaturated zone; gases in the unsaturated zone; water and tritium movement in the saturated zone; and water chemistry. Implications specific to each research topic and those based on overlapping research topics are summarized as to their potential effect on the selection, characterization, design, operation, and decommissioning processes of future low-level radioactive-waste disposal sites. Unconsolidated deposits at the site are diverse in lithologic character and are spatially and stratigraphically complex. Thickness of these Quaternary deposits ranges from 3 to 27 meters and averages 17 meters. The unconsolidated deposits overlay 140 meters of Pennsylvanian shale, mudstone, siltstone, and coal. Approximately 90,500 cubic meters of waste were buried from August 1967 through August 1978, in 21 trenches that were constructed in glacial materials by using a cut-and-fill process. Trenches generally were constructed below grade and ranged from 11 to 180 meters long, 2.4 to 21 meters wide, and 2.4 to about 7.9 meters deep. Research on microclimate and evapotranspiration at the site was conducted from July 1982 through June 1984. Continuous measurements were made of precipitation, incoming and reflected solar (shortwave) radiation, incoming and emitted terrestrial (longwave) radiation, horizontal windspeed and direction, wet- and dry-bulb air temperature, barometric pressure, soil-heat fluxes, and soil temperature. Soil-moisture content, for this research phase, was measured approximately biweekly. Evapotranspiration rates were estimated by using three techniques--energy budget, aerodynamic profile, and water budget. Although monthly totals for each method differed, estimated annual evapotranspiration averages ranged from 630 to 693 millimeters or about 70 percent of precipitation. Tritium concentrations in leaf water from on-site plants were determined for 125 vegetation samples collected during the summers of 1982 through 1986. Concentrations varied significantly among some locations and plant types. Tritium concentrations ranged from the detection limit of 0 .2 to 1,330 nanocuries per liter, with alfalfa (Medicago sativa) having the highest concentrations, followed by brome grass (Bromus inermis), and then red clover (Trifoleum pratense); these variations in concentration are most likely a result of root depth. Runoff and sediment transport were measured from July 1982 through December 1985 in four basins--three comprising almost two-thirds of the 8.1-hectare site and one comprising a 1.4-hectare undisturbed area. Volumes and equivalent weights of collapses were estimated from records of site surficial conditions from October 1978 through December 1985. Runoff showed a direct relation to degree of land modification; lowest mean yields were measured at the undisturbed area, and highest mean yields were measured from the basin composed wholly of trench and intertrench areas. Sediment yield measured onsite averaged 3.4 megagrams per hectare. A total of 315 collapse cavities, corresponding to a cumulative volume of about 500 cubic meters, were documented. Most collapses were recorded after periods of rainfall or snowmelt when soil moisture was near maximum. Almost two-thirds of the collapses, corresponding to 63 percent of the cumulative cavity volume, occurred during February through April. Data for the study of water movement through a trench cover were collected from July 1982 through June 1934. Pressure-head data were collected at four different clusters at depths ranging from 50 to 1,850 millimeters within a selected trench cover. Soil-moisture content f

Distribution and formation of high-fluorine groundwater in China

NASA Astrophysics Data System (ADS)

Fuhong, Ren; Shuqin, Jiao

1988-08-01

In China, high-fluorine groundwater, which contains more than 1.0 mg/l fluorine, is mainly distributed in shallow aquifers of unconsolidated deposits in some arid and semiarid areas, deep aquifers of unconsolidated deposits in semiarid areas, as well as in hot springs of bed rock mountainous area and aquifers of fluorite-mine area. Its formation is controlled by regional climate factors, seepage conditions of groundwater, as well as the hydrogeochemical environment. The physicochemical properties of soil mass of the aeration zone play an important role in fluorine concentration in shallow groundwater. In the coastal plain areas, where groundwater is mainly recharged and discharged vertically, and its regime type belongs to the type of infiltration—evaporation, the grain size of soil mass of aeration zone directly influences the amount of fluorine transferred from solid medium into water; and the chemical constituents of the soil mass of aeration zone controls the chemical characteristics of the shallow groundwater, consequently influencing the concentration condition of fluorine in water. Fluorine ion in groundwater continuously migrates and concentrates under the comprehensive influence of many factors. High-fluorine groundwater exceeding the sanitary standard (1.0 mg/l) has an obvious zonality in regional distribution in China. Based on current statistics, there are roughly 50 million people (Zheng Qifu 1986) who have consumed water which exceeds standards in China. In highfluorine groundwater areas, endemic fluorine-poisoning often arises to different extents, affecting human health seriously. At the end of 1983, over 20 million patients were suffering from fluorine-poisoning diseases in China (Xu Guozhang, unpublished data). Therefore, research of the distribution feature and formation mechanism of fluorine ion in groundwater has become an important task.

Quaternary basaltic volcanism in the Golden Trout Volcanic Field, southern Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Browne, Brandon L.; Becerra, Raul; Campbell, Colin; Saleen, Phillip; Wille, Frank R.

2017-09-01

The Golden Trout Volcanic Field (GTVF) produced the only Quaternary eruptions of mafic magma within the southern Sierra Nevada block. Approximately 38 × 106 m3 of basalt, trachy-basalt, basaltic trachy-andesite, and basaltic andesite (50.1-56.1% SiO2, 1.1-1.9% K2O, and 5.4-9.1% MgO) was erupted from four vents within a 10 km2 portion of the GTVF, which also includes rhyolite domes that are not considered in this study. The vents include, from oldest to youngest: Little Whitney Cone, South Fork Cone, Tunnel Cone, and unglaciated Groundhog Cone. Little Whitney Cone is a 120 m-high pile of olivine-CPX-phyric scoria produced during a Strombolian-style eruption overlying two columnar jointed lava flows. Tunnel Cone formed through a Hawaiian-style eruption along a 400 m-long north-south trending fissure that excavated at least three 25-65 m-wide craters. Crater walls up to 12 m high are composed of plagioclase-olivine-phyric spatter-fed flows that dip radially away from the crater center and crumble to form Tunnel Cone's steep unconsolidated flanks. South Fork Cone is a 170 m-high pile of plagioclase-olivine-phyric scoria that formed during Strombolian to violent Strombolian eruptions. South Fork Cone overlies the South Fork Cone lava, a 9.5 km-long flow ( 12 × 106 km3) that reached the Kern River Canyon to the west. Scoria and airfall deposits originating from South Fork Cone are located up to 2 km from the vent. Groundhog Cone is a 140 m-tall cinder and spatter cone breached on the north flank by a 13 × 106 m3 lava flow that partially buried the South Fork Cone lava and extends 7.5 km west to Kern River Canyon. Incompatible trace element concentrations and ratios show vent-specific trends but are unsystematic when plotted in terms of all mafic GTVF vents, implying that GTVF basalts were derived from a lithospheric mantle source and ascended through thick granitic Sierra Nevada crust as discrete batches that underwent different degrees of crustal contamination, differentiation, and magma mixing. Clinopyroxene-liquid thermobarometry calculations of the oldest and most primitive GTVF sample indicate that most clinopyroxene crystals record nucleation conditions of 1172-1196 °C and 896-1115 MPa. These pressures correspond to depths equivalent to, or up to 10 km shallower than, the Moho in this region. Deposits from the oldest GTVF vents are more primitive and homogeneous in terms of major and trace element concentrations, phenocryst textures and compositions, and their general absence of crustal xenoliths and xenocrysts compared to younger eruptive products. The eruption rate of the GTVF ( 0.05 km3/Myr) is two orders of magnitude less than neighboring and contemporaneous Big Pine and Coso volcanic fields to the north and east, respectively. We interpret these differences to result from a relative lack of strain in the GTVF region of the southern Sierra Nevada block, which limits magma accumulation and ascent.

The marine geology of the eastern Santa Barbara Channel, with particular emphasis on the ground water basins offshore from the Oxnard Plain, Southern California

USGS Publications Warehouse

Greene, H. Gary; Wolf, Stephen C.; Blom, Ken G.

1978-01-01

Marine geophysical investigations provide new data concerning the stratigraphy, tectonic and sedimentary history, and the ground water geology of the southeastern Santa Barbara Channel region. The offshore stratigraphy identified in seismic reflection profiles includes a succession of Neogene to Quaternary strata. The middle Miocene Conejo volcanics form an acoustical basement and the overlying late Cenozoic sedimentary rocks attain a thickness greater than 2,500 m. These sedimentary deposits fill a structurally controlled, physiographic and depositional depression called the Ventura Basin. Structure consists generally of a gently folded, east-trending Tertiary synclinorium bordered on the north by a regional thrust fault and on the south by a steep asymmetrical anticlinal ridge. Most structures show evidence of north-south compression that occurred during early Pleistocene time. Three well-defined unconformities represent widespread erosion in late Miocene, early to middle Pleistocene, and late Pleistocene time. The boundaries of Miocene, Pliocene, and lower Pleistocene strata continue uninterrupted eastward along the southern part of Santa Barbara basin to Hueneme Canyon, where they turn northeast and can be traced to the coast near Port Hueneme. These limits probably represent the south edge of the Santa Barbara basin during Pliocene and Pleistocene time. Fresh water-bearing materials of the Oxnard plain are unconsolidated Quaternary sediment laid down on more consolidated Tertiary rocks. Offshore, the total fresh water-bearing materials distinguished in the seismic reflection profiles attain a thickness of about 356 m and have an areal extent of over 760 km2. Strata that contain the offshore continuation of the five major on-land aquifers (Grimes Canyon, Fox Canyon, Hueneme, Mugu, and Oxnard aquifers) are identified in the seismic reflection profiles. These strata make up the two offshore ground-water basins, the Mound and Oxnard plain ground-water basins, which are separated by the east-west trending Oak Ridge fault. Possible entrance areas for salt water intrusion into fresh water aquifers are found along the walls of the submarine canyons and along the northern slopes of Santa Barbara and Santa Monica basins. Hueneme and Mugu aquifers are probably exposed locally in all five submarine canyons of the Oxnard offshore area and may also crop out along the upper northern slope of Santa Monica basin. In all of these areas, salt water readily intrudes the aquifers. A salinity-temperature-depth study made in April, 1971, does not indicate any great dilution of surface ocean water by fresh water that could be 'leaking' from the exposed aquifers along the walls of Hueneme Canyon and the landward slope of Santa Barbara Channel. Earthquakes in the vicinity of the Oxnard plain suggest that the region is seismically active. Epicenters are widely dispersed over the region. No distinct trend or alignment of earthquake epicenters occurs near the trace of any of the faults, although many epicenters are scattered around the Oak Ridge zone of deformation in the northern part of the region. The largest magnitude earthquake recorded in the area was a magnitude 5.7 that occurred on February 21, 1973, offshore of Point Mugu, south of the Oxnard plain.

Quaternary Geologic Framework of the St. Clair River between Michigan and Ontario, Canada

USGS Publications Warehouse

Foster, David S.; Denny, Jane F.

2009-01-01

Concern about the effect of geomorphic changes in the St. Clair River on water levels in the Upper Great Lakes resulted in the need for information on the geologic framework of the river. A geophysical survey of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada, was conducted to determine the Quaternary geologic framework of the region. Previously available and new sediment samples and photographic and video data support the interpretation of the seismic stratigraphy and surficial geology. Three seismic stratigraphic units and two unconformities were identified. Glacial drift, consisting of interbedded till and glaciolacustrine deposits, overlies shale. Glaciofluvial and modern fluvial processes have eroded the glacial drift. Glaciofluvial, glaciolacustrine, fluvial, and lacustrine deposits overlie this unconformity. Seismic facies were interpreted to identify areas where these geologic facies exist; however, in the absence of distinct boundaries between facies, these deposits were mapped as one undifferentiated unit. This unit is thickest in the northernmost 3 kilometers of the river, where it consists of relatively coarse-grained fluvial, reworked glaciofluvial, and possibly glaciofluvial deposits. To the south, this coarse-grained unit thins or is absent. The undifferentiated unit comprises most of the surficial deposits in the northernmost river area. Some areas of glacial drift, predominantly till, are exposed at the lake and riverbed. The shale is not exposed anywhere in the region. Geophysical surveys at sites downriver, together with the results of previous studies, indicate that the geologic framework is similar to that in the northernmost river area except for the absence or reduced thickness of the coarse-grained fluvial deposits. Instead, glacial drift is exposed at the riverbed or is covered by a veneer of sediment. This information on the substrate is important for ongoing sediment transport studies.

New seismo-stratigraphic and marine magnetic data of the Gulf of Pozzuoli (Naples Bay, Tyrrhenian Sea, Italy): inferences for the tectonic and magmatic events of the Phlegrean Fields volcanic complex (Campania)

NASA Astrophysics Data System (ADS)

Aiello, Gemma; Marsella, Ennio; Fiore, Vincenzo Di

2012-06-01

A detailed reconstruction of the stratigraphic and tectonic setting of the Gulf of Pozzuoli (Naples Bay) is provided on the basis of newly acquired single channel seismic profiles coupled with already recorded marine magnetics gathering the volcanic nature of some seismic units. Inferences for the tectonic and magmatic setting of the Phlegrean Fields volcanic complex, a volcanic district surrounding the western part of the Gulf of Naples, where volcanism has been active since at least 50 ka, are also discussed. The Gulf of Pozzuoli represents the submerged border of the Phlegrean caldera, resulting from the volcano-tectonic collapse induced from the pyroclastic flow deposits of the Campanian Ignimbrite (35 ka). Several morpho-depositional units have been identified, i.e., the inner continental shelf, the central basin, the submerged volcanic banks and the outer continental shelf. The stratigraphic relationships between the Quaternary volcanic units related to the offshore caldera border and the overlying deposits of the Late Quaternary depositional sequence in the Gulf of Pozzuoli have been highlighted. Fourteen main seismic units, both volcanic and sedimentary, tectonically controlled due to contemporaneous folding and normal faulting have been revealed by geological interpretation. Volcanic dykes, characterized by acoustically transparent sub-vertical bodies, locally bounded by normal faults, testify to the magma uprising in correspondence with extensional structures. A large field of tuff cones interlayered with marine deposits off the island of Nisida, on the western rim of the gulf, is related to the emplacement of the Neapolitan Yellow Tuff deposits. A thick volcanic unit, exposed over a large area off the Capo Miseno volcanic edifice is connected with the Bacoli-Isola Pennata-Capo Miseno yellow tuffs, cropping out in the northern Phlegrean Fields.

Quaternary alluvial deposits of Wadi Gaza in the middle of the Gaza Strip (Palestine): Facies, granulometric characteristics, and their paleoflow direction

NASA Astrophysics Data System (ADS)

Ubeid, Khalid Fathi

2016-06-01

The Quaternary rocks of the Gaza Strip mainly consist of clastic sedimentary rocks. In Wadi Gaza, the outcropping rocks consist of brownish fine-grained deposits, sandstones, and conglomerates. The deposits have been studied from a genetic point of view, and six facies have been described: (i) graded clast-supported conglomerates, (ii) cross-bedded clast-supported conglomerates, (iii) sandy matrix conglomerates, (iv) cross-laminated medium-grained sandstones, (v) graded coarse-grained sandstones, and (vi) massive sandstones. The field work observations and granulometric analysis show that the sphericity of the grains increase toward the west, where its value ranges from ∼0.64 in the east to ∼0.70 in the west. In addition, the grain forms tend to be disc shape in the east, whereas they tend to be disc-to spheroid shape in the west, and they become well rounded to well sorted toward the west. Moreover, the features, geometry, and spatial relationship among these facies suggest that the Wadi Gaza was meandering wadi fed from Beir Sheva and the Northern Negev in the southeast of Gaza Strip through Wadi Al Shallala and Wadi Sheneq and from Hebron mountains in the West Bank at the east through Wadi Al Shari'a alluvials. Within the Gaza Strip, paleocurrent data ranges from 210° to 310°, indicating a mean a paleoflow direction to the W (276°) and a median value about 275°. The sedimentary rocks in the Wadi Gaza are considered to be deposited in two periods of climate conditions: the coarse-grained rocks were deposited during the period of wet condition before 12.4 ka age, whereas the eolinite fine-grained rocks were deposited during semiarid climate conditions which are younger in age than 12.4 ka.

Geologic framework of the regional ground-water flow system in the Upper Deschutes Basin, Oregon

USGS Publications Warehouse

Lite, Kenneth E.; Gannett, Marshall W.

2002-12-10

Geologic units in the Deschutes Basin were divided into several distinct hydrogeologic units. In some instances the units correspond to existing stratigraphic divisions. In other instances, hydrogeologic units correspond to different facies within a single stratigraphic unit or formation. The hydrogeologic units include Quaternary sediment, deposits of the Cascade Range and Newberry Volcano, four zones within the Deschutes Formation and age-equivalent rocks that roughly correspond with depositional environments, and pre-Deschutes-age strata.

Anthropogenically accelerated mass movement, Kulu Valley, Himachal Pradesh, India

NASA Astrophysics Data System (ADS)

Sah, M. P.; Mazari, R. K.

1998-12-01

A devastating landslide occurred on 12 September 1995 near Luggar Bhatti, Kulu, Himachal Pradesh, and killed 65 people. An estimated 0.96×10 6 m 3 of unconsolidated mass slid SSE down the terminal part of a thick alluvial fan of Quaternary age on the left bank of the Beas River. About 0.03×10 6 m 3 of dislodged material formed a 15-m high and 150-m long hump at the bottom of the failed slope; a shallow sag pond developed in the rear. The slide occurred after heavy rains on 3-6 September in the region when the Beas rose to a bankfull position. Factors involved in this toppling-cum-debris slide include steep slope, continuous seepage with high pore water pressure in unconsolidated material, a road-cut obliterating the foot of the fan slope, and impinging by the Beas River during the flood. A survey in the area showed that a variety of mass movement processes were triggered by the heavy rains in September; the most predominant being a series of slope failures on the outside of meander loops and bank erosion caused by turbulence of the overflowing Beas River. Extensive damage was sustained by National Highway-21 (NH-21), a bridge ramp near Bhuntar, a suspension bridge at Kulu and two other bridges upstream. Most damage occurred in the Manali area where massive buildings were washed away by the flash flood. This paper examines the factors and processes responsible for triggering widespread mass movement and related damages in the Kulu Valley. Whereas some smaller events occurred in the early and middle part of this century, the recurrence and intensity of mass movements are recent phenomena attributed mainly to escalating socio-economic development, growth of tourism, and population pressure. Some long term policy is suggested for mitigation of landslides and other denudational processes in relation to impelling human factors.

Geologic map of the East of Grotto Hills Quadrangle, California: a digital database

USGS Publications Warehouse

Nielson, Jane E.; Bedford, David R.

1999-01-01

The East of Grotto Hills 1:24,000-scale quadrangle of California lies west of the Colorado River about 30 km southwest of Searchlight, Nevada, near the boundary between the northern and southern parts of the Basin and Range Province. The quadrangle includes the eastern margin of Lanfair Valley, the southernmost part of the Castle Mountains, and part of the northwest Piute Range. The generally north-trending Piute Range aligns with the Piute and Dead Mountains of California and the Newberry and Eldorado Mountains and McCullough Range of Nevada. The southern part of the Piute Range adjoins Homer Mountain (Spencer and Turner, 1985) near Civil War-era Fort Piute. Adjacent 1:24,000-scale quadrangles include Castle Peaks, Homer Mountain, and Signal Hill, Calif.; also Hart Peak, Tenmile Well, and West of Juniper Mine, Calif. and Nev. The mapped area contains Tertiary (Miocene) volcanic and sedimentary rocks, interbedded with and overlain by Tertiary and Quaternary surficial deposits. Miocene intrusions mark conduits that served as feeders for the Miocene volcanic rocks, which also contain late magma pulses that cut the volcanic section. Upper Miocene conglomerate deposits interfinger with the uppermost volcanic flows. Canyons and intermontane valleys contain dissected Quaternary alluvial-fan deposits, mantled by active alluvial-fan deposits and detritus of active drainages. The alluvial materials were derived largely from Early Proterozoic granite and gneiss complexes, intruded by Mesozoic granite, dominate the heads of Lanfair Valley drainages in the New York Mountains and Mid Hills (fig. 1; Jennings, 1961). Similar rocks also underlie Tertiary deposits in the Castle Peaks, Castle Mountains, and eastern Piute Range.

Seismic stratigraphy and depositional history of late Quaternary deposits at the eastern Yellow Sea shelf

NASA Astrophysics Data System (ADS)

Yoo, Dong-Geun; Lee, Gwang-Soo; Kim, Gil-Young; Chang, Se-Won; Kim, Kyoung-Jin

2017-04-01

The late Quaternary stratigraphy and sedimentation at the eastern Yellow Sea shelf was studied using a dense network of high-resolution, single-channel seismic reflection profiles and sediment data. The shelf sequence in this area consists of six seismic units formed since the LGM. During the LGM, the study area was completely exposed, resulting in subaerial erosion associated with paleo-channel incision by the Huanghe and Korean Rivers. As the shelf was flooded, the incised channels were backfilled fluvial or coastal sediments, forming incised channel-fill deposits (SU1). The paleo-river may have supplied abundant terrigenous sediments to the study area around the paleo-river mouth and adjacent area. These sediments were trapped within the paleo-estuary and formed SU2, regarded as an estuarine deposit. Two types of serial sand ridges (SU3 and SU5) which correspond to transgressive deposits developed. SU3 on the southern part, west of Jeju Island (80 110 m deep) is regarded as a moribund-type mainly formed during the early to middle stage of transgression. These are thought to have ceased growing and remobilizing. In contrast, SU5 (occurring 30 50 m deep off the Korean Peninsula) is generally regarded as active sand ridges deposited during the late stage of transgression and is partly modified by modern tidal currents. As the transgression continued, the near-surface sediments were reworked and redistributed by shelf erosion, resulting in a thin veneer of transgressive sands (SU4). The uppermost unit (SU6) formed the Heuksan Mud Belt (HMB), which is one of the most prominent mud deposits in the Yellow Sea. The lower part of the HMD corresponds to shelf-mud deposited during the late stage of transgression, whereas the upper part consists of a recent shelf-delta developed after the highstand sea level at about 7 ka BP.

Quaternary deposits and landscape evolution of the central Blue Ridge of Virginia

USGS Publications Warehouse

Eaton, L. Scott; Morgan, Benjamin A.; Kochel, R. Craig; Howard, Alan D.

2003-01-01

A catastrophic storm that struck the central Virginia Blue Ridge Mountains in June 1995 delivered over 775 mm (30.5 in) of rain in 16 h. The deluge triggered more than 1000 slope failures; and stream channels and debris fans were deeply incised, exposing the stratigraphy of earlier mass movement and fluvial deposits. The synthesis of data obtained from detailed pollen studies and 39 radiometrically dated surficial deposits in the Rapidan basin gives new insights into Quaternary climatic change and landscape evolution of the central Blue Ridge Mountains.The oldest depositional landforms in the study area are fluvial terraces. Their deposits have weathering characteristics similar to both early Pleistocene and late Tertiary terrace surfaces located near the Fall Zone of Virginia. Terraces of similar ages are also present in nearby basins and suggest regional incision of streams in the area since early Pleistocene–late Tertiary time. The oldest debris-flow deposits in the study area are much older than Wisconsinan glaciation as indicated by 2.5YR colors, thick argillic horizons, and fully disintegrated granitic cobbles. Radiocarbon dating indicates that debris flow activity since 25,000 YBP has recurred, on average, at least every 2500 years. The presence of stratified slope deposits, emplaced from 27,410 through 15,800 YBP, indicates hillslope stripping and reduced vegetation cover on upland slopes during the Wisconsinan glacial maximum.Regolith generated from mechanical weathering during the Pleistocene collected in low-order stream channels and was episodically delivered to the valley floor by debris flows. Debris fans prograded onto flood plains during the late Pleistocene but have been incised by Holocene stream entrenchment. The fan incision allows Holocene debris flows to largely bypass many of the higher elevation debris fan surfaces and deposit onto the topographically lower surfaces. These episodic, high-magnitude storm events are responsible for transporting approximately half of the sediment from high gradient, low-order drainage basins to debris fans and flood plains.

Mineral and energy resources of the BLM Roswell Resource Area, east-central New Mexico

USGS Publications Warehouse

Bartsch-Winkler, Susan B.

1992-01-01

The sedimentary formations of the Roswell Resource Area have significant mineral and energy resources. Some of the pre-Pennsylvanian sequences in the Northwestern Shelf of the Permian Basin are oil and gas reservoirs, and Pennsylvanian rocks in Tucumcari basin are reservoirs of oil and gas as well as source rocks for oil and gas in Triassic rocks. Pre-Permian rocks also contain minor deposits of uranium and vanadium, limestone, and associated gases. Hydrocarbon reservoirs in Permian rocks include associated gases such as carbon dioxide, helium, and nitrogen. Permian rocks are mineralized adjacent to the Lincoln County porphyry belt, and include deposits of copper, uranium, manganese, iron, polymetallic veins, and Mississippi-valley-type (MVT) lead-zinc. Industrial minerals in Permian rocks include fluorite, barite, potash, halite, polyhalite, gypsum, anhydrite, sulfur, limestone, dolomite, brine deposits (iodine and bromine), aggregate (sand), and dimension stone. Doubly terminated quartz crystals, called "Pecos diamonds" and collected as mineral specimens, occur in Permian rocks along the Pecos River. Mesozoic sedimentary rocks are hosts for copper, uranium, and small quantities of gold-silver-tellurium veins, as well as significant deposits of oil and gas, COa, asphalt, coal, and dimension stone. Mesozoic rocks contain limited amounts of limestone, gypsum, petrified wood, dinosaur remains, and clays. Tertiary rocks host ore deposits commonly associated with intrusive rocks, including platinum group elements, iron skarns, manganese, uranium and vanadium, molybdenum, polymetallic vein deposits, gold-silver- tellurium veins, and thorium-rare earth veins. Museum-quality quartz crystals in Lincoln County were formed in association with intrusive rocks in the Lincoln County porphyry belt. Industrial minerals in Tertiary rocks include fluorite, vein- and bedded-barite, caliche, limestone, and aggregate. Tertiary and Quaternary sediments host important placer deposits of gold and titanium, and minor silver, uranium occurrences, as well as important industrial commodities, including caliche, limestone and dolomite, and aggregate (sand). Quaternary basalt contains sub-ore-grade uranium, scoria, and clay deposits.

Mineral and energy resources of the Roswell Resource Area, East-Central New Mexico

USGS Publications Warehouse

Bartsch-Winkler, Susan B.; Donatich, Alessandro J.

1995-01-01

The sedimentary formations of the Roswell Resource Area have significant mineral and energy resources. Some of the pre-Pennsylvanian sequences in the Northwestern Shelf of the Permian Basin are oil and gas reservoirs, and Pennsylvanian rocks in Tucumcari Basin are reservoirs of oil and gas as well as source rocks for oil and gas in Triassic rocks. Pre-Permian rocks also contain minor deposits of uranium and vanadium, limestone, and gases. Hydrocarbon reservoirs in Permian rocks include associated gases such as carbon dioxide, helium, and nitrogen. Permian rocks are mineralized adjacent to the Lincoln County porphyry belt, and include deposits of copper, uranium, manganese, iron, polymetallic veins, and Mississippi-Valley-type lead-zinc. Industrial minerals in Permian rocks include fluorite, barite, potash, halite, polyhalite, gypsum, anhydrite, sulfur, limestone, dolomite, brine deposits (iodine and bromine), aggregate (sand), and dimension stone. Doubly terminated quartz crystals, called 'Pecos diamonds' and collected as mineral specimens, occur in Permian rocks along the Pecos River. Mesozoic sedimentary rocks are hosts for copper, uranium, and small quantities of gold-silver-tellurium veins, as well as significant deposits of oil and gas, carbon dioxide, asphalt, coal, and dimension stone. Mesozoic rocks contain limited amounts of limestone, gypsum, petrified wood, and clay. Tertiary rocks host ore deposits commonly associated with intrusive rocks, including platinum-group elements, iron skarns, manganese, uranium and vanadium, molybdenum, polymetallic vein deposits, gold-silver-tellurium veins, and thorium-rare-earth veins. Museum-quality quartz crystals are associated with Tertiary intrusive rocks. Industrial minerals in Tertiary rocks include fluorite, vein- and bedded-barite, caliche, limestone, and aggregate. Tertiary and Quaternary sediments host important placer deposits of gold and titanium, and occurrences of silver and uranium. Important industrial commodities include caliche, limestone and dolomite, and aggregate. Quaternary basalt contains sub-ore-grade uranium, scoria, and clay deposits.

A Ground-based Search for Lunar Resources Using High-resolution Imaging in the Infrared

NASA Technical Reports Server (NTRS)

Coombs, C. R.; Mckechnie, T. S.

1992-01-01

When humans return to the Moon, lunar resources will play an important role in the successful deployment and maintenance of the lunar base. Previous studies have illustrated the abundance of resource materials available on the surface of the Moon, as well as their ready accessibility. Particularly worth considering are the lunar regional (2,000-30,000 sq km) pyroclastic deposits scattered about the lunar nearside. These 30-50-m-thick deposits are composed of fine-grained unconsolidated titanium- and iron-rich mafic glasses and may be used as bulk feedstock for the beneficiation of oxygen, iron, titanium, sulfur, and other solar wind gases, or simply used as is for construction and shielding purposes. A groundbased observing survey of the resource-rich regions on the lunar nearside using a new imaging technique designed to obtain much higher resolution images, and more precise compositional analyses than previously obtainable is proposed.

Test of airborne fluorometer over land surfaces and geologic materials

NASA Technical Reports Server (NTRS)

Stoertz, G. E.; Hemphill, W. R.

1970-01-01

Response of an experimental Fraunhofer line discriminator to a wide range of surficial deposits common in deserts and semideserts was tested in the laboratory and from an H-19 helicopter. No signals attributable to fluorescence were recorded during 540 miles of aerial traverses over southeastern California and west-central Arizona. It was concluded that exposed surfaces of target materials throughout the traverses were either nonluminescent at 5890 A or not sufficiently so to be detectable. It cannot be ruled out that the lack of fluorescence is partly attributable to surficial coatings of nonluminescent weathered material. The principal route surveyed from the air was from Needles, California to Furnace Creek Ranch, Death Valley and return, via the Amargosa River valley, Silurian Lake (dry), Silver Lake (dry), and Soda Lake (dry). Principal targets traversed were unconsolidated clastic sediments ranging from silty clay to cobbles, and a wide range of evaporite deposits.

Windblown Pliocene diatoms and East Antarctic Ice Sheet retreat

PubMed Central

Scherer, Reed P.; DeConto, Robert M.; Pollard, David; Alley, Richard B.

2016-01-01

Marine diatoms in tillites along the Transantarctic Mountains (TAMs) have been used to suggest a diminished East Antarctic Ice Sheet (EAIS) during Pliocene warm periods. Updated ice-sheet modelling shows significant Pliocene EAIS retreat, creating marine embayments into the Wilkes and Aurora basins that were conducive to high diatom productivity and rapid accumulation of diatomaceous sediments. Here we show that subsequent isostatic uplift exposed accumulated unconsolidated marine deposits to wind erosion. We report new atmospheric modelling utilizing Pliocene climate and derived Antarctic landscapes indicating that prevailing mid-altitude winds transported diatoms towards the TAMs, dominantly from extensive emerged coastal deposits of the Aurora Basin. This result unifies leading ideas from competing sides of a contentious debate about the origin of the diatoms in the TAMs and their link to EAIS history, supporting the view that parts of the EAIS are vulnerable to relatively modest warming, with possible implications for future sea-level rise. PMID:27649516

New chronological data for the timing of the Saalian- and Elsterian glacial cycle in Europe - studies on a key site within the type area

NASA Astrophysics Data System (ADS)

Lauer, Tobias; Weiß, Marcel; Wansa, Stefan

2017-04-01

The type area for the Elsterian- and Saalian glacial cycles is located in central Germany (Saxony, Saxony-Anhalt and Thuringia) where the gravel deposits of the rivers Saale- and Elster interfinger with tills and meltwater deposits of both glacial cycles in proximity to the maximum extensions of the Middle-Pleistocene Scandinavian ice-sheets in Central Europe. The Elsterian- and Saalian glacial cycles, including the corresponding interglacial periods are also correlated with first human appearance in the area (see Haidle and Pawlik 2010). Nevertheless, the timing of these glacial cycles is still unclear due to a lack of resilient chronological data on sediments representing the advance- and retreat of the glaciers. The Elsterian is defined to be terminated by the Holsteinian, but for the latter, a correlation to MIS 9 or 11 is still a matter of debate (e. g. Sirocko et al. 2006; Nitychoruk et al. 2007). Consequently, a correlation of the Elsterian to MIS 10 or 12 is possible. Within the last decades, new luminescence dating techniques such as pIRIR-luminescence protocols or infrared-radiofluorescence dating made it possible to extent the datable age range and hence, it is now possible to establish reliable chronologies also for deposits beyond the last glacial-/interglacial cycle. In the present study, we dated the quaternary sequence of Uichteritz (close to the Saale-river near Weissenfels, Saxony-Anhalt) using luminescence and infrared-radiofluorescence dating. The base of the quaternary layers consists of Elsterian sediments pre-dating the first Elsterian ice advance. This is evidenced mainly by the lithology, especially the absence of Nordic components in the composition of the gravel. Additionally, remains of the advancing Saalian ice sheet, represented by fluvial sediments from the Middle-Pleistocene river Saale, as well as till, glaciofluvial and glaciolacustrine sediments, cover the Elsterian succession. The upper part of the fluvial Elsterian sediments also includes a palaeosol (Bt-horizon, Meng & Wansa 2005), exposed below Saalian meltwater sediments and till. Furthermore, the Middle-Pleistocene sediments yielded Lower/Middle Palaeolithic stone artefacts (Rudolph et al. 2005), probably representing the earliest human appearance in central Germany. In conclusion, the sequence of Uichteritz has the potential to provide important new chronological data for the timing of the Elsterian and Saalian glacial cycles as well as the presence of humans in Central Europe. References Haidle, M. N., Pawlik, A. F., 2010. The earliest settlement of Germany: Is there anything out there? Quaternary International 223-224, 143-153. Meng, S., Wansa, S., 2005. Lithologie, Stratigraphie und Paläoökologie des Mittelpleistozäns im Markröhlitzer Tal (Lkr. Weißenfels/Sachsen-Anhalt). Eiszeitalter und Gegenwart (Quaternary Science Journal) 55, 174-214. Nitychoruk, J., Bińka, K., Ruppert, H., Schneider, J., 2005. Holsteinian Interglacial = Marine Isotope Stage 11? Quaternary Science Reviews 25, 2678-2681. Rudolph, A., Laurat, T. & Bernhardt, W., 2005. Die altpaläolithischen Artefaktfunde von Uichteritz, Ldkr. Weißenfels. Eiszeitalter und Gegenwart (Quaternary Science Journal) 55, 215-226. Sirocko, F. et al., 2006. Chronology and climate forcing of the last four interglacials. In: Sirocko, F., Claussen, Sánchez Goñi, M.F., Litt, T. (Eds.). The Climate of Past Interglacials. Developments in Quaternary Science 7, Amsterdam, Elsevier, pp. 597-614.

