Isostatic gravity map of Yukon Flats, east-central Alaska

USGS Publications Warehouse

Morin, Robert L.

2002-01-01

The gravity data used to make this map were collected between 1959 and 1984. The data were collected by automobile, aircraft, and watercraft. Most of the data were collected as part of a U.S. Geological Survey (USGS) regional gravity data collection project. Some of the data were collected as part of other USGS local projects. One data set was collected by the NGS (National Geodetic Survey). This map ranges from 65° to 68° N latitude and 141° to 152° W longitude. The names of the 12 1:250,000-scale U.S. Geological Survey quadrangle maps that make up this map are labeled on the map. The western edge of the map is 1 degree of longitude east of the edge of the three most western quadrangles.

Geochemical evidence for a brooks range mineral belt, Alaska

USGS Publications Warehouse

Marsh, S.P.; Cathrall, J.B.

1981-01-01

Geochemical studies in the central Brooks Range, Alaska, delineate a regional, structurally controlled mineral belt in east-west-trending metamorphic rocks and adjacent metasedimentary rocks. The mineral belt extends eastward from the Ambler River quadrangle to the Chandalar and Philip Smith quadrangles, Alaska, from 147?? to 156??W. longitude, a distance of more than 375 km, and spans a width from 67?? to 69??N. latitude, a distance of more than 222 km. Within this belt are several occurrences of copper and molybdenum mineralization associated with meta-igneous, metasedimentary, and metavolcanic rocks; the geochemical study delineates target areas for additional occurrences. A total of 4677 stream-sediment and 2286 panned-concentrate samples were collected in the central Brooks Range, Alaska, from 1975 to 1979. The -80 mesh ( 2.86) nonmagnetic fraction of the panned concentrates from stream sediment were analyzed by semiquantitative spectrographic methods. Two geochemical suites were recognized in this investigation; a base-metal suite of copper-lead-zinc and a molybdenum suite of molybdenum-tin-tungsten. These suites suggest several types of mineralization within the metamorphic belt. Anomalies in molybdenum with associated Cu and W suggest a potential porphyry molybdenum system associated with meta-igneous rocks. This regional study indicates that areas of metaigneous rocks in the central metamorphic belt are target areas for potential mineralized porphyry systems and that areas of metavolcanic rocks are target areas for potential massive sulfide mineralization. ?? 1981.

Publications - PIR 2015-6 | Alaska Division of Geological & Geophysical

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content DGGS PIR 2015-6 Publication Details Title: Geologic map of the Talkeetna Mountains C-4 Quadrangle ., Freeman, L.K., and Lande, L.L., 2015, Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining Sheets Sheet 1 Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska

Emsian (late Early Devonian) sponges from west-central and south-central Alaska

USGS Publications Warehouse

Rigby, J.K.; Blodgett, R.B.; Anderson, N.K.

2009-01-01

Relatively common specimens of the hypercalcified agelasiid sponge Hormospongia labyrinthica Rigby and Blodgett, 1983 and specimens of associated species of Hormospongia have been previously reported from Emsian and Eifelian stratigraphic units at several localities in south-central and southeastern Alaska (Rigby and Blodgett, 1983). Those sponges were first described from the type section of the Eifelian Cheeneetnuk Limestone in the McGrath A-5 quadrangle. Since then several additional specimens of Hormospongia labyrinthica have also been collected from a new locality in the Talkeetna C-6 quadrangle in southcentral Alaska (Figs. 1, 2.1), and are documented here.

The Alaskan Mineral Resource Assessment Program; background information to accompany folio of geologic and mineral resource maps of the Circle quadrangle, Alaska

USGS Publications Warehouse

Foster, Helen Laura; Menzie, W.D.; Cady, J.W.; Simpson, S.L.; Aleinikoff, J.N.; Wilson, Frederic H.; Tripp, R.B.

1987-01-01

The geology, geochemistry, geophysics, and Landsat imagery of the Circle quadrangle were investigated by an interdisciplinary research team for the purpose of assessing the mineral potential of the area. The quadrangle covers approximately 15,765 km2 in east-central Alaska; most of it is included in the mountainous Yukon-Tanana Upland physiographic division, but the northernmost part is in the low-lying Yukon Flats section. The Circle mining district, in the east-central part of the quadrangle, has been a major producing area of placer gold since its discovery in 1893. For descriptive purposes, the Circle quadrangle is divided into three areas: the northwest Circle quadrangle, the area north of the Tintina fault zone, and the area south of the Tintina fault zone. The Tintina fault zone extends northwesterly through the northern part of the quadrangle. The northwest Circle quadrangle contains mostly folded and faulted, slightly metamorphosed sedimentary rocks that are intruded by Tertiary granitic plutons. In the northern part of the area north of the Tintina fault zone (Little Crazy Mountains and northern east Crazy Mountains), the rocks consist primarily of the gabbro and basalt of the Circle Volcanics and minor associated chert, graywacke, and limestone. Elsewhere in this area (south of the Circle Volcanics and in the western Crazy Mountains), the rocks are mostly slightly metamorphosed Paleozoic sedimentary rocks that have been folded and faulted. Rocks in the largest part of the quadrangle, the area south of the Tintina fault zone, consist largely of pelitic rocks that are regionally metamorphosed to greenschist and amphibolite facies. Felsic plutons, mostly Tertiary in age, occur throughout the area. The metamorphic rocks are separated from sedimentary rocks on the northwest by thrust faulting. The aeromagnetic and gravity data show clear differences between the areas north and south of the Tintina fault zone. The metamorphic terrane to the south has low overall gravity and local gravity lows over exposed granitic plutons. It is hypothesized that magnetic chlorite schist infolded with nonmagnetic quartzite and schist account for east-northeast-trending magnetic highs that approximately parallel the regional strike of the most prominent foliation in the metamorphic rocks. North of the Tintina fault zone, the Circle Volcanics are characterized by high gravity and east-west-trending magnetic highs. The Tintina fault zone has an intense magnetic high near the western margin of the Circle quadrangle overlying the magnetic granodiorite of the Victoria Mountain pluton. A magnetic high near Circle Hot Springs is less intense, but broader, and could reflect a buried magnetic pluton similar to that of the Victoria Mountain pluton. Computer-enhanced Landsat images of the Circle quadrangle show trends and patterns of concentrations of linear features. Features trending northeast-southwest predominate throughout the quadrangle; northwest-southeast-trending linear features are found mostly south of the Tintina fault zone. High concentrations of linear features were not found to correspond to areas of known mineralization in any consistent or significant way that could presently be used in locating areas of mineralization. Geochemical and mineralogical studies of stream sediment and heavy-mineral concentrates from the Circle quadrangle identify areas of anomalous concentrations of metallic elements, including gold, silver, tin, tungsten, lead, antimony, zinc, thorium, uranium, and beryllium. The data delineate areas of known mineral occurrences and areas that may contain undiscovered mineral resources. To date, placer gold has been the only significant metallic mineral resource from the Circle quadrangle, but the general geologic setting, especially the presence of post-orogenic plutons, is similar to that of regions that contain tin greisen deposits, tungsten skarn deposits, lode gold deposits in metasedimentary roc

Aeromagnetic survey of Howard Pass quadrangle and the East half of Misheguk Mountain quadrangle, Alaska—a Web site for the distribution of data

USGS Publications Warehouse

Brown, Philip J.

2009-01-01

U.S. Geological Survey Open-File-Report 2009-1256 is for the preliminary release of magnetic data (and associated contractor reports) for an airborne survey in the Brooks Range, northwest of Bettles, Alaska.

Publications - RI 2015-7 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS RI 2015-7 Publication Details Title: Surficial geology of the Tyonek area, south-central of the Tyonek area, south-central Tyonek Quadrangle, Alaska: Alaska Division of Geological &

Provenance and petrofacies, Upper Devonian sandstones, Philip Smith Mountains and Arctic quandrangles, Brooks Range, Alaska: Final report, Project No. 3

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

Anderson, A.V.; Coney, P.J.

1987-11-01

Late Devonian sandstone beds are exposed as allochthonous sequences that extend for over 1000 km along the east-west strike of the Brooks Range in northern Alaska. These horizons, at least in part, record Late Devonian tectonism and deposition along the southern margin of the Arctic Alaska block. This study identifies clastic petrofacies in the western Philip Smith Mountains and southern Arctic quadrangles and infers the composition of the source terrane. The paleogeography is not known and the original distribution of lithofacies is uncertain, owing to the extensive post-depositional tectonism. In the study area the sandstones are exposed along rugged mountainmore » tops and high ridges. Although exposures are excellent, access is often difficult. Samples were collected from exposures near the western end of the Chandalar Shelf, Atigun Pass, and the Atigun River valley in the Philip Smith Mountains quadrangle and from the Crow Nest Creek and Ottertail Creek areas in the Arctic quadrangle. 34 refs., 17 figs.« less

Gravity and Aeromagnetic Gradients within the Yukon-Tanana Upland, Black Mountain Tectonic Zone, Big Delta Quadrangle, east-central Alaska

USGS Publications Warehouse

Saltus, R.W.; Day, W.C.

2006-01-01

The Yukon-Tanana Upland is a complex composite assemblage of variably metamorphosed crystalline rocks with strong North American affinities. At the broadest scale, the Upland has a relatively neutral magnetic character. More detailed examination, however, reveals a fundamental northeast-southwest-trending magnetic gradient, representing a 20-nT step (as measured at a flight height of 300 m) with higher values to the northwest, that extends from the Denali fault to the Tintina fault and bisects the Upland. This newly recognized geophysical gradient is parallel to, but about 100 km east of, the Shaw Creek fault. The Shaw Creek fault is mapped as a major left-lateral, strike-slip fault, but does not coincide with a geophysical boundary. A gravity gradient coincides loosely with the southwestern half of the magnetic gradient. This gravity gradient is the eastern boundary of a 30-mGal residual gravity high that occupies much of the western and central portions of the Big Delta quadrangle. The adjacent lower gravity values to the east correlate, at least in part, with mapped post-metamorphic granitic rocks. Ground-based gravity and physical property measurements were made in the southeastern- most section of the Big Delta quadrangle in 2004 to investigate these geophysical features. Preliminary geophysical models suggest that the magnetic boundary is deeper and more fundamental than the gravity boundary. The two geophysical boundaries coincide in and around the Tibbs Creek region, an area of interest to mineral exploration. A newly mapped tectonic zone (the Black Mountain tectonic zone of O'Neill and others, 2005) correlates with the coincident geophysical boundaries.

Radiometric dates from Alaska: A 1975 compilation

USGS Publications Warehouse

Turner, D.L.; Grybeck, Donald; Wilson, Frederic H.