Erosion of ejecta at Meteor Crater, Arizona

NASA Technical Reports Server (NTRS)

Grant, John A.; Schultz, Peter H.

1993-01-01

New methods for estimating erosion at Meteor Crater, Arizona, indicate that continuous ejecta deposits beyond 1/4-1/2 crater radii from the rim have been lowered less than 1 m on the average. This conclusion is based on the results of two approaches: coarsening of unweathered ejecta into surface lag deposits and calculation of the sediment budget within a drainage basin on the ejecta. Preserved ejecta morphologies beneath thin alluvium revealed by ground-penetrating radar provide qualitative support for the derived estimates. Although slightly greater erosion of less resistant ejecta locally has occurred, such deposits were limited in extent, particularly beyond 0.25R-0.5R from the present rim. Subtle but preserved primary ejecta features further support our estimate of minimal erosion of ejecta since the crater formed about 50,000 years ago. Unconsolidated deposits formed during other sudden extreme events exhibit similarly low erosion over the same time frame; the common factor is the presence of large fragments or large fragments in a matrix of finer debris. At Meteor Crater, fluvial and eolian processes remove surrounding fines leaving behind a surface lag of coarse-grained ejecta fragments that armor surfaces and slow vertical lowering.

Late Quaternary paleoenvironments and paleoclimatic conditions in the distal Andean piedmont, southern Mendoza, Argentina

NASA Astrophysics Data System (ADS)

Tripaldi, Alfonsina; Zárate, Marcelo A.; Brook, George A.; Li, Guo-Qiang

2011-09-01

The Andean piedmont of Mendoza is a semiarid region covered by extensive and partially vegetated dune fields consisting of mostly inactive aeolian landforms of diverse size and morphology. This paper is focused on the San Rafael plain (SRP) environment, situated in the distal Andean piedmont of Mendoza (34° 30'S), and reports the sedimentology and OSL chronology of two representative exposures of late Quaternary deposits, including their paleoenvironmental and paleoclimatic significance. Eleven facies, including channel, floodplain, fluvio-aeolian interaction, and reworked pyroclastic and aeolian deposits, were described and grouped into two facies associations (FA1 and FA2). FA1 was formed by unconfined sheet flows, minor channelized streams and fluvial-aeolian interaction processes. FA2 was interpreted as aeolian dune and sand-sheet deposits. OSL chronology from the SRP sedimentary record indicates that between ca. 58-39 ka and ca. 36-24 ka (MIS 3), aggradation was governed by ephemeral fluvial processes (FA1) under generally semiarid conditions. During MIS 2, the last glacial maximum (ca. 24-12 ka), a major climatic shift to more arid conditions is documented by significant aeolian activity (FA2) that became the dominant sedimentation process north of the Diamante-Atuel fluvial system. The inferred paleoenvironmental conditions from the SRP sections are in broad agreement with regional evidence.

Imprint of Late Quaternary Climate Change on the Mid-Atlantic Landscape

NASA Astrophysics Data System (ADS)

Pavich, M.; Markewich, H.; Newell, W. L.; Litwin, R.; Smoot, J.; Brook, G.

2009-12-01

Recent geomorphic, lithostratigraphic, palynologic and chronostratigraphic investigations of the mid-Atlantic region show that much of the modern landscape flanking the Chesapeake Bay and the Potomac River is developed on late Quaternary sediments. These deposits, dated by OSL and 14C, include transgressive marine and estuarine sediments deposited between 120ka and 32ka, and parabolic dunes formed between 32ka and 15ka. The stacked estuarine units were deposited in a subsiding basin as eustatic sea level fell from +7m to -60m. The estuarine units contain pollen that provides evidence for millennial scale climate fluctuations. The dunes formed during the period of rapid expansion of the Laurentide Ice Sheet as sea level fell to -120m. Permafrost features such as frost wedges and periglacial “pots” formed during cold intervals associated with marine oxygen isotope stages 4 and 2. This periglacial climate, along with glacioisostatic adjustments to growth and decay of the Laurentide Ice Sheet, affected landscape processes at least as far south as the Potomac River valley. While many of these features were recognized in earlier mapping and stratigraphic investigations, OSL dating has greatly extended the range of available dates and significantly improved our understanding of the impacts of highly variable periglacial climate on this region.

Geophysical techniques applied to urban planning in complex near surface environments. Examples of Zaragoza, NE Spain

NASA Astrophysics Data System (ADS)

Pueyo-Anchuela, Ó.; Casas-Sainz, A. M.; Soriano, M. A.; Pocoví-Juan, A.

Complex geological shallow subsurface environments represent an important handicap in urban and building projects. The geological features of the Central Ebro Basin, with sharp lateral changes in Quaternary deposits, alluvial karst phenomena and anthropic activity can preclude the characterization of future urban areas only from isolated geomechanical tests or from non-correctly dimensioned geophysical techniques. This complexity is here analyzed in two different test fields, (i) one of them linked to flat-bottomed valleys with irregular distribution of Quaternary deposits related to sharp lateral facies changes and irregular preconsolidated substratum position and (ii) a second one with similar complexities in the alluvial deposits and karst activity linked to solution of the underlying evaporite substratum. The results show that different geophysical techniques allow for similar geological models to be obtained in the first case (flat-bottomed valleys), whereas only the application of several geophysical techniques can permit to correctly evaluate the geological model complexities in the second case (alluvial karst). In this second case, the geological and superficial information permit to refine the sensitivity of the applied geophysical techniques to different indicators of karst activity. In both cases 3D models are needed to correctly distinguish alluvial lateral sedimentary changes from superimposed karstic activity.

Elastic stress interaction between faulting and volcanism in the Olacapato-San Antonio de Los Cobres area (NW Argentina)

NASA Astrophysics Data System (ADS)

Bonali, F. L.; Tibaldi, A.; Corazzato, C.; Lanza, F.; Cavallo, A.; Nardin, A.

2012-04-01

The aim of this work is to describe the relationships between Plio-Quaternary tectonics, palaeoseismicity and volcanism along the NW-trending Calama-Olacapato-El Toro (COT) lineament that crosses the Andean chain and the Puna Plateau and continues within the eastern Cordillera at about 24° S. Field and satellite data have been collected from the Chile-Argentina border to a few km east of the San Antonio del Los Cobres village. These data revealed the presence of seven Quaternary NW-striking normal left-lateral fault segments in the southeastern part of the studied area and of a Plio-Quaternary N-S-striking graben structure in the northwestern part. The NW-striking Chorrillos fault (CF) segment shows the youngest motions, of late Pleistocene age, being marked by several fault scarps, sag-ponds and offset Quaternary deposits and landforms. Offset lavas of 0.78±0.1 Ma to 0.2±0.08 Ma indicate fault kinematics characterized by a pitch angle of 20° to 27° SE, a total net displacement that ranges from 31 to 63.8 m, and a slip-rate of 0.16 to 0.08 mm/yr. This fault segment is 32 km long and terminates to the northwest near a set of ESE-dipping thrust faults affecting Tertiary strata, while to the southeast it terminates 10 km further from San Antonio. In the westernmost part of the examined area, in Chile at altitudes of 4000 m, recent N-S-striking normal fault scarps depict the 5-km-wide and 10-km-long graben structure. Locally, fault pitches indicate left-lateral normal kinematics. These faults affect deposits up to ignimbrites of Plio-Quaternary age. Scarp heights are from a few metres to 24 m. Despite this area is located along the trace of the COT strike-slip fault system, which is reported as a continuous structure from Chile to Argentina in the literature, no evidence of NW-striking Plio-Quaternary strike-slip structures is present here. A series of numerical models were developed in an elastic half-space with uniform isotropic elastic properties using the Coulomb 3.2 code. We studied the stress changes caused by slip along the various Quaternary COT fault segments, showing that the last motions occurred along the Chorrillos fault might promote in the future further displacement along nearby fault segments located to the northwest. Furthermore, slip along the NW-striking fault segments imparts normal stress changes on the nearby Tuzgle volcano feeding system. Cumulative effects of fault reactivation disadvantage future Tuzgle eruptions.

Heavy mineral analyses as a powerful tool in fluvial geomorphology

NASA Astrophysics Data System (ADS)

von Suchodoletz, Hans; Gärtner, Andreas; Faust, Dominik

2014-05-01

The Marneuli depression is a tectonic sub-basin of the Transcaucasian depression in eastern Georgia, filled with several decametres of fluvial, lacustrine and aeolian Quaternary sediments. In order to reconstruct past landscape evolution of the region we studied Late Quaternary fluvial sediments found along several rivers that flow through that depression. Whereas Holocene river sediments could generally easily be assigned to corresponding rivers, this was not always the case for older fluvial sediments. For this reason, we studied the heavy mineral contents of five recent rivers and of four sedimentary deposits of potential precursors. A total of 4088 analysed heavy mineral grains enabled us to set up the characteristic heavy mineral distribution pattern for each sample. Using these data, we were able to reconstruct the most likely source areas of the Late Pleistocene fluvial sediments and to link them with the catchment areas of recent rivers. This allowed us to identify and to substantiate significant Late Quaternary river diversions that could at least partly be assigned to ongoing tectonic processes.

Growth of quaternary InAlGaN barrier with ultrathin thickness for HEMT application

NASA Astrophysics Data System (ADS)

Li, Zhonghui; Li, Chuanhao; Peng, Daqing; Zhang, Dongguo; Dong, Xun; Pan, Lei; Luo, Weike; Li, Liang; Yang, Qiankun

2018-06-01

Quaternary InAlGaN barriers with thickness of 7 nm for HEMT application were grown on 3-inch semi-insulating 4H-SiC substrates by metal organic chemical vapor deposition (MOCVD). Focused on growth mechanism of the InAlGaN barrier, the surface morphology and characteristics of InAlGaN/AlN/GaN heterostructures were studied with different growth parameters, including the temperature, Al/Ga ratio and chamber pressure. Among the as-grown samples, high electron mobility is consistent with smooth surface morphology, while high crystalline quality of the quaternary barrier is confirmed by measurements of Photoluminescence (PL) and Mercury-probe Capacity-Voltage (C-V). The recommended heterostructures without SiN passivation is characterized by mobility of 1720 cm2/(V·s), 2DEG density of 1.71*1013 cm-2, sheet resistance of about 210 Ω/□ with a smooth surface morphology and moderate tensile state, specially applied for microwave devices.

Application of multispectral radar and LANDSAT imagery to geologic mapping in death valley

NASA Technical Reports Server (NTRS)

Daily, M.; Elachi, C.; Farr, T.; Stromberg, W.; Williams, S.; Schaber, G.

1978-01-01

Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quaternary alluvial and evaporite deposits in Death Valley, California. Unprocessed radar imagery revealed considerable variation in microwave backscatter, generally correlated with surface roughness. For Death Valley, LANDSAT imagery is of limited value in discriminating the Quaternary units except for alluvial units distinguishable by presence or absence of desert varnish or evaporite units whose extremely rough surfaces are strongly shadowed. In contrast, radar returns are most strongly dependent on surface roughness, a property more strongly correlated with surficial geology than is surface chemistry.

Influence of groundwater recharge and well characteristics on dissolved arsenic concentrations in southeastern Michigan groundwater

USGS Publications Warehouse

Meliker, J.R.; Slotnick, M.J.; Avruskin, G.A.; Haack, S.K.; Nriagu, J.O.

2009-01-01

Arsenic concentrations exceeding 10 ??g/l, the United States maximum contaminant level and the World Health Organization guideline value, are frequently reported in groundwater from bedrock and unconsolidated aquifers of southeastern Michigan. Although arsenic-bearing minerals (including arsenian pyrite and oxide/hydroxide phases) have been identified in Marshall Sandstone bedrock of the Mississippian aquifer system and in tills of the unconsolidated aquifer system, mechanisms responsible for arsenic mobilization and subsequent transport in groundwater are equivocal. Recent evidence has begun to suggest that groundwater recharge and characteristics of well construction may affect arsenic mobilization and transport. Therefore, we investigated the relationship between dissolved arsenic concentrations, reported groundwater recharge rates, well construction characteristics, and geology in unconsolidated and bedrock aquifers. Results of multiple linear regression analyses indicate that arsenic contamination is more prevalent in bedrock wells that are cased in proximity to the bedrock-unconsolidated interface; no other factors were associated with arsenic contamination in water drawn from bedrock or unconsolidated aquifers. Conditions appropriate for arsenic mobilization may be found along the bedrock-unconsolidated interface, including changes in reduction/oxidation potential and enhanced biogeochemical activity because of differences between geologic strata. These results are valuable for understanding arsenic mobilization and guiding well construction practices in southeastern Michigan, and may also provide insights for other regions faced with groundwater arsenic contamination. ?? Springer-Verlag 2008.

Late Quaternary loess in northeastern Colorado: Part I - Age and paleoclimatic significance

USGS Publications Warehouse

Muhs, D.R.; Aleinikoff, J.N.; Stafford, Thomas W.; Kihl, R.; Been, J.; Mahan, S.A.; Cowherd, S.

1999-01-01

Loess in eastern Colorado covers an estimated 14000 km2, and is the westernmost part of the North American midcontinent loess province. Stratigraphic studies indicate there were two periods of loess deposition in eastern Colorado during late Quaternary time. The first period spanned ca. 20 000 to 12 000 14C yr B.P. (ca. 20-14 ka) and correlates reasonably well with the culmination and retreat of Pinedale glaciers in the Colorado Front Range during the last glacial maximum. The second period of loess deposition occurred between ca. 11 000 and 9000 14C yr B.P. This interval may be Holocene or may correlate with a hypothesized Younger Dryas glacial advance in the Colorado Front Range. Sedimentologic, mineralogic, and geochemical data indicate that as many as three sources could have supplied loess in eastern Colorado. These sources include glaciogenic silt (derived from the Colorado Front Range) and two bedrock sources, volcaniclastic silt from the White River Group, and clays from the Pierre Shale. The sediment sources imply a generally westerly paleowind during the last glacial maximum. New carbon isotope data, combined with published faunal data, indicate that the loess was probably deposited on a cool steppe, implying a last glacial maximum July temperature depression, relative to the present, of at least 5-6??C. Overall, loess deposition in eastern Colorado occurred mostly toward the end of the last glacial maximum, under cooler and drier conditions, with generally westerly winds from more than one source.

Compiling and Mapping Global Permeability of the Unconsolidated and Consolidated Earth: GLobal HYdrogeology MaPS 2.0 (GLHYMPS 2.0)

NASA Astrophysics Data System (ADS)

Huscroft, Jordan; Gleeson, Tom; Hartmann, Jens; Börker, Janine

2018-02-01

The spatial distribution of subsurface parameters such as permeability are increasingly relevant for regional to global climate, land surface, and hydrologic models that are integrating groundwater dynamics and interactions. Despite the large fraction of unconsolidated sediments on Earth's surface with a wide range of permeability values, current global, high-resolution permeability maps distinguish solely fine-grained and coarse-grained unconsolidated sediments. Representative permeability values are derived for a wide variety of unconsolidated sediments and applied to a new global map of unconsolidated sediments to produce the first geologically constrained, two-layer global map of shallower and deeper permeability. The new mean logarithmic permeability of the Earth's surface is -12.7 ± 1.7 m2 being 1 order of magnitude higher than that derived from previous maps, which is consistent with the dominance of the coarser sediments. The new data set will benefit a variety of scientific applications including the next generation of climate, land surface, and hydrology models at regional to global scales.

Influence of fluvial processes on the quaternary geologic framework of the continental shelf, North Carolina, USA

USGS Publications Warehouse

Boss, S.K.; Hoffman, C.W.; Cooper, B.

2002-01-01

Digital, single-channel, high-resolution seismic reflection profiles were acquired from the insular continental shelf of North Carolina, USA along a data grid extending from Oregon Inlet northward 48 km to Duck, North Carolina and from the nearshore zone seaward approximately 28 km (total surveyed area= 1334 km2). These data were processed and interpreted to delineate principal reflecting horizons and develop a three-dimensional seismic stratigraphic framework for the continental shelf that was compared to stratigraphic data from the shoreward back-barrier (estuarine) and barrier island system. Six principal reflecting horizons (designated R0 through R5) were present within the upper 60 m of the shelf stratigraphic succession. Three-dimensional mapping of reflector R1 demonstrated its origin from fluvial incision of the continental shelf during an episode (or episodes) of lowered sea-level. Fluvial processes during development of reflector R1 were responsible for extensive reworking and re-deposition of sediment throughout most of the northern half of the study area. Five seismic stratigraphic units (designated S1 through S5) were tentatively correlated with depositional sequences previously identified from the North Carolina back-barrier (estuarine) and barrier island system. These five stratigraphic units span the Quaternary Period (S1 = early Holocene; S2 = 51-78 ka; S3 = 330-530 ka; S4 = 1.1-1.8 Ma; S5 = earliest Pleistocene). Unit S1 is composed of fine-grained fluvial/estuarine sediment that back-filled incised streams during early Holocene sea-level rise. The four other stratigraphic units (S2-S5) display tabular depositional geometries, low total relief, and thicken toward the east-southeast as their basal reflectors dip gently between 0.41 m km-1 (0.02??) and 0.54 m km-1 (0.03??). Knowledge of the three-dimensional subsurface stratigraphic architecture of the continental shelf enhances understanding of the development of shelf depositional successions and provides a framework for development of better Quaternary sea-level data, especially offshore North Carolina where such data are sparse. ?? 2002 Elsevier Science B.V. All rights reserved.

Integrated magnetostratigraphy and lithostratigraphy of five cores in Yangtze delta, China : significance of sedimentary evolution

NASA Astrophysics Data System (ADS)

Peng, Jie; Yang, XiaoQiang; Qiang, XiaoKe; Liu, YeBo; Zhou, QiXian

2017-04-01

The sedimentary history and characteristics of the Yangtze delta help us understand the tectonic evolution and geological formation process in the Eastern coastal area of China since the Cenozoic Era. Previous chronology of sediments in this area are not detailed or precise. Furthermore, when the delta area reached the maximum is still debatable. Palaeomagnetic polarity reversal and excursions, AMS14C dating, optically stimulated luminescence (OSL) dating, and the hard clay marker layer analysis were integrated to establish the chronostratigraphic framework of five drilling cores from the south Yangtze delta. Results from the bottom part of core CSB6 suggested Gauss normal polarity chron, an age of more than about 2600 ka. The other four cores showed initial deposition time between 200-60 ka B.P., significantly later than CSB6. We infer the reason is that CSB6 locating in the Changxin-Fenghua Fracture. Combined with data from referenced magnetostratigraphic cores in the Yangtze River Delta, we suggest that tectonic movement resulted in a much longer depositional age in some parts of the Yangtze River Delta and influenced the sedimentary characteristics of thick (North) to thin (South) and thick (East) to thin (West). In conclusion, a relatively wide range of deposition in the Yangtze River Delta occurred since about 200 ka B.P. The deposition of fine particles (clay-silt), which was controlled by slow tectonic subsidence and sea-level changes, expanded to the whole delta region after about 60 ka B.P. We propose that this time scale maybe used for further study on the evolution of the Yangtze delta's paleoclimate and paleoenvironment. References [1]Peng J,Yang X Q,Qiang X K,et al.Magnetostratigraphy characteristics of several cores around the Qiantang River mouth and its significance.Chinese J.Geophys.(in Chinese),2016,59(8):2949-2964. [2]Li C X, Chen Q Q, Zhang J Q,et al. Stratigraphy and paleoenvironmental changes in the Yangtze Delta during the Late Quaternary[J].Journal of Asian Earth Sciences, 2000, 18(2000):453-469. [3]Brad S.Singer. A Quaternary geomagnetic instability time scale[J]. Quaternary Geochronology, 2014,21:29-54.

Geological evolution of Paniri volcano, Central Andes, northern Chile

NASA Astrophysics Data System (ADS)

Godoy, Benigno; Lazcano, José; Rodríguez, Inés; Martínez, Paula; Parada, Miguel Angel; Le Roux, Petrus; Wilke, Hans-Gerhard; Polanco, Edmundo

2018-07-01

Paniri volcano, in northern Chile, belongs to a volcanic chain trending across the main orientation of the Central Andean volcanic province. Field work mapping, stratigraphic sequences, and one new 40Ar/39Ar and eleven previous published 40Ar/39Ar, and K/Ar ages, indicate that the evolution of Paniri involved eruption of seven volcanic units (Malku, Los Gordos, Las Lenguas, Las Negras, Viscacha, Laguna, and Llareta) during four main stages occurring over more than 1 Myr: Plateau Shield (>800 ka); Main Edifice (800-400 ka); Old Cone (400-250 ka); and New Cone (250-100 ka). Considering glacial and fluvial action, an estimated 85.3 km3 of volcanic material were erupted during the eruptive history of Paniri volcano, giving a bulk eruption rate of 0.061 km3/ka, with major activity in the last 150 kyr (eruption rate of 0.101 km3/ka). Lava flows from Paniri show abundant plagioclase together with subordinate ortho-, and clino-pyroxene, and amphibole as main phenocrysts. Moreover, although true basalts are scarce in the Central Andes, olivine-bearing lavas were erupted at Paniri at ∼400 ka. Also, scarce phenocrysts of biotite, quartz, rutile, and opaque minerals (Fe-Ti oxides) were identified. The groundmass of these flows is composed mainly of glass along with pyroxene and plagioclase microlites. Consolidated and unconsolidated pyroclastic deposits of dacitic composition are also present. The consolidated deposits correspond to vitreous tuffs, whilst unconsolidated deposits are composed of pumice clasts up to 5 cm in diameter. Both pyroclastic deposits are composed of glassy groundmass (up to 80% vol.), and subordinated plagioclase, hornblende, and biotite phenocrysts up to 1 cm in length. Results of twenty-four new, coupled with previous published compositional analyses show that volcanic products of Paniri vary from 57% (basaltic-andesite) to 71% (rhyolite) vol. SiO2, with significant linear correlations between major element-oxide and trace-element concentrations. 87Sr/86Sr isotope ratios range from 0.7070 to 0.7075, indicating that Paniri, similar to other volcanoes of the San Pedro - Linzor volcanic chain, have undergone significant crustal contamination of its parental magmas. However, the almost constant Sr-isotope compositions of the different volcanic units defined for Paniri volcano, suggested later fractional crystallization of magmas at upper crustal levels.

The formation age of ores from the Pebble Cu-Au-Mo giant deposit (Alaska, United States)

NASA Astrophysics Data System (ADS)

Kremenetskii, A. A.; Popov, V. S.; Gromalova, N. A.

2012-02-01

Zircons from the porphyry-like quartz-diorite boss of the Pebble Cu-Au-Mo deposit (southwest Alaska) have been examined. By their appearance and internal structure (cathode luminescence and electron probing), the zircons have been subdivided into four genetic groups: (1) xenogenic detrital (mainly rounded); (2) magmatogene (protolith crystal in the center and growth zone at the edge); (3) hydrothermally altered (with new-formed regeneration edges in growth zones); (4) metamict-altered (unconsolidated center of the crystal and sectoring in growth zones). Based on SHRIMP U-Pb dating for the principal heterogeneous elements in every group, the following stages of ore formation have been identified for the Pebble deposit: (a) crystallization of quartz diorite-porphyry bosses (95-92 Ma, the concordant age is 94.7 ± 1.5 Ma); (b) late magmatic metasomatic alterations with copper-molybdenum mineralization (92-85 Ma, the concordant age is 90.15 ± 0.78 Ma); (c) postmagmatic argillization with epithermal gold-sulfide mineralization (82-80 Ma, the concordant age is 82.9 ± 2.7 Ma).

Little Ice Age mapping as a tool for identifying hazard in the paraglacial environment: The case study of Trentino (Eastern Italian Alps)

NASA Astrophysics Data System (ADS)

Zanoner, Thomas; Carton, Alberto; Seppi, Roberto; Carturan, Luca; Baroni, Carlo; Salvatore, Maria Cristina; Zumiani, Matteo

2017-10-01

The Little Ice Age (LIA) is a well-recognized climatic event during which the glaciers in the Alps advanced and reached their maximum Holocene extent. During their retreat following the LIA, the glaciers left large areas of loose or poorly consolidated glacial deposits in their forelands, which are subject to paraglacial reworking and may represent potential hazards for human infrastructures. In this study, we present a regional scale mapping of the LIA and post-LIA glacial deposits and a reconstruction of the maximum LIA extents of glaciers in the same area. This work is motivated by a local law requiring the classification of areas subject to natural hazards in Trentino (Italian Alps). Results highlight that glaciers shrunk by 63% from the LIA maximum, leaving 30 km2 of unconsolidated deposits, which are subject to geomorphic paraglacial processes. Potentially hazardous consequences can occur, in particular, during high-magnitude instantaneous events, causing debris and mud flows, mass wasting from debris-covered ice, and floods from small moraine-dammed lakes.

Late Cretaceous to Miocene phosphatic sediments in the Georges Bank Basin, U.S. North Atlantic outer continental shelf

USGS Publications Warehouse

Poppe, L.J.; Manheim, F. T.; Popenoe, P.

1992-01-01

Phosphorite and phosphatic sediments are present in the Georges Bank Basin in marine, Late Cretaceous to Miocene strata equivalent to the Dawson Canyon Formation and Banquereau Formation of offshore Nova Scotia. The Late Cretaceous to Paleocene phosphorite occurs predominantely as sand- and gravel-sized pellets and as cement in conglomeratic aggregates. The Eocene and Miocene phosphate occurs mainly as fine-very fine sand-size spheroidal-avoidal pellets in unconsolidated clayey silts. The older phosphorites form intraformational conglomerates that are the result of a winnowed finer-grained matrix, leaving lag deposits of phosphorite. We present evidence that most of the Eocene and Miocene phosphate is primary and formed during marine trangressions. Our observations extend the geographic and temporal limits of the major phosphogenic system of the Western North Atlantic northward and through time. However, compared to the well-known phosphorite deposits along the southeastern margin of the U.S.A., these northern deposits are not of commercial scale due to a high terrigenous input and the lack of a mechanism capable of driving persistant upwelling. ?? 1992.

The Geophysical Investigation of Drinkable Water at Shkodra Region

NASA Astrophysics Data System (ADS)

Jata, I. B.; Kavaja, V. S.; Kotori, A. N.

2002-12-01

The drinkable water has been and is a great problem for the population of Shkodra region, NW of Albania. Many studies have been widely used in this domain by Geophysical Center of Tirana.Two case histories are presented in this paper.One, the Drini river terraces and other example near coast line.Actually, the need from fresh water are increasing due to the high demand for water supply. In compliance with geographical and geological classification the survey is in a narrow sense belongs to marginal part of the Nenshkodra plain. Geological situation of survey area consists on diverse geological make up.The stratigrafic section begins with carbonate formations (Cr2) have a monoclyne structure, nearly NW-SE trending. Paleogene formations is composed mainly: by carbonatic flysch (Pg2), alevrolitic-sanstone formation(Pg31 - Pg32) and Oligocene deposits with alevrolitic-clay-sandston formation (Pg13). Quaternary formation interbeded by silt, clay, sand and gravel layers. In survey area the thickness of concerned younger deposits does not surpass 50-70m, therefor we were able to draw up a picture of the thickness and depositional conditions of the Quaternary accumulations as corresponding in precision to given scale. The aim of the study is been delineation of aquifers and aquicludes soils extension within terrace profile based in the resistivity parameter as well as zone of aeration and water table. In the paper are described all the phases from field measurements, data processing and interpretation, as well as the soil thickness and resistivity maps, the thickness and resistivity maps of gravel terraces was build up. The high resistivity values show best aquifers gravel deposits. But when the gravel terrace companies with large thickness of the layers it is practical to multiply these two parameters, Hi x *i = S. In the other hand, one and more important maps are the correlation of rocks permeability T (sq.m/day) with transversal resistivity (S) parameters. In preparing such maps the descriptive logs of latest survey boreholes and resistivity data of field have been provided by vertical electric soundings extending over whole area was fundamental.Histories of terrestrial erosion,near shore sediment and land-sea interaction are obvious now. For a gravel deposition, in addition to the usual parameter maps as resistivity and thickness maps, combined multiparametric characterization maps have been plotted. These maps are more application on hydrogeologic domain than conventional parameter maps. Based in above maps are shown prospective areas in Quaternary deposits, in which the drillings have the positive results for fresh water.

Integrated Historical Tsunami Event and Deposit Database

NASA Astrophysics Data System (ADS)

Dunbar, P. K.; McCullough, H. L.

2010-12-01

The National Geophysical Data Center (NGDC) provides integrated access to historical tsunami event, deposit, and proxy data. The NGDC tsunami archive initially listed tsunami sources and locations with observed tsunami effects. Tsunami frequency and intensity are important for understanding tsunami hazards. Unfortunately, tsunami recurrence intervals often exceed the historic record. As a result, NGDC expanded the archive to include the Global Tsunami Deposits Database (GTD_DB). Tsunami deposits are the physical evidence left behind when a tsunami impacts a shoreline or affects submarine sediments. Proxies include co-seismic subsidence, turbidite deposits, changes in biota following an influx of marine water in a freshwater environment, etc. By adding past tsunami data inferred from the geologic record, the GTD_DB extends the record of tsunamis backward in time. Although the best methods for identifying tsunami deposits and proxies in the geologic record remain under discussion, developing an overall picture of where tsunamis have affected coasts, calculating recurrence intervals, and approximating runup height and inundation distance provides a better estimate of a region’s true tsunami hazard. Tsunami deposit and proxy descriptions in the GTD_DB were compiled from published data found in journal articles, conference proceedings, theses, books, conference abstracts, posters, web sites, etc. The database now includes over 1,200 descriptions compiled from over 1,100 citations. Each record in the GTD_DB is linked to its bibliographic citation where more information on the deposit can be found. The GTD_DB includes data for over 50 variables such as: event description (e.g., 2010 Chile Tsunami), geologic time period, year, deposit location name, latitude, longitude, country, associated body of water, setting during the event (e.g., beach, lake, river, deep sea), upper and lower contacts, underlying and overlying material, etc. If known, the tsunami source mechanism (e.g., earthquake, landslide, volcanic eruption, asteroid impact) is also specified. Observations (grain size, sedimentary structure, bed thickness, number of layers, etc.) are stored along with the conclusions drawn from the evidence by the author (wave height, flow depth, flow velocity, number of waves, etc.). Geologic time periods in the GTD_DB range from Precambrian to Quaternary, but the majority (70%) are from the Quaternary period. This period includes events such as: the 2004 Indian Ocean tsunami, the Cascadia subduction zone earthquakes and tsunamis, the 1755 Lisbon tsunami, the A.D. 79 Vesuvius tsunami, the 3500 BP Santorini caldera collapse and tsunami, and the 7000 BP Storegga landslide-generated tsunami. Prior to the Quaternary period, the majority of the paleotsunamis are due to impact events such as: the Tertiary Chesapeake Bay Bolide, Cretaceous-Tertiary (K/T) Boundary, Cretaceous Manson, and Devonian Alamo. The tsunami deposits are integrated with the historical tsunami event database where applicable. For example, users can search for articles describing deposits related to the 1755 Lisbon tsunami and view those records, as well as link to the related historic event record. The data and information may be viewed using tools designed to extract and display data (selection forms, Web Map Services, and Web Feature Services).

Surveying the Alentejo continental shelf for minerals and Quaternary environmental changes: preliminary results of the MINEPLAT project survey

NASA Astrophysics Data System (ADS)

Noiva, João; Ribeiro, Carlos; Terrinha, Pedro; Brito, Pedro; Neres, Marta

2017-04-01

The tectonic uplift of South Portugal in the last 5 Million years (My) was firstly identified on the basis of morphologic criteria by Mariano Feio (1952, "The evolution of the relief of Baixo Alentejo and Algarve", transl.). However, the assessment of continental vertical movements off Portugal and its relation with tectonics was only initiated in the 1990-ies. This work was carried out in the framework of FP6 and FP7 in the domains of Natural Hazards funded by the European Community. The swath bathymetry cartography of the southwest part of the Iberian Peninsula resulted from the effort of European and national projects, of 19 oceanographic surveys, a total of 200 ship time days executed from 2000 to 2006, involving 14 research institutions from 7 European countries. As a result of this effort together with acquisition and interpretation of thousands of km of seismic reflection profiles, the Pliocene-Quaternary uplift of the Alentejo continental margin (SW Portugal) is now widely accepted by the scientific community. This uplift has not been yet quantified but it is possible that can have contributed to erosion and deposition of metallic ores as placers in the continental shelf. This argues in favor of the potential existence of placers in the continental shelf and the need for the detailed investigation that will allow determination of ideal location for placers deposition in the past Pliocene-Quaternary (5 My). The source for metals can arguably be associated to the Iberian Pyrite Belt ores hosted in the Alentejo Paleozoic formations and to the hyper-alkaline intrusions of Sines and Monchique of Late Cretaceous age. Artificial renourishment of beaches with offshore sand has not been assessed for the Alentejo littoral, despite that the coast located to the south of the Sines segment shows high susceptibility to erosion. This has been observed on a regular basis as the beaches are frequently devoid of sand, thus jeopardizing their touristic potential. The detailed assessment of good quality sand deposits between approximately 30m and 50m below sea level aims at minimizing this problem that affects the economy of littoral of Alentejo. The MINEPLAT project (Assessment of the mineral resources potential in the continental shelf of Alentejo and of the environmental conditions caused by the tectonic uplift in the Pliocene-Quaternary) aims at assessing the existence of mineral deposits off the Alentejo. The MINEPLAT-1 geophysical survey acquired very high resolution multi-channel reflection seismics, swath bathymetry, backscatter and magnetic data in a test area. The preliminary results show: previously unknown NNW-SSE aligned magnetic anomalies, possibly corresponding to buried Late Cretaceous alkaline rocks; faults affecting recent sediments; well defined patches of sediments associated to morphologic traps. Future work will involve ground-truthing to characterize the shallow deposits. Acknowledgement: This work was funded by Alentejo 2020 contract ALT20-03-0145-FEDER-000013

Hydrology, water quality, and effects of drought in Monroe County, Michigan

USGS Publications Warehouse

Nicholas, J.R.; Rowe, Gary L.; Brannen, J.R.

1996-01-01

Monroe County relies heavily on its aquifers and streams for drinking water, irrigation, and other ~ses; however, increased water use, high concentrations of certain constituents in ground water, and droughts may limit the availability of water resources. Although the most densely populated parts of the county use water from the Great Lakes, large amounts of ground water are withdrawn for quarry dewatering, domestic supply, and irrigation.Unconsolidated deposits and bedrock of Silurian and Devonian age underlie Mon_roe County. The unconsolidated deposits are mostly clayey and less than 50 feet thick. Usable amounts of ground water generally are obtained from thin, discontinuous surficial sand deposits or, in the northwestern part of the county, from deep glaciofluvial deposits. In most of the county, however, ground water in unconsolidated deposits is highly susceptible to effects of droughts and to contamination.The bedrock is mostly carbonate rock, and usable quantities of ground water can be obtained from fractures and other secondary openings throughout the county. Transmissivities of the Silurian-Devonian aquifer range from 10 to 6,600 feet squared per day. Aquifer tests and historical informati.on indicate that the Silurian-Devonian aquifer is confmed throughout most of the county. The major recharge area for the Silurian-Devonian aquifer in Monroe County is in the southwest, and groundwater flow is mostly southeastward toward Lake Erie. In the northeastern and southeastern parts of the county, the potentiometric surface of the SilurianDevonian aquifers has been lowered by pumpage to below the elevation of Lake Erie.Streams and artificial drains in Monroe County are tributary to Lake Erie. Most streams are perennial because of sustained discharge from the sand aquifer and the Silurian-Devonian aquifer; however, the lower reaches of River Raisin and Plum Creek lost water to the Silurian-Devonian aquifer in July 1990.The quality of ground water and of streamwater at low flow is suitable for most domestic u~es, irrigation, and recreation. In ground water, dissolved solids and hydrogen sulfide are present at concentrations objectionable to some users. Indicators of ground-water contamination from agricultural activities-pesticides and nitrates-were not present at detectable concentrations or were below U.S. Environmental Protection Agency (USEPA) limits. In streamwater, some treatment to remove bacteria may be necessary in summer months; nitrate concentrations, however, were found to be below USEPA limits.Tritium concentrations indicative of recent recharge to the Silurian-Devonian aquifer are present in a southwest-to-northeast-trending band from Whiteford to Berlin Townships. Generally, where glacial deposits are thicker than 30 feet, rech~rge.takes more than 40 years. Carbon isotope data md1cate that some of the ground water in the Silurian-Devonian aquifer is more than 14,000 years old.Mild droughts are common in Michigan, but long severe droughts, such as those during 1930-37 and 1960-67, are infrequent. The most recent drought, during 1988, was severe but short. Ground-water levels declined throughout the county; the largest declines were probably in the southwest. Shallow bedrock wells completed in only the upper part of the Silurian-Devonian aquifer and near large uses of ground water were especially susceptible to the effects of drought. Deep bedrock wells continued to produce water through the drought of 1988.During droughts, streamflow is reduced because of low ground-water levels and high consumptive uses of surface water. In 1988, annual discharge on the River Raisin was near normal, but monthly averages were below normal from March through August. The quality of surface water during droughts is similar to that during normal lowflow conditions.

Quaternary landscape evolution of tectonically active intermontane basins: the case of the Middle Aterno River Valley (Abruzzo, Central Italy)

NASA Astrophysics Data System (ADS)

Falcucci, Emanuela; Gori, Stefano; Della Seta, Marta; Fubelli, Giandomenico; Fredi, Paola

2014-05-01

The Middle Aterno River Valley is characterised by different Quaternary tectonic depressions localised along the present course of the Aterno River (Central Apennine) .This valley includes the L'Aquila and Paganica-Castelnuovo-San Demetrio tectonic basins, to the North, the Middle Aterno Valley and the Subequana tectonic basin, to the South. The aim of this contribution is to improve the knowledge about the Quaternary geomorphological and tectonic evolution of this portion of the Apennine chain. A synchronous lacustrine depositional phase is recognized in all these basins and attributed to the Early Pleistocene by Falcucci et al. (2012). At that time, this sector of the chain showed four distinct closed basins, hydrologically separated from each other and from the Sulmona depression. This depression, actually a tectonic basin too, was localized South of the Middle Aterno River Valley and it was drained by an endorheic hydrographic network. The formation of these basins was due to the activity of different fault systems, namely the Upper Aterno River Valley-Paganica system and San Pio delle Camere fault, to the North, and the Middle Aterno River Valley-Subequana Valley fault system to the South. These tectonic structures were responsible for the origin of local depocentres inside the depressions which hosted the lacustrine basins. Ongoing surveys in the uppermost sectors of the Middle Aterno River Valley revealed the presence of sub-horizontal erosional surfaces that are carved onto the carbonate bedrock and suspended several hundreds of metres over the present thalweg. Gently dipping slope breccias referred to the Early Pleistocene rest on these surfaces, thus suggesting the presence of an ancient low-gradient landscape adjusting to the local base level.. Subsequently, this ancient low relief landscape underwent a strong erosional phase during the Middle Pleistocene. This erosional phase is testified by the occurrence of valley entrenchment and of coeval fluvial deposition within the Middle Aterno River Valley. These fluvial deposits are deeply embedded into the lacustrine sequence, thus suggesting the happening of a hydrographic connection among the originally separated tectonic depressions. This was probably due to the headward erosion by streams draining the Sulmona depression that progressively captured the hydrological networks of the Subequana basin, the Middle Aterno Valley, the L'Aquila and Paganica-Castelnuovo-San Demetrio basins to the North. Stream piracy was probably helped by an increase of the regional uplift rate, occurred between the Lower and the Middle Pleistocene. To reconstruct the paleo-landscape that characterised the early stages of these basins formation we sampled the remnants of the Quaternary erosinal/depositional surfaces and reconstructed the ancient topographic surfaces using the Topo to Raster tool of ArcGIS 10.0 package. Finally we have cross-checked the geological and geomorphological data with the model of the Middle Aterno River paleo-drainage basin obtained through the GIS based method. References Falcucci E., Scardia G., Nomade S., Gori S., Giaccio B., Guillou H., Fredi P. (2012). Geomorphological and Quaternary tectonic evolution of the Subequana basin and the Middle Aterno Valley (central Apennines).16th Joint Geomorphological Meeting Morphoevolution of Tectonically Active Belts Rome, July 1-5, 2012

Occurrence of Quaternary turbidite deposits in the central South China Sea: Response to global sea-level changes

NASA Astrophysics Data System (ADS)

Liu, Z.; Zhang, X.; Christophe, C.; Peleo-Alampay, A.; Guballa, J. D. S.; Li, P.; Liu, C.

2016-12-01

Terrigenous turbidite layers frequently occur at the upper 150-m-thick sedimentary sequence of Hole U1431D (15º22.54'N, 117 º00.00'E, 4240.5 m water depth), International Ocean Discovery Program (IODP) Expedition 349, near the relict spreading ridge in the central South China Sea. This study implies visual statistics combined with grain size, clay mineralogy, and Nd-Sr isotope analyses to reconstruct the occurrence of these turbidite layers. The age-model of combined calcareous nannofossils, planktonic foraminifers, and paleomagnetism suggests that the sedimentary sequence spans the entire Quaternary with an age of 2.6 Ma at the depth of 150 mcd below the seafloor. Our results show that the turbidite deposits are dominated by silt with sandy silt and silty clay, poorly sorted, and grading upward with erosion base. The occurrence of turbidite layers are highly frequent with about 3.06 layers per meter and an average thickness of 14.64 cm per layer above 96 mcd ( 1.6 Ma), while the lower part turbudite layers are less frequently developed with 1.16 layers per meter and an average thickness of 5.67 cm. Provenance analysis indicates that Taiwan, about 900 km northward to the studied site, is the major source for these terrigenous sediments, implying the long run-out turbidity current activity over the very low-gradient deep-sea plain of the South China Sea. The frequency of the turbidite layer occurrence is well correlated to the Quaternary global sea-level change history, with the high frequency occurred during the lower sea-level stands. Our study suggests that the glacial-interglacial-scale sea-level change has controlled terrigenous sediment input from Taiwan and the northern shelf of the South China Sea during the Quaternary. The increase of turbidite layer frequency since 1.6 Ma in the central South China Sea could be triggered by the enlarged amplitude of sea-level change.

An aminostratigraphy for the British Quaternary based on Bithynia opercula

PubMed Central

Penkman, Kirsty E.H.; Preece, Richard C.; Bridgland, David R.; Keen, David H.; Meijer, Tom; Parfitt, Simon A.; White, Tom S.; Collins, Matthew J.

2013-01-01

Aminostratigraphies of Quaternary non-marine deposits in Europe have been previously based on the racemization of a single amino acid in aragonitic shells from land and freshwater molluscs. The value of analysing multiple amino acids from the opercula of the freshwater gastropod Bithynia, which are composed of calcite, has been demonstrated. The protocol used for the isolation of intra-crystalline proteins from shells has been applied to these calcitic opercula, which have been shown to more closely approximate a closed system for indigenous protein residues. Original amino acids are even preserved in bithyniid opercula from the Eocene, showing persistence of indigenous organics for over 30 million years. Geochronological data from opercula are superior to those from shells in two respects: first, in showing less natural variability, and second, in the far better preservation of the intra-crystalline proteins, possibly resulting from the greater stability of calcite. These features allow greater temporal resolution and an extension of the dating range beyond the early Middle Pleistocene. Here we provide full details of the analyses for 480 samples from 100 horizons (75 sites), ranging from Late Pliocene to modern. These show that the dating technique is applicable to the entire Quaternary. Data are provided from all the stratotypes from British stages to have yielded opercula, which are shown to be clearly separable using this revised method. Further checks on the data are provided by reference to other type-sites for different stages (including some not formally defined). Additional tests are provided by sites with independent geochronology, or which can be associated with a terrace stratigraphy or biostratigraphy. This new aminostratigraphy for the non-marine Quaternary deposits of southern Britain provides a framework for understanding the regional geological and archaeological record. Comparison with reference to sites yielding independent geochronology, in combination with other lines of evidence, allows tentative correlation with the marine oxygen isotope record. PMID:23396683

Analysis of the Variations in Rock Magnetic Properties of the Quaternary Blackwater Draw (Eolian) Formation, West Texas

NASA Astrophysics Data System (ADS)

Stine, J. M.; Ferguson, J. F.; Geissman, J. W.; Sweet, D. E.

2017-12-01

The Quaternary Blackwater Draw Formation consists of the surficial deposits ( 10 + m thick) that directly overlie the Neogene Ogallala Formation in the Southern High Plains (SHP). These Quaternary deposits display a rhythmic pattern where eolian derived sediments (loess) are in turn punctuated by several paleosol layers, implying that Quaternary glacial-interglacial climate cycles are recorded in the Blackwater Draw Formation. In order to investigate this hypothesis, several rock magnetic parameters obtained from the Blackwater Draw Formation were analyzed using exploratory data analysis (EDA) techniques. The Blackwater Draw Formation was sampled at high resolution (2.5-5 cm intervals in depth, which serves as a proxy for time). Rock magnetic parameters measured are bulk magnetic susceptibility (χ, median: 1.56 * 10-4 SI volume), anhysteretic remanent magnetization (ARM, median: 0.1612 A/m), and isothermal remanent magnetization (IRM, median: 2.5367 A/m) intensity, which allow for the determination of two common environmental magnetic ratios (ARM/χ and ARM/IRM, medians: 1051 and 0.068 respectively) that are often used to approximate magnetic grain size. The data were analyzed using robust EDA methods for classification, correlation, and signal extraction. Using these techniques, it becomes evident that a good correspondence exists between the geophysical data and the geologic model (stratigraphy). For example, the cross plots showed that the magnetic data segregate into clusters corresponding to stratigraphy. Smoothing of the magnetic ratio data produces an oscillatory signal that may correspond to climate cyclicity. Additionally the smoothed models show a noticeable change in periodicity, where the ARM, IRM and χ values in the uppermost section exhibit a much higher amplitude and lower frequency than the bottom part of the section (with the reverse being true for the ratios). When comparing the data to the geologic model this change appears to correlate with the Mid-Pleistocene Transition (MPT), when the Earth's climate cycle periodicity changed from 41 ka to 100 ka.

Late Quaternary eolian and alluvial response to paleoclimate, Canyonlands, southeastern Utah

USGS Publications Warehouse

Reheis, M.C.; Reynolds, R.L.; Goldstein, H.; Roberts, H.M.; Yount, J.C.; Axford, Y.; Cummings, L.S.; Shearin, N.

2005-01-01

In upland areas of Canyonlands National Park, Utah, thin deposits and paleosols show late Quaternary episodes of eolian sedimentation, pedogenesis, and climate change. Interpretation of the stratigraphy and optically stimulated luminescence ages of eolian and nearby alluvial deposits, their pollen, and intercalated paleosols yields the following history: (1) Eolian deposition at ca. 46 ka, followed by several episodes of alluviation from some time before ca. 40 ka until after 16 ka (calibrated). (2) Eolian deposition from ca. 17 ka to 12 ka, interrupted by periods of pedogenesis, coinciding with late Pleistocene alluviation as local climate became warmer and wetter. (3) A wetter period from 12 to 8.5 ka corresponding to the peak of summer monsoon influence, during which soils formed relatively quickly by infiltration of eolian silt and clay, and trees and grasses were more abundant. (4) A drier period between ca. 8.5 and 6 ka during which sheetwash deposits accumulated and more desertlike vegetation was dominant; some dunes were reactivated at ca. 8 ka. (5) Episodic eolian and fluvial deposition during a wetter, cooler period that began at ca. 6 ka and ended by ca. 3-2 ka, followed by a shift to drier modern conditions; localized mobilization of dune sand has persisted to the present. These interpretations are similar to those of studies at the Chaco dune field, New Mexico, and the Tusayan dune field, Arizona, and are consistent with paleoclimate interpretations of pollen and packrat middens in the region. A period of rapid deposition and infiltration of eolian dust derived from distant igneous source terranes occurred between ca. 12 and 8 ka. Before ca. 17 ka, and apparently back to at least 45 ka, paleosols contain little or no such infiltrated dust. After ca. 8 ka, either the supply of dust was reduced or the more arid climate inhibited translocation of dust into the soils. ?? 2005 Geological Society of America.

Syntectonic Deposition of Plio-Quaternary Sediments in the Santa Rosalia Basin of Baja California Sur, Mexico

NASA Astrophysics Data System (ADS)

Michels, A.; Johnson, L.; Niemi, T. M.

2017-12-01

Plio-Quaternary sediments of the Tirabuzón, Infierno, and Santa Rosalía formations record syntectonic deposition in the Santa Rosalía basin—an oblique-rift-margin basin along the Gulf of California in Baja California Sur, Mexico. These deposits unconformably overlie the upper Miocene, Cu-Zn-Co-Mn-rich Boleo Formation. The Mesa Soledad outcrops, exposed on the Minera Boleo mine property, show interfingering of marine and terrestrial deposits of the three formations along the inland margin of the basin in an area that has not previously been studied. Faults that cut the Pliocene section of the mesa are mostly steeply-dipping, NW- and NE-striking faults with normal displacement determined from stratigraphic offset and steep plunge in striations. Two stratigraphic sections were measured on either side of one of these high-angle, NW-striking fault that has a normal throw of 26 m. Our analyses of sediment grain size, fossil assemblages, and sedimentary petrography indicate a mismatch of the stratigraphic units across the fault and suggest a component of strike slip. North of the fault, poorly-sorted, well-rounded, fluvial gravels from the Pliocene-aged, Tirabuzón Formation unconformably underlie fossiliferous marine deposits from the late-Pliocene to Pleistocene? -aged Infierno Formation. South of the fault, marine deposits of the Tirabuzón Formation grade upward into imbricated, clast-supported beach gravel, and finally into non-marine conglomerates. The absence of the Infierno Formation on the southern side of the fault suggests the deposits were either eroded unevenly due to uplift or laterally displaced by strike-slip movement. Fossiliferous sandstones and conglomerates of the Santa Rosalía Formation unconformably cap the entire outcrop and show no displacement from faulting. The Santa Rosalía Formation is overlain by the 1.4 Ma La Reforma ignimbrite (Schmidt 2006), indicating that the style of deformation of the basin changed at approximately this time.

Mapping and characterization from aeromagnetic data of the Foum Zguid dolerite Dyke (Anti-Atlas, Morocco) a member of the Central Atlantic Magmatic Province (CAMP)

NASA Astrophysics Data System (ADS)

Bouiflane, Mustapha; Manar, Ahmed; Medina, Fida; Youbi, Nasrrddine; Rimi, Abdelkrim

2017-06-01

A high-resolution aeromagnetic survey was carried out in the Anti- Atlas, Morocco covering the main areas traversed by the Great CAMP Foum Zguid dyke (FZD). This ;doleritic; dyke belongs to the Central Atlantic Magmatic Province (CAMP), a Large Igneous Province which is associated with the fragmentation of the supercontinent Pangaea and the initial stages of rifting of the Central Atlantic Ocean. It also coincides in time with the mass extinction of the Triassic - Jurassic boundary. Based on the study of geological maps and Google Earth satellite images, it appears that the FZD is poorly exposed and, often covered by Quaternary deposits. This work proposes aeromagnetic modelling and interpretation of the FZD in order to better constrain its structural extent. The data have allowed (i) mapping of the dyke over great distances, under the Quaternary deposits and through areas where it was poorly characterized on the geological map; (ii) identifying major tectonic lineaments interpreted as faults; (iii) recognizing magnetic anomalies related to mafic intrusive bodies; and (iv) informing about regional structural context.

Links between Iron Fertilization and Biological Pump Efficiency in the Bering Sea Over the Last 3.5 Myrs

NASA Astrophysics Data System (ADS)

Bartoli, G. L.; Studer, A. S.; Martinez Garcia, A.; Haug, G. H.

2011-12-01

The Bering Sea is one of the major sink of atmospheric CO2 today, due to the efficiency of its biological pump, despite a limitation by iron. Here we present records of iron fertilization by aeolian dust deposition (n-alkane concentration) and phytoplankton nutrient consumption (diatom-bound δ15N record) over the last 3.5 Myrs in the southwestern Bering Sea at Site U1341 drilled during IODP Expedition 323. During the Pliocene Epoch, when sea surface temperatures were 3-4°C warmer than today and sea-ice cover was reduced, the biological pump efficiency during glacial and interglacial stages was minimal, similar to Quaternary interglacials. Low iron deposition and weaker surface water stratification resulting in higher nutrient inputs contributed to reduce the biological pump efficiency until 1.5 Ma. After the intensification of glacial conditions in the Bering Sea and the increase in sea-ice cover and iron inputs, the biological pump efficiency progressively increased, reaching values similar to Quaternary glacials after the mid-Pleistocene transition.

Surficial Geologic Map of the Worcester North-Oxford- Wrentham-Attleboro Nine-Quadrangle Area in South- Central Massachusetts

USGS Publications Warehouse

Stone, Byron D.; Stone, Janet R.; DiGiacomo-Cohen, Mary L.

2008-01-01

The surficial geologic map layer shows the distribution of nonlithified earth materials at land surface in an area of nine 7.5-minute quadrangles (417 mi2 total) in south-central Massachusetts (fig. 1). Across Massachusetts, these materials range from a few feet to more than 500 ft in thickness. They overlie bedrock, which crops out in upland hills and in resistant ledges in valley areas. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (such as grain size and sedimentary structures), constructional geomorphic features, stratigraphic relationships, and age. Surficial materials also are known in engineering classifications as unconsolidated soils, which include coarse-grained soils, fine-grained soils, or organic fine-grained soils. Surficial materials underlie and are the parent materials of modern pedogenic soils, which have developed in them at the land surface. Surficial earth materials significantly affect human use of the land, and an accurate description of their distribution is particularly important for water resources, construction aggregate resources, earth-surface hazards assessments, and land-use decisions. The mapped distribution of surficial materials that lie between the land surface and the bedrock surface is based on detailed geologic mapping of 7.5-minute topographic quadrangles, produced as part of an earlier (1938-1982) cooperative statewide mapping program between the U.S. Geological Survey and the Massachusetts Department of Public Works (now Massachusetts Highway Department) (Page, 1967; Stone, 1982). Each published geologic map presents a detailed description of local geologic map units, the genesis of the deposits, and age correlations among units. Previously unpublished field compilation maps exist on paper or mylar sheets and these have been digitally rendered for the present map compilation. Regional summaries based on the Massachusetts surficial geologic mapping studies discuss the ages of multiple glaciations, the nature of glaciofluvial, glaciolacustrine, and glaciomarine deposits, and the processes of ice advance and retreat across Massachusetts (Koteff and Pessl, 1981; papers in Larson and Stone, 1982; Oldale and Barlow, 1986; Stone and Borns, 1986; Warren and Stone, 1986). This compilation of surficial geologic materials is an interim product that defines the areas of exposed bedrock and the boundaries between glacial till, glacial stratified deposits, and overlying postglacial deposits. This work is part of a comprehensive study to produce a statewide digital map of the surficial geology at a 1:24,000-scale level of accuracy. This surficial geologic map layer covering nine quadrangles revises previous digital surficial geologic maps (Stone and others, 1993; MassGIS, 1999) that were compiled on base maps at regional scales of 1:125,000 and 1:250,000. The purpose of this study is to provide fundamental geologic data for the evaluation of natural resources, hazards, and land information within the Commonwealth of Massachusetts.

A major change in precipitation gradient on the Chinese Loess Plateau at the Pliocene-Quaternary boundary

NASA Astrophysics Data System (ADS)

Peng, Wenbin; Nie, Junsheng; Wang, Zhao; Qiang, Xiaoke; Garzanti, Eduardo; Pfaff, Katharina; Song, Yougui; Stevens, Thomas

2018-04-01

Spatiotemporal variations in East Asian Monsoon (EAM) precipitation during the Quaternary have been intensively studied. However, spatial variations in pre-Quaternary EAM precipitation remain largely uninvestigated, preventing a clear understanding of monsoon dynamics during a warmer climatic period. Here we compare the spatial differences in heavy mineral assemblages between Quaternary loess and pre-Quaternary Red Clay on the Chinese Loess Plateau (CLP) to analyze spatial patterns in weathering. Prior studies have revealed that unstable hornblende is the dominant (∼50%) heavy mineral in Chinese loess deposited over the past 500 ka, whereas hornblende content decreases to <10% in strata older than ∼1 Ma in the central CLP because of diagenesis. In the present study we found that hornblende is the dominant heavy mineral in 2-2.7 Ma loess on the northeastern CLP (at Jiaxian), which today receives little precipitation. Conversely, hornblende content in the upper Miocene-Pliocene Red Clay at Jiaxian is <10%, as in the central CLP. The early Quaternary abundance of hornblende at Jiaxian indicates that the current northwestward-decreasing precipitation pattern and consequent dry climate at Jiaxian must have been initiated since ∼2.7 Ma, preventing hornblende dissolution to amounts <10% as observed in the central CLP. By contrast, the 7 Ma and 3 Ma Jiaxian Red Clay hornblende content is significantly less than that of the Xifeng samples, despite the fact that today Xifeng receives more precipitation than Jiaxian, with expected enhanced hornblende weathering. This suggests that the northeastern CLP received more precipitation during the Late Miocene-Pliocene than at Xifeng, indicating that the precipitation gradient on the CLP was more east-west during the Late Miocene-Pliocene rather than northwest-southeast as it was in the Quaternary. A comparison of magnetic susceptibility records for these sections confirms this inference. We attribute this major change in climatic patterns at ∼2.7 Ma to decreased northward moisture transportation associated with Northern Hemisphere glaciation and cooling in the Quaternary. This study therefore demonstrates the potential usefulness of employing heavy mineral analysis in both paleoclimatic and paleooceanographic reconstructions.

Aleksis Dreimanis: a legacy in Quaternary science

NASA Astrophysics Data System (ADS)

Hicock, Stephen R.; Menzies, John

2000-12-01

Aleksis Dreimanis was born and raised in Latvia. His interest in Quaternary and glacial geology began early and developed into a career that has spanned 7 decades. At age 20 he published his first paper in glacial geology and soon after began teaching at the University of Latvia. Teaching and research were interrupted by World War II but resumed at the Baltic University (Pinneberg, Germany), then at the University of Western Ontario where he has been ever since. Throughout his career, Dreimanis has successfully balanced the twin disciplines of Quaternary history and glacial geology. He was among the first to study quantitatively the relationship between till lithology and till formation and to study how glacial transport and dynamics affect till texture and deformation. With co-workers he developed the well-known stratigraphic scheme of the last glaciation in the Great Lakes region of North America. Aleksis became world-renowned through his committee work, especially as President of the INQUA Commission on Genesis and Lithology of Glacial Quaternary Deposits. His diplomacy, enthusiasm, and passion for his subject have inspired students and colleagues around the globe and resulted in remarkable international dialogue, cooperation, and consensus. Professor Aleksis Dreimanis is an honest scientist, a gentleman, and a true scholar who has left a rich legacy for future Quaternarists.

Age and genesis of the Upper Cenozoic deposits of the Tyumen oblast (Western Siberia) enriched in biogenic silica

NASA Astrophysics Data System (ADS)

Aleksandrova, G. N.; Oreshkina, T. V.; Smirnov, P. V.; Konstantinov, A. O.; Kuzmina, O. B.

2017-07-01

An integrated micropaleontological study of deposits enriched in biogenic silica was conducted on material drilled in the Zyryanka and Uspenka fields of the southwestern Tyumen oblast (Western Siberia). The data obtained on palynology and diatoms allowed the assignment of the Zyryanka Field to the Turtas Formation (lower part of the Chattian Stage of the Oligocene) and the deposits of the Uspenka Field to be dated as Pleistocene. The absence in the Zyryanka Field diatom assemblage of in situ marine taxa and the mass occurrence of freshwater species, gemmuloscleres of freshwater sponges, and zygospores of Zygnematales algae suggest that a nonmarine basin existed in the early Turtas time. A considerable proportion of redeposited diatoms and dinocysts in the Quaternary deposits of the Uspenka Field suggest strong erosional processes during the time of deposition.

Reconstruction of the Palaeo-environment of the Alluvial Deposits in the Eastern Free State, South Africa

NASA Astrophysics Data System (ADS)

Evans, M. Y.

2009-04-01

Small alluvial fan systems have formed off the hillslopes of the remnant Karoo koppies at Heelbo in the Eastern Free State, South Africa. The landform geometry is a result of complex relationships between climate, lithology, structure and vegetation. This research area, which includes a large mammal mass death site, potentially contains a wealth of palaeo-environmental and specifically palaeoclimatic information. Palaeo-environmental information and proxy records on past climates in southern Africa has traditionally been obtained from a variety of techniques including stable isotope analysis of speleothems, pollen , faunal analyses at archeological sites, animal remains and crater-lake sediments (see references below). However, little information exists in the scientific literature on the use of palaeosols for defining the depositional palaeoenvironments in southern Africa. The aim of this research is to attempt to address the lack of palaeo-environmental information by extracting palaeoclimatic information from the sedimentary processes and the palaeosols at the Heelbo farm that have been extensively exposed through gullying. The sedimentary fans in the area have experienced climatically controlled histories of erosion, sedimentation and pedogenesis. Extreme sedimentation is assumed to have occurred during relatively arid climatic intervals, when decreased vegetation cover provided little surface protection. In contrast pedogenesis occurs during humid intervals when vegetation cover is restored, the land stabilizes and the uppermost gravely sands weather to form soils. A combined approach of both radiocarbon- and luminescence -dating may provide a detailed chronology of these successive hillslope events in order to relate hillslope instability to climatic forcing factors. Preliminary results indicate that at least 3 depositional events are recorded within the large mammal mass death site, which have been confirmed by the radiocarbon dates of 3,610 ±110 in the top section and 4,610 ±30 at the bottom section. References: Klein, R.G., Cruz-Uribe, K., Beaumont, P.B., 1991. Environmental, ecological, and paleoanthropological implications of the Late Pleistocene mammalian fauna from Equus Cave, northern Cape Province, South Africa. Quaternary Research. 36, 94 119. Lee-Thorp, J.A., Beaumont. PB., 1995. Vegetation and seasonality shift during the late Quaternary deduced from 13C/12C ratios of grazers at Equus Cave, South Africa. Quaternary Research. 43, 426 432. Partridge, T.C., Demenocal, P.B., Lorentz, S.A., Paiker, M.J., Vogel, J.C., 1997: Orbital forcing of climate over South Africa: A 200,000-year rainfall record from Pretoria Saltpan, Quaternary Science Reviews, 16, 1125-1133. Partridge, T.C., Kerr, S.J., Metcalfe, S.E., Scott, L., Vogel, J.C., 1993: The Pretoria Saltpan: A 200,000 year South African lacustrine sequence. Palaeogeography, Palaeoclimatology, Palaeoecology, 101, 317-337. Scott, L. and Thackeray, J.F., 1987: Multivariate analysis of late Pleistocene and Holocene pollen spectra from Wonderkrater, Transvaal, South Africa. South African Journal of Science, 83, 93- 98. Talma, A.S. and Vogel, J.C., 1992: Late Quaternary palaeotemperatures derived from a speleotherm from Cango Caves, Cape Province, South Africa, Quaternary Research, 37, 203-213. Vogel, J.C., 1983. Isotopic evidence for past climates and vegetation of southern Africa. Bothalia 14, 391-394.

Ross Sea Till Properties: Implications for Ice Sheet Bed Interaction

NASA Astrophysics Data System (ADS)

Halberstadt, A. R.; Anderson, J. B.; Simkins, L.; Prothro, L. O.; Bart, P. J.

2015-12-01

Since the discovery of a pervasive shearing till layer underlying Ice Stream B, the scientific community has categorized subglacial diamictons as either deformation till or lodgement till primarily based on shear strength. Deformation till is associated with streaming ice, formed through subglacial deformation of unconsolidated sediments. Lodgement till is believed to be deposited by the plastering of sediment entrained at the base of slow-flowing ice onto a rigid bed. Unfortunately, there has been a paucity of quantitative data on the spatial distribution of shear strength across the continental shelf. Cores collected from the Ross Sea on cruises NBP1502 and NBP9902 provide a rich dataset that can be used to interpret till shear strength variability. Till strengths are analyzed within the context of: (1) geologic substrate; (2) water content and other geotechnical properties; (3) ice sheet retreat history; and (4) geomorphic framework. Tills display a continuum of shear strengths rather than a bimodal distribution, suggesting that shear strength cannot be used to distinguish between lodgement and deformation till. Where the substrate below the LGM unconformity is comprised of older lithified deposits, till shear strengths are both highly variable within the till unit, as well as highly variable between cores. Conversely, where ice streams flowed across unconsolidated Plio-Pleistocene deposits, shear strengths are low and less variable within the unit and between cores. This suggests greater homogenization of cannibalized tills, and possibly a deeper pervasive shear layer. Coarser-grained tills are observed on banks and bank slopes, with finer tills in troughs. Highly variable and more poorly sorted tills are found in close proximity to sediment-based subglacial meltwater channels, attesting to a change in ice-bed interaction as subglacial water increases. Pellets (rounded sedimentary clasts of till matrix) are observed in Ross Sea cores, suggesting a history of deformation responsible for pellet formation. Till strength was measured in a variety of environments, including mega-scale lineations and grounding zone wedges; ongoing work focuses on evaluating till shear strengths within a geomorphic context. These analyses are used to re-evaluate till genesis, transport, and characterization.