1975-01-01

The following table of radiometric dates from Alaska includes published material through 1972 as well as some selected later data. The table includes 726 mineral and whole-rock dates determined by the K-Ar, Rb-Sr, fission-track U-Pb, and Pb-alpha techniques.The data are organized in alphabetical order of the 1:250,000 scale quadrangles in which the dated rocks are located. The latitude and longitude of each sample are given. In addition, each sample is located on a 1:250,000 quadrangle map by a grid system. The initial point of the grid is taken as the southwest corner of the quadrangle and the location of the sample is measured in inches east and inches north from that corner, e.g., "156E 126N" indicated 15.6 inches east and 12.6 inches north of the southwest corner of the quadrangle. Zeroes in the location columns for some dates indicate that accurate locations are not available.Rock type, dating method, mineral dated, radiometric age, sample identification number, and reference are also listed where possible. Short comments, mostly geographic locality names, are given for some dates. These comments have been taken from the original references.Sample identification numbers beginning with "AA" or "BB" have been assigned arbitrarily in cases where sample numbers were not assigned in the original references. Abbreviations are explained in the appendix at the end of table 1.

Publications - RI 2005-1B | Alaska Division of Geological & Geophysical

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half of the Solomon C-5 Quadrangle, Seward Peninsula, Alaska Authors: Werdon, M.B., Newberry, R.J publication sales page for more information. Quadrangle(s): Solomon Bibliographic Reference Werdon, M.B area, northern half of the Solomon C-5 Quadrangle, Seward Peninsula, Alaska: Alaska Division of

Publications - RDF 2003-2 | Alaska Division of Geological & Geophysical

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geochemical data from rocks collected in the Big Delta Quadrangle, Alaska in 2002 Authors: Werdon, M.B . Quadrangle(s): Big Delta Bibliographic Reference Werdon, M.B., Newberry, R.J., Athey, J.E., Szumigala, D.J -element, and geochemical data from rocks collected in the Big Delta Quadrangle, Alaska in 2002: Alaska

Geologic strip map along the Hines Creek Fault showing evidence for Cenozoic displacement in the western Mount Hayes and northeastern Healy quadrangles, eastern Alaska Range, Alaska

USGS Publications Warehouse

Nokleberg, Warren J.; Aleinikoff, John N.; Bundtzen, Thomas K.; Hanshaw, Maiana N.

2013-01-01

Geologic mapping of the Hines Creek Fault and the adjacent Trident Glacier and McGinnis Glacier Faults to the north in the eastern Alaska Range, Alaska, reveals that these faults were active during the Cenozoic. Previously, the Hines Creek Fault, which is considered to be part of the strike-slip Denali Fault system (Ridgway and others, 2002; Nokleberg and Richter, 2007), was interpreted to have been welded shut during the intrusion of the Upper Cretaceous Buchanan Creek pluton (Wahrhaftig and others, 1975; Gilbert, 1977; Sherwood and Craddock, 1979; Csejtey and others, 1992). Our geologic mapping along the west- to west-northwest-striking Hines Creek Fault in the northeastern Healy quadrangle and central to northwestern Mount Hayes quadrangle reveals that (1) the Buchanan Creek pluton is truncated by the Hines Creek Fault and (2) a tectonic collage of fault-bounded slices of various granitic plutons, metagabbro, metabasalt, and sedimentary rock of the Pingston terrane occurs south of the Hines Creek Fault.

Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, Central Alaska

USGS Publications Warehouse

Reifenstuh, Rocky R.; Dover, James H.; Newberry, Rainer J.; Calutice, Karen H.; Liss, Shirley A.; Blodgett, Robert B.; Budtzen, Thomas K.; Weber, Florence R.

1997-01-01

This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed bedrock, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.

Publications - RI 2005-1A | Alaska Division of Geological & Geophysical

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the Solomon C-5 Quadrangle, Seward Peninsula, Alaska Authors: Werdon, M.B., Stevens, D.S.P., Newberry please see our publication sales page for more information. Quadrangle(s): Solomon Bibliographic , Geologic map of the Big Hurrah area, northern half of the Solomon C-5 Quadrangle, Seward Peninsula, Alaska

Publications - PIR 2001-3C | Alaska Division of Geological & Geophysical

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content DGGS PIR 2001-3C Publication Details Title: Surficial-geologic map of the Eagle A-2 Quadrangle publication sales page for more information. Quadrangle(s): Eagle Bibliographic Reference Pinney, D.S., 2001 , Surficial-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Alaska Division of

Geologic Map of the Yukon-Koyukuk Basin, Alaska

USGS Publications Warehouse

Patton, William W.; Wilson, Frederic H.; Labay, Keith A.; Shew, Nora B.

2009-01-01

This map and accompanying digital files represent part of a systematic effort to release geologic data for the United States in a uniform manner. All the geologic data in this series will be published as parts of the U.S. Geological Survey Data Series. The geologic data in this series have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The data are presented for use at a nominal scale of 1:500,000, although individual datasets may contain data suitable for use at larger scales. The metadata associated with each release will provide more detailed information on sources and appropriate scales for use. Associated attribute databases accompany the spatial database of the geology and are uniformly structured for ease in developing regional- and national-scale maps. The 1:500,000-scale geologic map of the Yukon-Koyukuk Basin, Alaska, covers more than 200,000 square kilometers of western Alaska or nearly 15 percent of the total land area of the state. It stretches from the Brooks Range on the north to the Kuskokwim River and lower reaches of the Yukon River on the south and from Kotzebue Sound, Seward Peninsula, and Norton Sound on the west to the Yukon-Tanana Uplands and Tanana-Kuskokwim Lowlands on the east. It includes not only the northern and central part of the basin, but also the lands that border the basin. The area is characterized by isolated clusters of hills and low mountain ranges separated by broad alluviated interior and coastal lowlands. Most of the lowlands, except those bordering Kotzebue Sound and Norton Sound, support a heavy vegetation cover. Exposures of bedrock are generally limited to rubble-strewn ridgetops and to cutbanks along the rivers. The map of the Yukon-Koyukuk Basin was prepared largely from geologic field data collected between 1953 and 1988 by the U.S. Geological Survey and published as 1:250,000-scale geologic quadrangle maps. Additional data for parts of the Wiseman, Ruby, Medfra, and Ophir quadrangles came from 1:63,360-scale quadrangle maps published by the Alaska Division of Geological and Geophysical Surveys. The map also incorporates some unpublished field data for the Ruby quadrangle collected by R.M. Chapman between 1944 and 1977 and for parts of the Tanana, Bettles, Norton Bay, and Candle quadrangles collected by W.W. Patton, Jr. and others between 1954 and 1985. Sources of geologic map data for each of the eighteen 1:250,000-scale quadrangles used in compiling this 1:500,000-scale map of the Yukon-Koyukuk Basin as well as sources of general geologic information pertaining to the entire map area are provided in the 'Sources of Information' section.

Publications - STATEMAP Project | Alaska Division of Geological &

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., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska , Engineering - geologic map, Alaska Highway corridor, Delta Junction to Dot Lake, Alaska: Alaska Division of geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska Division of Geological

Publications - GMC 417 | Alaska Division of Geological & Geophysical

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the Sun Prospect, Ambler Mining District, Survey Pass Quadrangle, Alaska Authors: ALS Minerals Sun Prospect, Ambler Mining District, Survey Pass Quadrangle, Alaska: Alaska Division of Geological

Publications - RI 2005-1D | Alaska Division of Geological & Geophysical

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content DGGS RI 2005-1D Publication Details Title: Geologic map of the Council Area, Solomon D-4 and publication sales page for more information. Quadrangle(s): Bendeleben; Solomon Bibliographic Reference Council Area, Solomon D-4 and Bendeleben A-4 quadrangles, Seward Peninsula, Alaska: Alaska Division of

Publications - PDF 98-37A v. 1.1 | Alaska Division of Geological &

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main content DGGS PDF 98-37A v. 1.1 Publication Details Title: Geologic map of the Tanana A-1 and A-2 ., 1998, Geologic map of the Tanana A-1 and A-2 quadrangles, central Alaska: Alaska Division of Geological & Other Oversized Sheets Maps & Other Oversized Sheets Sheet 1 Preliminary geologic map of the

Publications - RDF 2011-1 | Alaska Division of Geological & Geophysical

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Solomon Quadrangle, Seward Peninsula, Alaska Authors: Werdon, M.B. Publication Date: Mar 2011 Publisher or please see our publication sales page for more information. Quadrangle(s): Solomon Bibliographic Reference Werdon, M.B., 2011, Outcrop structural data collected in 2006 in the Solomon Quadrangle, Seward

Evidence for prolonged mid-Paleozoic plutonism and ages of crustal sources in east-central Alaska from SHRIMP U-Pb dating of syn-magmatic, inherited, and detrital zircon

USGS Publications Warehouse

Dusel-Bacon, C.; Williams, I.S.

2009-01-01

Sensitive high-resolution ion microprobe (SHRIMP) U-Pb analyses of igneous zircons from the Lake George assemblage in the eastern Yukon-Tanana Upland (Tanacross quadrangle) indicate both Late Devonian (???370 Ma) and Early Mississippian (???350 Ma) magmatic pulses. The zircons occur in four textural variants of granitic orthogneiss from a large area of muscovite-biotite augen gneiss. Granitic orthogneiss from the nearby Fiftymile batholith, which straddles the Alaska-Yukon border, yielded a similar range in zircon U-Pb ages, suggesting that both the Fiftymile batholith and the Tanacross orthogneiss body consist of multiple intrusions. We interpret the overall tectonic setting for the Late Devonian and Early Mississippian magmatism as an extending continental margin (broad back-arc region) inboard of a northeast-dipping (present coordinates) subduction zone. New SHRIMP U-Pb ages of inherited zircon cores in the Tanacross orthogneisses and of detrital zircons from quartzite from the Jarvis belt in the Alaska Range (Mount Hayes quadrangle) include major 2.0-1.7 Ga clusters and lesser 2.7-2.3 Ga clusters, with subordinate 3.2, 1.4, and 1.1 Ga clusters in some orthogneiss samples. For the most part, these inherited and core U-Pb ages match those of basement provinces of the western Canadian Shield and indicate widespread potential sources within western Laurentia for most grain populations; these ages also match the detrital zircon reference for the northern North American miogeocline and support a correlation between the two areas.

Publications - RDF 2007-4 | Alaska Division of Geological & Geophysical

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, and non-carbonate carbon data from rocks collected in the Solomon and Nome quadrangles, Seward information. Quadrangle(s): Nome; Solomon Bibliographic Reference Werdon, M.B., Newberry, R.J., Szumigala, D.J -carbonate carbon data from rocks collected in the Solomon and Nome quadrangles, Seward Peninsula, Alaska in

Publications - PIR 2002-1A | Alaska Division of Geological & Geophysical

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content DGGS PIR 2002-1A Publication Details Title: Geologic map of the Eagle A-1 Quadrangle, Fortymile publication sales page for more information. Quadrangle(s): Eagle Bibliographic Reference Szumigala, D.J ., 2002, Geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Alaska Division of

Publications - GMC 411 | Alaska Division of Geological & Geophysical

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outcrop samples from the 2001 DGGS Salcha River-Pogo project, Big Delta Quadrangle, Alaska Authors . Quadrangle(s): Big Delta Bibliographic Reference Newberry, R.J., 2012, Whole-rock and trace element analyses of two amphibolite outcrop samples from the 2001 DGGS Salcha River-Pogo project, Big Delta Quadrangle

Geologic map of the Tuba City 30' x 60' quadrangle, Coconino County, northern Arizona

USGS Publications Warehouse

Billingsley, George H.; Stoffer, Philip W.; Priest, Susan S.

2012-01-01

The Tuba City 30’ x 60’ quadrangle encompasses approximately 5,018 km² (1,920 mi²) within Coconino County, northern Arizona. It is characterized by nearly flat lying to gently dipping sequences of Paleozoic and Mesozoic strata that overly tilted Precambrian strata or metasedimentary and igneous rocks that are exposed at the bottom of Grand Canyon. The Paleozoic rock sequences from Cambrian to Permian age are exposed in the walls of Grand Canyon, Marble Canyon, and Little Colorado River Gorge. Mesozoic sedimentary rocks are exposed in the eastern half of the quadrangle where resistant sandstone units form cliffs, escarpments, mesas, and local plateaus. A few Miocene volcanic dikes intrude Mesozoic rocks southwest, northwest, and northeast of Tuba City, and Pleistocene volcanic rocks representing the northernmost extent of the San Francisco Volcanic Field are present at the south-central edge of the quadrangle. Quaternary deposits mantle much of the Mesozoic rocks in the eastern half of the quadrangle and are sparsely scattered in the western half. Principal folds are the north-south-trending, east-dipping Echo Cliffs Monocline and the East Kaibab Monocline. The East Kaibab Monocline elevates the Kaibab, Walhalla, and Coconino Plateaus and parts of Grand Canyon. Grand Canyon erosion has exposed the Butte Fault beneath the east Kaibab Monocline, providing a window into the structural complexity of monoclines in this part of the Colorado Plateau. Rocks of Permian and Triassic age form the surface bedrock of Marble Plateau and House Rock Valley between the East Kaibab and Echo Cliffs Monoclines. The Echo Cliffs Monocline forms a structural boundary between the Marble Plateau to the west and the Kaibito and Moenkopi Plateaus to the east. Jurassic rocks of the Kaibito and Moenkopi Plateaus are largely mantled by extensive eolian sand deposits. A small part of the northeast-dipping Red Lake Monocline is present in the northeast corner of the quadrangle. A broad and gentle elongated anticline, the Limestone Ridge Anticline, forms the crest of Marble Plateau. Here, Paleozoic and Mesozoic strata generally dip less than 1° to 2° in all directions from a central high area along Limestone Ridge north of Bodaway Mesa and east of Cedar Ridge and The Gap. The Limestone Ridge Anticline plunges gently southeast toward the Painted Desert at the south edge of the quadrangle and northward toward Lees Ferry, Arizona, at the north-central edge of the quadrangle. The Tuba City Syncline is a very broad northwest-southeast-oriented-synclinal downwarp that parallels the Echo Cliffs Monocline north of Tuba City. The Preston Mesa Anticline is a small fold present on Kaibito Plateau north of Tuba City.

Publications - PIR 2001-3B | Alaska Division of Geological & Geophysical

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content DGGS PIR 2001-3B Publication Details Title: Bedrock geologic map of the Eagle A-2 Quadrangle more information. Quadrangle(s): Eagle Bibliographic Reference Werdon, M.B., Newberry, R.J., and Szumigala, D.J., 2001, Bedrock geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska

Publications - RDF 2002-3 | Alaska Division of Geological & Geophysical

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geochemical data from the rocks collected in the Big Delta Quadrangle, Alaska in 2001 Authors: Athey, J.E or please see our publication sales page for more information. Quadrangle(s): Big Delta Bibliographic , minor-oxide, trace-element, and geochemical data from the rocks collected in the Big Delta Quadrangle

Geologic map of the Seldovia quadrangle, south-central Alaska

USGS Publications Warehouse

Bradley, Dwight C.; Kusky, Timothy M.; Haeussler, Peter J.; Karl, Susan M.; Donley, D. Thomas

1999-01-01

This is a 1:250,000-scale map of the bedrock geology of the Seldovia quadrangle, south-central Alaska. The map area covers the southwestern end of the Kenai Peninsula, including the Kenai Lowlands and Kenai Mountains, on either side of Kachemak Bay. The waters of Cook Inlet cover roughly half of the map area, and a part of the Alaska Peninsula near Iliamna Volcano lies in the extreme northwest corner of the map. The bedrock geology is based on new reconnaissance field work by the U.S. Geological Survey during parts of the 1988-1993 field seasons, and on previous mapping from a number of sources. The new mapping focused on the previously little-known Chugach accretionary complex in the Kenai Mountains. Important new findings include the recognition of mappable subdivisions of the McHugh Complex (a subduction melange of mostly Mesozoic protoliths), more accurate placement of the thrust contact between the McHugh Complex and Valdez Group (Upper Cretaceous trench turbidites), and the recognition of several new near-trench plutons of early Tertiary age.

Publications - PIR 2008-3B | Alaska Division of Geological & Geophysical

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, Delta Junction to Dot Lake, Alaska Authors: Reger, R.D., and Solie, D.N. Publication Date: Dec 2008 : Download below or please see our publication sales page for more information. Quadrangle(s): Big Delta , Alaska Highway corridor, Delta Junction to Dot Lake, Alaska: Alaska Division of Geological &

Publications - GMC 336 | Alaska Division of Geological & Geophysical

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Oil Company OCS Y-0197-1 (Tern Island #3) at the Alaska GMC Authors: Shell Oil Company, and Alaska information. Quadrangle(s): Alaska Statewide Bibliographic Reference Shell Oil Company, and Alaska Geological Materials Center, 2006, Core Photographs (12915'-13361.5') dated June 2003 of the Shell Oil Company OCS Y

Publications - RDF 2015-4 | Alaska Division of Geological & Geophysical

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, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska publication sales page for more information. Quadrangle(s): Bendeleben; Candle; Kotzebue; Solomon drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon

Hydrologic overlay maps of the Cape Canaveral Quadrangle, Florida

USGS Publications Warehouse

Frazee, James M.; Laughlin, Charles P.

1979-01-01

Brevard County is an area of some 1,300 square miles located on the east coast of central Florida.  The Cape Canaveral quadrangle, in central Brevard, includes part of the Merritt Island National Wildlife Refuge, John F. Kennedy Space Center (NASA), and Cape Canaveral Air Force Station.  The eastern part of the quadrangle is occupied by the Atlantic Ocean and the western part by estuarine waters of the Banana River.  Topography is characterized by numerous elongate sand dumes, with altitudes up to 10 feet or greater, which roughly parallel the estuary and ocean.

Geologic and Fossil Locality Maps of the West-Central Part of the Howard Pass Quadrangle and Part of the Adjacent Misheguk Mountain Quadrangle, Western Brooks Range, Alaska

USGS Publications Warehouse

Dover, James H.; Tailleur, Irvin L.; Dumoulin, Julie A.

2004-01-01

The map depicts the field distribution and contact relations between stratigraphic units, the tectonic relations between major stratigraphic sequences, and the detailed internal structure of these sequences. The stratigraphic sequences formed in a variety of continental margin depositional environments, and subsequently underwent a complexde formational history of imbricate thrust faulting and folding. A compilation of micro and macro fossil identifications is included in this data set.

Publications - RI 2005-1C | Alaska Division of Geological & Geophysical

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half of the Solomon C-5 Quadrangle, Seward Peninsula, Alaska Authors: Stevens, D.S.P. Publication Date ): Solomon Bibliographic Reference Stevens, D.S.P., 2005, Surficial geologic map of the Big Hurrah area , northern half of the Solomon C-5 Quadrangle, Seward Peninsula, Alaska: Alaska Division of Geological &

Publications - RI 2004-1C | Alaska Division of Geological & Geophysical

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, Big Delta Quadrangle, Alaska Authors: Reger, R.D., Burns, P.C., and Staft, L.A. Publication Date: Dec Delta Bibliographic Reference Reger, R.D., Burns, P.C., and Staft, L.A., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska Division of Geological &

Geologic map of the Nelson quadrangle, Lewis and Clark County, Montana

USGS Publications Warehouse

Reynolds, Mitchell W.; Hays, William H.

2003-01-01

The geologic map of the Nelson quadrangle, scale 1:24,000, was prepared as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of an area in the geologically complex southern part of the Montana disturbed belt. In the Nelson area, rocks ranging in age from Middle Proterozoic through Cretaceous are exposed on three major thrust plates in which rocks have been telescoped eastward. Rocks within the thrust plates are folded and broken by thrust faults of smaller displacement than the major bounding thrust faults. Middle and Late Tertiary sedimentary and volcaniclastic rocks unconformably overlie the pre-Tertiary rocks. A major normal fault displaces rocks of the western half of the quadrangle down on the west with respect to strata of the eastern part. Alluvial and terrace gravels and local landslide deposits are present in valley bottoms and on canyon walls in the deeply dissected terrain. Different stratigraphic successions are exposed at different structural levels across the quadrangle. In the northeastern part, strata of the Middle Cambrian Flathead Sandstone, Wolsey Shale, and Meagher Limestone, the Middle and Upper Cambrian Pilgrim Formation and Park Shale undivided, the Devonian Maywood, Jefferson, and lower part of the Three Forks Formation, and Lower and Upper Mississippian rocks assigned to the upper part of the Three Forks Formation and the overlying Lodgepole and Mission Canyon Limestones are complexly folded and faulted. These deformed strata are overlain structurally in the east-central part of the quadrangle by a succession of strata including the Middle Proterozoic Greyson Formation and the Paleozoic succession from the Flathead Sandstone upward through the Lodgepole Limestone. In the east-central area, the Flathead Sandstone rests unconformably on the middle part of the Greyson Formation. The north edge, northwest quarter, and south half of the quadrangle are underlain by a succession of rocks that includes not only strata equivalent to those of the remainder of the quadrangle, but also the Middle Proterozoic Newland, Greyson, and Spokane Formations, Pennsylvanian and Upper Mississippian Amsden Formation and Big Snowy Group undivided, the Permian and Pennsylvanian Phosphoria and Quadrant Formations undivided, the Jurassic Ellis Group and Lower Cretaceous Kootenai Formation. Hornblende diorite sills and irregular bodies of probable Late Cretaceous age intrude Middle Proterozoic, Cambrian and Devonian strata. No equivalent intrusive rocks are present in structurally underlying successions of strata. In this main part of the quadrangle, the Flathead Sandstone cuts unconformably downward from south to north across the Spokane Formation into the upper middle part of the Greyson Formation. Tertiary (Miocene?) strata including sandstone, pebble and cobble conglomerate, and vitric crystal tuff underlie, but are poorly exposed, in the southeastern part of the quadrangle where they are overlain by late Tertiary and Quaternary gravel. The structural complexity of the quadrangle decreases from northeast to southwest across the quadrangle. At the lowest structural level (Avalanche Butte thrust plate) exposed in the canyon of Beaver Creek, lower and middle Paleozoic rocks are folded in northwest-trending east-inclined disharmonic anticlines and synclines that are overlain by recumbently folded and thrust faulted Devonian and Mississippian rocks. The Mississippian strata are imbricated adjacent to the recumbent folds. In the east-central part of the quadrangle, a structurally overlying thrust plate, likely equivalent to the Hogback Mountain thrust plate of the Hogback Mountain quadrangle adjacent to the east (Reynolds, 20xx), juxtaposes recumbently folded Middle Proterozoic and unconformably overlying lower Paleozoic rocks on the complexly folded and faulted rocks of the Avalanche Butte thrust plate. The highest structural plate, bounded below

Publications - AR 2015 | Alaska Division of Geological & Geophysical

Science.gov Websites

Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic publication sales page for more information. Quadrangle(s): Alaska General Bibliographic Reference DGGS Staff

Publications - GMC 402 | Alaska Division of Geological & Geophysical

Science.gov Websites

Authors: Full Metal Minerals Publication Date: Aug 2012 Publisher: Alaska Division of Geological & information. Quadrangle(s): Talkeetna Mountains Bibliographic Reference Full Metal Minerals, 2012, Borehole

Publications - GMC 381 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 381 Publication Details Title: 1974 summary report of exploration activities, Orange Hill information. Quadrangle(s): Nabesna Bibliographic Reference Trautwein, C.M., 2010, 1974 summary report of exploration activities, Orange Hill, Alaska: Alaska Division of Geological & Geophysical Surveys Geologic

Reconnaissance exploration geochemistry in the central Brooks Range, northern Alaska: Implications for exploration of sediment-hosted zinc-lead-silver deposits

USGS Publications Warehouse

Kelley, K.D.; Kelley, D.L.