Geohydrology, simulation of regional groundwater flow, and assessment of watermanagement strategies, Twentynine Palms area, California

USGS Publications Warehouse

Li, Zhen; Martin, Peter

2011-01-01

The Marine Corps Air Ground Combat Center (MCAGCC) Twentynine Palms, California, overlies the Surprise Spring, Deadman, Mesquite, and Mainside subbasins of the Morongo groundwater basin in the southern Mojave Desert. Historically, the MCAGCC has relied on groundwater pumped from the Surprise Spring subbasin to provide all of its potable water supply. Groundwater pumpage in the Surprise Spring subbasin has caused groundwater levels in the subbasin to decline by as much as 190 feet (ft) from 1953 through 2007. Groundwater from the other subbasins contains relatively high concentrations of fluoride, arsenic, and (or) dissolved solids, making it unsuitable for potable uses without treatment. The potable groundwater supply in Surprise Spring subbasin is diminishing because of pumping-induced overdraft and because of more restrictive Federal drinking-water standards on arsenic concentrations. The U.S. Geological Survey, in cooperation with the MCAGCC, completed this study to better understand groundwater resources in the area and to help establish a long-term strategy for regional water-resource development. The Surprise Spring, Deadman, Mesquite, and Mainside subbasins are filled with sedimentary deposits of Tertiary age, alluvial fan deposits of Quaternary-Tertiary age, and younger alluvial and playa deposits of Quaternary age. Combined, this sedimentary sequence reaches a maximum thickness of more than 16,000 ft in the Deadman and Mesquite subbasins. The sedimentary deposits of Tertiary age yield a small amount of water to wells, and this water commonly contains high concentrations of fluoride, arsenic, and dissolved solids. The alluvial fan deposits form the principal water-bearing unit in the study area and have a combined thickness of 250 to more than 1,000 ft. The younger alluvial and playa deposits are unsaturated throughout most of the study area. Lithologic and downhole geophysical logs were used to divide the Quaternary/ Tertiary alluvial fan deposits into two aquifers (referred to as the upper and the middle aquifers) and the Tertiary sedimentary deposits into a single aquifer (referred to as the lower aquifer). In general, wells perforated in the upper aquifer yield more water than wells perforated in the middle and lower aquifers. The study area is dominated by extensive faulting and moderate to intense folding that has displaced or deformed the pre-Tertiary basement complex as well as the overlying Tertiary and Quaternary deposits. Many of these faults act as barriers to the lateral movement of groundwater flow and form many of the boundaries of the groundwater subbasins. The principal recharge to the study area is groundwater underflow across the western and southern boundaries that originates as runoff in the surrounding mountains. Groundwater discharges naturally from the study area as spring flow, as groundwater underflow to downstream basins, and as water vapor to the atmosphere by transpiration of phreatophytes and direct evaporation from moist soil. The annual volume of water that naturally recharged to or discharged from the groundwater flow system in the study area during predevelopment conditions was estimated to be 1,010 acre-feet per year (acre-ft/yr). About 90 percent of this recharge originated as runoff from the Little San Bernardino and the Pinto Mountains to the south, and the remainder originated as runoff from the San Bernardino Mountains to the west. Evapotranspiration by phreatophytes near Mesquite Lake (dry) was the primary form of predevelopment groundwater discharge. From 1953 through 2007, approximately 139,400 acre-feet (acre-ft) of groundwater was pumped by the MCAGCC from the Surprise Spring subbasin. A regional-scale numerical groundwater flow model was developed using MODFLOW-2000 for the Surprise Spring, Deadman, Mesquite, and Mainside subbasins. The aquifer system was simulated by using three model layers representing the upper, middle, and lower aquifers. Measured groundwater levels

Chronology of Quaternary coastal aeolianite deposition and the drowned shorelines of southwestern Western Australia - a reappraisal

NASA Astrophysics Data System (ADS)

Brooke, B. P.; Olley, J. M.; Pietsch, T.; Playford, P. E.; Haines, P. W.; Murray-Wallace, C. V.; Woodroffe, C. D.

2014-06-01

Aeolianite successions of low-gradient continental margins commonly show complex records of coastal dune deposition linked to a wide range of sea-level positions and climatic periods of the middle and late Pleistocene, recording both regional and broader-scale drivers of sediment production, coastal dune development and landform preservation. To better characterise the general pattern of sedimentation that occurs over Quaternary glacial-interglacial cycles on low-gradient, temperate carbonate continental shelves we examine the morphology, stratigraphy and age of aeolianite deposits in the Perth region, Western Australia. This includes an analysis of well-defined drowned coastal landforms preserved on the adjacent shelf. New and previously published optical ages provide a preliminary timeframe for the deposition of aeolianite in the Perth region and on Rottnest Island, 17 km offshore. An extensive aeolianite ridge near Perth, representing a former barrier, has Optically Stimulated Luminesence (OSL) ages that range from 120 ± 12 to 103 ± 10 ka (MIS 5e-5a in the context of associated age uncertainties). OSL ages for an exposure in the same ridge 2.5 km inland, record the onlap of much older aeolianite, OSL age 415 ± 70 ka, by shell-rich estuarine beds, OSL age 290 ± 30 ka. A further 5.5 km inland from the coast, two thick aeolianite units, separated by a well-developed palaeosol, have stratigraphically consistent OSL ages of 310 ± 30 and 155 ± 20 ka. In contrast, aeolianite units that form the northern coast of Rottnest Island have OSL ages of 77 ± 12 ka and 27 ± 5 ka. The new OSL ages and previously reported TL and U/Th ages indicate that the bulk of the island comprises dunes deposited around the end of the Last Interglacial sensu lato (MIS 5a-4) and during the Last Glacial (MIS 4-2), accumulating over a Last Interglacial coral reef and basal calcarenite. Drowned barrier and dune landforms preserved on the adjacent continental shelf reveal that barriers were formed during periods of intermediate sea level (e.g. MIS 3) and significant dune mobility occurred when the shelf was subaerially exposed. The pattern of shelf sedimentation discernible in the Perth region - large-scale coastal carbonate dune deposition during periods of high and intermediate sea level and reactivation during glacial lowstands - is largely consistent with published stratigraphic and age data for large-scale aeolianite deposits on other low-gradient carbonate shelves. Based on these data, a general model is proposed for the cycle of Quaternary sedimentation and landform evolution that occurs on these shelves, which are dynamic sedimentary environments with coastal landforms and sedimentary successions that are very sensitive to erosion and sediment reworking.

Reconnaissance geologic map of the Muwassam Quadrangle, sheet 16/42 D, Kingdom of Saudi Arabia

USGS Publications Warehouse

Blank, H. Richard

1985-01-01

All of the mapped area is occupied by coastal plain bordering the Red Sea. The flat coastal plain is covered by Quaternary surficial deposits overlying a sequence of Tertiary rocks as much as 5 km thick. The coastal plain is separated from the Red Sea by zone of supratidal sabkha deposits, offshore bars, islands, tidal md flats, and shallow lagoons. The sea is shallow, less than 200 m deep, and forms part of the shelf marginal to the main axial trough of the Red Sea.

Micromorphological investigations of the Late Quaternary loess-paleosol sequences of the Kashmir Valley, India

NASA Astrophysics Data System (ADS)

Dar, Reyaz Ahmad; Chandra, Rakesh; Romshoo, Shakil Ahmad; Kowser, Nazia

2015-11-01

The loess-paleosol sequences of the Karewa Group preserve a valuable repository of the Late Quaternary climatic changes and the landscape evolution history of the Karewa Basin of Kashmir Valley in their lithological and pedogenic records. Three representative loess-paleosol sections at Shankerpora (SP), Khan Sahib (KS) and Pattan (PT) localities were chosen for detailed lithostratigraphic fieldwork and micromorphological observations of thin sections. Lithostratigraphic analysis revealed lateral and vertical variation in thickness and number of paleosol profiles from south-west to north-west of the Karewa Basin suggesting the availability of land-surface for periodic loess deposition. The SP section is marked by 6 (SP-S6, S7, S8, S9, S10, S12), KS section by 3 (KS-S2, S4, S5) and PT section by 2 (PT-S1, S3) thick mature paleosol profiles. Theses paleosols have well developed 'Ah' and 'Btk' horizons representing prolonged land-surface stability when pedogenic processes outpace loess deposition. On the other hand comparatively thin to thick paleosol profiles represent weak to moderate pedogenic maturity indicating short stratigraphic breaks with rapid loess deposition. Micromorphological observations of thin sections suggested that clay illuviation and CaCO3 accumulation have operated within the paleosol profiles. CaCO3 features are often associated with clay coatings suggesting decalcification of carbonates followed by clay illuviation. Pedogenic CaCO3 probably resulted from the precipitation of the soil solution near the average depth of wetting front. The pedogenic CaCO3, illuvial clay, mottles, iron manganese features, pedal microstructure and blocky aggregates reveal variation in the pedogenic maturity among and within the loess-paleosol sections. The morphological (both micro- and macro-morphological) attributes of loess-paleosols suggest variation of climatic conditions during the Late Quaternary period in the Karewa Basin of Kashmir Valley, India.

Quaternary fault-controlled volcanic vents and crustal thinning: new insights from the magma-rich Tyrrhenian passive margin (Italy)

NASA Astrophysics Data System (ADS)

Cardello, Giovanni Luca; Conti, Alessia; Consorti, Lorenzo; Do Couto, Damien

2017-04-01

The discover of monogenic Quaternary volcanic vents, that were recently mapped along major fault zones both inland and offshore the Tyrrhenian magma-rich passive margin, poses questions about: timing and role they had into Plio-Pleistocene crustal thinning with relevant consequences for the hazard assessment of an area inhabited by some 0.5 million people. The present-day margin is stretched over 100 km between the Volsci Range (VR) and the Pontian escarpment, being defined by moderate shallow seismicity (Mw≤4.6), relative high geothermal gradient and ongoing hydrothermal activity. Although major central volcanoes (e.g., Colli Albani), occurring at major fault intersections are well studied, smaller volcanic fields were so far unconstrained. Both field survey in the VR and offshore high-resolution geophysical data, allow us to: 1) better define the anatomy of the poorly known VR volcanic field; 2) furnish new insights on the regional Quaternary dynamics; 3) propose modes and reason of magma emplacement. The VR is composed of about 40 punctual and linear monogenic and mostly phreatomagmatic vents occurring at the edges of the Apennine carbonate fold-and-thrust belt and within the VR backbone. Volcanites are characterized by zeolitized to incoherent tuffs and surge deposits locally covered by lavas and slope deposits. Most explosive units host carbonate-rich lithics with different degrees of rounding and decarbonation, which frequently belong to Albian-Cenomanian aquifers. By comparing cross-section with lithic analyses we demonstrate that fragmentation, transport, progressive disintegration and decarbonation occur at multiple depths, depending on the fold-and-thrust belt setting. Thus, along the same vent zone, juvenile lithic composition proves repeated fragmentation within pressured-aquifers, testifying for fissural activity with implications for local seismic and volcanic assessment. Pyroclastic deposits occur as well in the Pontina and Fondi coastal plains at shallow depth suggesting recent (<10 kyr) and possibly local eruptions. Offshore, 25 km north of Ventotene, a middle Pleistocene 200 m-high truncated volcano was found partially covered by middle to recent deposits. It is delimited by well defined WNW-striking fault-controlled escarpment dissected by NE-striking faults. As on the Ponza-Zannone high, volcanic complex occur on a horst intersecting the two main regional trends, possibly associated with younger SE-stretching. Quaternary stretching rotation occurs as a response to Tyrrhenian back-arc opening and contemporaneous inarching of the Apennine front. In this frame, frontal to lateral slab tearing and retreat is tracked by E-rejuvenated volcanic activity along the Palmarola-Vesuvius lineament. In conclusion, we argue about the role NE-dipping crustal detachment(s) may have played into crustal thinning, driving and occasionally hampering magma-emplacement.

Assessing Biological and Stratigraphic Determinants of Fossil Abundance: A Case Example from the Late Quaternary of Po Plain, Italy

NASA Astrophysics Data System (ADS)

Kowalewski, Michal; Azzarone, Michele; Kusnerik, Kristopher; Dexter, Troy; Wittmer, Jacalyn; Scarponi, Daniele

2017-04-01

Absolute fossil abundance [AFA] can be defined as a relative concentration of identifiable fossils per unit of sediment. AFA, or "sediment shelliness", is controlled by the interplay between the rate of input of skeletal remains (biological productivity), pace of shell destruction (taphonomy), rate of sedimentation, and sediment compaction. Understanding the relative importance of those drivers can augment both stratigraphic and biological interpretations of the fossil record. Using 336 samples from a network of late Quaternary cores drilled in Po Plain (Italy), we examined the importance of those factors in controlling the stratigraphic distribution of fossils. All samples were vertically and volumetrically equivalent, each representing a 10 cm long interval of a core with a diameter of 7 cm ( 0.375 dm3 sediment per sample). Sample-level estimates of AFA (1) varied over 4 orders of magnitudes (from <4 to 44200 specimens per dm3 of sediment); (2) appeared invariant to core depth (rho=-0.04, p=0.72); (3) were statistically indistinguishable (chi-square=1.53, p=0.46) across systems tracts; and (4) did not vary substantially across facies (chi-square=6.04, p=0.20) representing a wide range of depositional and taphonomic settings. These outcomes indicate that compaction (which should increase downcore), sedimentation rates (which vary predictably across systems tracts), and pace of shell destruction (expected to differ across depositional settings) are unlikely to have played important role in controlling fossils density in the sampled cores. In contrast, samples with very high shell density (AFA > 4000 specimens per dm3) were characterized by exceedingly low evenness reflecting dominance by one super-abundant species (Berger-Parker index > 0.8 in all cases). These super-abundant species were limited to small r-selective mollusks capable of an explosive population growth: the marine corbulid bivalve Lentidium mediterraneum and the brackish hyrdobiid gastropod Ecrobia ventrosa. Moreover, despite high mollusk diversity (534 species total), >80% of samples are dominated by one of the five mollusk species, which all represent small, r-selective, deposit and suspension feeders. Trends in absolute fossil abundance within late Quaternary deposits of the Po Plain appear to have been driven primarily by biological productivity of opportunistic shelly species from lowest trophic levels. In the studied system, biodiversity and shelliness of samples is unlikely to reflect stratigraphic or taphonomic overprints, but rather records the ecological importance of r-selective species that dominated the investigated area throughout the late Quaternary. The joint consideration of sequence stratigraphy, facies architecture, and paleontological data, can provide insights regarding both stratigraphic (the origin of sedimentary biofabrics) and biological (the drivers of bio-productivity and observed biodiversity) aspects of the fossil record.

Leg 67: the Deep Sea Drilling Project Mid-America Trench transect off Guatemala.

USGS Publications Warehouse

von Huene, Roland E.

1980-01-01

Drilling on the Cocos plate recovered a basal chalk sequence deposited during early and mid-Miocene time, a short interval of abyssal red clay, and an upper sequence of late Miocene and younger sediment deposited within an area influenced by a terrigenous source. In the trench, a mud and sand fill less than 400,000 yr old overlies the oceanic sequence. The entire section shows no evidence of compressive deformation. In contrast, the section cored on the trench's landward slope 3 km from the trench axis is affected by tectonism. The section contains a Cretaceous to Pliocene claystone sequence capped by Pliocene to Quaternary hemipelagic slope deposits.- from Authors

Geology and mineral deposits of Churchill County, Nevada

USGS Publications Warehouse

Willden, Ronald; Speed, Robert C.

1974-01-01

Churchill County, in west-central Nevada, is an area of varied topography and geology that has had a rather small total mineral production. The western part of the county is dominated by the broad low valley of the Carson Sink, which is underlain by deposits of Lake Lahontan. The bordering mountain ranges to the west and south are of low relief and underlain largely by Tertiary volcanic and sedimentary units. Pre-Tertiary rocks are extensively exposed east of the Carson Sink in the Stillwater Range, Clan Alpine Mountains, Augusta Mountains, and New Pass Mountains. The eastern valleys are underlain by Quaternary alluvial and lacustrine deposits contemporaneous with the western deposits of Lake Lahontan. The eastern mountain ranges are more rugged than the western ranges and have higher relief; the eastern valleys are generally narrower.

Diatom community and palaeoenvironmental properties of Karacaören diatomite deposits (Nevşehir, Central Anatolia, Turkey)

NASA Astrophysics Data System (ADS)

Yıldız, Ayşegül; Gürel, Ali; Dursun, Yusuf Gökhan

2017-10-01

The diatom community and palaeoenvironmental properties of volcano genetic diatomite deposits that outcrop in the Karacaören (Nevşehir) area are described. Two stratigraphic sections were measured in the study area. One of these sections was measured in Quaternary lake units (K1), and the other in lacustrine sediments of the late Miocene-Pliocene Ürgüp Formation's Bayramhacılı Member (K2). According to stratigraphic and chemical characteristics of the sections, two distinct paleogeographic domains were determined in the study area. One of these, the shallow lacustrine to fluvial area (Quaternary) which is represented by an alternating sequence of diatomite, silt/mud, and tuffite. The other was the deeper lacustrine stage (late Miocene) which is represented by diatomites with some interbedded mud facies, chert and volcanics. From the diatomite samples of these sections, twenty-five species of 10 different diatom genera were identified. When evaluated together, the ecological properties and the distribution of numerical values of the determined diatom genera and species, showed that the study area's diatomite was generally deposited in shallow, high temperature, nutrient-rich water, where nitrogen and phosphorus were abundant and which was an alkaline (pH > 7) freshwater lake environment. Over time the pH value of the environment decreased (pH < 7), and the environment became acidic.

Climatic cycles inferred from the aminostratigraphy and aminochronology of Quaternary dunes and palaeosols from the eastern islands of the Canary Archipelago

NASA Astrophysics Data System (ADS)

Ortiz, J. E.; Torres, T.; Yanes, Y.; Castillo, C.; de La Nuez, J.; Ibáñez, M.; Alonso, M. R.

2006-03-01

Aminochronological and aminostratigraphical methods have been used to study the Quaternary aeolian deposits from the islands located east of the Canary Archipelago (Fuerteventura and Lanzarote islands and La Graciosa, Montaña Clara and Alegranza islets). The extent of racemisation/epimerisation of four amino acids (isoleucine, aspartic acid, phenylalanine and glutamic acid) was measured in land snail shells of the genus Theba. The age calculation algorithms of these amino acids have been determined to permit the numerical dating of these deposits. Eight Aminozones, each defining dune/palaeosol-formation episodes, have been distinguished and dated at 48.6 +/- 6.4, 42.5 +/- 6.0, 37.8 +/- 4.6, 29.4 +/- 4.8, 22.4 +/- 4.5, 14.9 +/- 3.6, 11.0 +/- 4.0 and 5.4 +/- 1.1 ka BP, the first five of them defining cycles of 5-7ka.The alternation of palaeosols and aeolian deposits, which are related to abrupt transitions from humid to arid conditions, are the reflection of globally induced changes in North Africa palaeoenvironmental conditions linked to the effect of African palaeomonsoons on the trade winds and the Saharan Air Layer. Probably these aeolian cycles, with a recurrence period of 5-7ka, are the expression of multiples of the 2.4ka solar-cycle.

Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile.

PubMed

Whelley, Patrick L; Jay, J; Calder, E S; Pritchard, M E; Cassidy, N J; Alcaraz, S; Pavez, A

Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Based on ground penetrating radar images, the fractures are observed to have propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to 1 cm/year -1 occurred between 1993 and 1996 with continued subsidence occurring at a slower rate thereafter. In situ measurements show that 1 m below the surface, the 1993 deposits remain 5°C to 15°C hotter, 18 years after emplacement, than adjacent deposits. Based on the observed subsidence as well as estimated cooling rates, the fractures are inferred to be the combined result of deaeration, thermal contraction, and sedimentary compaction in the months to years following deposition. Significant environmental factors, including regional earthquakes in 1995 and 2007, accelerated settling at punctuated moments in time. The spatially variable fracture pattern relates to surface slope and lithofacies variations as well as substrate lithology. Similar fractures have been reported in other ignimbrites but are generally exposed only in cross section and are often attributed to formation by external forces. Here we suggest that such interpretations should be invoked with caution, and deformation including post-emplacement subsidence and fracturing of loosely packed ash-rich deposits in the months to years post-emplacement is a process inherent in the settling of pyroclastic material.

Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States

USGS Publications Warehouse

Hosman, R.L.

1991-01-01

Although Cenozoic deposits are not uniformly differentiated, interstate correlations of major Paleocene and Eocene units are generally established throughout the area. Younger deposits are not as well differentiated. Some stratigraphic designations made at surface exposures cannot be extended into the sub-surface, and the scarcity of distinct geologic horizons has hampered differentiation on a regional scale. The complexities of facies development in Oligocene and younger coastal deposits preclude the development of extensive recognizable horizons needed for stratigraphic applications. Coastal deposits are a heterogeneous assemblage of deltaic, lagoonal, lacustrine, palustrine, eolian, and fluvial clastic facies and local calcareous reef facies. Even major time boundaries, as between geologic series, are not fully resolved. Surficial Quaternary deposits overlie the truncated subcrops of Tertiary strata and generally are distinguishable, although some contacts between Pleistocene and underlying Pliocene deposits have been a ?lstoncal source of controversy. Glacially related terraces are characteristic of the Pleistocene Epoch, and alluvium of aggrading streams typifies the Holocene. 

Surficial Geologic Map of the Tanacross B-4 Quadrangle, East-Central Alaska

USGS Publications Warehouse

Carrara, Paul E.

2006-01-01

The Tanacross B-4 1:63,360-scale quadrangle, through which the Alaska Highway runs, is in east-central Alaska about 100 mi west of the Yukon border. The surficial geologic mapping in the quadrangle is in support of the 'Geologic Mapping in support of land, resources, and hazards issues in Alaska' Project of the USGS National Cooperative Geologic Mapping Program. The Tanacross B-4 quadrangle contains parts of two physiographic provinces, the Yukon-Tanana Upland and the Northway-Tanana Lowland. The gently rolling hills of the Yukon-Tanana Upland, in the northern and eastern map area, rise to about 3,100 ft. The Northway-Tanana Lowland, in the western and southern map area, contains the westerly flowing Tanana River. Elevations along the floor of the lowland generally range between 1,540 and 1,700 ft. The dominant feature within the map is the Tok fan, which occupies about 20 percent of the map area. This large, nearly featureless fan contains a high percentage of volcanic clasts derived from outside the present-day drainage of the Tok River. The map provides interpretations of the Quaternary surficial deposits and associated geologic hazards in this area of the upper Tanana valley. Because the map area is dominated by various surficial deposits, the map depicts 13 different Quaternary surficial units consisting of man-made, alluvial, colluvial, organic, lacustrine, and eolian deposits. Deposits shown on this map are generally greater than 1 m thick. The map is accompanied by a text containing unit descriptions incorporating information pertaining to material type, location, associated hazards, resource use (if any), and thickness.

New research on the origin of mottled clay in Quaternary basins in the coastal area of south China

NASA Astrophysics Data System (ADS)

Wang, Jing; Chen, Zhen; Gao, Quanzhou; Chen, Guoneng

2018-06-01

Last Glacial Maximum (LGM) mottled clay occurs widely in Late Quaternary basins in south China coastal areas. Current research attributes its origin to exposure weathering of Late Pleistocene marine/fluvial deposits during the LGM. However, field data suggest that this is not the case as there is no gradual transition in lithology, grain size, structure and material composition among these layers. Instead, the mottled clay possesses sedimentary characteristics of exotic dust. In this study, three typical drill cores in the Pearl River Delta were studied using grain size analysis, diffuse reflection spectroscopy (DRS) and geochemical analysis to ascertain the clay's sedimentary characteristics and origin. Grain size distribution patterns and parameters of the mottled clay were similar to those of a typical loess, indicating aeolian origin. In DRS curves, the peak height of hematite > goethite, indicating that the mottled clay had not experienced strong hydration and constitutes a continental product. This conforms to a typical loess but differs from the underlying marine/fluvial deposits. The chemical composition of the mottled clay was homogeneous in the vertical and planar directions. Upper continental crust (UCC) normalized curves of major and trace elements of the mottled clay were close to the average UCC and were consistent with typical aeolian deposits. The spatial and temporal distribution characteristics and relationship with the underlying layer suggest that the mottled clay was a loess-like deposit during the LGM and its mottled structure originated from strong modification of oxidation during the postglacial period after homogeneous dust had accumulated.

Late Cenozoic fluvial successions in northern and western India: an overview and synthesis

NASA Astrophysics Data System (ADS)

Sinha, R.; Kumar, R.; Sinha, S.; Tandon, S. K.; Gibling, M. R.

2007-11-01

Late Cenozoic fluvial successions are widespread in India. They include the deposits of the Siwalik basin which represent the accumulations of the ancient river systems of the Himalayan foreland basin. Palaeomagnetic studies reveal that fluvial architecture and styles of deposition were controlled by Himalayan tectonics as well as by major climatic fluctuations during the long (∼13 Ma) span of formation. The Indo-Gangetic plains form the world's most extensive Quaternary alluvial plains, and display spatially variable controls on sedimentation: Himalayan tectonics in the frontal parts, climate in the middle reaches, and eustasy in the lower reaches close to the Ganga-Brahmaputra delta. Climatic effects were mediated by strong fluctuations in the SW Indian Monsoon, and Himalayan rivers occupy deep valleys in the western Ganga plains where stream power is high, cut in part during early Holocene monsoon intensification; the broad interfluves record the simultaneous aggradation of plains-fed rivers since ∼100 ka. The eastward increase in precipitation across the Ganga Plains results in rivers with low stream power and a very high sediment flux, resulting in an aggradational mode and little incision. The river deposits of semi-arid to arid western India form important archives of Quaternary climate change through their intercalation with the eolian deposits of the Thar Desert. Although the synthesis documents strong variability-both spatial and temporal-in fluvial stratigraphy, climatic events such as the decline in precipitation during the Last Glacial Maximum and monsoon intensification in the early Holocene have influenced fluvial dynamics throughout the region.

Quaternary geologic map of the Havre 1° x 2° quadrangle

USGS Publications Warehouse

Compilations by Fullerton, David S.; Colton, Roger B.; Bush, Charles A.

2012-01-01

The Havre quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S./Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes parts of the Bearpaw Mountains, the Little Rocky Mountains, and the Boundary Plateau. The primary river is the Milk River. The ancestral Missouri River was diverted south of the Bearpaw Mountains by a Laurentide ice sheet. The fill in the buried ancestral valley at and southwest of Havre contains a complex stratigraphy of fluvial, glaciofluvial, ice-contact, glacial, lacustrine, and eolian deposits. The old valley east of Havre now is occupied by the Milk River. The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (e.g., ground-moraine deposits, end-moraine deposits, stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 24 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. On the glaciated plains and on the Boundary Plateau the surficial deposits are glacial, ice-contact, glaciofluvial, catastrophic flood, alluvial, lacustrine, eolian, and colluvial deposits. In the Bearpaw Mountains and Little Rocky Mountains beyond the limit of Quaternary glaciation they are fluvial, colluvial, and mass-wasting deposits and residual materials. Tills of late Wisconsin and Illinoian ages are represented by map units. Tills of two pre-Illinoian glaciations are not mapped but are widespread in the subsurface and are identified in stratigraphic sections. Thirteen stratigraphic sections document a complex glacial and interglacial history in the quadrangle. Pliocene continental glaciation possibly is represented by erratic blocks of garnet gneiss and pegmatite from the Canadian Shield, perched high on drainage divides in the western Bearpaw Mountains. Glacial striations on bedrock, two boulder trains, and linear ice-molded landforms (primarily drumlins) indicate the possible presence of an east-southeast flowing ice stream in the Havre glacial lobe during late Wisconsin glaciation.

The zeolite deposits of Greece

USGS Publications Warehouse

Stamatakis, M.G.; Hall, A.; Hein, J.R.

1996-01-01

Zeolites are present in altered pyroclastic rocks at many localities in Greece, and large deposits of potential economic interest are present in three areas: (1) the Evros region of the province of Thrace in the north-eastern part of the Greek mainland; (2) the islands of Kimolos and Poliegos in the western Aegean; and (3) the island of Samos in the eastern Aegean Sea. The deposits in Thrace are of Eocene-Oligocene age and are rich in heulandite and/or clinoptilolite. Those of Kimolos and Poliegos are mainly Quaternary and are rich in mordenite. Those of Samos are Miocene, and are rich in clinoptilolite and/or analcime. The deposits in Thrace are believed to have formed in an open hydrological system by the action of meteoric water, and those of the western Aegean islands in a similar way but under conditions of high heat flow, whereas the deposits in Samos were formed in a saline-alkaline lake.

Hydrothermal processes at Gusev Crater: An evaluation of Paso Robles class soils

USGS Publications Warehouse

Yen, A. S.; Morris, R.V.; Clark, B. C.; Gellert, Ralf; Knudson, A.T.; Squyres, S.; Mittlefehldt, D. W.; Ming, D. W.; Arvidson, R.; McCoy, T.; Schmidt, M.; Hurowitz, J.; Li, R.; Johnson, J. R.

2008-01-01

The Mars Exploration Rover Spirit analyzed multiple occurrences of sulfur-rich, light-toned soils along its traverse within Gusev Crater. These hydrated deposits are not readily apparent in images of undisturbed soil but are present at shallow depths and were exposed by the actions of the rover wheels. Referred to as 'Paso Robles' class soils, they are dominated by ferric iron sulfates, silica, and Mg-sulfates. Ca-sulfates, Ca-phosphates, and other minor phases are also indicated in certain specific samples. The chemical compositions are highly variable over both centimeter-scale distances and between the widely separated exposures, but they clearly reflect the elemental signatures of nearby rocks. The quantity of typical basaltic soil mixed into the light-toned materials prior to excavation by the rover wheels is minimal, suggesting negligible reworking of the deposits after their initial formation. The mineralogy, geochemistry, variability, association with local compositions, and geologic setting of the deposits suggest that Paso Robles class soils likely formed as hydrothermal and famarolic condensates derived from magma degassing and/ or oxidative alteration of crustal iron sulfide deposits. Their occurrence as unconsolidated, near-surface soils permits, though does not require, an age that is significantly younger than that of the surrounding rocks. Copyright 2008 by the American Geophysical Union.

Geomorphic characterization of the U.S. Atlantic continental margin

USGS Publications Warehouse

Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.

2013-01-01

The increasing volume of multibeam bathymetry data collected along continental margins is providing new opportunities to study the feedbacks between sedimentary and oceanographic processes and seafloor morphology. Attempts to develop simple guidelines that describe the relationships between form and process often overlook the importance of inherited physiography in slope depositional systems. Here, we use multibeam bathymetry data and seismic reflection profiles spanning the U.S. Atlantic outer continental shelf, slope and rise from Cape Hatteras to New England to quantify the broad-scale, across-margin morphological variation. Morphometric analyses suggest the margin can be divided into four basic categories that roughly align with Quaternary sedimentary provinces. Within each category, Quaternary sedimentary processes exerted heavy modification of submarine canyons, landslide complexes and the broad-scale morphology of the continental rise, but they appear to have preserved much of the pre-Quaternary, across-margin shape of the continental slope. Without detailed constraints on the substrate structure, first-order morphological categorization the U.S. Atlantic margin does not provide a reliable framework for predicting relationships between form and process.

Characterization of geologic deposits in the vicinity of US Ecology, Amargosa Basin, southern Nevada

USGS Publications Warehouse

Taylor, Emily M.

2010-01-01

Multiple approaches have been applied to better understand the characteristics of geologic units exposed at the surface and buried at depth in the vicinity of US Ecology (USE), a low-level commercial waste site in the northern Amargosa Desert, Nevada. Techniques include surficial geologic mapping and interpretation of the subsurface using borehole data. Dated deposits at depth were used to estimate rates of sediment accumulation. The subsurface lithologies have been modeled in three dimensions. Lithologic cross sections have been created from the three-dimensional model and have been compared to resistivity data at the same location. Where deposits appear offset, a fault was suspected. Global Positioning System elevation transects were measured and trenches were excavated to locate a strand of the Carrara Fault. The presence of the fault helps to better understand the shape of the potentiometric surface. These data will be used to better understand the hydrologic parameters controlling the containment of the waste at US Ecology.Quaternary geologic units exposed at the surface, in the vicinity of US Ecology, are derived from the alluvium shed off the adjacent range front and the Amargosa River. These deposits vary from modern to early Pleistocene in age. At depth, heterogeneous sands and gravel occur. Observed in deep trenches and boreholes, the subsurface deposits are characterized as fining-upward sequence of sediment from 5- to 8-meters thick. No volcanic units or fine-grained playa deposits were described in the boreholes to a depth of 200 meters. Based on Infrared Stimulated Luminescence dated core samples, short-term rates of sediment accumulation (<70,000 years) are an average of 2.7 millimeters per year, however, long-term rates (<3,900,000 years) are orders of magnitude less. Resistivity data, when compared to lithologic cross sections, generally are consistent with lithology grain size and probable soil carbonate accumulations. Surface resistivity displays a fining-upward sequence of sediments at the surface with a soil carbonate imprint. Finally, trenching north of US Ecology successfully exposed offset Quaternary deposits on a splay of the Carrara Fault. Holocene deposits do not appear to be faulted, however, a fault zone does intersect middle and late Pleistocene aged units.

Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary

NASA Astrophysics Data System (ADS)

Chauhan, Teena; Noormets, Riko; Rasmussen, Tine L.

2016-04-01

Palaeo-bottom current strength of the West Spitsbergen Current (WSC) and the influence of the Svalbard-Barents Sea Ice Sheet (SBIS) on the depositional environment along the northern Svalbard margins are poorly known. Two gravity cores from the southern Yermak Plateau and the upper slope north of Nordaustlandet, covering marine isotope stage (MIS) 1 to MIS 5, are investigated. Five lithofacies, based on grain size distribution, silt/clay ratio, content and mean of sortable silt (SS), are distinguished to characterise the contourite-dominated sedimentary environments. In addition, depositional environments are described using total organic carbon (TOC), total sulphur (TS) and calcium carbonate (CaCO3) contents of sediments. Facies A, containing coarse SS, suggests strong bottom current activity and good bottom water ventilation conditions as inferred from low TOC content. This facies was deposited during the glacial periods MIS 4, MIS 2 and during the late Holocene. Facies B is dominated by fine SS indicating weak bottom current and poor ventilation (cf. high TOC content of 1.2-1.6%), and correlates with the MIS 4/3 and MIS 2/1 transition periods. With an equal amount of clay and sand, fine SS and high content of TOC, facies C indicates reduced bottom current strength for intervals with sediment supply from proximal sources such as icebergs, sea ice or meltwater discharge. This facies was deposited during the last glacial maximum. Facies D represents mass-flow deposits on the northern Svalbard margin attributed to the SBIS advance at or near the shelf edge. Facies E sediments indicating moderate bottom current strength were deposited during MIS 5 and MIS 3, and during parts of MIS 2. This first late Quaternary proxy record of the WSC flow and sedimentation history from the northern Svalbard margin suggests that the oceanographic conditions and ice sheet processes have exerted first-order control on sediment properties.