1992-01-01

A reconnaissance geochemical survey was conducted in the southern Killik River quadrangle, central Brooks Range, northern Alaska. The Brooks Range lies within the zone of continuous permafrost which may partially inhibit chemical weathering and oxidation. The minus 30-mesh and nonmagnetic heavy-mineral concentrate fractions of sediment samples were chosen as the sample media for the survey so that mechanical rather than chemical dispersion patterns would be enhanced. A total of 263 sites were sampled within the southern half of the Killik River quadrangle at an average sample density of approximately one sample per 12 km2. All samples were submitted for multi-element analyses. In the western and central Brooks Range, several known sediment-hosted Zn-Pb-Ag(-Ba) deposits occur within a belt of Paleozoic rocks of the Endicott Mountains allochthon. Exploration for this type of deposit in the Brook Range is difficult, due to the inherently high background values for Ba, Zn and Pb in shale and the common occurrence of metamorphic quartz-calcite veins, many of which contain traces of sulfide minerals. Stream sediments derived from these sources produce numerous geochemical anomalies which are not necessarily associated with significant mineralization. R-mode factor analysis provides a means of distinguishing between element associations related to lithology and those related to possible mineralization. Factor analysis applied to the multi-element data from the southern Killik River quadrangle resulted in the discovery of two additional Zn-Pb-Ag mineral occurrences of considerable areal extent which are 80-100 km east of any previously known deposit. These have been informally named the Kady and Vidlee. Several lithogeochemical element associations, or factors, and three factors which represent sulfide mineralization were identified: Ag-Pb-Zn (galena and sphalerite) and Fe-Ni-Co-Cu (pyrite ?? chalcopyrite) in the concentrate samples and Cd-Zn-Pb-As-Mn in the sediment samples. The distribution of high scores for each individual mineralization factor outlined several relatively large (200-250 km2) geochemically favorable areas. When the distribution of high scores for all three factors were superimposed, samples characterized by high scores for one or both of the concentrate mineralization factors and the mineralization factor in sediments define basin areas of approximately 48 and 64 km2 surrounding Kady and Vidlee, respectively. ?? 1992.

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.

Publications - PIR 2001-5 | Alaska Division of Geological & Geophysical

Science.gov Websites

Delta B-2 and B-3 quadrangles, Alaska Authors: Werdon, M.B., Newberry, R.J., Szumigala, D.J., and Burns information. Quadrangle(s): Big Delta Bibliographic Reference Werdon, M.B., Newberry, R.J., Szumigala, D.J ., and Burns, L.E., 2001, Reconnaissance bedrock geology of the Pogo area, Big Delta B-2 and B-3

Publications - RI 2004-1B | Alaska Division of Geological & Geophysical

Science.gov Websites

Delta Quadrangle, Alaska Authors: Werdon, M.B., Newberry, R.J., Athey, J.E., and Szumigala, D.J page for more information. Quadrangle(s): Big Delta Bibliographic Reference Werdon, M.B., Newberry, R.J ., Athey, J.E., and Szumigala, D.J., 2004, Bedrock geologic map of the Salcha River-Pogo area, Big Delta

Publications - GMC 332 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 332 Publication Details Title: X-Ray Diffraction analysis and flow testing of Hemlock information. Quadrangle(s): Alaska Statewide Bibliographic Reference BJ Services Company , 2006, X-Ray

Aeroradioactivity Survey and Areal Geology of Parts of East-Central New York and West-Central New England (ARMS-I)

DTIC Science & Technology

1964-10-01

27. J. A. MacFadyen, Jr., The Geology of the Bennington Area Vermont , Vermont Geol. Survey, Bull. No. 7, 71 pp. (1956). 28. M. P. Billings, J. B...14 3. Aeroradioactivity Profile in the Keene and Brattleboro Quadrangles, New Hampshire and Vermont , Showing Relationship to Bedrock Geology and...Quadrangles, New Hampshire and Vermont , Showing Radioactivity Units, Geology , and Flight Lines . 20 4b. Aeroradioactivity Profiles along Flight Lines 178

Publications - PIR 2001-3A | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PIR 2001-3A Publication Details Title: Geologic map of the Eagle A-2 Quadrangle, Fortymile ): Eagle Bibliographic Reference Werdon, M.B., Newberry, R.J., Szumigala, D.J., and Pinney, D.S., 2001 , Geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Alaska Division of Geological

Geologic Map of the Utukok River Quadrangle, Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

2006-01-01

This map is a product of the USGS Digital Geologic Maps of Northern Alaska project, which captures in digital format quadrangles across the entire width of northern Alaska. Sources include geologic maps previously published in hardcopy format and recent updates and revisions based on field mapping by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey. Individual quadrangles are digitized at either 1:125,000 or 1:250,000 depending on the resolution of source maps. The project objective is to produce a set of digital geologic maps with uniform stratigraphic nomenclature and structural annotation, and publish those maps electronically.

Stream-sediment samples reanalyzed for major, rare earth, and trace elements from seven 1:250,000-scale quadrangles, south-central Alaska, 2007-09

USGS Publications Warehouse

Gamble, Bruce M.; Bailey, Elizabeth A.; Shew, Nora B.; Labay, Keith A.; Schmidt, Jeanine M.; O'Leary, Richard M.; Detra, David E.

2010-01-01

During the 1960s through the 1980s, the U.S. Geological Survey conducted reconnaissance geochemical surveys of drainage basins throughout most of the Iliamna, Lake Clark, Lime Hills, and Talkeetna 1:250,000-scale quadrangles and parts of the McGrath, Seldovia, and Tyonek 1:250,000-scale quadrangles in Alaska. These geochemical surveys provide data necessary to assess the potential for undiscovered mineral resources and provide data that may be used to determine regional-scale element baselines. This report provides new data for 1,075 of the previously collected stream-sediment samples. The new analyses include a broader spectrum of elements and provide data that are more precise than the original analyses. All samples were analyzed for arsenic by hydride generation atomic absorption spectrometry, for gold, palladium, and platinum by inductively coupled plasma-mass spectrometry after lead button fire assay separation, and for a suite of 55 major, rare earth, and trace elements by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry after sodium peroxide sinter at 450 degrees Celsius.

Reconnaissance geology of the Jabal Dalfa Quadrangle, sheet 21/43 C, Kingdom of Saudi Arabia

USGS Publications Warehouse

Greene, Robert C.

1983-01-01

The Jabal Dalfa quadrangle (sheet 21/43 C) is part of the Najd province in west-central Saudi Arabia. The quadrangle is mostly a plain, tilted gently northeastward, but local inselbergs and two areas of dissected uplands rise as much as 200 m above the plain. Wadi Bishah and Wadi Ranyah terminate in the quadrangle. The quadrangle is underlain by Precambrian metavolcanic, metasedimentary, and plutonic rocks. The gneiss outcrops in the northeast and east-central parts of the quadrangle are apparently the oldest rocks. After they were emplaced, a wide variety of metavolcanic and metasedimentary rocks were deposited at Jabal Dalfa and Umm Shat, and in the northeast part of the quadrangle as the Arfan formation. Subsequently, granite gneiss was emplaced in the west part of the quadrangle and intruded by gabbro. Metabasalt and meta-andesite were extruded in a wide north-trending belt through the middle of the quadrangle and at Jabal Silli. Intrusion of small bodies of granitic rocks and Najd faulting conclude the Precambrian history of the area. Surficial deposits include sand and gravel covering the plains, alluvial fans, and voluminous dune sands. In the southeast part of the quadrangle, the layered rocks strike north and dip steeply. They are oriented parallel to the Nabitah fault zone. In the northeast and east-central parts of the quadrangle, layered rocks and gneiss are sheared into slices by the southernmost faults of the major Najd fault zone. Bedding and foliation in these slices strike northwest, parallel to the faults. Gneiss in the west part of the quadrangle also strikes northwest, and dips steeply to vertically; layered rocks underlying Jabal Silli strike northeast. Layered metamorphic rocks in the Jabal Dalfa quadrangle are mostly in the greenschist facies. Projection of data from other quadrangles suggests that the oldest gneiss is about 780 Ma old and the Arfan formation, Umm Shat, and Jabal Dalfa layered rocks are about 775 to 745 Ma old. The gneiss of Shaib Hadhaq is probably about 720 Ma old, the gabbro is 640 to 625 Ma old, and the granite is about 600 Ma old. The airborne magnetometer survey suggests that considerable additional gabbro underlies the west part of the quadrangle. Concealed serpentinite bodies, particularly in the Nabitah fault zone, are also suggested. Elongate anomalies and linear gradients indicate that the northeast part of the quadrangle is probably part of the Najd fault zone. A number of gold-bearing quartz veins in the quadrangle were mined in ancient times, and on, at Jabal Umm Matirah has been drilled and found to be uneconomic. A nickel-copper prospect has proved uneconomic. geochemical survey for additional deposits of metals was completed in 1982.

Geologic map of the Mead quadrangle (V-21), Venus

USGS Publications Warehouse

Campbell, Bruce A.; Clark, David A.

2006-01-01

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the Venusian atmosphere on October 12, 1994. Magellan Mission objectives included (1) improving the knowledge of the geological processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving the knowledge of the geophysics of Venus by analysis of Venusian gravity. The Mead quadrangle (V-21) of Venus is bounded by lat 0 deg and 25 deg N., long 30 deg and 60 deg E. This quadrangle is one of 62 covering Venus at 1:5,000,000 scale. Named for the largest crater on Venus, the quadrangle is dominated by effusive volcanic deposits associated with five major coronae in eastern Eistla Regio (Didilia, Pavlova, Calakomana, Isong, and Ninmah), corona-like tectonic features, and Disani Corona. The southern extremity of Bell Regio, marked by lava flows from Nyx Mons, north of the map area, forms the north-central part of the quadrangle. The shield volcanoes Kali, Dzalarhons, and Ptesanwi Montes lie south and southwest of the large corona-related flow field. Lava flows from sources east of Mead crater flood low-lying areas along the east edge of the quadrangle.