Climatic, eustatic, and tectnoic controls on Quarternary deposits and landforms, Red Sea coast, Egypt

NASA Technical Reports Server (NTRS)

Arvidson, Raymond; Becker, Richard; Shanabrook, Amy; Luo, Wei; Sturchio, Neil; Sultan, Mohamed; Lofty, Zakaria; Mahmood, Abdel Moneim; El Alfy, Zeinhom

1994-01-01

The degree to which local climatic variations, eustatic sea level fluctuations, and tectonic uplift have influenced the development of Quaternary marine and fluvial landforms and deposits along the Red Sea coast, Eastern Desert, was investigated using a combination of remote sensing and field data, age determinations of corals, and numerical simulations. False color composites generated from Landsat Thematic Mapper and SPOT image data, digital elevation models derived from sterophotogrammetric analysis of SPOT data, and field observations document that a approximately 10-km wide swath inland from the coast is covered in many places with coalescing alluvial fans of Quaternary age. Wadis cutting through the fans exhibit several pairs of fluvial terraces, and wadi walls expose alluvium interbedded with corraline limestone deposits Further, three distinct coral terraces are evident along the coatline. Climatic, eustatic, and tectonic uplift controls on the overall system were simulated using a cellular automata algorithm with the following characteristics: (1) uplift as a function of position and time, as defined by the elevations and ages of corals; (2) climatic variations driven by insolation changes associated with Milankovitch cycles; (3) sea level fluctuations based on U/Th ages of coral terraces and eustatic data; and (4) parametrized fluvial erosion and deposition. Results imply that the fans and coralline limestones were generated in a setting in which the tectonic uplift rate decreased over the Quarternary to negligible values at present. Coralline limestones formed furing eustatic highstands when alluvium was trapped uspstream and wadis filled with debris. During lowstands, wadis cut into sedimentary deposits; coupled with continuing uplift, fans were dissected, leaving remnant surfaces, and wadi-related terraces were generated by down cutting. Only landforms from the past three to four eustatic sea level cycles (i.e., approximately 300 to 400 kyr) are likely to have survived erosion and deposition associated with fluvial processes.

Stratigraphy of Upper Cretaceous and Cenozoic deposits of the Bakchar iron ore deposit (southwestern Siberia): New data

NASA Astrophysics Data System (ADS)

Lebedeva, N. K.; Kuzmina, O. B.; Sobolev, E. S.; Khazina, I. V.

2017-01-01

The results of complex palynological and microfaunistic studies of Upper Cretaceous and Cenozoic deposits of the Bakchar iron ore deposit are presented. Geochronologically, the age of the deposits varies from Campanian to Quaternary. It was established that the Slavgorod, Gan'kino, and Jurki (?) formations contain four biostratons in the rank of beds with dinocysts and three biostratons in the rank of beds with spores and pollen. The Cenozoic continental deposits contain four biostratons in the rank of beds, containing spores and pollen. As a result of the study, a large stratigraphic gap in the Cretaceous-Paleogene boundary deposits, covering a significant part of the Maastrichtian, Paleocene, Ypresian, and Lutetian stages of the Eocene, was established. The remnants of a new morphotype of heteromorphic ammonites of genus Baculites were first described in deposits of the Slavgorod Formation (preliminarily, upper Campanian). The distribution features of the different palynomorph groups in the Upper Cretaceous-Cenozoic deposits in the area of study due to transgressive-regressive cycles and climate fluctuations were revealed.

Sedimentologic and Stratigraphic Aspects of Late Quaternary (<14 cal. ka?) Valley Fill (Paleo-Roanoke River) Beneath the Barrier Islands of the Outer Banks, North Carolina, USA

NASA Astrophysics Data System (ADS)

Farrell, K. M.; Brooks, R. W.

2002-12-01

Provided here is a preliminary interpretation of the late Pleistocene (<14 cal. ka) facies succession that infilled the paleo-Roanoke River valley, and its transition into the overlying barrier island complex beneath the Outer Banks of North Carolina. Previous work (e.g. Riggs and others, 1992) reported that the Albemarle Embayment of eastern N.C. is underlain by a series of Pleistocene paleovalley complexes and provided hypotheses to test regarding valley distribution, sea level changes, and the ages of facies and sequences generated in response to coastal evolution. This report provides stratigraphic and sedimentologic criteria to support collaborative interpretations of eight cores acquired by a coastal geology cooperative research program on the Outer Banks to test these hypotheses. In cores OBX-02, 03, and 05, the late Quaternary (<14 cal. ka) fill is about 41 m thick. Here it erosionally overlies a bioturbated marine shelf deposit (OBX-2, 3, 5) that Wehmiller (personal communication) correlated (at OBX-05, depth -41 m) with the early/middle Pleistocene aminozone, AZ-4 (see Riggs and others, 1992). Above this, the late Quaternary fill (in cores OBX-02, 03, 05, 06) includes a succession of four facies units: 1) a basal sandy gravel (<6 m), 2) a dark gray complexly interbedded mud and gravel (<9 m), 3) bioturbated muddy sand (<15 m), and 4) an upward fining sand, with a basal gravel (<15 m). (Dimensional aspects of these units remain undefined until integration with GPR and seismic profiles). Six radiocarbon dates (from Thieler, personal communication) on samples from unit 2 (OBX-05: from -32.3, -33.6 and -35 m; OBX-02: from -27.7, -33.0, and -33.0 m) fall within the range 10 to 14 cal. ka. These were deposited during the Younger Dryas (Mallinson and others, Thieler, personal communications). Stratigraphic relations suggest that unit 1, although not dated, was deposited at the onset of this phase of global cooling. Unit 1, interpreted as fluvial thalweg and channel bar deposits, fines upward into unit 2. Unit 2 includes deltaic like features such as laminations, wavy, flaser and lenticular bedding, coarse lags with gravel, detrital organics, chaotic bedding, and slump blocks. It was deposited subaqueously with no evidence of subaerial exposure in a non-marine setting. The interbedding of high-energy lags and suspension deposits in unit 2 suggests that periods of intense flooding alternated with standing water deposition. Units 3 and 4 are Holocene. Unit 3 appears to either coarsen upward from a basal interbedded zone with unit 2 (OBX-02, 05), or is a sharp-based upward fining unit (OBX-03). It has common Ophiomorpha and Thalassinoides burrows (OBX-02, 03, 05, 06), traces of parallel laminations (OBX-02, 03, 06), and zones of mud intraclasts (OBX-05 only). Unit 3 formed as accretionary shoreface deposits that laterally infilled the embayment during the Holocene transgression. The contact at the base of unit 3 is a significant flooding surface. Unit 4 represents a complex of inlet, shoreface and regressive beach ridge deposits.

Thermomagnetic properties of peat-soil layers from Sag pond near Lembang Fault, West Java, Indonesia

NASA Astrophysics Data System (ADS)

Iryanti, Mimin; Wibowo, Dimas Maulana; Bijaksana, Satria

2015-09-01

Sag pond is a body of water near fault system as water flows blocked by the fault. Sag pond is a special type of environment for peat formation as peat layers in were deposited as the fault moves in episodic fashion. Depending on the history of the fault, peat layers are often interrupted by soil layers. In this study, core of peat-soil layers from a Sag pond in Karyawangi Village near Lembang Fault was obtained and analyzed for its magnetic properties. The 5 m core was obtained using a hand auger. Individual samples were obtained every cm and measured for their magnetic susceptibility. In general, there are three distinct magnetic susceptibility layers that were associated with peat and soil layers. The upper first 1 m is unconsolidated mud layer with its relatively high magnetic susceptibility. Between 1-2.81 m, there is consolidated mud layer and the lowest part (2.82-5) m is basically peat layer. Six samples were then measured for their thermomagnetic properties by measuring their susceptibility during heating and cooling from room temperature to 700°C. The thermomagnetic profiles provide Curie temperatures for various magnetic minerals in the cores. It was found that the upper part (unconsolidated mud) contains predominantly iron-oxides, such as magnetite while the lowest part (peat layer) contains significant amount of iron-sulphides, presumably greigite.

Identifying the pollen of an extinct spruce species in the Late Quaternary sediments of the Tunica Hills region, south-eastern United States

USGS Publications Warehouse

Luke Mander,; Jacklyn Rodriguez,; Pietra G. Mueller,; Jackson, Stephen T.; Surangi W. Punyasena,

2014-01-01

Late Quaternary fluvial deposits in the Tunica Hills region of Louisiana and Mississippi are rich in spruce macrofossils of the extinct species Picea critchfieldii, the one recognized plant extinction of the Late Quaternary. However, the morphology of P. critchfieldii pollen is unknown, presenting a barrier to the interpretation of pollen spectra from the last glacial of North America. To address this issue, we undertook a morphometric study of Picea pollen from Tunica Hills. Morphometric data, together with qualitative observations of pollen morphology using Apotome fluorescence microscopy, indicate that Picea pollen from Tunica Hills is morphologically distinct from the pollen of P. glauca, P. mariana and P. rubens. Measurements of grain length, corpus width and corpus height indicate that Picea pollen from Tunica Hills is larger than the pollen of P. mariana and P. rubens, and is slightly larger than P. glauca pollen. We argue that the morphologically distinctive Tunica Hills Picea pollen was probably produced by the extinct spruce species P. critchfieldii. These morphological differences could be used to identify P. critchfieldii in existing and newly collected pollen records, which would refine its paleoecologic and biogeographic history and clarify the nature and timing of its extinction in the Late Quaternary.

Middle to Late Pleistocene coastal deposits of Eivissa (Western Mediterranean): Chronology and evolution.

NASA Astrophysics Data System (ADS)

Del Valle, Laura; Pomar, Francisco; Fornós, Joan J.; Gómez-Pujol, Lluís; Anechitei-Deacu, Valentina; Timar-Gabor, Alida

2016-04-01

This study deals with the sedimentary and stratigraphical description of Pleistocene deposits from seven coastal areas of Eivissa (Balearic Islands). Twenty two sedimentary facies have been described involving the succession of eolian, colluvial and edaphic environments. Carbonate sandstones, breccias and silty deposits are the main component of these sequences. Despite the extensive eolian systems outcropping along the coast of Eivissa, there are very few studies performed to chronological framework of these deposits. Luminescence measurements were carried out using an automated RisØ TL/OSL-DA-20 reader in the Luminescence Dating Laboratory of Babes-Bolyai University (Cluj-Napoca, Romania) under low intensity red light. OSL dating of nineteen eolian levels indicate that their deposition took place between the Middle and Late Pleistocene, establishing a paleoclimatic evolution of Eivissa Island since 755 ka to 70 Ka. Eolian activity in the Eivissa Island can be correlated with regression episodes which took place during cold periods associated with different isotopic stages, concretely the MIS 18, 16, 12, 10, 8, 6 and 4. Similar results have been obtained from many sites along the western Mediterranean Sea such as Mallorca (Pomar i Cuerda, 1979; Nielsen et al, 2004; Fornós et al, 2009), Sardinia (Andreucci et al, 2009; Pascucci et al, 2014), Liguria (Pappalardo et al., 2013). Keywords: Eolian dunes, Pleistocene, Climatic evolution, Eivissa. References - Andreucci, S.; Pascucci, V.; Murray, A. S.; Clemmensen, L. B. 2009. Late Pleistocene coastal evolution of San Giovanni di Sinis, west Sardinia (Western Mediterranean). Sedimentary Geology, 216: 104- 116 - Fornós, J.J.; Clemmensen, L.B.; Gómez-Pujol, L.; Murray, A. 2009. Late Pleistocene carbonate aeolianites on Mallorca, Western Mediterranean: a luminescence chronology. Quaternary Science reviews 28: 2697-2709. -Nielsen, K.A.; Clemmensen, L.B.; Fornós, J.J. 2004. Middle Pleistocene magnetostratigraphy and susceptibility stratigraphy: data from a carbonate aeolian system, Mallorca, Western Mediterranean. Quaternary Science Reviews, 23: 1733-1756 -Pappalardo, M.; Chelli, A.; Ciampalini, A.; Rellini, I.; Biagioni, F.; Brückner, H.; Fülling, A.; Firpo, M. 2013. Evolution of an Upper Pleistocene aeolianite in the northern Mediterranean (Liguria, NW Italy). Ital. j. Geosci. Vol. 132, 2: 290-303 -Pascucci, V.; Sechi, D.; Andreucci, S. 2014. Middle Pleistocene to Holocene coastal evolution of NW Sardinia (Mediterranean Sea, Italy). Quaternary International, 328-329: 3-20 -Pomar, L.; Cuerda, J. 1979. Los depósitos marinos pleistocénicos en Mallorca Acta Geológica Hispánica. Homenatge a Lluís Soler i Sarabaris. Vol. 14: 505-513

Bryozoans from rio grande do sul continental shelf, southern Brazil.

PubMed

Ramalho, Laís V; Calliari, Lauro

2015-05-06

The continental shelf of Rio Grande do Sul (RS) is predominantly composed of unconsolidated sediments with a few hard substrates represented principally by beachrock. In this area there are elongate deposits of shell gravel material which are interpreted as indicators of the palaeo-shorelines. These Pleistocene deposits are overlapped by Holocene sediments (Recent), but are exposed during erosive events caused by extra-tropical cyclones, which provide the mixture of both sediments mainly during autumn and winter. The few studies on bryozoans made in this area previously recorded seven species, one fossil and the other six from Recent fluvial and marine environments. The aim of the present study was to describe the eight most abundant bryozoan species that occur in the inner RS shelf. Of these, four are new records for RS State (Arachnopusia aff. pusae, Hippomonavella brasiliensis, Turbicellepora pourtalesi, and Lifuella gorgonensis), and the other four are new to science (Chaperia taylori, Micropora nodimagna, Cellaria riograndensis, and Exochella moyani).

Summary of the stratigraphy and structural elements related to plate convergence of the Quetta-Muslim Bagh-Sibi region, Balochistan, west-central Pakistan

USGS Publications Warehouse

Maldonado, Florian; Mengal, Jan M.; Khan, Shahid H.; Warwick, Peter D.

2011-01-01

The four major faults that bound the structural terrane are the Frontal (F), Ghazaband-Zhob (GZ), Gwal-Bagh (GB), and Chaman (C) faults. Four major periods of deformation are recognized: (1) emplacement of ophiolitic rocks onto the continental margin of the India plate; (2) convergence of the India-Eurasia plates; (3) deposition of Tertiary-Quaternary molasse units followed by major folding and thrusting, and formation of strike-slip faults; and (4) deposition of Pleistocene molasse units with subsequent folding, thrusting, and strike-slip motion that continues to the present.

Age of Palos Verdes submarine debris avalanche, southern California

USGS Publications Warehouse

Normark, W.R.; McGann, M.; Sliter, R.

2004-01-01

The Palos Verdes debris avalanche is the largest, by volume, late Quaternary mass-wasted deposit recognized from the inner California Borderland basins. Early workers speculated that the sediment failure giving rise to the deposit is young, taking place well after sea level reached its present position. A newly acquired, closely-spaced grid of high-resolution, deep-tow boomer profiles of the debris avalanche shows that the Palos Verdes debris avalanche fills a turbidite leveed channel that extends seaward from San Pedro Sea Valley, with the bulk of the avalanche deposit appearing to result from a single failure on the adjacent slope. Radiocarbon dates from piston-cored sediment samples acquired near the distal edge of the avalanche deposit indicate that the main failure took place about 7500 yr BP. ?? 2003 Elsevier B.V. All rights reserved.

Sedimentology of polar carbonate systems

NASA Astrophysics Data System (ADS)

Frank, T. D.; James, N. P.

2013-12-01

The key attributes, processes, and products associated with carbonate accumulation and diagenesis at tropical and temperate latitudes are well known. Comparatively little work has concentrated on carbonate deposition at the coldest end of the depositional spectrum, the polar shelves. Such deposits are not abundant, but they have the potential to provide unique insights into paleoceanographic and paleoclimatic conditions in regions of the planet that are arguably the most sensitive to global change. We examined skeletal assemblages, facies, stratigraphy, petrography, geochemistry, and diagenesis of Quaternary deposits from the Ross Sea, Antarctica and Permian counterparts from Gondwana (now eastern Australia). These modern and ancient polar carbonate factories possess several unique characteristics that set them apart from better-known systems of the temperate and tropical latitudes. All production is biogenic and there are no significant calcareous phototrophs. Carbonate communities are not capable of building rigid frameworks, and thus their deposits are prone to winnowing and reworking by waves and bottom currents. The seawater, although frigid, is isothermal, and thus deep-water benthic communities can exist near the surface. Carbonate saturation, which is at or below solubility for both aragonite and high-Mg calcite, plays a key role in determining the dominant mineralogy of benthos as well as the preservation potential of skeletal debris. As many taxa precipitate low-Mg calcite in isotopic equilibrium, deposits have potential to provide geochemical proxy information for use in paleoceanographic and paleoclimatic reconstructions. More than any other type of carbonate system, the slow biogenic carbonate production and accumulation in cold waters is achieved firstly by arresting siliciclastic sedimentation and secondly by increasing nutrient availability. Thus, carbonate deposition may occur during the coldest of times, such as during glacial advance when terrigenous clastics are sequestered inboard and invigorated ocean circulation enhances upwelling. Radiocarbon data from Quaternary deposits in the Ross Sea indicate that short windows of accumulation during favorable conditions are followed by longer intervals of non-productivity, during which skeletal debris undergoes dissolution and infestation by endolithic borers, carbonate sediments are reworked by bottom currents, and glacigene siliciclastic facies are deposited. Similar patterns are evident in Permian deposits. We interpret the post-carbonate depositional periods as not only due to increased terrigenous input but also dramatically reduced trophic resources. The foregoing hypothesis is at odds with most current thinking about carbonate deposition and points to an evolving paradigm within which polar carbonate deposition is dramatically different than that in temperate and tropical settings.

Geomorphology of the Trinity River floodplain in Dallas County, Texas

NASA Astrophysics Data System (ADS)

Haugen, B. D.; Roig-Silva, C.; Manning, A. R.; Harrelson, D. W.; Olsen, R. S.; Dunbar, J. P.; Pearson, M. L.

2010-12-01

Data from more than 1,800 geologic borings and over 500 cone penetrometer tests (CPTs) were used to characterize the geomorphology of the Trinity River floodplain in the Dallas Metropolitan Area. Historical maps, aerial photographs and other published information were used to prepare a preliminary geomorphic map. Boring logs and CPT data were then used to refine the preliminary map, produce a series of two-dimensional (2D) and three-dimensional (3D) cross sections, and interpret the recent geologic history of the area. Geomorphologic interpretations - most importantly the locations of paleo-channel deposits of sands and gravels - were used to identify reaches of the levees managed by the United States Army Corps of Engineers (USACE) and the City of Dallas that may be at significant risk for under-seepage. Boring logs and CPT data collected atop the levees were used to assess through-seepage risks. Local bedrock is comprised of cretaceous-age Eagle Ford Shale and Austin Chalk. Depth to bedrock in the study area averaged 14.6 m (47.8 ft). The uppermost surface of bedrock has been deeply incised by a meandering river. Vertical relief between the shallowest bedrock sections and deepest portion of the incised paleo-channel is more than 15 m (50 ft). In places the incised paleo-channel is more than 0.8 km (0.5 mi) wide. These data confirm the presence of an erosional unconformity between local bedrock and overlying quaternary floodplain deposits. The observed erosional unconformity is attributed to a higher-energy fluvial environment that occurred as a result of a drop in base level. Recent floodplain deposits consist of interlobate point bar, channel and overbank sediments that are generally distributed in a fining-upward sequence. Buried channel dimensions vary widely, but are more than 250 m (820 ft) in some areas - much larger than the current channel. A semi-continuous basal layer of quaternary sands and gravels approximately 2 to 5 m (7 to 16 ft) thick exists in much of the study area. These data indicate that the discharge rate of the Trinity River today is at its lowest since quaternary deposition began. Large terraces of varying geometry and elevation observed at the edge of the floodplain show that the Trinity River has been geographically constrained to its current floodplain since the late Cretaceous, and perhaps even earlier.

Microfaunal analysis of late Quaternary deposits of the northern Bering Sea.

USGS Publications Warehouse

McDougall, K.

1982-01-01

Holocene microfaunal associations and distribution patterns define three inner-shelf (1-20m) biofacies in Norton Sound, northern Bering Sea. The Holocene facies relations are the basis for interpreting early Holocene and late Pleistocene environmental conditions in the NE Bering Sea area. Norton Sound cores provide evidence of two marine transgressions and a varying river input.-from Author

Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

USGS Publications Warehouse

Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

2015-01-01

The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary sedimentary and volcanic rocks and Quaternary deposits.

Synthesis of Quaternary Ammonium Salts Based on Diketopyrrolopyrroles Skeletons and Their Applications in Copper Electroplating.

PubMed

Chen, Biao; Xu, Jie; Wang, Limin; Song, Longfeng; Wu, Shengying

2017-03-01

A series of DPP derivatives bearing quaternary ammonium salt centers with different lengths of carbon chains have been designed and synthesized. Their inhibition actions on copper electroplating were first investigated. A total of four diketopyrrolopyrrole (DPP) derivatives showed different inhibition capabilities on copper electroplating. To investigate interactions between metal surface and additives, we used quantum chemical calculations. Static and dynamic surface tension of four DPP derivatives had been measured, and the results showed DPP-10C (1c) with a faster-decreasing rate of dynamic surface tension among the four derivatives, which indicated higher adsorption rate of additive on the cathode surface and gives rise to stronger inhibiting effect of copper electrodeposition. Then, DPP-10C (1c) as the representative additive, was selected for the systematic study of the leveling influence during microvia filling through comprehensive electroplating tests. In addition, field-emission scanning electron microscope images and X-ray diffraction results showed the surface morphology, which indicated that addition of DPP derivative (1c) could lead a fine copper deposit and cause the preferential orientations of copper deposits to change from [220] to [111], which happened in particular at higher concentrations.

Response to “Comment on 'The transition on North America from the warm humid Pliocene to the glaciated Quaternary traced by eolian dust deposition at a benchmark North Atlantic Ocean drill site', by David Lang et al.”

NASA Astrophysics Data System (ADS)

Lang, David C.; Bailey, Ian; Wilson, Paul A.; Foster, Gavin L.; Bolton, Clara T.; Friedrich, Oliver; Gutjahr, Marcus

2014-11-01

In volume 93 of Quaternary Science Reviews we published a new record of terrigenous inputs to Integrated Ocean Drilling Program (IODP) Site U1313 that tracks the history of aeolian dust deposition in the North Atlantic Ocean and aridity on North America during the late Pliocene-earliest Pleistocene intensification of northern hemisphere glaciation (iNHG, 3.3 to 2.4 Ma). Naafs et al. (2014) are generally supportive but question one of our conclusions, specifically our argument that "glacial grinding and transport of fine grained sediments to mid latitude outwash plains is not the fundamental mechanism controlling the magnitude of the flux of higher plant leaf waxes from North America to Site U1313 during iNHG." They suggest that our argument is predominantly based on our observation that the relationship between sediment lightness (L*)-based terrigenous inputs and dust-derived biomarkers, which is observed to be linear elsewhere (Martínez-Garcia et al., 2011), is non-linear at Site U1313.

Effect of pH and sulfur precursor concentration on electrochemically deposited CZTS thin films using glycine as the complexing agent

NASA Astrophysics Data System (ADS)

Paraye, Akanksha; Sani, Rabiya; Ramachandran, Manivannan; Selvam, Noyel Victoria

2018-03-01

Copper zinc tin sulfide (CZTS) a promising quaternary chalcogenide material was deposited using single step electrodeposition using glycine as the complexing agent. The deposition was studied at different sulfur concentrations and at different pH. The pH of the electrolyte was found to influence the stoichiometry of the deposits significantly. The deposits formed at pH 2.5 showed satisfactory stoichiometry. The thickness of the deposits was observed to decrease with increase in sulfur concentration and pH. The transmission electron spectroscopy analysis showed the formation of flower shaped core shell particles from the electrolyte that contained 80 mM sulfur precursor at pH 2.5. The band gap of the deposits was found to be in the range from 1.57 eV to 2.1 eV. X-ray diffraction analysis showed that the as synthesized particles were amorphous in nature, the crystallinity of which improved with annealing. The Mott Schottky analysis of the deposits in 0.1 M sodium perchlorate showed that the particles exhibited p-type conductivity.

Mercury contamination from historical gold mining in California

USGS Publications Warehouse

Alpers, Charles N.; Hunerlach, Michael P.; May, Jason T.; Hothem, Roger L.

2005-01-01

Mercury contamination from historical gold mines represents a potential risk to human health and the environment. This fact sheet provides background information on the use of mercury in historical gold mining and processing operations in California, with emphasis on historical hydraulic mining areas. It also describes results of recent USGS projects that address the potential risks associated with mercury contamination. Miners used mercury (quicksilver) to recover gold throughout the western United States. Gold deposits were either hardrock (lode, gold-quartz veins) or placer (alluvial, unconsolidated gravels). Underground methods (adits and shafts) were used to mine hardrock gold deposits. Hydraulic, drift, or dredging methods were used to mine the placer gold deposits. Mercury was used to enhance gold recovery in all the various types of mining operations; historical records indicate that more mercury was used and lost at hydraulic mines than at other types of mines. On the basis of USGS studies and other recent work, a better understanding is emerging of mercury distribution, ongoing transport, transformation processes, and the extent of biological uptake in areas affected by historical gold mining. This information has been used extensively by federal, state, and local agencies responsible for resource management and public health in California.

Liquefaction at Oceano, California, during the 2003 San Simeon earthquake

USGS Publications Warehouse

Holzer, T.L.; Noce, T.E.; Bennett, M.J.; Tinsley, J. C.; Rosenberg, L.I.

2005-01-01

The 2003 M 6.5 San Simeon, California, earthquake caused liquefaction-induced lateral spreading at Oceano at an unexpectedly large distance from the seismogenic rupture. We conclude that the liquefaction was caused by ground motion that was enhanced by both rupture directivity in the mainshock and local site amplification by unconsolidated fine-grained deposits. Liquefaction occurred in sandy artificial fill and undisturbed eolian sand and fluvial deposits. The largest and most damaging lateral spread was caused by liquefaction of artificial fill; the head of this lateral spread coincided with the boundary between the artificial fill and undisturbed eolian sand deposits. Values of the liquefaction potential index, in general, were greater than 5 at liquefaction sites, the threshold value that has been proposed for liquefaction hazard mapping. Although the mainshock ground motion at Oceano was not recorded, peak ground acceleration was estimated to range from 0.25 and 0.28g on the basis of the liquefaction potential index and aftershock recordings. The estimates fall within the range of peak ground acceleration values associated with the modified Mercalli intensity = VII reported at the U.S. Geological Survey (USGS) "Did You Feel It?" web site.

Small-scale seismogenic soft sediment deformation (Hirlatzhöhle, Upper Austria)

NASA Astrophysics Data System (ADS)

Salomon, Martina Lan; Grasemann, Bernhard; Plan, Lukas; Gier, Susanne

2014-05-01

The Hirlatz Cave lies in the Dachstein Massif about 2 km SW of Hallstatt, in the Upper Austrian Salzkammergut. With a length of 101 km, this karst cave, located in the Dachstein nappe (Northern Calcareous Alps), is the second largest known cave system in Austria. Within the cave, in the so-called Lehmklamm, located 2.8 km southeast of the cave entrance, laminated (mm-scale) Quaternary clay-sized sediments with interbedded fine-grained sandy layers are preserved. In these layers, numerous soft sediment deformation structures are preserved in many layers. The unconsolidated sediments show rhythmic layering of brighter, carbonate and quartz rich, and darker, more clay mineral rich horizontal varve-like layers, that are assumed to be fluvio-lacustrine deposits. The present study focuses on a very detailed documentation of an approximately 6.8 x 3 m vertical outcrop that was cut by a small brook. Centimeter to millimeter sized water escape structures (intruded cusps and flame structures), folds (detachment folds, fault bend folds) and faults (normal faults, fault propagation folds, bookshelf faults) are described. Because of the geometric analogy to seismogenic structures which have been described at two orders of magnitude larger scales from areas close to the Dead Sea Fault, we suggest that the formation of the investigated soft-sediment structures was also triggered by seismic events. The structures were mainly formed by three different mechanism: (i) North directed gravitational gliding near the sediment surface; (ii) Liquefaction resulting in a density discontinuity and decreasing in shear strength within in the stratified layers; (iii) Extensional faulting that cut through the stratified layers. Observations of coarsening upwards into sandy layers on the top of the outcrop and current ripple indicate a north-directed flow under phreatic conditions, which is opposite to the present flow direction of the vadose water in the cave. The fact that deformation and erosion mostly occur in the uppermost meter of the outcrop wall suggests a higher seismic activity and at least periodically higher flow rates during sedimentation of the younger deposits. Since several extremely deformed layers occur between undeformed ones, we suggest that deformation of the layers occurred only in the uppermost highly water saturated sediments and that several seismic events lead to the formation of the observed structures. A possible source responsible for the seismic event is the Salzach-Ennstal-Mariazeller-Puchberger (SEMP) strike-slip fault, which accommodates the active extrusion of the Eastern Alps towards the Pannonian Basin.

Digital data sets that describe aquifer characteristics of the Rush Springs Aquifer in western Oklahoma

USGS Publications Warehouse

Runkle, D.L.; Becker, M.F.; Rea, Alan

1997-01-01

This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Rush Spring aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Stephens, and Washita Counties. These digital data sets were developed by Mark F. Becker to use as input into a computer model that simulated ground-water flow in the Rush Springs aquifer (Mark F. Becker, U.S. Geological Survey, written commun., 1997). For the purposes of modeling the ground-water flow in the Rush Springs aquifer, Mark F. Becker (written commun., 1997) defined the Rush Springs aquifer to include the Rush Springs Formation, alluvial and terrace deposits along major streams, and parts of the Marlow Formations, particularly in the eastern part of the aquifer boundary area. The Permian-age Rush Springs Formation consists of highly cross-bedded sandstone with some interbedded dolomite and gypsum. The Rush Springs Formation is overlain by Quaternary-age alluvial and terrace deposits that consist of unconsolidated clay, silt, sand, and gravel. The Rush Springs Formation is underlain by the Permian-age Marlow Formation that consists of interbedded sandstones, siltstones, mudstones, gypsum-anhydrite, and dolomite beds (Mark F. Becker, written commun., 1997). The parts of the Marlow Formation that have high permeability and porosity are where the Marlow Formation is included as part of the Rush Springs aquifer. The Rush Springs aquifer underlies about 2,400 square miles of western Oklahoma and is an important source of water for irrigation, livestock, industrial, municipal, and domestic use. Irrigation wells are reported to have well yields greater than 1,000 gallons per minute (Mark F. Becker, written commun., 1997). Mark F. Becker created some of the aquifer boundaries, hydraulic conductivity, and recharge data sets by digitizing parts of previously published surficial geology maps. The hydraulic conductivity and recharge values are the input data to the ground-water flow model (Mark F. Becker, written commun., 1997). The water-level elevation data set was prepared at a scale of 1:250,000 by Mark F. Becker (written commun., 1997) from water levels measured in wells prior to the year 1950. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Geology of the San Francisco Peaks, Northern Arizona.

DTIC Science & Technology

geology of the volcanic rocks and ash and (2) surficial geology, the study of the unconsolidated fluvial, glacial, periglacial and mass movement... sediments derived from the San Francisco Peaks volcanics. The study of the consolidated and unconsolidated rocks provides the basis for inferences on the

Preliminary results of hydrogeologic investigations Humboldt River Valley, Winnemucca, Nevada

USGS Publications Warehouse

Cohen, Philip M.

1964-01-01

Most of the ground water of economic importance and nearly all the ground water closely associated with the flow o# the Humboldt River in the. 40-mile reach near Winnemucca, Nev., are in unconsolidated sedimentary deposits. These deposits range in age from Pliocene to Recent and range in character from coarse poorly sorted fanglomerate to lacustrine strata of clay, silt, sand, and gravel. The most permeable deposit consists of sand and gravel of Lake Lahontan age--the so-called medial gravel unit--which is underlain and overlain by fairly impermeable silt and clay also of Lake Lahontan age. The ultimate source of nearly all the water in the study area is precpitation within the drainage basin of the Humboldt River. Much of this water reaches the study, area as flow or underflow of the Humboldt River and as underflow from other valleys tributary to the study area. Little if any flow from the tributary streams in the study area usually reaches the Humboldt River. Most of the tributary streamflow within the study area evaporates or is transpired by vegetation, but a part percolates downward through unconsolidated deposits of the alluvial fans flanking the mountains and move downgradient as ground-water underflow toward the Humboldt River. Areas that contribute significant amounts of ground-water underflow to. the valley of the Humboldt River within the study area are (1) the valley of the Humboldt River upstream from the study area, (2) the Pole Creek-Rock Creek area, (3) Paradise Valley, and (4) Grass Valley and the northwestern slope of the Sonoma Range. The total average underflow from these areas in the period 1949-61 was about 14,000-19,000 acre-feet per year. Much of this underflow discharged into the Humboldt River within the study area and constituted a large part of the base flow of the river. Streamflow in the Humboldt River increases substantially in the early spring, principally because of runoff to the river in the reaches upstream from the study area. The resulting increase of the stage of the river causes the river to lose large amounts of water by infiltration to the ground-water reservoir in the study area. In addition, there is much recharge to the ground-water reservoir in the spring and early summer as a result of seepage losses from irrigation ditches and the downward percolation of some of the excess water applied for irrigation. The average net increase of ground water in storage in the deposits beneath and adjacent to the flood plain of the Humboldt River during the spring and early summer is about 10,000 acre-feet.

Late Quaternary eolian dust in surficial deposits of a Colorado Plateau grassland: Controls on distribution and ecologic effects

USGS Publications Warehouse

Reynolds, R.L.; Reheis, M.C.; Neff, J.C.; Goldstein, H.; Yount, J.