Geology of the Lachesis Tessera Quadrangle (V-18), Venus

NASA Technical Reports Server (NTRS)

McGowan, Eileen M.; McGill, George G.

2010-01-01

The Lachesis Tessera Quadrangle (V-18) lies between 25deg and 50deg north, 300deg and 330deg east. Most of the quadrangle consists of "regional plains" (1) of Sedna and Guinevere Planitiae. A first draft of the geology has been completed, and the tentative number of mapped units by terrain type is: tesserae - 2; plains - 4; ridge belts - 1; fracture belts - 1 (plus embayed fragments of possible additional belts); coronae - 5; central volcanoes - 2; shield flows - 2; paterae - 1; impact craters - 13; undifferentiated flows - 1; bright materials - 1.

Preliminary Geologic Map of the White Sulphur Springs 30' x 60' Quadrangle, Montana

USGS Publications Warehouse

Reynolds, Mitchell W.; Brandt, Theodore R.

2006-01-01

The geologic map of the White Sulphur Springs quadrangle, scale 1:100,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of the geologically complex area in west-central Montana. The quadrangle encompasses about 4,235 km2 (1,635 mi2), across part of the Smith River basin, the west end of the Little Belt Mountains, the Castle Mountains, and the upper parts of the basins of the North Forks of the Smith and Musselshell Rivers and the Judith River. Geologically the quadrangle extends across the eastern part of the Helena structural salient in the Rocky Mountain thrust belt, a segment of the Lewis and Clark tectonic zone, west end of the ancestral central Montana uplift, and the southwest edge of the Judith basin. Rocks and sediments in the White Sulphur Springs quadrangle are assigned to 88 map units on the basis of rock or sediment type and age. The oldest rock exposed is Neoarchean diorite that is infolded with Paleoproterozoic metamorphic rocks including gneiss, diorite, granite, amphibolite, schist, and mixed metamorphic rock types. A thick succession of the Mesoproterozoic Belt Supergroup unconformably overlies the metamorphic rocks and, in turn, is overlain unconformably by Phanerozoic sedimentary and volcanic rocks. Across most of the quadrangle, the pre-Tertiary stratigraphic succession is intruded by Eocene dikes, sills, and plutons. The central part of the Little Belt Mountains is generally underlain by laccoliths and sheet-like bodies of quartz monzonite or dacite. Oligocene andesitic basalt flows in the western and southern part of the quadrangle document both the configuration of the late Eocene erosional surfaces and the extent of extensional faulting younger than early Oligocene in the area. Pliocene, Miocene, and Oligocene strata, mapped as 11 units, consist generally of interbedded sand, gravel, and tuffaceous sedimentary rock. Quaternary and Quaternary-Tertiary sediments rest across the older Cenozoic deposits and across all older rocks. The Quaternary and Quaternary-Tertiary deposits generally are gravels that mantle broad erosional surfaces on the flanks of the mountains, gravels in stream channels, and colluvium and landslide deposits on hill sides. Glacial deposits, representing at least two stages of glaciation, are present in the northern part of the Little Belt Mountains. The geologic structure of much of the northwest part of the quadrangle is a broad uplift, in the core of which the Paleoproterozoic and Neoarchean metamorphic rocks are exposed. Down plunge to the east, the succession of Phanerozoic sedimentary rocks define an east-trending arch, cored locally by Mesoproterozoic strata of the Belt Supergroup. The north flank of the arch dips steeply north as a monocline. Stratigraphic relations among Mississippian, Pennsylvanian, and Jurassic strata document the recurrent uplift and erosion on that north flank. The broader arch of the Little Belt Mountains reflects the west plunge of the ancestral Central Montana uplift. The eastern extension of the Lewis and Clark tectonic zone is exposed in the southern half of the quadrangle where the Volcano Valley fault zone curves from west to southeast as a reverse fault along which the latest movement is up on the south side. The fault zone ends in an anticline in the south-central margin of the quadrangle. Stratigraphic overlap of Phanerozoic strata over the truncated edges of Mesoproterozoic units documents that the area of the eastern terminus of the fault zone was tectonically recurrently active. Northeast trending strike-slip faults displace Mesoproterozoic rocks in the northwest and south-central parts of the quadrangle. Several of those faults are overlain unconformably by the Middle Cambrian Flathead Sandstone. Other north-east and west-trending faults across the central part of the quadrangle are intruded by middle Eocene plutons. You

Surficial Geologic Map of the Death Valley Junction 30' x 60' Quadrangle, California and Nevada

USGS Publications Warehouse

Slate, Janet L.; Berry, Margaret E.; Menges, Christopher M.

2009-01-01

This surficial geologic map of the Death Valley Junction 30' x 60' quadrangle was compiled digitally at 1:100,000 scale. The map area covers the central part of Death Valley and adjacent mountain ranges - the Panamint Range on the west and the Funeral Mountains on the east - as well as areas east of Death Valley including some of the Amargosa Desert, the Spring Mountains and Pahrump Valley. Shaded relief delineates the topography and appears as gray tones in the mountain ranges where the bedrock is undifferentiated and depicted as a single unit.

The Alaskan mineral resource assessment program; background information to accompany folio of geologic and mineral resource maps of the Ambler River Quadrangle, Alaska

USGS Publications Warehouse

Mayfield, Charles F.; Tailleur, I.L.; Albert, N.R.; Ellersieck, Inyo; Grybeck, Donald; Hackett, S.W.

1983-01-01

The Ambler River quadrangle, consisting of 14,290 km2 (5,520 mi2) in northwest Alaska, was investigated by an interdisciplinary research team for the purpose of assessing the mineral resource potential of the quadrangle. This report provides background information for a folio of maps on the geology, reconnaissance geochemistry, aeromagnetics, Landsat imagery, and mineral resource evaluation of the quadrangle. A summary of the geologic history, radiometric dates, and fossil localities and a comprehensive bibliography are also included. The quadrangle contains jade reserves, now being mined, and potentially significant resources of copper, zinc, lead, and silver.

Presentations - Herriott, T.M. and others, 2011 | Alaska Division of

Science.gov Websites

Details Title: Detailed geologic mapping and overview of structural and stratigraphic studies in the east Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of in the east-central North Slope foothills, Alaska (poster): 3P Arctic, The Polar Petroleum Potential

The Alaska Mineral Resource Assessment Program; guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska

USGS Publications Warehouse

Berg, Henry C.

1982-01-01

The Ketchikan and Prince Rupert 1-degree by 2-degree quadrangles, which encompass about 16,000 km2 at the south tip of southeastern Alaska, have been investigated by integrated field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat data interpretation to determine their mineral-resource potential. Mineral deposits in the study area have been mined or prospected intermittently since about 1900, and production of small tonnages of ores containing gold, silver, copper, lead, zinc, and tungsten has been recorded. Extensive exploration and development currently (1981) is underway at a molybdenum prospect about 65 km east of Ketchikan. Our mineral-resource assessment indicates that the area contains potentially significant amounts of those metallic commodities, as well as of molybdenum, iron, antimony, and barite. The results of these studies have been published in a folio of maps accompanied by descriptive texts, diagrams, tables, and pertinent references. The present report serves as a guide to these investigations, provides relevant background information, and integrates the component maps and reports. It also describes revisions to the geology based on studies completed since the folio was published and includes a list of specific and general references on the geology and mineral deposits of the study area.

Geologic Map of Central (Interior) Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Dover, James H.; Bradley, Dwight C.; Weber, Florence R.; Bundtzen, Thomas K.; Haeussler, Peter J.

1998-01-01

Introduction: This map and associated digital databases are the result of a compilation and reinterpretation of published and unpublished 1:250,000- and limited 1:125,000- and 1:63,360-scale mapping. The map area covers approximately 416,000 sq km (134,000 sq mi) and encompasses 25 1:250,000-scale quadrangles in central Alaska. The compilation was done as part of the U.S. Geological Survey National Surveys and Analysis project, whose goal is nationwide assemble geologic, geochemical, geophysical, and other data. This map is an early product of an effort that will eventually encompass all of Alaska, and is the result of an agreement with the Alaska Department of Natural Resources, Division of Oil And Gas, to provide data on interior basins in Alaska. A paper version of the three map sheets has been published as USGS Open-File Report 98-133. Two geophysical maps that cover the identical area have been published earlier: 'Bouguer gravity map of Interior Alaska' (Meyer and others, 1996); and 'Merged aeromagnetic map of Interior Alaska' (Meyer and Saltus, 1995). These two publications are supplied in the 'geophys' directory of this report.

Reconnaissance bedrock geology of the southeastern part of the Kenai quadrangle, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

USGS Publications Warehouse

Bradley, Dwight C.; Wilson, Frederic H.

2000-01-01

We present a new reconnaissance geologic map of the southeastern part of the Kenai quadrangle that improves on previously published maps. Melange of the McHugh Complex is now known to form a continuous strike belt that can be traced from the Seldovia to the Valdez quadrangle; a problematic 75-km-long gap in the McHugh Complex in the Kenai and Seldovia quadrangles does not exist. An Eocene near-trench pluton underlies a range of nunataks in Harding Icefield.

Publications - Quadrangle Search | Alaska Division of Geological &

Science.gov Websites

Publication Sales. Access bibliography for: Quadrangle name will appear as your mouse scrolls across Alaska Long Mountains Misheguk Mountain Howard Pass Killik River Chandler Lake Philip Smith Mountains Arctic Table Mountain Noatak Baird Mountains Ambler River Survey Pass Wiseman Chandalar Christian Coleen

Geochemical maps showing the distribution and abundance of selected elements in stream-sediment samples, Solomon and Bendeleben 1 degree by 3 degree quadrangles, Seward Peninsula, Alaska

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

Smith, S.C.; King, H.D.; O'Leary, R.M.

Geochemical maps showing the distribution and abundance of selected elements in stream-sediment samples, Solomon and Bendeleben 1{degree} by 3{degree} quadrangles, Seward Peninsula, Alaska is presented.

Geologic Map of the Point Lay Quadrangle, Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

2008-01-01

This map is a product of the USGS Digital Geologic Maps of Northern Alaska project, which captures in digital format quadrangles across the entire width of northern Alaska. Sources include geologic maps previously published in hardcopy format and recent updates and revisions based on field mapping by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey. Individual quadrangles are digitized at either 1:125,000 or 1:250,000 depending on the resolution of source maps. The project objective is to produce a set of digital geologic maps with uniform stratigraphic nomenclature and structural annotation, and publish those maps electronically. The paper version of this map is available for purchase from the USGS Store.

Geologic Map of the Ikpikpuk River Quadrangle, Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

2005-01-01

This map is a product of the USGS Digital Geologic Maps of Northern Alaska project, which captures in digital format quadrangles across the entire width of northern Alaska. Sources include geologic maps previously published in hardcopy format and recent updates and revisions based on field mapping by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey. Individual quadrangles are digitized at either 1:125,000 or 1:250,000 depending on the resolution of source maps. The project objective is to produce a set of digital geologic maps with uniform stratigraphic nomenclature and structural annotation, and publish those maps electronically. The paper version of this map is available for purchase from the USGS Store.

Geologic Map of the Lookout Ridge Quadrangle, Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

2006-01-01

This map is a product of the USGS Digital Geologic Maps of Northern Alaska project, which captures in digital format quadrangles across the entire width of northern Alaska. Sources include geologic maps previously published in hardcopy format and recent updates and revisions based on field mapping by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey. Individual quadrangles are digitized at either 1:125,000 or 1:250,000 depending on the resolution of source maps. The project objective is to produce a set of digital geologic maps with uniform stratigraphic nomenclature and structural annotation, and publish those maps electronically. The paper version of this map is available for purchase from the USGS Store.

Hydrogeochemical and stream sediment reconnaissance basic data for Philip Smith Mountains Quadrangle, Alaska

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

Not Available

1981-05-29

Field and laboratory data are presented for 1128 water samples from the Philip Smith Mountains Quadrangle, Alaska. The samples were collected by Los Alamos Scientific Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Reconnaissance Geologic Map of the Hayfork 15' Quadrangle, Trinity County, California

USGS Publications Warehouse

Irwin, William P.

2010-01-01

The Hayfork 15' quadrangle is located just west of the Weaverville 15' quadrangle in the southern part of the Klamath Mountains geologic province of northern California. It spans parts of six generally north-northwest-trending tectonostratigraphic terranes that are, from east to west, the Eastern Klamath, Central Metamorphic, North Fork, Eastern Hayfork, Western Hayfork, and Rattlesnake Creek terranes. Remnants of a once-widespread postaccretionary overlap assemblage, the Cretaceous Great Valley sequence, crop out at three localities in the southern part of the Hayfork quadrangle. The Tertiary fluvial and lacustrine Weaverville Formation occupies a large, shallow, east-northeast-trending graben in the south half of the quadrangle. The small area of Eastern Klamath terrane is part of the Oregon Mountain outlier, which is more widely exposed to the east in the Weaverville 15' quadrangle. It was originally mapped as a thrust plate of Bragdon(?) Formation, but it is now thought by some to be part of an outlier of Yreka terrane that has been dislocated 60 km southward by the La Grange Fault. The Central Metamorphic terrane, which forms the footwall of the La Grange Fault, was formed by the eastward subduction of oceanic crustal basalt (the Salmon Hornblende Schist) and its overlying siliceous sediments with interbedded limestone (the Abrams Mica Schist) beneath the Eastern Klamath terrane. Rb-Sr analysis of the Abrams Mica Schist indicates a Middle Devonian metamorphic age of approximately 380 Ma, which probably represents the age of subduction. The North Fork terrane, which is faulted against the western boundary of the Central Metamorphic terrane, consists of the Permian(?) North Fork ophiolite and overlying broken formation and melange of Permian to Early Jurassic (Pliensbachian) marine metasedimentary and metavolcanic rocks. The ophiolite, which crops out along the western border of the terrane, is thrust westward over the Eastern Hayfork terrane. The Eastern Hayfork terrane is a broken formation and melange of volcanic and sedimentary rocks, including chert and blocks of amphibolite, limestone, and serpentinized ultramafic rocks. The chert contains radiolarians of Permian and Triassic ages, but none of clearly Jurassic age. In contrast, the cherts of the North Fork terrane contain Early and Middle Jurassic radiolarians in addition to those of Permian and Triassic ages; also, some limestones of the Eastern Hayfork terrane contain fossil faunas of Tethyan affinity, but those of the North Fork terrane do not. The Western Hayfork terrane is an andesitic volcanic arc that was accreted to the Eastern Hayfork terrane. It consists mainly of metavolcaniclastic andesitic agglomerate and tuff, as well as argillite and chert, and it includes the dioritic Ironside Mountain batholith, which intruded during Middle Jurassic time. Two large patches of Western Hayfork terrane mapped in the central part of the Eastern Hayfork terrane may be exposed through windows in the Eastern Hayfork terrane, although the structural relation is not clear. The Rattlesnake Creek terrane is a melange that occupies only a small area in the southwest corner of the Hayfork quadrangle; however, it is a major unit in the Hyampom 15' quadrangle to the west. It consists mainly of broken and sheared ophiolitic rocks of probable Permian or early Mesozoic age. The Cretaceous Great Valley sequence overlap assemblage here postdates the Early Cretaceous (approximately 136 Ma) emplacement of the Shasta Bally batholith, which is widely exposed to the east in the Weaverville 15' quadrangle. The Great Valley sequence once covered much of the southern Klamath Mountains; however, in the Hayfork quadrangle, only three small patches remain near its southern boundary. Weakly consolidated nonmarine sedimentary rocks of the Weaverville Formation of mid-Tertiary age, which contain abundant fossil plants, occupy a large, shallow, east-northeast-trending graben

Preliminary Geological Map of the Ac-H-3 Dantu Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

NASA Astrophysics Data System (ADS)

Kneissl, T.; Schmedemann, N.; Neesemann, A.; Williams, D. A.; Crown, D. A.; Mest, S. C.; Buczkowski, D.; Scully, J. E. C.; Frigeri, A.; Ruesch, O.; Hiesinger, H.; Walter, S. H. G.; Jaumann, R.; Roatsch, T.; Preusker, F.; Nathues, A.; Platz, T.; Hoffmann, M.; Schäfer, M.; De Sanctis, M. C.; Raymond, C. A.; Russell, C. T.; Kersten, E.; Naß, A.

2015-12-01

We are using Dawn spacecraft data to create a geologic map of the Ac-H-3 Dantu Quadrangle of dwarf planet Ceres. The quadrangle is located between 21-66˚N and 90-180˚E and includes the following dominant features: 1) the central and northern portion of the 124.6 km diameter impact crater Dantu; 2) crater chains and/or grooves oriented in an east-west direction; 3) a portion of the 84 km diameter impact crater Gaue, whose ejecta blanket covers the SW corner of the quadrangle. Dantu is a complex impact crater showing terraces, a central pit structure, concentric fractures, and smooth deposits on the crater floor. The materials interpreted to be ejecta deposits of Dantu show low crater frequencies and dominate the southern half of the quadrangle. These deposits appear to be relatively bright and correspond to parts of the #2 high albedo region observed by (1) with the HST indicating different composition and/or material properties than the surroundings. The east-west striking crater chains and grooves are mainly found in the southern half of the quadrangle. They seem to be connected to the crater chains found in Ac-H-4 Ezinu, the neighboring quadrangle to the east, and are potentially related to ballistic ejecta emplacement (see 2). Further work will be focused on Dantu crater and its complex interior and exterior. The current geologic map is based on Framing Camera (FC) image mosaics derived from Approach (~1.3 km/px) and Survey (~400 m/px) data as well as digital terrain models (DTMs) derived from stereo imagery. In the course of the mission, we will incorporate mosaics from the High Altitude Mapping Orbit (~140 m/px, Fall 2015) and Low Altitude Mapping Orbit (~35 m/px, Spring 2016) phases. We acknowledge the support of the Dawn Instrument, Operations, and Science Teams. This work is partly supported by the German Space Agency (DLR), grant 50 OW 1101. (1) Li, J-Y. et al. (2006), Icarus, 182, 143-160. (2) Scully, J.E.C. et al. (2015), this conference.

Preliminary results of potassium-argon age determinations from the Ugashik quadrangle, Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1980

USGS Publications Warehouse

Wilson, Frederic H.; Shew, Nora B.

1982-01-01

Early and preliminary results of potassiumargon dating work on samples from 12 sites in the Ugashik quadrangle indicate a continuation of the geologic trends seen in the Chignik and Sutwik Island quadrangles to the south (Wilson, 1980). Tertiary volcanic and hypabyssal rocks apparently fall into two age groups: early Tertiary-late Eocene to earliest Miocene and late Tertiary and Quaternary-late Miocene to Holocene (fig. 53).

Geologic Map of the Denver West 30' x 60' Quadrangle, North-Central Colorado

USGS Publications Warehouse

Kellogg, Karl S.; Shroba, Ralph R.; Bryant, Bruce; Premo, Wayne R.

2008-01-01

The Denver West quadrangle extends east-west across the entire axis of the Front Range, one of numerous uplifts in the Rocky Mountain region in which Precambrian rocks are exposed. The history of the basement rocks in the Denver West quadrangle is as old as 1,790 Ma. Along the east side of the range, a sequence of sedimentary rocks as old as Pennsylvanian, but dominated by Cretaceous-age rocks, overlies these ancient basement rocks and was upturned and locally faulted during Laramide (Late Cretaceous to early Tertiary) uplift of the range. The increasingly coarser grained sediments up section in rocks of latest Cretaceous to early Tertiary age record in remarkable detail this Laramide period of mountain building. On the west side of the range, a major Laramide fault (Williams Range thrust) places Precambrian rocks over Cretaceous sedimentary rocks. The geologic history of the quadrangle, therefore, can be divided into four major periods: (1) Proterozoic history, (2) Pennsylvanian to pre-Laramide, Late Cretaceous history, (3) Late Cretaceous to early Tertiary Laramide mountain building, and (4) post-Laramide history. In particular, the Quaternary history of the Denver West quadrangle is described in detail, based largely on extensive new mapping.

Geology of the Huntsville quadrangle, Alabama

USGS Publications Warehouse

Sanford, T.H.; Malmberg, G.T.; West, L.R.

1961-01-01

The 7 1/2-minute Huntsville quadrangle is in south-central Madison County, Ala., and includes part of the city of Hunstville. The south, north, east, and west boundaries of the quadrangle are about 3 miles north of the Tennessee River, 15 1/2 miles south of the Tennessee line, 8 miles west of the Jackson County line, and 9 miles east of the Limestone County line. The bedrock geology of the Huntsville quadrangle was mapped by the U.S. Geological Survey in cooperation with the city of Hunstville and the Geological Survey of Alabama as part of a detailed study of the geology and ground-water resources of Madison County, with special reference to the Huntsville area. G. T. Malmberg began the geologic mapping of the county in July 1953, and completed it in April 1954. T. H. Sanford, Jr., assisted Malmberg in the final phases of the county mapping, which included measuring geologic sections with hand level and steel tape. In November 1958 Sanford, assisted by L. R. West, checked contacts and elevations in the Hunstville quadrangle; made revisions in the contact lines; and wrote the text for this report. The fieldwork for this report was completed in April 1959.

Publications - RI 2000-1C | Alaska Division of Geological & Geophysical

Science.gov Websites

Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Authors: Pinney, D.S. Publication Date: 2000 Publisher Bibliographic Reference Pinney, D.S., 2000, Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Sheets Sheet 1 Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North

Publications - PIR 2002-2 | Alaska Division of Geological & Geophysical

Science.gov Websites

for more information. Quadrangle(s): Philip Smith Mountains Bibliographic Reference Harris, E.E., Mull , scale 1:63,360 (14.0 M) Digital Geospatial Data Digital Geospatial Data Philip Smith Mountains: Geologic Smith Mountains: Topo Data Download psm-topo Shapefile 11.5 M Metadata - Read me Keywords Alaska, State

Geochemical maps showing the distribution and abundance of selected elements in nonmagnetic heavy-mineral-concentrate samples from stream sediment, Solomon and Bendelehen 1 degree by 3 degree Quadrangles , Seward Peninsula, Alaska

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

King, H.D.; Smith, S.C.; Sutley, S.J.