2006-01-01

In a semi-arid, upland setting on the Colorado Plateau that is underlain by nutrient-poor Paleozoic eolian sandstone, alternating episodes of dune activity and soil formation during the late Pleistocene and Holocene have produced dominantly sandy deposits that support grass and shrub communities. These deposits also contain eolian dust, especially in paleosols. Eolian dust in these deposits is indicated by several mineralogic and chemical disparities with local bedrock, but it is most readily shown by the abundance of titaniferous magnetite in the sandy deposits that is absent in local bedrock. Magnetite and some potential plant nutrients (especially, P, K, Na, Mn, and Zn) covary positively with depth (3-4 m) in dune-crest and dune-swale settings. Magnetite abundance also correlates strongly and positively with abundances of other elements (e.g., Ti, Li, As, Th, La, and Sc) that are geochemically stable in these environments. Soil-property variations with depth can be ascribed to three primary factors: (1) shifts in local geomorphic setting; (2) accumulation of relatively high amounts of atmospheric mineral dust inputs during periods of land-surface stability; and (3) variations in dust flux and composition that are likely related to changes in dust-source regions. Shifts in geomorphic setting are revealed by large variations in soil texture and are also expressed by changes in soil chemical and magnetic properties. Variable dust inputs are indicated by both changes in dust flux and changes in relations among magnetic, chemical, and textural properties. The largest of these changes is found in sediment that spans late Pleistocene to early Holocene time. Increased dust inputs to the central Colorado Plateau during this period may have been related to desiccation and shrinkage of large lakes from about 12 to 8 ka in western North America that exposed vast surfaces capable of emitting dust. Soil properties that result from variable dust accumulation and redistribution in these surficial deposits during the late Quaternary are important to modern ecosystem dynamics because some plants today utilize nutrients deposited as long ago as about 12-15 ky and because variations in fine-grained (silt) sediment, including eolian dust, influence soil-moisture capacity.

Geochemical, isotopic (Sr-Nd-Pb) and geochronological (Ar-Ar and U-Pb) constraints on Quaternary bimodal volcanism of the Nigde Volcanic Complex (Central Anatolia, Turkey)

NASA Astrophysics Data System (ADS)

Aydin, F.; Siebel, W.; Uysal, I.; Ersoy, E. Y.; Schmitt, A. K.; Sönmez, M.; Duncan, R.

2012-04-01

The Nigde Volcanic Complex (NVC) is a major Late Neogene-Quaternary volcanic centre within the Cappadocian Volcanic Province of Central Anatolia. The Late Neogene evolution of the NVC generally initiated with the eruption of extensive andesitic-dacitic lavas and pyroclastic flow deposits, and minor basaltic lavas. This stage was followed by a Quaternary bimodal magma suite which forms Na-alkaline/transitional basaltic and high-K calc-alkaline to alkaline silicic volcanic rocks. In this study, we present new geochemical, isotopic (Sr-Nd-Pb) and geochronological (Ar-Ar and U-Pb) data for the bimodal volcanic suite within the NVC. Recent data suggest that the eruption of this suite took place ranges between ~650 and ~220 ka (Middle-Late Pleistocene). Silicic rocks consisting of rhyolite and associated pumice-rich pyroclastic fall out and surge deposits define a narrow range of 143Nd/144Nd isotope ratios (0.5126-0.5127), and show virtually no difference in Pb isotope composition (206Pb/204Pb = 18.84-18.87, 207Pb/204Pb = 15.64-15.67 and 208Pb/204Pb = 38.93-38.99). 87Sr/86Sr isotopic compositions of the silicic (0.704-0.705) and basaltic rocks (0.703-0.705) are rather similar reflecting a common source. The most mafic sample from basaltic rocks related to monogenetic cones is characterized by 87Sr/86Sr = 0.704, 143Nd/144Nd = 0.5127, 206Pb/204Pb = 18.80, 207Pb/204Pb = 15.60 and 208Pb/204Pb = 38.68. These values suggest a moderately depleted signature of the mantle source. The geochronological and geochemical data suggest that NVC silicic and basaltic rocks are genetically closely related to each other. Mantle derived differentiated basaltic melts which experienced low degree of crustal assimilation are suggested to be the parent melt of the rhyolites. Further investigations will focus on the spatial and temporal evolution of Quaternary bimodal magma suite in the NVC and the genetic relation between silicic and basaltic rocks through detailed oxygen isotope analysis and (U-Th)/He zircon geochronology.

Hydrogeologic Framework of the Salt Basin, New Mexico and Texas

NASA Astrophysics Data System (ADS)

Ritchie, A. B.; Phillips, F. M.

2010-12-01

The Salt Basin is a closed drainage basin located in southeastern New Mexico (Otero, Chaves, and Eddy Counties), and northwestern Texas (Hudspeth, Culberson, Jeff Davis, and Presidio Counties), which can be divided into a northern and a southern system. Since the 1950s, extensive groundwater withdrawals have been associated with agricultural irrigation in the Dell City, Texas region, just south of the New Mexico-Texas border. Currently, there are three major applications over the appropriations of groundwater in the Salt Basin. Despite these factors, relatively little is known about the recharge rates and storage capacity of the basin, and the estimates that do exist are highly variable. The Salt Basin groundwater system was declared by the New Mexico State Engineer during 2002 in an attempt to regulate and control growing interest in the groundwater resources of the basin. In order to help guide long-term management strategies, a conceptual model of groundwater flow in the Salt Basin was developed by reconstructing the tectonic forcings that have affected the basin during its formation, and identifying the depositional environments that formed and the resultant distribution of facies. The tectonic history of the Salt Basin can be divided into four main periods: a) Pennsylvanian-to-Early Permian, b) Mid-to-Late Permian, c) Late Cretaceous, and d) Tertiary-to-Quaternary. Pennsylvanian-to-Permian structural features affected deposition throughout the Permian, resulting in three distinct hydrogeologic facies: basin, shelf-margin, and shelf. Permian shelf facies rocks form the primary aquifer within the northern Salt Basin, although minor aquifers occur in Cretaceous rocks and Tertiary-to-Quaternary alluvium. Subsequent tectonic activity during the Late Cretaceous resulted in the re-activation of many of the earlier structures. Tertiary-to-Quaternary Basin-and-Range extension produced the current physiographic form of the basin.

Astronomically calibrated 40Ar/39Ar age for the Toba supereruption and global synchronization of late Quaternary records

PubMed Central

Storey, Michael; Roberts, Richard G.; Saidin, Mokhtar

2012-01-01

The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated 40Ar/39Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our 40Ar/39Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard–Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our 40Ar/39Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of 14C dating. PMID:23112159

Astronomically calibrated 40Ar/39Ar age for the Toba supereruption and global synchronization of late Quaternary records

NASA Astrophysics Data System (ADS)

Storey, Michael; Roberts, Richard G.; Saidin, Mokhtar

2012-11-01

The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated 40Ar/39Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our 40Ar/39Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard-Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our 40Ar/39Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of 14C dating.

Astronomically calibrated 40Ar/39Ar age for the Toba supereruption and global synchronization of late Quaternary records.

PubMed

Storey, Michael; Roberts, Richard G; Saidin, Mokhtar

2012-11-13

The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated (40)Ar/(39)Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our (40)Ar/(39)Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard-Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our (40)Ar/(39)Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of (14)C dating.

Influence of the Amlia fracture zone on the evolution of the Aleutian Terrace forearc basin, central Aleutian subduction zone

USGS Publications Warehouse

Ryan, Holly F.; Draut, Amy E.; Keranen, Katie M.; Scholl, David W.

2012-01-01

During Pliocene to Quaternary time, the central Aleutian forearc basin evolved in response to a combination of tectonic and climatic factors. Initially, along-trench transport of sediment and accretion of a frontal prism created the accommodation space to allow forearc basin deposition. Transport of sufficient sediment to overtop the bathymetrically high Amlia fracture zone and reach the central Aleutian arc began with glaciation of continental Alaska in the Pliocene. As the obliquely subducting Amlia fracture zone swept along the central Aleutian arc, it further affected the structural evolution of the forearc basins. The subduction of the Amlia fracture zone resulted in basin inversion and loss of accommodation space east of the migrating fracture zone. Conversely, west of Amlia fracture zone, accommodation space increased arcward of a large outer-arc high that formed, in part, by a thickening of arc basement. This difference in deformation is interpreted to be the result of a variation in interplate coupling across the Amlia fracture zone that was facilitated by increasing subduction obliquity, a change in orientation of the subducting Amlia fracture zone, and late Quaternary intensification of glaciation. The change in coupling is manifested by a possible tear in the subducting slab along the Amlia fracture zone. Differences in coupling across the Amlia fracture zone have important implications for the location of maximum slip during future great earthquakes. In addition, shaking during a great earthquake could trigger large mass failures of the summit platform, as evidenced by the presence of thick mass transport deposits of primarily Quaternary age that are found in the forearc basin west of the Amlia fracture zone.

Use of the Cone Penetration Testing (CPT) method to interpret late Quaternary tide-dominated successions: A case study from the eastern China coastal plain

NASA Astrophysics Data System (ADS)

Zhang, Xia; Lin, Chun-Ming; Dalrymple, Robert W.; Gao, Shu; Canas, Daniel T.

2018-06-01

We evaluate the applicability of cone penetration testing (CPT), calibrated using adjacent cores, as a tool for the sedimentological and stratigraphic examination of late Quaternary tide-dominated successions in the eastern China coastal plain. The results indicate that the sedimentary facies and sequence-stratigraphic surfaces can be readily distinguished using CPT profiles in the Qiantang River incised-valley system because of their distinctive mechanical behavior. The lithologic character of the various facies, which is controlled mainly by sediment supply, dynamic processes and post-depositional diagenesis, is the key factor affecting how well the CPT technique works. Within this particular macrotidal environment, which is dominated by non-cohesive sand and silt in the tidal channels, the accumulation of fluid mud is rare. Consequently, the tidal-channel deposits exhibit the geotechnical properties of coarse-grained sediments, and can be easily distinguished from the mud-dominated facies. However, in the nearby Changjiang delta system which is characterized by very high suspended-sediment concentrations and an abundance of fine-grained cohesive sediments, the presence of channel-bottom fluid muds makes it difficult to recognize channel deposits, because of the lack of a sharp lithologic contrast at their base. Consequently, the CPT method might not be as universally effective in tide-dominated systems as it appears to be in wave-dominated settings. Care is needed in the interpretation of the results from tide-dominated successions because of the widespread presence of fluid muds, the heterolithic nature of tidal deposits, the rheological similarity between adjacent facies, and the averaging of geotechnical properties between the alternating finer and coarser layers.

Gravity and magnetic data in the vicinity of Virgin Valley, southern Nevada

USGS Publications Warehouse

Morin, Robert L.

2006-01-01

This report contains 10 interpretive cross sections and an integrated text describing the geology of parts of the Colorado, White River, and Death Valley regional ground-water flow systems, Nevada, Utah, and Arizona. The primary purpose of the report is to provide geologic framework data for input into a numerical ground-water model. Therefore, the stratigraphic and structural summaries are written in a hydrogeologic context. The oldest rocks (basement) are Early Proterozoic metamorphic and intrusive crystalline rocks that are considered confining units because of their low permeability. Late Proterozoic to Lower Cambrian clastic units overlie the crystalline rocks and are also considered confining units within the regional flow systems. Above the clastic units are Middle Cambrian to Lower Permian carbonate rocks that are the primary aquifers in the flow systems. The Middle Cambrian to Lower Permian carbonate rocks are overlain by a sequence of mainly clastic rocks of late Paleozoic to Mesozoic age that are mostly considered confining units, but they may be permeable where faulted. Tertiary volcanic and plutonic rocks are exposed in the northern and southern parts of the study area. In the Clover and Delamar Mountains, these rocks are highly deformed by north- and northwest-striking normal and strike-slip faults that are probably important conduits in transmitting ground water from the basins in the northern Colorado and White River flow systems to basins in the southern part of the flow systems. The youngest rocks in the region are Tertiary to Quaternary basin-fill deposits. These rocks consist of middle to late Tertiary sediments consisting of limestone, conglomerate, sandstone, tuff, and gypsum, and younger Quaternary surficial units consisting of alluvium, colluvium, playa deposits, and eolian deposits. Basin-fill deposits are both aquifers and aquitards.

Statistical analyses of soil properties on a quaternary terrace sequence in the upper sava river valley, Slovenia, Yugoslavia

USGS Publications Warehouse

Vidic, N.; Pavich, M.; Lobnik, F.

1991-01-01

Alpine glaciations, climatic changes and tectonic movements have created a Quaternary sequence of gravely carbonate sediments in the upper Sava River Valley, Slovenia, Yugoslavia. The names for terraces, assigned in this model, Gu??nz, Mindel, Riss and Wu??rm in order of decreasing age, are used as morphostratigraphic terms. Soil chronosequence on the terraces was examined to evaluate which soil properties are time dependent and can be used to help constrain the ages of glaciofluvial sedimentation. Soil thickness, thickness of Bt horizons, amount and continuity of clay coatings and amount of Fe and Me concretions increase with soil age. The main source of variability consists of solutions of carbonate, leaching of basic cations and acidification of soils, which are time dependent and increase with the age of soils. The second source of variability is the content of organic matter, which is less time dependent, but varies more within soil profiles. Textural changes are significant, presented by solution of carbonate pebbles and sand, and formation is silt loam matrix, which with age becomes finer, with clay loam or clayey texture. The oldest, Gu??nz, terrace shows slight deviation from general progressive trends of changes of soil properties with time. The hypothesis of single versus multiple depositional periods of deposition was tested with one-way analysis of variance (ANOVA) on a staggered, nested hierarchical sampling design on a terrace of largest extent and greatest gravel volume, the Wu??rm terrace. The variability of soil properties is generally higher within subareas than between areas of the terrace, except for the soil thickness. Observed differences in soil thickness between the areas of the terrace could be due to multiple periods of gravel deposition, or to the initial differences of texture of the deposits. ?? 1991.

Fossil diatoms and neogene paleolimnology

USGS Publications Warehouse

Platt, Bradbury J.

1988-01-01

Diatoms have played an important role in the development of Neogene continental biostratigraphy and paleolimnology since the mid-19th Century. The history of progress in Quaternary diatom biostratigraphy has developed as a result of improved coring techniques that enable sampling sediments beneath existing lakes coupled with improved chronological control (including radiometric dating and varve enumeration), improved statistical treatment of fossil diatom assemblages (from qualitative description to influx calculations of diatom numbers or volumes), and improved ecological information about analogous living diatom associations. The last factor, diatom ecology, is the most critical in many ways, but progresses slowly. Fortunately, statistical comparison of modern diatom assemblages and insightful studies of the nutrient requirements of some common freshwater species are enabling diatom paleolimnologists to make more detailed interpretations of the Quaternary record than had been possible earlier, and progress in the field of diatom biology and ecology will continue to refine paleolimnological studies. The greater age and geologic setting of Tertiary diatomaceous deposits has prompted their study in the contexts of geologic history, biochronology and evolution. The distribution of diatoms of marine affinities in continental deposits has given geologists insights about tectonism and sea-level change, and the distribution of distinctive (extinct?) diatoms has found utilization both in making stratigraphic correlations between outcrops of diatomaceous deposits and in various types of biochronological studies that involve dating deposits in different areas. A continental diatom biochronologic scheme will rely upon evolution, such as the appearance of new genera within a family, in combination with regional environmental changes that are responsible for the wide distribution of distinctive diatom species. The increased use of the scanning electron microscope for the detailed descriptions of fossil diatoms will provide the basis for making more accurate correlations and identifications, and the micromorphological detail for speculations about evolutionary relationships. ?? 1988.

Geologic map of the Hart Peak Quadrangle, California and Nevada: a digital database

USGS Publications Warehouse

Nielson, Jane E.; Turner, Ryan D.; Bedford, David R.

1999-01-01

The Hart Peak 1:24,000-scale quadrangle is located about 12 km southwest of Searchlight, Nevada, comprehending the eastern part of the Castle Peaks, California, and most of the Castle Mountains and the northwestern part of the Piute Range, in California and Nevada. The Castle Peaks area constitutes the northeasternmost part of the northeast-trending New York Mountains. The Castle Mountains straddle the California-Nevada State line between the Castle Peaks and north-trending Piute Range. The southern part of the Piute Range, near Civil War-era Fort Piute, adjoins Homer Mountain mapped by Spencer and Turner (1985). Adjacent and nearby 1:24,000-scale quadrangles include Castle Peaks, East of Grotto Hills, Homer Mountain, and Signal Hill, Calif.; also Tenmile Well and West of Juniper Mine, Calif. and Nev. The oldest rocks in the Hart Peak quadrangle are Early Proterozoic gneiss and foliated granite that crop out in the northern part of the quadrangle on the eastern flank of the Castle Peaks and in the central Castle Mountains (Wooden and Miller, 1990). Paleozoic rocks are uncommon and Mesozoic granitic rocks are not found in the map area. The older rocks are overlain nonconformably by several km of Miocene volcanic deposits, which accumulated in local basins. Local dikes and domes are sources of most Miocene eruptive units; younger Miocene intrusions cut all the older rocks. Upper Miocene to Quaternary gravel deposits interfinger with the uppermost volcanic flows; the contact between volcanic rocks and the gravel deposits is unconformable locally. Canyons and intermontane valleys contain dissected Quaternary alluvialfan deposits that are mantled by active drainage and alluvial fan detritus.

Using SOTEM Method to Detect BIF Bodies Buried Under Very Thick and Conductive Quaternary Sediments, Huoqiu Deposit, China

NASA Astrophysics Data System (ADS)

Chen, Weiying; Xue, Guoqiang; Khan, Muhammad Younis; Li, Hai

2017-03-01

Huoqiu iron deposit is a typical Precambrian banded iron-formation (BIF) field which is located in the North China Craton (NCC). To detect the deep ore bodies around Dawangzhuang Village in Yingshang County, north of the Huoqiu deposit field, electromagnetic methods were tested. As the ore bodies are buried under very thick conductive Quaternary sediments, the use of EM methods is a great challenge. Short-offset transient electromagnetic method (SOTEM) was applied in the area as we wanted to test due to its detection depth and resolution. A 2D model was first built according to the geology information and magnetic measurement results. Then, 2D forward and 1D inversion were carried out using FDTD and Occam's algorithm, respectively. The synthetic modeling results helped us with the survey design and interpretation. Two 1400-m-long survey lines with offset of 500 and 1000 m were laid perpendicular to the BIF's strike, and the transmitting parameters were selected by a test measurement at the vicinity of a local village. Finally, the structure of survey area and BIF bodies were determined based on the 1D inversion results of real data, and showed a consistency with the subsequent drill results. Our application of SOTEM in detecting hidden BIF buried under very thick conductive layer has shown that the method is capable of penetrating great depth more than 1000 m even in a very conductive environment and will be an effective tool for deep resources investigation.

Sedimentary and structural patterns on the northern Santa Rosa-Cortes Ridge, southern California

USGS Publications Warehouse

Field, M.E.; Richmond, W.C.

1980-01-01

The Santa Rosa-Cortes Ridge is an 1800 m high, 180 km long feature lying approximately 90 km off the coast of southern California and directly south of the northern group of Channel Islands. Geophysical profiling and sampling cruises to the northern part of the ridge, an area of recent and future lease sales for petroleum development, provide a strong data base for interpretation of structural and sedimentary patterns and their relation to potential geologic hazards. The northern part of the ridge is a complexly folded and faulted northwest-trending anticlinorium composed mostly of lower and middle Miocene shale and mudstone. Erosional remnants of upper Miocene and Pliocene rocks unconformably overlie highly folded pre-upper Miocene strata. The major structure of the ridge developed almost continuously from Oligocene or early Miocene time to the end of the Tertiary; many small folds formed between post-late Miocene and pre-late Pleistocene time. Numerous small faults cut the rocks on the ridge top. Faults cut basement rocks on the west side of the ridge along the Ferrelo fault zone. Published data on historical epicenters and evidence of offsets on the seafloor from seismic reflection and side-scan profiles, including limited evidence of possible strike-slip movement along fault traces, indicate that the northern Santa Rosa-Cortes Ridge is tectonically active. The crest of the ridge was truncated as the result of repeated sea-level fluctuations in the Quaternary. A thin veneer of unconsolidated medium to fine sand, less than 3 m thick, mantles most of the ridge; locally in topographically low areas and on the upper flanks of the ridge, thickness exceeds 20 m. The meager sediment cover, coupled with available evidence of relatively strong currents flowing across the ridge top, indicate that the ridge is an area of nondeposition or winnowing of fine sediments. Modern sediments become thicker and finer-grained from the ridge top to the ridge flanks, suggesting active accretion in those areas. Slumps are present at various depths on the flanks, and it seems probable that the thicker deposits (> 20 m) of modern sediments on the upper flanks will be sites of future slumping. ?? 1980.

Time-lapse seismic waveform inversion for monitoring near-surface microbubble injection

NASA Astrophysics Data System (ADS)

Kamei, R.; Jang, U.; Lumley, D. E.; Mouri, T.; Nakatsukasa, M.; Takanashi, M.

2016-12-01

Seismic monitoring of the Earth provides valuable information regarding the time-varying changes in subsurface physical properties that are caused by natural or man-made processes. However, the resulting changes in subsurface properties are often small both in terms of magnitude and spatial extent, leading to seismic data differences that are difficult to detect at typical non-repeatable noise levels. In order to better extract information from the time-lapse data, exploiting the full seismic waveform information can be critical, since detected amplitude or traveltime changes may be minimal. We explore methods of waveform inversion that estimate an optimal model of time-varying elastic parameters at the wavelength scale to fit the observed time-lapse seismic data with modelled waveforms based on numerical solutions of the wave equation. We apply acoustic waveform inversion to time-lapse cross-well monitoring surveys of 64-m well intervals, and estimate the velocity changes that occur during the injection of microbubble water into shallow unconsolidated Quaternary sediments in the Kanto basin of Japan at a depth of 25 m below the surface. Microbubble water is comprised of water infused with air bubbles of a diameter less than 0.1mm, and may be useful to improve resistance to ground liquefaction during major earthquakes. Monitoring the space-time distribution and physical properties of microbubble injection is therefore important to understanding the full potential of the technique. Repeated monitoring surveys (>10) reveal transient behaviours in waveforms during microbubble injection. Time-lapse waveform inversion detects changes in P-wave velocity of less than 1 percent, initially as velocity increases and subsequently as velocity decreases. The velocity changes are mainly imaged within a thin (1 m) layer between the injection and the receiver well, inferring the fluid-flow influence of the fluvial sediment depositional environment. The resulting velocity models fit the observed waveforms very well, supporting the validity of the estimated velocity changes. In order to further improve the estimation of velocity changes, we investigate the limitations of acoustic waveform inversion, and apply elastic waveform inversion to the time-lapse data set.

Stratigraphy and depositional sequences of the US Atlantic shelf and slope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poag, C.W.; Valentine, P.C.

1985-01-01

Litho-, bio-, and seismostratigraphic analyses of Georges Bank basin, Baltimore Canyon trough, and Blake Plateau basin reveal common aspects of stratigraphic framework and depositional history. Synrift graben-fill is inferred to be chiefly coarse terrigenous siliciclastics of Triassic-Early Jurassic age, as thick as 5 km. Following widespread erosion, restricted marine carbonates and evaporites formed initial post-rift deposits during an Early-Middle Jurassic transition to sea floor spreading. As sea floor spreading proceeded, shallow-water limestones and shelf-edge reefs built up, culminating in a discontinuous, margin-rimming reefal bank during the Late Jurassic-Early Cretaceous. During the Early Cretaceous, thick siliciclastics buried the shelf-edge barrier northmore » of Cape Hatteras, whereas shallow-water carbonates persisted in the Blake Plateau basin. Late Cretaceous deposits became increasingly finer-grained as they accumulated beneath a deepening shelf-sea; maximum thickness is more than 2 km. Cretaceous deposition was terminated by marginwide erosion and followed by widespread carbonate deposition in the Paleogene. Neogene and Quaternary deposition was chiefly siliciclastic, characterized by deltaic progradation. Cenozoic sediment thickness reaches 2 km in the Baltimore Canyon trough.« less

Late Quaternary stratigraphy and luminescence geochronology of the northeastern Mojave Desert

USGS Publications Warehouse

Mahan, S.A.; Miller, D.M.; Menges, C.M.; Yount, J.C.

2007-01-01

The chronology of the Holocene and late Pleistocene deposits of the northeastern Mojave Desert have been largely obtained using radiocarbon ages. Our study refines and extends this framework using optically stimulated luminescence (OSL) to date deposits from Valjean Valley, Silurian Lake Playa, Red Pass, and California Valley. Of particular interest are eolian fine silts incorporated in ground-water discharge (GWD) deposits bracketed at 185-140 and 20-50 ka. Alluvial fan deposits proved amenable for OSL by dating both eolian sand lenses and reworked eolian sand in a matrix of gravel that occurs within the fan stratigraphy. Lacustrine sand in spits and bars also yielded acceptable OSL ages. These OSL ages fill gaps in the geochronology of desert deposits, which can provide data relevant to understanding the responses of several depositional systems to regional changes in climate. This study identifies the most promising deposits for future luminescence dating and suggests that for several regions of the Mojave Desert, sediments from previously undated landforms can be more accurately placed within correct geologic map units.

Architecture and sedimentology of turbidite reservoirs from Miocene Moco T and Webster zones, Midway-Sunset field, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Link, M.H.; Hall, B.R.

1989-03-01

Thirty-five turbidite sandstone bodies from the Moco T and Webster reservoir zones were delineated for enhanced oil recovery projects in Mobil's MOCO FEE property, south Midway-Sunset field. The recognition of these sand bodies is based on mappable geometries determined from wireline log correlations, log character, core facies, reservoir characteristics, and comparison to nearby age-equivalent outcrops. These turbidite sands are composed of unconsolidated arkosic late Miocene sandstones (Stevens equivalent, Monterey Formation). They were deposited normal to paleoslope and trend southwest-northeast in an intraslope basin. Reservoir quality in the sandstone is very good, with average porosities of 33% and permeabilities of 1more » darcy.« less

Environmental Impact Statement for Proposed Closure of Eaker Air Force Base, Arkansas

DTIC Science & Technology

1990-05-01

alluvial floodplain of the Mississippi River . Quaternary deposits composed of clay, sandy clay, sand , and gravel occur to a depth of approximately 125...Protection Agency 1988 Bossier Parish , Louisiana : Mississippi County, Arkansas: Pulaski County, Arkansas: and Taylor County. Texas Air Quality Inventory...receiving bases: Malmstrom AFB, Montana; Barksdale AFB, Louisiana ; and Plattsburgh AFB, New York. Additional documents may be prepared 3 when the

Reconnaissance study of an inferred Quaternary maar structure in the western part of the Bohemian Massif near Neualbenreuth, NE-Bavaria (Germany)

NASA Astrophysics Data System (ADS)

Rohrmüller, J.; Kämpf, H.; Geiß, E.; Großmann, J.; Grun, I.; Mingram, J.; Mrlina, J.; Plessen, B.; Stebich, M.; Veress, C.; Wendt, A.; Nowaczyk, N.

2018-06-01

After a comprehensive geophysical prospecting the Quaternary Mýtina Maar, located on a line between the two Quaternary scoria cones Komorní hůrka/Kammerbühl and Železná hůrka/Eisenbühl, could be revealed by a scientific drilling at the German-Czech border in 2007. Further geophysical field investigations led to the discovery of another geological structure about 2.5 km ESE of the small town Neualbenreuth (NE-Bavaria, Germany), inferred to be also a maar structure, being the fourth volcanic feature aligned along the NW-SE trending Tachov fault zone. It is only faintly indicated as a partial circular rim in the digital elevation model. Though not expressed by a clear magnetic anomaly, geoelectric and refraction seismic tomography strongly indicates a bowl-shaped depression filled with low-resistivity and low-velocity material, correlating well with the well-defined negative gravity anomaly of - 2.5 mGal. Below ca. 15 m-thick debris layer, successions of mostly laminated sediments were recovered in a 100 m-long sediment core in 2015. Sections of finely laminated layers, likely varves, rich in organic matter and tree pollen, were recognized in the upper (22-30 m) and lower (70-86 m) part of the core, respectively, interpreted as interglacials, whereas mostly minerogenic laminated deposits, poor in organic matter, and (almost) barren of tree pollen are interpreted as clastic glacial deposits. According to a preliminary age model based on magnetostratigraphy, palynology, radiocarbon dating, and cyclostratigraphy, the recovered sediments span the time window from about 85 ka back to about 270 ka, covering marine isotope stages 5-8. Sedimentation rates are in the range of 10 cm ka-1 in interglacials and up to 100 cm ka-1 in glacial phases. The stratigraphic record resembles the one from Mýtina Maar, with its eruption date being derived from a nearby tephra deposit at 288 ± 17 ka, thus supporting the age model of the inferred Neualbenreuth Maar.

A model of late quaternary landscape development in the Delaware Valley, New Jersey and Pennsylvania

USGS Publications Warehouse

Ridge, J.C.; Evenson, E.B.; Sevon, W.D.

1992-01-01

In the Delaware Valley of New Jersey and eastern Pennsylvania the late Quaternary history of colluviation, fluvial adjustment, and soil formation is based on the ages of pre-Wisconsinan soils and glacial deposits which are indicated by feld relationships and inferred from mid-latitude climate changes indicated by marine oxygen-isotope records. The area is divided into four terranes characterized by sandstone, gneiss, slate and carbonate rocks. Since the last pre-Wisconsinan glaciation (> 130 ka, inferred to be late Illinoian), each terrane responded differently to chemical and mechanical weathering. During the Sangamon interglacial stage (??? 130-75 ka) in situ weathering is inferred to have occurred at rates greater than transportation of material which resulted in the formation of deep, highly weathered soil and saprolite, and dissolution of carbonate rocks. Cold climatic conditions during the Wisconsinan, on the other hand, induced erosion of the landscape at rates faster than soil development. Upland erosion during the Wisconsinan removed pre-Wisconsinan soil and glacial sediment and bedrock to produce muddy to blocky colluvium, gre??zes lite??es, and alluvial fans on footslopes. Fluvial gravel and overlying colluvium in the Delaware Valley, both buried by late Wisconsinan outwash, are inferred to represent episodes of early and middle Wisconsinan (??? 75-25 ka) upland erosion and river aggradiation followed by river degradation and colluvium deposition. Early-middle Wisconsinan colluvium is more voluminous than later colluvium despite colder, possibly permafrost conditions during the late Wisconsinan ??? 25-10 ka). Extensive colluviation during the early and middle Wisconsinan resulted from a longer (50 kyr), generally cold interval of erosion with a greater availability of easily eroded pre-Wisconsinan surficial materials on uplands than during the late Wisconsinan. After recession of late Wisconsinan ice from its terminal position, soil formation and landscape stability were delayed until the Holocene by a lingering cold climate, slope erosion, colluvium and alluvial fan deposition, and eolian sedimentation. Late Quaternary erosion in the Delaware Valley was dominated by glacial and periglacial processes during glacial stages. During the warm interglacial stages, soils developed on a more stable landscape. These souls were easily colluviated by periglacial erosion during periods of intermittent cold climate. ?? 1992.

Using tephra layers as absolute and relative chronological markers: an example from Lake Suigetsu, Japan

NASA Astrophysics Data System (ADS)

Smith, V.; Albert, P. G.; Staff, R.; Mark, D. F.; Bronk Ramsey, C.; Nakagawa, T.

2014-12-01

The Lake Suigetsu cores (SG06 and SG14) from Honshu Island, central Japan, provide a high-resolution paleoenvironmental record for the last ~200 kyrs. The composite record is ~85 m-long and it contains numerous tephras, more than 35 visible and numerous non-visible layers (cryptotephra). The major and trace element glass chemistry of these tephras allows the layers to be correlated to specific eruptions and tephra layers in other archives [1]. The record preserves large eruptions from volcanoes from Kyushu, Honshu, South Korea, and smaller explosive events from more proximal volcanoes, Daisen and Sanbe. The Lake Suigetsu has a very detailed varve and radiocarbon chronology [2] that has been exploited to provide precise ages for the tephra layers from the last 50 kyrs [1]. These ages can constrain the tempo of volcanic activity, and the age models of other sedimentary (paleoenvironmental and archaeological) records that contain the tephra. The deeper parts of the Suigetsu core are not continuosly annually laminated and are outside the radiocarbon timeframe and therefore do not have a well constrined chronology. The tephra layers can be used to provide an absolute chronology as eruption deposits from South Korea, Daisen and Sanbe often contain K-rich crystal phases, which can be dated using 40Ar/39Ar methods. Correlating these distal tephra layers in Lake Suigetsu to proximal deposits, using the glass chemistry, is essential as large crystals are required to obtain precise 40Ar/39Ar ages and these are only abundant in the coarser proximal deposits [3, 4]. These widespread marker layers can be also be used for relative chronology. Identifying the same tephras in disparate high-resolution archives allows them to be directly compared so that leads and lags in paleoclimate can be identified on the regional to continental scale, providing some insight into the fundamental drivers of the Earth's climate system. References: [1] Smith et al. (2013) Quaternary Science Reviews 67, 121-137. [2] Bronk Ramsey et al. (2012) Science 338, 370-374. [3] Smith et al. (2011) Quaternary Science Reviews 30, 2845-2850. [4] Mark et al. (2014) Quaternary Geochronology 21, 90-103.

Neogene Seismic Stratigraphic Framework and Fill History of the Northeastern Albemarle Embayment, North Carolina

NASA Astrophysics Data System (ADS)

Mallinson, D. J.; Riggs, S. R.; Thieler, R.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.; Wehmiller, J.; Foster, D. S.