Geochemical maps showing the distribution and abundance of selected elements in nonmagnetic heavy-mineral-concentrate samples from stream sediment, Solomon and Bendelehen 1{degree} by 3{degree} Quadrangles , Seward Peninsula, Alaska is presented.

The Alaska Mineral Resource Assessment Program : guide to information contained in folio of geologic and mineral resource maps of the Philip Smith Mountains quadrangle, Alaska

USGS Publications Warehouse

Reiser, H.N.; Brosge, W.P.; Hamilton, T.D.; Singer, D.A.; Menzie, W. D.; Bird, K.J.; Cady, J.W.; Le Compte, J. R.; Cathrall, J.B.

1983-01-01

The geology and mineral resources of the Philip Smith Mountains quadrangle were virtually unexplored until the investigations for oil began in northern Alaska. Construction of the Trans-Alaskan Pipeline System has now made the quadrangle accessible by road. In 1975 and 1976 a team of geologists, geochemists, and geophysicists investigated the quadrangle in order to assess its mineral resource potential. This report is a guide to the resulting folio of twelve maps that describe the geology, stream sediment geochemistry, aeromagnetic features, Landsat imagery, and mineral resources of the area. The bedrock geology and aeromagnetic surveys show that mineral deposits associated with intrusive rocks are probably absent. However, the geology and geochemical anomalies do indicate the possibility of vein and strata-bound deposits of copper, lead, and zinc in the Paleozoic shale and carbonate rocks in the southern part of the quadrangle and of stratabound deposits of zinc and copper in the Permian and Mesozoic shales along the mountain front. The northwestern part of the quadrangle has a low to moderate potential for oil or gas; Mississippian carbonate rocks are the most likely reservoir. The only minerals produced to date have been construction materials.

Geologic Map of the Diana Chasma Quadrangle (V-37), Venus

USGS Publications Warehouse

Hansen, V.L.; DeShon, H.R.

2002-01-01

Diana Chasma quadrangle hosts some of the steepest topography on Venus. Altimetry measurements range from -2.5 to 4.7 km (0.0 = mean planetary radius), with a surface mean of 0.6 km. Fractures and faults within the central fracture/rift zone create large blocks of down-dropped material, especially along the east-central edge of the map area. The Dali and Diana chasmata display slopes of >30°, the steepest and deepest trenches on Venus. Both chasmata host landslide deposits presumably sourced from the steep chasmata walls. The tessera inlier, coronae, and ridge belts sit topographically above Rusalka and Zhibek planitiae. Rusalka Planitia topography describes broad undulations having northwest-trending ridges spaced ~200 km apart. The most distinctive ridge, Vetsorgo Dorsum, centered at 6.5° S., 163° E., is a Class I ridge belt owing to its simple arch morphology. The central interior of Markham crater sits topographically lower than the surrounding region, which slopes downward to the east.

Radioactivity at the Copper Creek copper lode prospect, Eagle district, east-central Alaska

USGS Publications Warehouse

Wedow, Helmuth; Tolbert, Gene Edward

1952-01-01

Investigation of radioactivity anomalies at the Copper Creek copper lode prospect, Eagle district, east-central Alaska, during 1949 disclosed that the radioactivity is associated with copper mineralization in highly metamorphosed sedimentary rocks. These rocks are a roof pendant in the Mesozoic "Charley River" batholith. The radioactivity is probably all due to uranium associated with bornite and malachite.

Publications - PIR 2002-1D | Alaska Division of Geological & Geophysical

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content DGGS PIR 2002-1D Publication Details Title: Engineering - geologic map of the Eagle A-1 Quadrangle please see our publication sales page for more information. Quadrangle(s): Eagle Bibliographic Reference Stevens, D.S.P., 2012, Engineering - geologic map of the Eagle A-1 Quadrangle, Fortymile mining district

Geologic Map of the Tower Peak Quadrangle, Central Sierra Nevada, California

USGS Publications Warehouse

Wahrhaftig, Clyde

2000-01-01

Introduction The Tower Peak quadrangle, which includes northernmost Yosemite National Park, is located astride the glaciated crest of the central Sierra Nevada and covers an exceptionally well-exposed part of the Sierra Nevada batholith. Granitic plutonic rocks of the batholith dominate the geology of the Tower Peak quadrangle, and at least 18 separate pre-Tertiary intrusive events have been identified. Pre-Cretaceous metamorphic rocks crop out in the quadrangle in isolated roof pendants and septa. Tertiary volcanic rocks cover granitic rocks in the northern part of the quadrangle, but are not considered in this brief summary. Potassium-argon (K-Ar) age determinations for plutonic rocks in the quadrangle range from 83 to 96 million years (Ma), including one of 86 Ma for the granodiorite of Lake Harriet (Robinson and Kistler, 1986). However, a rubidium-strontium whole-rock isochron age of 129 Ma has been obtained for the Lake Harriet pluton (Robinson and Kistler, 1986), which field evidence indicates is the oldest plutonic body within the quadrangle. This suggests that some of the K-Ar ages record an episode of resetting during later thermal events and are too young. The evidence indicates that all the plutonic rocks are of Cretaceous age, with the youngest being the Cathedral Peak Granodiorite at about 83 Ma. The pre-Tertiary rocks of the Tower Peak quadrangle fall into two groups: (1) an L-shaped area of older plutonic and metamorphic rocks, 3 to 10 km wide, that extends diagonally both northeast and southeast from near the center of the quadrangle; and (2) a younger group of large, probably composite intrusions that cover large areas in adjacent quadrangles and extend into the Tower Peak quadrangle from the east, north, and southwest.

Publications - RDF 2015-8 | Alaska Division of Geological & Geophysical

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from the Tonsina area, Valdez Quadrangle, Alaska: Alaska Division of Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - Geospatial Data | Alaska Division of Geological &

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from rocks collected in the Richardson mining district, Big Delta Quadrangle, Alaska: Alaska Division , 40Ar/39Ar data, Alaska Highway corridor from Delta Junction to Canada border, parts of Mount Hayes

Regional Geochemical Results from Analyses of Stream-Water, Stream-Sediment, Soil, Soil-Water, Bedrock, and Vegetation Samples, Tangle Lakes District, Alaska

USGS Publications Warehouse

Wang, Bronwen; Gough, L.P.; Wanty, R.B.; Lee, G.K.; Vohden, James; O'Neill, J. M.; Kerin, L.J.

2008-01-01

We report chemical analyses of stream-water, stream-sediment, soil, soil-water, bedrock, and vegetation samples collected from the headwaters of the Delta River (Tangle Lakes District, Mount Hayes 1:250,000-scale quadrangle) in east-central Alaska for the period June 20-25, 2006. Additionally, we present mineralogic analyses of stream sediment, concentrated by panning. The study area includes the southwestward extent of the Bureau of Land Management (BLM) Delta River Mining District (Bittenbender and others, 2007), including parts of the Delta River Archeological District, and encompasses an area of about 500 km2(approximately bordered by the Denali Highway to the south, near Round Tangle Lake, northward to the foothills of the Alaska Range (fig. 1). The primary focus of this study was the chemical characterization of native materials, especially surface-water and sediment samples, of first-order streams from the headwaters of the Delta River. The impetus for this work was the need, expressed by the Alaska Department of Natural Resources (ADNR), for an inventory of geochemical and hydrogeochemical baseline information about the Delta River Mining District. This information is needed because of a major upturn in exploration, drilling, and general mineral-resources assessments in the region since the late 1990s. Currently, the study area, called the 'MAN Project' area is being explored by Pure Nickel, Inc. (http://www.purenickel.com/s/MAN_Alaska.asp), and includes both Cu-Au-Ag and Ni-Cu-PGE (Pt-Pd-Au-Ag) mining claims. Geochemical data on surface-water, stream-sediment, soil, soil-water, grayleaf willow (Salix glauca L.), and limited bedrock samples are provided along with the analytical methodologies used and panned-concentrate mineralogy. We are releasing the data at this time with only minimal interpretation.

Publications - RI 2011-4 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska district, Circle Quadrangle, Alaska, scale 1:50,000 (16.0 M) Digital Geospatial Data Digital Geospatial Business in Alaska Visiting Alaska State Employees

Regional patterns of Mesozoic-Cenozoic magmatism in western Alaska revealed by new U-Pb and 40Ar/39Ar ages: Chapter D in Studies by the U.S. Geological Survey in Alaska, vol. 15

USGS Publications Warehouse

Bradley, Dwight C.; Miller, Marti L.; Friedman, Richard M.; Layer, Paul W.; Bleick, Heather A.; Jones, James V.; Box, Steven E.; Karl, Susan M.; Shew, Nora B.; White, Timothy S.; Till, Alison B.; Dumoulin, Julie A.; Bundtzen, Thomas K.; O'Sullivan, Paul B.; Ullrich, Thomas D.

2017-03-02

In support of regional geologic framework studies, we obtained 50 new argon-40/argon-39 (40Ar/39Ar) ages and 33 new uranium-lead (U-Pb) ages from igneous rocks of southwestern Alaska. Most of the samples are from the Sleetmute and Taylor Mountains quadrangles; smaller collections or individual samples are from the Bethel, Candle, Dillingham, Goodnews Bay, Holy Cross, Iditarod, Kantishna River, Lake Clark, Lime Hills, McGrath, Medfra, Talkeetna, and Tanana quadrangles.A U-Pb zircon age of 317.7±0.6 million years (Ma) reveals the presence of Pennsylvanian intermediate igneous (probably volcanic) rocks in the Tikchik terrane, Bethel quadrangle. A U-Pb zircon age of 229.5±0.2 Ma from gabbro intruding the Rampart Group of the Angayucham-Tozitna terrane, Tanana quadrangle, confirms and tightens a previously cited Triassic age for this intrusive suite. A fresh mafic dike in Goodnews Bay quadrangle yielded a 40Ar/39Ar whole rock age of 155.0±1.9 Ma; this establishes a Jurassic or older age for the previously unconstrained (Paleozoic? to Mesozoic?) sandstone unit that it intrudes. A thick felsic tuff in the Gemuk Group in Taylor Mountains quadrangle yielded a U-Pb zircon age of 153.0±2.0 Ma, extending the age of magmatism in this part of the Togiak terrane back into the Late Jurassic. We report three new U-Pb zircon ages between 120 and 110 Ma—112.0±0.9 Ma from syenite in the Candle quadrangle, 114.9±0.3 Ma from orthogneiss assigned to the Ruby terrane in Iditarod quadrangle, and 116.6±0.1 Ma from a gabbro of the Dishna River mafic-ultramafic complex in Iditarod quadrangle. The latter result requires a substantial age revision, from Triassic to Cretaceous, for at least some rocks that have been mapped as the Dishna River mafic-ultramafic complex. A tuff in the Upper Cretaceous Kuskokwim Group yielded a U-Pb zircon (sensitive high-resolution ion microprobe, SHRIMP) age of 88.3±1.0 Ma; we speculate that the eruptive source was an arc along the trend of the Pebble porphyry copper deposit along the Gulf of Alaska continental margin. More than half of the new ages fall between 75 and 65 Ma, confirming the existence, based on conventional potassium-argon (K-Ar) ages, of a 70-Ma igneous flare-up across southwestern Alaska. Our new ages hint that during this pulse, the locus of magmatism shifted toward the Gulf of Alaska, that is, toward a more outboard position. This shift is consistent with the hypothesis that magmatism was the product of rollback of a subducted slab, which at that time would have been the Resurrection Plate. Intrusive rocks in the Taylor Mountains and Sleetmute quadrangles in the age range of 63 to 59 Ma were emplaced shortly before the onset of ridge subduction as dated by near-trench plutons in the adjacent part of the Chugach accretionary complex. Southwestern Alaska at this time would have been positioned above a very young subducted slab belonging to the Resurrection Plate; magmas, in this scenario, were generated near the edge of the slab window related to ridge subduction. A 56.3±0.2 Ma granite in Taylor Mountains quadrangle and a 54.7±0.7 Ma ashfall tuff in McGrath quadrangle were likely emplaced above the Resurrection-Kula slab window, which by this time is inferred to have entered the region. Another ashfall tuff in McGrath quadrangle, at 42.8±0.5 Ma, likely belongs to the Meshik Arc, the product of renewed subduction after inferred passage of the slab window. A 49.0±0.3-Ma rhyolite in Taylor Mountains quadrangle is about the age of the transition from slab window to renewed subduction. Two plutons in the western Alaska Range, at 31.8±0.4 and 30.9±0.6 Ma, belong to a suite of gabbro to peralkaline granite of unknown origin. Finally, a 4.6±0.1-Ma basalt from a flow in Taylor Mountains quadrangle belongs to the Neogene basaltic province of western Alaska. These rocks were erupted in a distal retroarc setting; the cause of magmatism is unknown. 