2002-12-01

Seismic and chirp sonar surveys were conducted in the eastern Albemarle Sound and adjacent tributaries and the inner continental shelf to define the geologic framework and evolution of the North Carolina coastal system. Surveys were utilized to target paleofluvial channels for drilling and core recovery for the assessment of sea level and climate change during the Quaternary. Lithostratigraphic and chronostratigraphic data are derived from eight drill sites on the Outer Banks, and the Mobil #1 well in the eastern Albemarle Sound. Within the study area, parallel-bedded, gently dipping Miocene beds occur at 100 to >180 mbsl, and are overlain by a southward-thickening Pliocene unit characterized by steeply inclined southward-prograding beds. The Quaternary section unconformably overlies the Pliocene unit, and consists of at least five depositional sequences exhibiting numerous incised channel-fill facies. The Quaternary section is 55 to 60 meters thick. Shallow stratigraphy (0-50 mbsl) is dominated by complex fill-stratigraphy within the incised paleo-Roanoke River valley. Radiocarbon and amino acid racemization (AAR) dates indicate that the valley-fill is late Pleistocene to Holocene in age. At least 6 distinct valley-fill units are identified in the seismic data based upon reflection geometry. Cores reveal a 3 to 6 meter thick basal fluvial channel lag that is overlain by a 15-meter thick unit of interbedded freshwater muds and sands. Organic materials within the freshwater deposits have ages of 13-11 cal. ka, and are overlain by several units comprised of shallow marine sediments. Shallow marine sediments within the valley are silty, fine- to medium-grained sands containing abundant neritic forams, suggesting that this area was an open embayment during much of the Holocene. Seismic data reveal that initial infilling occurred from the north and west during the late Pleistocene and early Holocene. Later infilling occurred from the east and is characterized by a large shoal body (Colington Island and Shoals; radiocarbon dated to 8.6 cal. ka) and adjacent inlet fill. Establishment of a continuous barrier island system resulted in the deposition of a final phase of fill characterized by estuarine organic-rich muds.

February 2011 sensitive clay landslides at the Çöllolar coalfield, eastern Turkey

NASA Astrophysics Data System (ADS)

Akçar, Naki; Yavuz, Vural; Ivy-Ochs, Susan; Nyffenegger, Franziska; Fredin, Ola; Stolz, Martin; Schlunegger, Fritz

2016-04-01

The Elbistan basin is an intramontane basin, which is located in the eastern Turkey and bound by the Taurus and Antitaurus Mountains. The basin covers an area of 900 km² at a mean elevation of about 1200 m. The basement rock in this field is karstic limestone, which is overlain by a thick layer of clay (>100 m), followed by 20-50 m thick Lignite series that is overlain by the 20-50 m thick Gyttja sequence. These deposits are overlain by Quaternary deposits, comprising the top surfaces of the terraces of the Hurman River, which drains the surface and ground water from the surrounding hills to the northeast towards the center of the Elbistan basin. The Çöllolar open pit mine, situated in the northwestern sector of the Elbistan basin, contains 90 km2 of mineable coal which has been excavated since 2008. In February 2011, two landslides in which 10 workers were killed, occurred in this field. Of the two landslides, the 2nd and largest which covers an area of ca. 2.3 km2,was caused by the collapse of the northeastern wall of the open-pit mine. The failure was made of successive rearward collapses with the debris flowing into the open-pit. In this study, we focus on the geologic factors that led to instability and the trigger of the landslides. To reveal these factors, we employ sedimentological and geotechnical analysis of deposits, with a special emphasis on the Pliocene lacustrine carbonaceous sediments and the sensitivity of the overlying Quaternary clays. First results from the fieldwork and the mineralogical composition and physical properties of the collected samples indicate that the landslide was caused by the liquefaction of one of the layers within the thick sequence of this part of the Elbistan basin based on the flow style of the movement and nature of the failure. In brief, we conclude that massive failures at the Çöllolar coalfield are unique examples of sensitive clay landslides occurred in a subtropical arid region beyond the extent of Quaternary glaciations.

Reconnaissance study of an inferred Quaternary maar structure in the western part of the Bohemian Massif near Neualbenreuth, NE-Bavaria (Germany)

NASA Astrophysics Data System (ADS)

Rohrmüller, J.; Kämpf, H.; Geiß, E.; Großmann, J.; Grun, I.; Mingram, J.; Mrlina, J.; Plessen, B.; Stebich, M.; Veress, C.; Wendt, A.; Nowaczyk, N.

2017-10-01

After a comprehensive geophysical prospecting the Quaternary Mýtina Maar, located on a line between the two Quaternary scoria cones Komorní hůrka/Kammerbühl and Železná hůrka/Eisenbühl, could be revealed by a scientific drilling at the German-Czech border in 2007. Further geophysical field investigations led to the discovery of another geological structure about 2.5 km ESE of the small town Neualbenreuth (NE-Bavaria, Germany), inferred to be also a maar structure, being the fourth volcanic feature aligned along the NW-SE trending Tachov fault zone. It is only faintly indicated as a partial circular rim in the digital elevation model. Though not expressed by a clear magnetic anomaly, geoelectric and refraction seismic tomography strongly indicates a bowl-shaped depression filled with low-resistivity and low-velocity material, correlating well with the well-defined negative gravity anomaly of - 2.5 mGal. Below ca. 15 m-thick debris layer, successions of mostly laminated sediments were recovered in a 100 m-long sediment core in 2015. Sections of finely laminated layers, likely varves, rich in organic matter and tree pollen, were recognized in the upper (22-30 m) and lower (70-86 m) part of the core, respectively, interpreted as interglacials, whereas mostly minerogenic laminated deposits, poor in organic matter, and (almost) barren of tree pollen are interpreted as clastic glacial deposits. According to a preliminary age model based on magnetostratigraphy, palynology, radiocarbon dating, and cyclostratigraphy, the recovered sediments span the time window from about 85 ka back to about 270 ka, covering marine isotope stages 5-8. Sedimentation rates are in the range of 10 cm ka-1 in interglacials and up to 100 cm ka-1 in glacial phases. The stratigraphic record resembles the one from Mýtina Maar, with its eruption date being derived from a nearby tephra deposit at 288 ± 17 ka, thus supporting the age model of the inferred Neualbenreuth Maar.

Are there Tuffs from Toba Supereruptions in Singapore?

NASA Astrophysics Data System (ADS)

Bergal-Kuvikas, O.; Bouvet de Maisonneuve, C.; Vazquez, J. A.

2016-12-01

Singapore is a dense transportation hub and the most highly populated area of SE Asia. In order to assess volcanic hazards for Singapore, we compiled a database of Quaternary eruptions from neighboring volcanoes and we investigated samples from 20 boreholes collected across 11 reservoirs and several natural outcrops in the NW parts of the city. We identified a deposit of white to slightly yellow clay with a visible thickness of 6-8 meters in the western part of Singapore. This deposit of very fine ash is silicic (SiO2 72-75 wt.%) and calk-alkaline (K2O 3.7-4.5 wt.%). The ash layer is clearly weathered as the LOI is around 5 wt.% and SEM images show the presence of clay minerals almost exclusively. Geochemical mapping shows that quartz crystals are characterized by textures similar to volcanic deposits. N-MORB normalized spiderdiagrams of whole-rocks show minimums in Nb and Ti, enrichments in LREE, and depletions of HREE. This suggests a subduction origin. One possible source for this voluminous weathered ash layer is the Toba caldera, which produced several super eruptions in the Quaternary (the Young Toba Tuff at 0.074 Ma, Middle Toba Tuff at 0.5 Ma, Old Toba Tuff at 0.84 Ma, and Haranggoal Dacite Tuff at 1.2 Ma). Recognizing distal Toba tuffs is problematic because most deposits are underwater. Most of the analyzed samples have geochemical compositions that are statistically similar to the Toba tuffs and characterized by high contents of HREE elements (e.g. Y, Er, Yb) and some REE (e.g. Eu, Ba, La, Th). Preliminary dating shows the presence of Triassic zircons, possibly due to geologic contamination. Additional dating is needed to ascertain the source and age of this ash. Our new geochemical data of likely distal Toba deposits will be an important component for tephrochronological and paleoenvironmental studies in addition to being of importance for hazards assessments in Singapore.

Insights into the Toba Super-Eruption using SEM Analysis of Ash Deposits

NASA Astrophysics Data System (ADS)

Gatti, E.; Achyuthan, H.; Durant, A. J.; Gibbard, P.; Mokhtar, S.; Oppenheimer, C.; Raj, R.; Shridar, A.

2010-12-01

The ~74 ka Youngest Toba Tuff (YTT) super-eruption of Toba volcano, Northern Sumatra, was the largest eruption of the Quaternary (magnitude M= 8.8) and injected massive quantities of volcanic gases and ash into the stratosphere. YTT deposits covered at least 40,000,000 km2 of Southeast Asia and are preserved in river valleys across peninsular India and Malaysia, and in deep-sea tephra layers in the Indian Ocean, Bay of Bengal and South China Sea. Initial studies hypothesized the eruption caused immediate and substantial global cooling during the ~ 1 kyr between Dansgaard-Oeschger events 19 and 20 which devastated ecosystems and hominid populations. A more recent review argues against severe post-YTT climatic deterioration and cannot find clear evidence for considerable impacts on ecosystems or bio-diversity. The determination of the eruptive parameters is crucial in this issue to document the eruption and understand the potential impacts from future super-volcanic eruptions. Volcanic ash deposits can offer dramatic insights into key eruptive parameters, including magnitude, duration and plume height. The composition and shape of volcanic ashes can be used to interpret physical properties of an erupting magma and tephra transport, while textural characteristics such as grain roughness and surface vescicularity can provide insights into degassing history, volatile content and explosive activity of the volcano. We present a stratigraphic and sedimentological analysis of YTT deposits in stratified contexts at three localities in India, at two sites in Peninsular Malaysia, and at several localities around Lake Toba and on Samosir Island, Sumatra. These sites offer excellent constraints on the spatial distribution of YTT deposits which can be used to infer dispersal directions of the cloud, and provide insights into environmental controls on preservation of tephra beds. The research aims at a systematic interpretation of the Toba tephra to understand the volcanic processes and environmental impacts of the largest known Quaternary volcanic eruption.

Graphene-assisted multiple-input high-base optical computing

PubMed Central

Hu, Xiao; Wang, Andong; Zeng, Mengqi; Long, Yun; Zhu, Long; Fu, Lei; Wang, Jian

2016-01-01

We propose graphene-assisted multiple-input high-base optical computing. We fabricate a nonlinear optical device based on a fiber pigtail cross-section coated with a single-layer graphene grown by chemical vapor deposition (CVD) method. An approach to implementing modulo 4 operations of three-input hybrid addition and subtraction of quaternary base numbers in the optical domain using multiple non-degenerate four-wave mixing (FWM) processes in graphene coated optical fiber device and (differential) quadrature phase-shift keying ((D)QPSK) signals is presented. We demonstrate 10-Gbaud modulo 4 operations of three-input quaternary hybrid addition and subtraction (A + B − C, A + C − B, B + C − A) in the experiment. The measured optical signal-to-noise ratio (OSNR) penalties for modulo 4 operations of three-input quaternary hybrid addition and subtraction (A + B − C, A + C − B, B + C − A) are measured to be less than 7 dB at a bit-error rate (BER) of 2 × 10−3. The BER performance as a function of the relative time offset between three signals (signal offset) is also evaluated showing favorable performance. PMID:27604866

Comment on “The transition on North America from the warm humid Pliocene to the glaciated Quaternary traced by eolian dust deposition at a benchmark North Atlantic Ocean drill site, by David Lang et al. Quaternary Science Reviews 93: 125-141”

NASA Astrophysics Data System (ADS)

Naafs, B. D. A.; Martínez-García, A.; Grützner, J.; Higgins, S.

2014-11-01

Integrated Ocean Drilling Project (IODP) Site U1313 is regarded as a benchmark site for Plio/Pleistocene North Atlantic palaeoceanography. In volume 93 of Quaternary Science Reviews, Lang et al. (2014) provide a record of terrigenous input across the Plio/Pleistocene estimated from variations in sedimentary lightness (L*). The paper provides an elegant addition to the growing number of high-resolution records from Site U1313. Although we support the majority of their findings, we disagree with the conclusion that "glacial grinding and transport of fine grained sediments to mid latitude outwash plains is not the fundamental mechanism controlling the magnitude of the flux of higher plant leaf waxes from North America to Site U1313 during iNHG.", which is predominantly based on their observation that the relationship between L*-based terrigenous input and dust-derived biomarkers, which is linear at other sites (Martínez-Garcia et al., 2011), is non-linear at Site U1313.

New optically stimulated luminescence ages provide evidence of MIS3 and MIS2 eolian activity on Black Mesa, northeastern Arizona, USA

USGS Publications Warehouse

Ellwein, A.L.; Mahan, S.A.; McFadden, L.D.

2011-01-01

Eolian deposition on the semiarid southern Colorado Plateau has been attributed to episodic aridity during the Quaternary Period. However, OSL ages from three topographically controlled (e.g. falling) dunes on Black Mesa in northeastern Arizona indicate that eolian sediments there were deposited in deep tributary valleys as early as 35-30. ka, with most sand deposited before 20. ka. In contrast, the oldest OSL ages for sand sheets fall within the Pleistocene-Holocene climatic transition (~. 12-8. ka). Thus most eolian sediment accumulated on Black Mesa under climatic conditions that were in general cooler, moister, and more variable than today, not more arid, pointing to a considerable increase in sediment supply. ?? 2010 University of Washington.

Water availability and geology of Sumter County, Alabama

USGS Publications Warehouse

Davis, Marvin E.; Sanford, Thomas H.; Jefferson, Patrick O.

1975-01-01

Geologic units that crop out in Sumter County include the Selma Group of Late Cretaceous age; the Midway and Wilcox Groups of Tertiary Age; and terrace deposits and alluvium of Quaternary age. The Tuscaloosa Group, consisting of the Coker and Gordo Formations, and Eutaw Formation of Late Cretaceous age underlie the entire county. The Cretaceous units dip southwestward about 45 feet per mile and strike northwestward. They consist chiefly of deposits of sand, gravel, chalk, and clay. Potential sources of large supplies of ground water are major aquifers in the Coker, Gordo, and Eutaw Formations; expected yields are 1.6 mgd (million gallons per day or more per well. The Naheola and Nanafalia formations, Tuscahome Sand, and terrace deposits and alluvium are expected to yield 10 to 50 gallons per minute per well.

Quaternary schematics for property engineering of CdSe thin films

NASA Astrophysics Data System (ADS)

Chavan, G. T.; Pawar, S. T.; Prakshale, V. M.; Sikora, A.; Pawar, S. M.; Chaure, N. B.; Kamble, S. S.; Maldar, N. N.; Deshmukh, L. P.

2017-12-01

The synthesis of quaternary Cd1-xZnxSySe1-y (0 ≤ x = y ≤ 0.35) thin films was done through indigenously developed chemical solution growth process. As-obtained thin films were subjected to the physical, chemical, structural and optical characterizations. The nearly hydrophobic nature of the as-deposited films except binary CdSe was observed through the wettability studies. The colorimetric studies supported a change in physical color attributes. The elemental analysis done confirmed the formation of Cd(Zn, S)Se and the chemical states of constituent elements as Cd2+, Zn2+, S2- and Se2-. Structural assessment suggested the formation of the polycrystalline quaternary phase of the hexagonal wurtzite structure. The Raman spectroscopy was also employed for the confirmation studies on Cd1-xZnxSySe1-y thin films. Morphological observations indicated microstructural transformation from an aggregated bunch of nano-sized globular grains into a rhomboid network of petal/flakes like crystallites. The atomic force micrographs (AFM) revealed the enhancement in the hillock structures. From advanced AFM characterizations, we observed that the CdSe thin film has leptokurtic (Sku = 3.23) surface, whereas, quaternary Cd(Zn, S)Se films have platykurtic (Sku < 3) surface. The orientation of the surface morphology was observed through the angular spectrum studies. The optical absorption studies revealed direct allowed transition for the films with a continuous modulation of the energy bandgap from 1.8 eV to 2.31 eV.

Physical properties of Oxia/Lunae Planum and Arabia-type units in the central equatorial region of Mars

NASA Technical Reports Server (NTRS)

Strickland, Edwin L., III

1992-01-01

Classification and mapping of surficial units in the central equatorial region of Mars Consortium data identified the relatively dark but 'red' materials that cover Lunae Planum and surround the Meridiani materials of Oxia Palus inertia region of Arabia. Oxia Province consists of the regions dominated by the characteristically dark 'red' Oxia materials, but it includes darker streaks and splotches of relatively 'blue' Meridiani materials and brighter 'red' deposits of dust belonging to Eos Province (the bright 'red' border between Oxia and regional Meridiani deposits to the south) and Xanthe Province (the moderately bright 'red' dust deposits in western Chryse Planitia and its vicinity, including the VL-1 landing site). Two Oxia units were recognized: a darker unit present on Lunae Planum and east of Oxia Palus that have intermediate to high inertias. Oxia Province surrounds the extremely low thermal inertia Arabia Province in the east part of the study area, and occurs as isolated patches within Arabia (often including splotches of Meridiani materials within the Oxia patches). Arabia Province's materials have been widely interpreted as unconsolidated dust deposits which are currently forming at this stage of Mars' precessional climate cycle, although the persistence of stable, moderately strong albedo contracts among Arabia materials has not been addressed in those models. A systematic interpretation of Oxia and Arabia Province materials based on currently available remote sensing data is given.

Geologic history of the polar regions of Mars based on Mars Global surveyor data. II. Amazonian period

USGS Publications Warehouse

Kolb, E.J.; Tanaka, K.L.

2001-01-01

Based on Mars Orbiter Laser Altimeter (MOLA) and Mars Orbiter Camera (MOC) observations of Amazonian polar layered deposits' (PLD) morphology, composition, and thickness, we conclude that the PLDs are composed of porous unconsolidated layers that have not experienced significant basal melting or other glacial-type processes. Morphologic features and associations within the PLD chasmata, including preserved craters and sinuous ridges, indicate that the dominant process of chasmata formation is wind scouring. Our detailed analysis of south polar spiral-trough topography, in conjunction with the identification of similar layered stratigraphy within north polar spiral troughs, suggests that trough migration due to preferential ablation of Sun-facing slopes cannot be demonstrated. Within the layered sequences, we have not identified widespread unconformities, discontinuities, or pinch-outs that would indicate an accublation origin of the PLDs. We therefore postulate that the well-defined PLDs at both poles eventually reached and maintained their present form following deposition without extensive deformation or redeposition. Large, cuspate ridges in the Ultimi lobe of Planum Australe appear to be layered and may be unusual erosional remnants of a once thicker PLD in this area. Beneath the north polar layered deposits in Planum Boreum, we have identified a platform of older, highly degraded polar deposits as much as a kilometer thick that may have once covered an area larger than Planum Boreum. ?? 2001 Elsevier Science.

Geologic map of the Bateman Spring Quadrangle, Lander County, Nevada

USGS Publications Warehouse

Ramelli, Alan R.; Wrucke, Chester T.; House, P. Kyle

2017-01-01

This 1:24,000-scale geologic map of the Bateman Spring 7.5-minute quadrangle in Lander County, Nevada contains descriptions of 24 geologic units and one cross section. Accompanying text includes full unit descriptions and references. This quadrangle includes lower Paleozoic siliciclastic sedimentary rocks of the Roberts Mountain allochthon, Miocene intrusive dikes, alluvial deposits of the northern Shoshone Range piedmont, and riverine deposits of the Reese and Humboldt rivers.Significant findings include: refined age estimates for the Ordovician-Cambrian Valmy Formation and Devonian Slaven Chert, based on new fossil information; and detailed mapping of late Quaternary fault traces along the Shoshone Range fault system.

Stratigraphy of the pedogenic manganese nodules in the Carletonville area, North West Province of South Africa: A case study of the General Nice Manganese Mine

NASA Astrophysics Data System (ADS)

Pharoe, Benedict Kinshasa; Liu, Kuiwu

2018-07-01

The lithostratigraphy of pedogenic manganese (Mn) nodules in the Carletonville area is similar to the Klipkuil, Ryedale, Wes Wits, and Houtkoppies deposits in the West Rand region of the Gauteng and North West Provinces and to a lesser extent the Bronkhorstfontein manganese deposit in the Limpopo Province of South Africa. The lithostratigraphy of the ore deposit at the General Nice Manganese Mine consists of a basal manganese wad, preserved in a typical karst setting on top of the underlying Malmani stromatolitic dolomites and Tertiary fluvial and secondary mineral deposits consisting of manganese nodules of variable size in a finer-grained soil matrix. At the top of the deposit is a Mn-depleted Quaternary sand cover. The Tertiary alluvial succession hosting Mn nodules was informally subdivided into A, B, C, D, E, F, G and H zones on the basis of geochemical analyses (XRD, XRF and SEM) of bulk zone samples and the manganese nodule size and concentration.

Surficial deposits in the Bear Lake Basin

USGS Publications Warehouse

Reheis, Marith C.; Laabs, Benjamin J.C.; Forester, Richard M.; McGeehin, John P.; Kaufman, Darrell S.; Bright, Jordon

2005-01-01

Mapping and dating of surficial deposits in the Bear Lake drainage basin were undertaken to provide a geologic context for interpretation of cores taken from deposits beneath Bear Lake, which sometimes receives water and sediment from the glaciated Bear River and sometimes only from the small drainage basin of Bear Lake itself. Analyses of core sediments by others are directed at (1) constructing a high-resolution climate record for the Bear Lake area during the late Pleistocene and Holocene, and (2) investigating the sources and weathering history of sediments in the drainage basin. Surficial deposits in the upper Bear River and Bear Lake drainage basins are different in their overall compositions, although they do overlap. In the upper Bear River drainage, Quaternary deposits derived from glaciation of the Uinta Range contain abundant detritus weathered from Precambrian quartzite, whereas unglaciated tributaries downstream mainly contribute finer sediment weathered from much younger, more friable sedimentary rocks. In contrast, carbonate rocks capped by a carapace of Tertiary sediments dominate the Bear Lake drainage basin.

Basaltic lava flows covering active aeolian dunes in the Paraná Basin in southern Brazil: Features and emplacement aspects

NASA Astrophysics Data System (ADS)

Waichel, Breno L.; Scherer, Claiton M. S.; Frank, Heinrich T.

2008-03-01

Burial of active aeolian dunes by lava flows can preserve the morphology of the dunes and generate diverse features related to interaction between unconsolidated sediments and lavas. In the study area, located in southern Brazil, burial of aeolian deposits by Cretaceous basaltic lava flows completely preserved dunes, and generate sand-deformation features, sand diapirs and peperite-like breccia. The preserved dunes are crescentic and linear at the main contact with basalts, and smaller crescentic where interlayered with lavas. The various feature types formed on sediment surfaces by the advance of the flows reflect the emplacement style of the lavas which are compound pahoehoe type. Four feature types can be recognized: (a) type 1 features are related to the advance of sheet flows in dune-interdune areas with slopes > 5°, (b) type 2 is formed where the lava flows advance in lobes and climb the stoss slope of crescentic dunes (slopes 8-12°), (c) type 3 is generated by toes that descend the face of linear dunes (slopes 17-23°) and (d) type 4 occurs when lava lobes descend the stoss slope of crescentic dunes (slopes 10-15°). The direction of the flows, the disposition and morphology of the dunes and the ground slope are the main factors controlling formation of the features. The injection of unconsolidated sand in lava lobes forms diapirs and peperite-like breccias. Sand diapirs occur at the basal portion of lobes where the lava was more solidified. Peperite-like breccias occur in the inner portion where lava was more plastic, favoring the mingling of the components. The generation of both features is related to a mechanical process: the weight of the lava causes the injection of sand into the lava and the warming of the air in the pores of the sand facilitates this process. The lava-sediment interaction features presented here are consistent with previous reports of basalt lavas with unconsolidated arid sediments, and additional new sand-deformation features formed by lava breakouts and sand diapir injections are presented.

Geologic map of the Fraser 7.5-minute quadrangle, Grand County, Colorado

USGS Publications Warehouse

Shroba, Ralph R.; Bryant, Bruce; Kellogg, Karl S.; Theobald, Paul K.; Brandt, Theodore R.

2010-01-01

The geologic map of the Fraser quadrangle, Grand County, Colo., portrays the geology along the western boundary of the Front Range and the eastern part of the Fraser basin near the towns of Fraser and Winter Park. The oldest rocks in the quadrangle include gneiss, schist, and plutonic rocks of Paleoproterozoic age that are intruded by younger plutonic rocks of Mesoproterozoic age. These basement rocks are exposed along the southern, eastern, and northern margins of the quadrangle. Fluvial claystone, mudstone, and sandstone of the Upper Jurassic Morrison Formation, and fluvial sandstone and conglomeratic sandstone of the Lower Cretaceous Dakota Group, overlie Proterozoic rocks in a small area near the southwest corner of the quadrangle. Oligocene rhyolite tuff is preserved in deep paleovalleys cut into Proterozoic rocks near the southeast corner of the quadrangle. Generally, weakly consolidated siltstone and minor unconsolidated sediments of the upper Oligocene to upper Miocene Troublesome Formation are preserved in the post-Laramide Fraser basin. Massive bedding and abundant silt suggest that loess or loess-rich alluvium is a major component of the siltstone in the Troublesome Formation. A small unnamed fault about one kilometer northeast of the town of Winter Park has the youngest known displacement in the quadrangle, displacing beds of the Troublesome Formation. Surficial deposits of Pleistocene and Holocene age are widespread in the Fraser quadrangle, particularly in major valleys and on slopes underlain by the Troublesome Formation. Deposits include glacial outwash and alluvium of non-glacial origin; mass-movement deposits transported by creep, debris flow, landsliding, and rockfall; pediment deposits; tills deposited during the Pinedale and Bull Lake glaciations; and sparse diamictons that may be pre-Bull Lake till or debris-flow deposits. Some of the oldest surficial deposits may be as old as Pliocene.

Mechanical Clogging Processes in Unconsolidated Porous Media Near Pumping Wells

NASA Astrophysics Data System (ADS)

de Zwart, B.; Schotting, R.; Hassanizadeh, M.

2003-12-01

In the Netherlands water supply companies produce over more than one billion cubic meters of drinking water every year. About 2500 water wells are used to pump up the groundwater from aquifers in the Dutch subsurface. More than 50% of these wells will encounter a number of technical problems during their lifetime. The main problem is the decrease in capacity due to well clogging. Clogging shows up after a number of operation years and results in extra, expensive cleaning operations and in early replacement of the pumping wells. This problem has been acknowledged by other industries, for example the metal, petroleum, beer industry and underground storage projects. Well clogging is the result of a number of interacting mechanisms creating a complex problem in the subsurface. In most clogging cases mechanical mechanisms are involved. A large number of studies have been performed to comprehend these processes. Investigations on mechanical processes are focused on transport of small particles through pores and deposition of particles due to physical or physical-chemical processes. After a period of deposition the particles plug the pores and decrease the permeability of the medium. Particle deposition in porous media is usually modelled using filtration theory. In order to get the dynamics of clogging this theory is not sufficient. The porous media is continuously altered due to deposition and mobilization. Therefore the capture characteristics will also continuously change and deposition rates will change in time. A new formula is derived to describe (re)mobilization of particles and allow changing deposition rates. This approach incorporates detachment and reattachment of deposited particles. This work also includes derivation of the filtration theory in radial coordinates. A comparison between the radial filtration theory and the new formula will be shown.

Mid-latitude trans-Pacific reconstructions and comparisons of coupled glacial/interglacial climate cycles based on soil stratigraphy of cover-beds

NASA Astrophysics Data System (ADS)

Alloway, B. V.; Almond, P. C.; Moreno, P. I.; Sagredo, E.; Kaplan, M. R.; Kubik, P. W.; Tonkin, P. J.

2018-06-01

South Westland, New Zealand, and southern Chile, are two narrow continental corridors effectively confined between the Pacific Ocean in the west and high mountain ranges in the east which impart significant influence over regional climate, vegetation and soils. In both these southern mid-latitude regions, evidence for extensive and repeated glaciations during cold phases of the Quaternary is manifested by arrays of successively older glacial drift deposits with corresponding outwash plain remnants. In South Westland, these variably aged glacial landforms are mantled by layered (multisequal) soils characterised by slow loess accretion and pedogenesis in an extreme leaching and weathering environment. These cover-bed successions have undergone repeated coupled phases of topdown and upbuilding soil formation that have been related to fluctuating cycles of interglacial/warm and glacial/cold climate during the Quaternary. In this study, we recognise multisequal soils overlying glacial landforms in southern continental Chile but, unlike the spodic (podzolic) soil sequences of South Westland, these are of dominantly volcanigenic (andic) provenance and are very similar to multisequal soils of andic provenance that predominate in, and adjacent to, areas of rhyolitic to andesitic volcanism in North Island, New Zealand. Here we develop a soil-stratigraphic model to explain the observed occurrence of multisequal soils mantling dominantly glacial landforms of southern continental Chile. Based on proxy data from southern Chile, we propose that persistent vegetation cover and high precipitation on the western side of the Andes, during colder-than-present episodes tended to suppress the widespread production of glacially-derived loessial materials despite the pervasive occurrence of glacial and glacio-fluvial deposits that have frequently inundated large tracts of this landscape during the Quaternary. Given the lack of loess cover-beds that have traditionally assisted in the relative dating of glacial episodes prior to the Late Quaternary, surface exposure dating techniques could provide another chronological alternative to address this issue. However, there have been two main obstacles to successfully apply this dating technique in Patagonia. First, minimum exposure ages may be obtained on moraines older than the last glacial cycle due to erosion, although dating outwash plains is more robust. Second, on the wet western side adjacent to the Andes, persistent vegetation cover during both glacial and post-glacial times, as well as widespread inundation by volcanic mass-flows, appear preventive. We make a case that soil genesis within this region appears to be dominated by a constant flux of intermittently erupted Andean-sourced tephra which has continued to upbuild soils at the ground surface separated by intervals where topdown weathering processes are intensified. As already demonstrated by New Zealand studies, multisequal soil successions have a clear implied connection to coupled glacial and interglacial climate cycles of the Quaternary. On this basis, similar sequences in northwest Patagonia provide a relatively untapped archive to enable Quaternary glacial and environmental changes in this pervasively glaciated volcanic region to be constructed.

Ground-water age, flow, and quality near a landfill, and changes in ground-water conditions from 1976 to 1996 in the Swinomish Indian Reservation, northwestern Washington

USGS Publications Warehouse

Thomas, B.E.; Cox, S.E.

1998-01-01

This report describes the results of two related studies: a study of ground-water age, flow, and quality near a landfill in the south-central part of the Swinomish Indian Reservation; and a study of changes in ground-water conditions for the entire reservation from 1976 to 1996. The Swinomish Indian Reservation is a 17-square-mile part of Fidalgo Island in northwestern Washington. The groundwater flow system in the reservation is probably independent of other flow systems in the area because it is almost completely surrounded by salt water. There has been increasing stress on the ground-water resources of the reservation because the population has almost tripled during the past 20 years, and 65 percent of the population obtain their domestic water supply from the local ground-water system. The Swinomish Tribe is concerned that increased pumping of ground water might have caused decreased ground-water discharge into streams, declines in ground-water levels, and seawater intrusion into the ground-water system. There is also concern that leachate from an inactive landfill containing mostly household and wood-processing wastes may be contaminating the ground water. The study area is underlain by unconsolidated glacial and interglacial deposits of Quaternary age that range from about 300 to 900 feet thick. Five hydrogeologic units have been defined in the unconsolidated deposits. From top to bottom, the hydrogeologic units are a till confining bed, an outwash aquifer, a clay confining bed, a sea-level aquifer, and an undifferentiated unit. The ground-water flow system of the reservation is similar to other island-type flow systems. Water enters the system through the water table as infiltration and percolation of precipitation (recharge), then the water flows downward and radially outward from the center of the island. At the outside edges of the system, ground water flows upward to discharge into the surrounding saltwater bodies. Average annual recharge is estimated to be about 3 inches, or 12 percent of the average annual precipitation. Ground water in the outwash aquifer near the landfill is estimated to be between 15 and 43 years old. Some deeper ground waters and ground water near the discharge areas close to the shoreline are older than 43 years. Analysis of water-quality data collected for this study and review of existing data indicate that material in the landfill has had no appreciable impact on the current quality of ground water outside of the landfill. The water quality of samples from seven wells near to and downgradient from the landfill appears to be similar to the ground-water quality throughout the entire study area. The high iron and manganese concentrations found in most of the samples from wells near the landfill are probably within the range of natural concentrations for the study area. Ground-water pumping during the past 20 years has not caused any large changes in ground-water discharge to streams, ground-water levels, or seawater intrusion into the ground-water system. Ground-water discharge into Snee-oosh Creek and Munks Creek had similar magnitudes in the summers of 1976 and 1996; flows in both creeks during those summers ranged from 0.07 t 0.15 cubic feet per second. Ground-water levels changed minimally between 1976 and 1996. The average water-level change for 20 wells with more than 10 years between measurements was -0.7 feet and the two largest waterlevel declines were 6 and 9 feet. No appreciable seawater intrusion was found in the ground water in 1996, and there was no significant increase in the extent of seawater intrusion from 1976 to 1996. Median chloride concentrations of water samples collected from wells were 22 milligrams per liter in 1976 and 18 milligrams per liter in 1996.

Stratigraphic evolution of the inner continental shelf in response to late Quaternary relative sea-level change, northwestern Gulf of Maine

USGS Publications Warehouse

Barnhardt, W.A.; Belknap, D.F.; Kelley, J.T.

1997-01-01

Accumulations of deltaic and littoral sediments on the inner continental shelf of Maine, Gulf of Maine, preserve a record of postglacial sea-level changes and shoreline migrations. The depositional response of coastal environments to a cycle of regression, lowstand, and transgression was examined with seismic-reflection profiles, vibracores, and radiocarbon dates collected from sediments at the mouths of the Kennebec and Penobscot Rivers. Sequence-stratigraphie analysis of these data reveals two distinctly different successions of late Quaternary deposits that represent end members in an evolutionary model for this glaciated coast. Seaward of the Kennebec River, coarsegrained shorelines with foreset beds occur at depths of 20-60 m and outline the lobate margin of the Kennebec River paleodelta, a complex, rock-framed accumulation of glaciomarine and deltaic sediments capped by estuarine and marine deposits. Sand derived from this system today supports large barrier spits and extensive salt marshes. In contrast, the mouth of the Penobscot River is characterized by thick deposits of glaciomarine mud overlain by marine mud of Holocene age, including gas-charged zones that have locally evolved into fields of pockmarks. The distinct lack of sand and gravel seaward of the Penobscot River and its abundance seaward of the Kennebec River probably reflect differences in sediment sources and the physiography of the two watersheds. The contrasting stratigraphie framework of these systems demonstrates the importance of understanding local and regional differences in sediment supply, sea-level change, bedrock structure, and exposure to waves and tides in order to model river-mouth deposition on glaciated coasts. Evolution of shelf deposits was largely controlled by relative sea level, which locally fell from a highstand (+60 to +70 m at 14 ka) contemporary with deglaciation to a lowstand (-55 m at 10.8 ka). The sea-level lowering was accompanied by fluvial incision of older deposits, producing a regressive, basal unconformity. Major rivers deposited abundant sediment over this surface. Sea level then rose at varying rates, extensively reworking formerly emergent parts of the shelf and producing a shoreface ravinement surface in areas exposed to waves. A tidal ravinement surface has developed in sheltered embayments where erosion is due mainly to tidal currents. Incised valleys in both settings preserve transgressive estuarine deposits that contain lagoonal bivalves and salt-marsh foraminifera at depths of 15-30 m. These deposits accumulated ca. 9.2-7.3 ka, locally a period of relatively slow sea-level rise.

High-Resolution Subsurface Imaging and Stratigraphy of Quaternary Deposits, Marapanim Estuary, Northern Brazil

NASA Astrophysics Data System (ADS)

Silva, C. A.; Souza Filho, P. M.; Gouvea Luiz, J.

2007-05-01

The Marapanim estuary is situated in the Para Coastal Plain, North Brazil. It is characterized by an embayed coastline developed on Neogene and Quaternary sediments of the Barreiras and Pos-Barreiras Group. This system is strongly influenced by macrotidal regimes with semidiurnal tides and by humid tropical climate conditions. The interpretation of GPR-reflections presented in this paper is based on correlation of the GPR signal with stratigraphic data acquired on the coastal plain through five cores that were taken along GPR survey lines from the recent deposits and outcrops observed along to the coastal area. The profiles were obtained using a Geophysical Survey Systems Inc., Model YR-2 GPR, with monostatic 700 MHz antenna that permitted to get records of subsurface deposits at 20m depth. Were collected 54 radar sections completing a total of 4.360m. The field data were analyzed using a RADAN software and applying different filters. The interpretation of radar facies following the principles of seismic stratigraphy that permitted analyze the sedimentary facies and facies architecture in order to understand the lithology, depositional environments and stratigraphic evolution of this sedimentary succession as well as to leading to a more precise stratigraphic framework for the Neogene to Quaternary deposits at Marapanim coastal plain. Facies characteristics and sedimentologic analysis (i.e., texture, composition and structure aspects) were investigated from five cores collected through a Rammkernsonde system. The locations were determined using a Global Positioning System. Remote sensing images (Landsat-7 ETM+ and RADARSAT-1 Wide) and SRTM elevation data were used to identify and define the distribution of the different morphologic units. The Coastal Plain extends west-east of the mouth of the Marapanim River, where were identified six morphologic units: paleodune, strand plain, recent coastal dune, macrotidal sandy beach, mangrove and salt marsh. The integration of GPR profiles and stratigraphy data allowed for the recognition of paleochannel geometry, with width of 150m and depth of 20m, developed on Barreiras Group, two discontinuity surfaces and three facies associations organized into sedimentary facies: (i) Tidal channel with mottled sand, Conglomerate with clay pebble and Ophiomorpha/linear Skolithos, channel-fill and tabular cross-bedding sand and sand/mud interlayer facies. (ii) Dune/interdune with wavy bedding and cross-bedding sand and planar bedding and tabular cross-bedding sand facies. (iii) infilled tidal channel with mottled sand, planar/flaser bedding sand, lenticular bedding clay and sand/mud interlayer facies. The present study demonstrates that some facies associations occur restricts to tidal paleochannels and shows features well preserved that are very important to reconstruction of the relative sea-level history in the Marapanim Estuary.

The interaction between surface processes and tectonics during the late Quaternary in the Middle Volturno River valley (southern Italy): new morpho-stratigraphic constraints from fluvial terraces

NASA Astrophysics Data System (ADS)

Amato, Vincenzo; Patrizio Ciro Aucelli, Pietro; Cesarano, Massimo; Filocamo, Francesca; Giralt, Santiago; Leone, Natalia; Rosskopf, Carmen Maria; Scorpio, Vittoria

2017-04-01

The Middle Volturno River valley is located in the inner part of the Southern Apennines of Italy, between the SW slope of the Matese Massif and the NE slopes of the Caserta mountains and is underlain by Meso-Cenozoic carbonate rocks and Miocene Flysch deposits. The study sector includes the lower Calore River valley and, below the Calore-Volturno confluence, the valley portion that extends until the Triflisco gorge, from Telese village to the Volturno dam. It is generally E-W, NW-SE and NE-SW elongated and characterized by rectilinear and meandering fluvial patterns. The main infilling of the two valley portions is locally preserved as remnants of fluvial terraces hanging over the local base level up to ca. 30-40 m. It is generally interfingered with and covered by several generations of alluvial fan and travertine deposits. New Ar/Ar datings on tephra layers interbedded in the oldest generations of the alluvial fan deposits and new U/Th datings on travertine deposits, allowed to constrain the main infilling to the late Middle and the early Upper Pleistocene. Both deposits are locally covered by the Campanian Ignimbrite Formation (CI, 39 ky BP) and are interested by high-angle faults generated during extensional tectonic phases that affected this sector of the Apennine chain since the Middle Pleistocene. Furthermore, the geomorphological analyses of aerial photos and topographic maps (1:5000 in scale) highlight the presence of a flight of fluvial terraces younger than the CI deposits that can be grouped into four orders. The stratigraphical data, based on field surveys and boreholes analyses, supported by new tephrostratigraphical constraints and literature data, allow to refer the older orders (I and II) to the late Upper Pleistocene. The III and IV orders, instead, can be referred to the early Holocene and historical times, respectively. These chronological constraints allow to hypothesize that the genesis of the I and II orders seem to be driven by late Quaternary tectonics, while climatic and land use changes played a key role for the formation of the younger orders.

An Assessment of the Suitability of Cone Penetration Testing in Identifying the Late Quaternary Successions Formed in Tide-dominated Tnvironments: A Case Study from the Eastern China Coastal Plain

NASA Astrophysics Data System (ADS)

Zhang, X.; Lin, C. M., Sr.; Dalrymple, R. W.; Gao, S., Sr.

2017-12-01

Cone penetration testing (CPT) has proved to be as an effective method for sedimentological purposes in wave-dominated coastal environments. This study, based upon interpretation of 500 CPTs, carried out in the late Quaternary Qiantang River incised-valley fill over the eastern China coastal plain, shows how CPTs can also be used for detailed facies characterization and identification of the key surfaces for sequence-stratigraphic interpretation in tide-dominated systems based upon estimation of three major parameters: cone-tip resistance (qc), sleeve friction (fs), and the ratio of fs and qc (FR). Plotting of qc versus FR, in combination with the CPT curve shape and the relative depth in profile, is adopted as the major tool. The lithologic character which is controlled mainly by sediment supply and dynamics, and post-depositional diagenesis is respected as the main factor affecting how well the CPT technique works. Within this particular tide-dominated environment, dominated by non-cohesive sand and silt, the accumulation of the materials from fluid muds is rare. As a result, the tidal-channel deposits exhibit the nature of coarse-grained deposits, different from that of the other mud-dominated facies associations. On the other hand, a distinct layer of fine-grained deposit at the base of the Holocene sequences was subjected to early diagenesis during the last glacial maximum and early transgression, to become uniformly hard and over-consolidated, geotechnically distinct from the overlying softer sediments. Besides, due to the different sediment dynamics, the tidal-flat and salt-marsh deposits exhibit a distinct geotechnical behavior with the offshore shallow marine muddy deposits. All the above mentioned situations provide the basis for the recognition of facies association and the correlated key surfaces, even for the mapping of the incised-valley boundary. As a consequence, the CPT method has a potential to be a very attractive alternative to economically less convenient methods for the geological mapping in the tide-dominated coastal plain areas.

Emergent littoral deposits in the eastern Canary Islands

NASA Astrophysics Data System (ADS)

Meco, Joaquin; Stearns, Charles E.

1981-03-01

K-Ar ages ( A. Abdel-Monem, P. D. Watkins, and P. W. Gast, 1971, American Journal of Science271, 490-521; this paper) and revised paleontological determinations ( J. Meco, 1977, "Los Strombus neogenos y cuatenarios del Atlantico euroafricano", Las Palmas, Ediciones del Excmo. Cabildo Insular de Gran Canaria) show that "Quaternary" ( R. Crofts, 1967, Quaternaria 9, 247-260; G. Lecointre, K. J. Tinkler, and G. Richards, 1967, Academy of Natural Science of Philadelphia Proceedings119, 325-344) littoral deposits on Lanzarote and Fuerteventura are early Pliocene and late Pleistocene. Early and middle Pleistocene strand lines are not represented. Early Pliocene littoral and marine deposits contain a characteristic fossil assemblage: Strombus coronatus, Nerità emiliana, Gryphaea virleti, Patella cf. intermedia, and Rothpletzia rudista. Differences in elevation record differential post-Pliocene uplift of the coastal platforms on which they lie. Late Pleistocene beach deposits at low elevations belong to two groups, an older with Strombus bubonius and a younger without. Differences in elevation of early Pliocene littoral deposits are reflected by differences in elevation of late Pleistocene beach deposits nearby.

A Procedure for Evaluation of Dust Potential in Desert Terrains,

DTIC Science & Technology

1985-01-01

Surficial Deposits, Silt, Clay, Sand. ABSTRACT ^•The evaluation of dust potential in hot deserts is based on the association of well de - fined dust...late Quaternary, which la heat understood, the efectiveaeas of climatic changes and the identification of euch •«ctuatioa in soils may he only roughly...ridges - ballenas . Nahal Roded, southern Arava Valley. „ ’ *m V J c^> ^ Mmmmmmmmmmmmmmmmw iu .......... . ^ ^^ - - _^^_^_m_ mm, PLATE S

Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands

USGS Publications Warehouse

Hein, J.R.; Gray, S.C.; Richmond, B.M.; White, L.D.

1992-01-01

The primary reef framework is considered to have been deposited during several highstands of sea level. Following partial to local recrystallization of the limestone, a signle episode of dolomitization occurred. Both tidal and thermal pumping drove large quantities of seawater through the porous rocks and perhaps maintained a wide mixing zone. However, the isotopic, geochemical and petrographic data do not clearly indicate the extent of seawater mixing. -from Authors

Preliminary Groundwater Assessment using Electrical Method at Quaternary Deposits Area

NASA Astrophysics Data System (ADS)

Hazreek, Z. A. M.; Raqib, A. G. A.; Aziman, M.; Azhar, A. T. S.; Khaidir, A. T. M.; Fairus, Y. M.; Rosli, S.; Fakhrurrazi, I. M.; Izzaty, R. A.

2017-08-01

Alternative water sources using groundwater has increasingly demand in recent years. In the past, proper and systematic study of groundwater potential was varies due to several constraints. Conventionally, tube well point was drilled based on subjective judgment of several parties which may lead to the uncertainties of the project success. Hence, this study performed an electrical method to investigate the groundwater potential at quaternary deposits area particularly using resistivity and induced polarization technique. Electrical method was performed using ABEM SAS4000 equipment based on pole dipole array and 2.5 m electrode spacing. Resistivity raw data was analyzed using RES2DINV software. It was found that groundwater was able to be detected based on resistivity and chargeability values which varied at 10 - 100 Ωm and 0 - 1 ms respectively. Moreover, suitable location of tube well was able to be proposed which located at 80 m from the first survey electrode in west direction. Verification of both electrical results with established references has shown some good agreement thus able to convince the result reliability. Hence, the establishment of electrical method in preliminary groundwater assessment was able to assist several parties in term groundwater prospective at study area which efficient in term of cost, time, data coverage and sustainability.

Taphonomic problems in reconstructing sea-level history from the late Quaternary marine terraces of Barbados

USGS Publications Warehouse

Muhs, Daniel; Simmons, Kathleen R.

2017-01-01

Although uranium series (U-series) ages of growth-position fossil corals are important to Quaternary sea-level history, coral clast reworking from storms can yield ages on a terrace dating to more than one high-sea stand, confounding interpretations of sea-level history. On northern Barbados, U-series ages corals from a thick storm deposit are not always younger with successively higher stratigraphic positions, but all date to the last interglacial period (~127 ka to ~112 ka), Marine Isotope Substage (MIS) 5.5. The storm deposit ages are consistent with the ages of growth-position corals found at the base of the section and at landward localities on this terrace. Thus, in this case, analysis of only a few corals would not have led to an error in interpreting sea-level history. In contrast, a notch cut into older Pleistocene limestone below the MIS 5.5 terrace contains corals that date to both MIS 5.5 (~125 ka) and MIS 5.3 (~108 ka). We infer that the notch formed during MIS 5.3 and the MIS 5.5 corals are reworked. Similar multiple ages of corals on terraces have been reported elsewhere on Barbados. Thus, care must be taken in interpreting U-series ages of corals that are reported without consideration of taphonomy.

Quaternary geology of Alameda County, and parts of Contra Costa, Santa Clara, San Mateo, San Francisco, Stanislaus, and San Joaquin counties, California: a digital database

USGS Publications Warehouse

Helley, E.J.; Graymer, R.W.

1997-01-01

Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map. The Quaternary deposits in Alameda County comprise three distinct depositional environments. One, forming a transgressive sequence of alluvial fan and fan-delta facies, is mapped in the western one-third of the county. The second, forming only alluvial fan facies, is mapped in the Livermore Valley and San Joaquin Valley in the eastern part of the county. The third, forming a combination of Eolian dune and estuarine facies, is restricted to the Alameda Island area in the northwestern corner of the county.

Quaternary Tectonic and Climatic Processes shaping the Central Andean hyperarid forearc (southern Peru)

NASA Astrophysics Data System (ADS)

Audin, Laurence; Benavente, Carlos; Zerathe, Swann; Saillard, Marianne; Hall, Sarah R.; Farber, Daniel L.

2015-04-01

Understanding the forearc structure and processes related to Quaternary evolution and uplift of the Western Andean Cordillera remains an outstanding scientific issue. Models of Andean Plateau evolution based on Tertiary volcanic stratigraphy since 5Ma suggest that the deformation was focused along the eastern margin of the plateau and that minimal uplift occurred along the Pacific margin. On the contrary, new tectonic data and Quaternary surface 10Be dating highlight the presence of recently active deformation, incision and alluvial processes within the upper Andean forearc together with a regional uplift of the coastal zone. Additionally, the high obliquity observed in the northern Arica Bend region makes it an ideal target to discuss whether partitioning of the oblique convergence is accommodated by the neotectonic features that dissect the Quaternary forearc. Our goals are both to decipher the Quaternary tectonic and climatic processes shaping the hyperarid forearc along strike and across strike. Finally, we aim to quantify the respective influence of these factors in the overall uplift of the Western Andes. Indeed, sequences of pediment surfaces, landslide products, paleolake deposits and marine terraces found along the oblique Peruvian margin are a unique set of datable markers that can be used to quantify the rates of Quaternary processes. In this study, we focus on the southern Peru hyperarid Atacama area where regional surfaces and tectonic markers (scarps, folds, temporary streams and paleolake levels offsets…) are well preserved for the Quaternary timescale. Numerous landsliding events align on the major fault segments and reflect Plio-Pleistocene climatic and tectonic activity together with filled and strath terraces. As the present day sea-level is one of the highest levels recorded for Quaternary time span, any emerged marine terrace is preserved by tectonic coastal uplift. In particular, the geomorphic and chronologic correlation between marine and continental planation surfaces or terraces permit to deduce net vertical rates and suggests that the along strike uplift affected not only the coast but also the overall ~50 km-wide forearc of the Western Andes. We produced a chronology of remnant low-relief surfaces and a new neotectonic map of the Central Andean forearc between ~14° and 18°S based on detailed field mapping and 10Be cosmogenic dating. We address 1) the spatial and temporal correlations of various markers, and 2) the correlation of the surface abandonment ages to various regional climatic events and 3) the description of neotectonic activity accommodating both uplift and partitioning. Multiple markers yield 10Be surface abandonment ages that spanning 35 ka to >2 Ma. Erosion surfaces >2 Ma yield low erosion rates of <0.1mm/yr. However uplift rates of ~0.1-1mm/yr and multiple surfaces dated at ~35 ka suggest that the hyperarid forearc landscape has been recently modified through Quaternary surface uplift and climatic events, contradicting the Miocene fossil forearc hypothesis. Generally, surface abandonment ages and activated landslides periods tend to correlate with cold wet periods preceding Plio Pleistocene deglaciation on the Altiplano. Finally, neotectonic oblique faults connecting at depth participate to topography building in the Arica Bend region and suggest that Quaternary surface abandonment is the result of both surface uplift in the forearc and specific high-discharge climate periods in the high Andes. Obtained Quaternary regional uplift rates and individual slip-rates suggest that the Andean forearc may accommodate as much as 0.5 to 1 mm/yr of regional uplift for the Quaternary time period.

Ancient and modern sites of natural CO2 leakage: Geochemistry and geochronology of Quaternary and modern travertine deposits on the Colorado Plateau, USA, and implications for CO2 sequestration

NASA Astrophysics Data System (ADS)

Priewisch, A.; Crossey, L. J.; Karlstrom, K. E.; McPherson, B. J.; Mozley, P.

2013-12-01

Travertine-precipitating springs and travertine deposits of the Colorado Plateau serve as natural analogues for evaluating potential leakage associated with geologic sequestration of carbon dioxide (CO2). Extensive Quaternary and modern travertine deposits occur along the Jemez lineament and Rio Grande rift in New Mexico and Arizona, and in the Paradox Basin in Utah, along the Little Grand Wash Fault and the Salt Wash Graben. These groundwater discharge deposits are interpreted to be sites of persistent and significant CO2 degassing along faults and above magmatic systems. Analysis of the geochemical and isotopic composition of U-series dated travertine deposits and modern travertine-precipitating waters allows evaluation of the flow paths of CO2-charged waters. Initial results from New Mexico and Arizona travertine deposits show characteristic rare earth element (REE) signatures for individual travertine deposits and yet generally overlap in concentrations of other trace elements such as Al, As, B, Ba, K, and Si. We report stable oxygen and carbon isotopes of the travertines in New Mexico, Arizona, and Utah. Different travertine deposits have different carbon-oxygen isotope variation patterns suggesting that these stable isotopes are tracers that have the ability to identify distinctive groundwater sources within and between spring groups based on the travertine record. Stable isotope analyses of travertine deposits in New Mexico and Arizona overlap substantially between deposits and cluster around -10‰ to -6‰ for δ18O and around 3.5‰ to 6.5‰ for δ13C. Travertine deposits in Utah show a distinctly different range of stable isotope values: δ18O values cluster around -14‰ to -10.5‰ and δ13C around 4.5‰ to 6.5‰. U-series dating of travertine deposits shows episodic travertine formation in New Mexico and Arizona over the last 700,000 years, and travertine accumulation over the last 400,000 years in Utah. We use U-series dating and volumetric analysis of the travertine deposits to estimate the minimum CO2 flux that was necessary to form the deposits and compare it to modern flux measurements in order to assess the extent of former and modern CO2 leakage. In addition, the thickness of dated travertine sections provides information about the longevity of travertine mound or spring systems that may be controlled by, e. g., sealing of faults, alternating wet/ dry paleohydrologic conditions, and/or rates of magmatic CO2 supply to springs. Understanding travertine deposition is important for the assessment of the long-term performance of a potential CO2 sequestration site because travertine deposits give insight into the complexities of CO2 pathways and leakage rates over timescales necessary for CO2 sequestration.

Erosion and deposition on the eastern margin of the Bermuda Rise in the late Quaternary

NASA Astrophysics Data System (ADS)

McCave, I. N.; Hollister, C. D.; Laine, E. P.; Lonsdale, P. F.; Richardson, M. J.

1982-05-01

A near-bottom survey has been made on the Eastward Scarp (32°50'N, 57°30'W) of the Bermuda Rise, which rises 1150 m above the 5500-m deep Sohm Abyssal Plain in the western North Atlantic. The survey reveals evidence of erosion and deposition at present and in the late Quaternary by the deeper levels of the westward flowing Gulf Stream Return Flow. Four distinct regions of increasing bed gradient show increasing sediment smoothing and scour in the transition from plateau to abyssal plain. Bedforms observed are current crescents, crag and tail, triangular ripples, elongate mounds, transverse mud ripples, lineations, and furrows ranging from 10 to 1 m or less in depth, decreasing generally with bed gradient. Measured near-bottom current speeds are up to 20 cm s -1. Temperature structure on the lower, steep, slopes suggests that detachment of bottom mixed layers may occur there. Extensive net erosion appears to be confined to the lower steep slopes of the scarp. Reflection profiles (4 kHz) show that there has been erosion in areas thinly draped with recent sediments and in areas that show development of small scarps. The distribution of subsurface acoustic characteristics of the region corresponds broadly to the areas characterized by bed gradient and distinct sedimentation conditions. Subsurface hyperbolae, possibly caused by buried furrows, show furrow persistence through several tens of metres of deposition. Erosion occurs up to the top of the scarp during episodes of presumed stronger currents, which may correspond with intensified circulation during glacials.

Analysis of soft-sediment deformation structures in Neogene fluvio-lacustrine deposits of Çaybağı Formation, Eastern Turkey

NASA Astrophysics Data System (ADS)

Koç Taşgin, Calibe; Türkmen, İbrahim

2009-06-01

During the Neogene, both strike-slip and extensional regimes coexisted in eastern Turkey and, a number of fault-bounded basins associated with the East Anatolian Fault System developed. The Çaybağı Formation (Late Miocene-Early Pliocene) deposited in one of these basins consists of fluvio-lacustrine deposits. Numerous soft-sediment deformation structures are encountered in this formation, particularly in conglomerates, medium- to coarse-grained tuffaceous sandstones and claystones: folded structures (slumps, convolute laminations, and simple recumbent folds), water-escape structures (intruded sands, internal cusps, interpenetrative cusps and sand volcanoes), and load structures (load casts, pseudonodules, flame structures, and pillow structures). These structures are produced by liquefaction and/or fluidization of the unconsolidated sediments during a seismic shock. Consequently, the existence of seismically-induced deformation structures in the Çaybağı Formation and the association with a Neogene intraformational unconformity, growth faults, and reverse faults in the Çaybağı basin attest to the tectonic activity in this area during the Late Miocene and Early Pliocene. The East Anatolian Fault System, in particular the Uluova fault zone, is the most probable seismogenic source. Earthquakes with a magnitude of over 5 in the Richter scale can be postulated.

Rock magnetic properties of sediments from Lake Sanabria and its catchment (NW Spain): paleoenvironmental implications

NASA Astrophysics Data System (ADS)

Larrasoaña, J. C.; Borruel, V.; Gómez-Paccard, M.; Rico, M.; Valero-Garces, B.; Moreno-Caballud, A.; Soto, R.

2013-12-01

Lake Sanabria is located in the NW Spanish mountains at 1000 m a.s.l., and constitutes the largest lake of glacial origin in the Iberian Peninsula. Here we present an environmental magnetic study of a Late Pleistocene-Holocene sediment core from Lake Sanabria and from different lithologies that crop out in its catchment, which includes Paleozoic plutonic, metamorphic and vulcanosedimentary rocks, and Quaternary deposits of glacial origin. This study was designed to complement sedimentologic and geochemical studies aimed at unraveling the climatic evolution of the NW Iberian Peninsula during the last deglaciation. Our results indicate that magnetite and pyrrhotite dominate the magnetic assemblage of both the sediments from the lower half of the studied sequence (25.6 - 13 cal kyr BP) deposited in a proglacial environment, and the Paleozoic rocks that make up most of the catchment of the lake. The occurrence of these minerals both in the catchment rocks and in the lake sediments indicates that sedimentation was then driven by the erosion of a glacial flour, which suffered minimal chemical transformation in response to a rapid and short routing to the lake. Sediments from the upper half of the studied sequence, accumulated after 12.4 cal kyr BP in a fluviolacustrine environment, contain magnetite and greigite. This points to a prominent role of post-depositional reductive dissolution, driven by a sharp increase in the accumulation of organic matter into the lake and the creation of anoxic conditions in the sediments, in shaping the magnetic assemblage of Holocene sediments. Pyrrhotite is stable under reducing conditions as opposed to magnetite, which is unstable. We therefore interpret that previous pedogenic processes occurred in the then deglaciated catchment of the lake were responsible for the oxidation of pyrrhotite and authigenic formation of magnetite, which survived subsequent reductive diagenesis given its initial larger concentrations. This interpretation is supported by the magnetic properties of Quaternary till sediments, which in some cases retain their original magnetic assemblage (magnetite and pyrrhotite) and in other cases include larger concentrations of magnetite. The Holocene sequence includes some discrete layers with a magnetic signature identical to that of the glacial flour. These layers are interpreted as being deposited during extreme runoff events that eroded Quaternary tills. The sharp change in magnetic properties observed in the lake sediments between 13 and 12.4 kyr BP supports the rapid deglaciation of the catchment of Lake Sanabria inferred in previous studies on the basis of sedimentological, geochemical and geomorphological data.

Quaternary geology of the Duck Hawk Bluffs, southwest Banks Island, Arctic Canada: a re-investigation of a critical terrestrial type locality for glacial and interglacial events bordering the Arctic Ocean

NASA Astrophysics Data System (ADS)

Evans, David J. A.; England, John H.; La Farge, Catherine; Coulthard, Roy D.; Lakeman, Thomas R.; Vaughan, Jessica M.

2014-05-01

Duck Hawk Bluffs, southwest Banks Island, is a primary section (8 km long and 60 m high) in the western Canadian Arctic Archipelago exposing a long record of Quaternary sedimentation adjacent to the Arctic Ocean. A reinvestigation of Duck Hawk Bluffs demonstrates that it is a previously unrecognized thrust-block moraine emplaced from the northeast by Laurentide ice. Previous stratigraphic models of Duck Hawk Bluffs reported a basal unit of preglacial fluvial sand and gravel (Beaufort Fm, forested Arctic), overlain by a succession of three glaciations and at least two interglacials. Our observations dismiss the occurrence of preglacial sediments and amalgamate the entire record into three glacial intervals and one prominent interglacial. The first glacigenic sedimentation is recorded by an ice-contact sandur containing redeposited allochthonous organics previously assigned to the Beaufort Fm. This is overlain by fine-grained sediments with ice wedge pseudomorphs and well-preserved bryophyte assemblages corresponding to an interglacial environment similar to modern. The second glacial interval is recorded by ice-proximal mass flows and marine rhythmites that were glacitectonized when Laurentide ice overrode the site from Amundsen Gulf to the south. Sediments of this interval have been reported to be magnetically reversed (>780 ka). The third interval of glacigenic sedimentation includes glacifluvial sand and gravel recording the arrival of Laurentide ice that overrode the site from the northeast (island interior) depositing a glacitectonite and constructing the thrust block moraine that comprises Duck Hawk Bluffs. Sediments of this interval have been reported to be magnetically normal (<780 ka). The glacitectonite contains a highly deformed melange of pre-existing sediments that were previously assigned to several formally named, marine and interglacial deposits resting in an undeformed sequence. In contrast, the tectonism associated with the thrust block moraine imparted pervasive deformation throughout all underlying units, highlighted by a previously unrecognized raft of Cretaceous bedrock. During this advance, Laurentide ice from the interior of Banks Island coalesced with an ice stream in Amundsen Gulf, depositing the interlobate Sachs Moraine that contains shells as young as ˜24 cal ka BP (Late Wisconsinan). During deglaciation, meltwater emanating from these separating ice lobes deposited outwash that extended to deglacial marine limit (11 m asl) along the west coast of Banks Island. Our new stratigraphic synthesis fundamentally revises and simplifies the record of past Quaternary environments preserved on southwest Banks Island, which serves as a key terrestrial archive for palaeoenvironmental change.

Paleohydrology of Late Quaternary floods in the Atacama Desert and their paleoclimate implications

NASA Astrophysics Data System (ADS)

Izquierdo, Tatiana; Abad, Manuel; Larrondo, Lidisy

2017-04-01

The Quaternary fluvial succession in the Copiapó Valley (northern Chile) have not been deeply studied even though they record a large amount of palaeoenvironmental and paleoclimate information in an area of great interest as the Atacama Desert. The city of Copiapó is located at the confluence between Quebrada Paipote (the most important tributary of the middle course) and Copiapó River which has been dry during the last decades due to the surface and groundwater exploitation for agricultural and mining activity purposes upstream. Despite that, historical chronicles describe numerous flooding events in the city during the last 400 years due to snowmelt during the summer months or unusually intense rains during any time of the year. The most recent event occurred on March 25, 2015 when 70% of the city flooded and more than 2.2 million m3 of sediment accumulated, mostly coming from Quebrada Paipote. The sedimentological analysis of the lower fluvial terrace of the Copiapó River has allowed us to identify a fluvial system that abruptly changes upward to paleoflood and aeolian deposits. The latter constitute the top of the lower fluvial terraces on which the city of Copiapó is built. The fluvial facies are mainly formed by imbricated to massive conglomerates and poorly sorted pebble and cobble sized conglomerates with laminated sandstones that probably were deposited in a braided gravel-bed river. The overlying deposits are constituted by several levels of massive sandy siltstones and well sorted fine sands of aeolian origin that are interpreted as overbank flood events linked to flooding episodes that alternate with long episodes of eolian dunes and sand sheets development that buried almost the entire alluvial plain. This sharp change in the facies association record an abrupt climate change in the southern Atacama Desert during the recent Quaternary towards more arid conditions, with a dominance of floods and aeolian morphogenesis over the typical fluvial system processes in a semiarid environment. Several authors have proposed two episodes of regional changes in groundwater recharge tied to long-term changes in precipitation in the Atacama Desert when wet periods were terminated by pronounced dry periods, from 9 to 8 ka and from 3 to 0 ka. The change recorded in the fluvial succession of the Copiapó Valley can probably be linked to one of this climate event what would be confirmed by means of the deposits dating. In addition, this will provide more information for the estimation of the recurrence period for this catastrophic processes.

Index of surface-water records, part 12, Pacific slope basins in Washington and upper Columbia River basin, to September 30, 1948

USGS Publications Warehouse

,

1949-01-01

The groundwater resources of Wood County, Wisconsin, are described. Groundwater is pumped only from wells drilled in Precambrian rock in the northern two-thirds of the county. The generally low permeability of this rock limits the availability of groundwater in this area. Saturated deposits of sand and gravel yield more than 500 gal/min to wells in the southern part of the county. Background groundwater quality and indicators of groundwater-quality problems, such as elevated concentrations of nitrate, chloride, hardness, and iron, are compared by aquifer for the entire county. An elevated concentration of iron is the major water quality problem in the county. Results of water quality analysis from observation wells drilled next to abandoned landfills throughout the county indicate that groundwater in the immediate vicinity of these landfills has been affected by leachate. The report includes maps of the thickness and saturated thickness of unconsolidated deposits, a water-table map, and tables of aquifer-production and well-production data from about 1,500 drillers ' well-construction reports. (USGS)

Rock magnetism and magnetostratigraphy of the loess-sol series of Ukraine (Roksolany, Boyanychi, and Korshev sections)

NASA Astrophysics Data System (ADS)

Bakhmutov, V. G.; Kazanskii, A. Yu.; Matasova, G. G.; Glavatskii, D. V.

2017-11-01

The results of the rock magnetic and paleomagnetic studies for the Quaternary loess-sol deposits of Ukraine are reported. The magnetic properties of the rocks composing the sections in the Pre-Black-Sea Depression (Roksolany) and Volyn Upland (Boyanychi and Korshev) are compared. Based on the highly precise measurements by modern instruments, the primary magnetization component is isolated in the rocks and its polarity is reliably determined in both the loess and soil horizons. The position of the Matuyama-Brunhes boundary in the Roksolany section is determined at a depth of 46.6 m at the contact of the Lubenskii and Martonoshskii soil horizons. This is consistent with the present-day notions of the group of Ukrainian scientists about the Quaternary stratigraphy of the south of Ukraine and inconsistent with the previous results that placed this boundary at a depth of 34 m in loesses above the PK7 level.

Occurrence and genesis of Quaternary microbialitic tufa at Hammam Al Ali, Oman

NASA Astrophysics Data System (ADS)

Khalaf, Fikry I.

2017-05-01

Remnants of late Quaternary microbialitic tufa occurs within a shallow depression in the Hammam Al Ali hot spring area, which is located approximately 14.5 km to the southwest of Muscat, Oman. The tufa precipitated from hot spring water supersaturated with respect to calcium carbonate and is mostly of a porous phytogenic type, with occasional detrital and stromatolitic types. Microscopic and nanoscopic examination revealed that the tufa deposits developed through two successive processes of calcite precipitation, biotic and abiotic, preceded by limited precipitation of unstable aragonite. It is suggested that biologically mediated precipitation results in the construction of incomplete skeletal calcite crystals. The latter provide a base for classical physiochemical precipitation and, eventually, the development of complete sparry calcite crystals. The initiation of dendritic calcite crystals in the stromatolitic tufa as incomplete biogenic skeletal crystals and their characteristic growth pattern indicates that the tufa represents a clear example of hot spring calcitic microbialite.