Publications - RDF 2015-9 | Alaska Division of Geological & Geophysical

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samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska: Alaska Division of Geological & Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2005-2 | Alaska Division of Geological & Geophysical

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, and non-carbonate carbon data from rocks collected in the Solomon, Bendeleben, and Nome quadrangles for more information. Quadrangle(s): Bendeleben; Nome; Solomon Bibliographic Reference Werdon, M.B , geochemical, and non-carbonate carbon data from rocks collected in the Solomon, Bendeleben, and Nome

Bedrock geology and mineral resources of the Knoxville 1° x 2° quadrangle, Tennessee, North Carolina, and South Carolina

USGS Publications Warehouse

Robinson, Gilpin R.; Lesure, Frank G.; Marlowe, J. I.; Foley, Nora K.; Clark, S.H.

2004-01-01

Vermiculite produced from a large deposit near Tigerville, S.C-, in the Inner Piedmont. Deposit worked out and mine backfilled. Smaller deposits associated with ultramafic rocks in the east flank of the Blue Ridge are now uneconomic and have not been worked in the past 20 years. C. Metals: Copper in three deposits, the Fontana and Hazel Creek mines in the Great Smoky Mountains Abstract Figure 1. Location of the Knoxville 1ºx2º quadrangle, with state and county boundaries National Park in the Central Blue Ridge, and the Cullowhee mine in the east flank of the Blue Ridge. D. Organic fuels: The rocks of the quadrangle contain no coal and probably lie outside the maximum range in thermal maturity permitting the survival of oil. The rocks in the Valley and Ridge and for a short distance eastward below the west flank of the Blue Ridge probably lie within a zone of thermal maturity permitting the survival of natural gas. Consequently the western part of the quadrangle is an area of high risk for hydrocarbon exploration. No exploration drilling has been done in this belt.

Publications - PDF 97-29I | Alaska Division of Geological & Geophysical

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igneous rocks of the Tanana B-1 Quadrangle and vicinity Authors: Newberry, R.J., and Haug, S.A , and Sr isotopic data for igneous rocks of the Tanana B-1 Quadrangle and vicinity: Alaska Division of ; Isotopes; Plutonic; STATEMAP Project; Trace Elements; Volcanic Top of Page Department of Natural Resources

Sample locality map and analytical data for potassium-argon ages in the Port Moller, Stepovak Bay, and Simeonof Island quadrangles, Alaska Peninsula

USGS Publications Warehouse

Wilson, Frederic H.; Shew, Nora B.; DuBois, Gregory D.; Bie, Scott W.

1994-01-01

Potassium-argon age determinations for 84 volcanic, intrusive, and hydrothermally altered rocks from the Port Moller, Stepovak Bay, and Simeonof Island quadrangles are reported here. Of these age determinations, 78 samples were analyzed as part of Alaska Mineral Resource Assessment Program (AMRAP) studies in the Port Moller, Stepovak Bay, and Simeonof Island quadrangles. Age deter- minations for 6 of the samples have been previously published (Burk, 1965; Kienle and Turner, 1976; Wilson and others, 1981). This report consists of a sample location map, analytical data (table 1), and rock descriptions (table 2).

Reconnaissance for radioactive deposits in Alaska, 1953

USGS Publications Warehouse

Matzko, John J.; Bates, Robert G.

1955-01-01

During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported; in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in places associated with base metal sulfides and hematite; in the vicinity of Port Malmesbury in southeastern Alaska to check a reported occurrence of pitchblende; and, in the Miller House-Circle Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaska. Tundra cover prevents satisfactory radiometric reconnaissance of the area, and methods of geochemical prospecting such as soil and vegetation sampling may ultimately prove more fruitful in the search for the uranothorianite-sulfide lode source than geophysical methods.

Publications - GMC 379 | Alaska Division of Geological & Geophysical

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Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic Info: Download below or please see our publication sales page for more information. Quadrangle(s

Publications - GMC 372 | Alaska Division of Geological & Geophysical

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DGGS GMC 372 Publication Details Title: 1928 Alaska Nebesna Corporation drill logs and assay records Nebesna Corporation drill logs and assay records for the Orange Hill Property, Nabesna Quadrangle, Alaska

Publications - GMC 377 | Alaska Division of Geological & Geophysical

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Quadrangle, Alaska: 1977-1980 Drill holes (Drill Logs and Assay Records) Authors: U.S. Borax Publication Date : 1977-1980 Drill holes (Drill Logs and Assay Records): Alaska Division of Geological & Geophysical

Stream-sediment samples reanalyzed for major, rare earth, and trace elements from ten 1:250,000-scale quadrangles, south-central Alaska, 2007-08

USGS Publications Warehouse

Bailey, Elizabeth A.; Shew, Nora B.; Labay, Keith A.; Schmidt, Jeanine M.; O'Leary, Richard M.; Detra, David E.

2010-01-01

During the 1960s through the 1980s, the U.S. Geological Survey (USGS) conducted reconnaissance geochemical surveys of the drainage basins throughout most of the Anchorage, Bering Glacier, Big Delta, Gulkana, Healy, McCarthy, Mount Hayes, Nabesna, Talkeetna Mountains, and Valdez 1:250,000-scale quadrangles in Alaska as part of the Alaska Mineral Resource Assessment Program (AMRAP). These geochemical surveys provide data necessary to assess the potential for undiscovered mineral resources on public and other lands, and provide data that may be used to determine regional-scale element baselines. This report provides new data for 366 of the previously collected stream-sediment samples. These samples were selected for reanalysis because recently developed analytical methods can detect additional elements of interest and have lower detection limits than the methods used when these samples were originally analyzed. These samples were all analyzed for arsenic by hydride generation atomic absorption spectrometry (HGAAS), for gold, palladium, and platinum by inductively coupled plasma-mass spectrometry after lead button fire assay separation (FA/ICP-MS), and for a suite of 55 major, rare earth, and trace elements by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry (ICP-AES-MS) after sodium peroxide sinter at 450 degrees Celsius.

Publications - GMC 322 | Alaska Division of Geological & Geophysical

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Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic Ordering Info: Download below or please see our publication sales page for more information. Quadrangle(s

Surficial Geologic Map of the Clinton-Concord-Grafton-Medfield 12-Quadrangle Area in East Central Massachusetts

USGS Publications Warehouse

Stone, Janet R.; Stone, Byron D.

2006-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of twelve 7.5-minute quadrangles (total 660 square miles) in east-central Massachusetts. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (grain size, sedimentary structures, mineral and rock-particle composition), constructional geomorphic features, stratigraphic relationships, and age. 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. 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 report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (12 PDF files), GIS data layers (ArcGIS shapefiles), scanned topographic base maps (TIF), metadata for the GIS layers, and a readme.txt file.

Lead-alpha age determinations of granitic rocks from Alaska

USGS Publications Warehouse

Matzko, John J.; Jaffe, H.W.; Waring, C.L.

1957-01-01

Lead-alpha activity age determinations were made on zircon from seven granitic rocks of central and southeastern Alaska. The results of the age determinations indicate two periods of igneous intrusion, one about 95 million years ago, during the Cretaceous period, and another about 53 million years ago, during the early part of the Tertiary. The individual ages determined on zircon from 2 rocks from southeastern Alaska and 1 from east-central Alaska gave results of 90, 100, and 96 million years; those determined on 4 rocks from central Alaska gave results of 47, 56, 58, and 51 million years.

Publications - GMC 404 | Alaska Division of Geological & Geophysical

Science.gov Websites

: Shennan, I., Barlow, N., Pierre, K., Stuart-Taylor, O., and Sea Level Research Unit, Department of information. Quadrangle(s): Seward Bibliographic Reference Shennan, I., Barlow, N., Pierre, K., Stuart-Taylor

Reanalysis of historical U.S. Geological Survey sediment samples for geochemical data from the western part of the Wrangellia terrane, Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Azain, Jaime S.; Granitto, Matthew

2014-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For the geochemical part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 1,682 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering the western half of the Wrangellia Terrane in the Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles of south-central Alaska (fig. 1). USGS was responsible for sample retrieval from the Denver warehouse through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Presentations - Emond, A.M. and others, 2015 | Alaska Division of

Science.gov Websites

: Download below or please see our publication sales page for more information. Quadrangle(s): Big Delta Creek Schist; Bush Prospect; Chicken Metamorphic Complex; Chicken Pluton; DIGHEM-V EM System; Delta

Publications - GMC 419 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 419 Publication Details Title: X-Ray diffraction analysis of cuttings samples from the Trading for more information. Quadrangle(s): Kenai Bibliographic Reference TIORCO Inc., 2013, X-Ray

Publications - PR 121 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

: Download below or please see our publication sales page for more information. Quadrangle(s): Philip Smith Philip Smith Mountains: Surficial Geology Data File Format File Size Info Download psm-surficial-geo

Publications - GMC 376 | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska DGGS GMC 376 Publication Details Title: NWE Drill Logs for the Orange Hill Property, Nabesna Quadrangle , Alaska: 1973 and 1974 Drill holes No. 112 through No. 123 Authors: Northwest Explorations Publication

Publications - GMC 389 | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska DGGS GMC 389 Publication Details Title: Core photographs, assay results, and 1988 drill logs from the Cominco DDH-1 through DDH-4 boreholes, Shadow Prospect, Tyonek Quadrangle, Alaska Authors: Millrock

Publications - PIR 2002-1B | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PIR 2002-1B Publication Details Title: Bedrock geologic map of the Eagle A-1 Quadrangle for more information. Quadrangle(s): Eagle Bibliographic Reference Szumigala, D.J., Newberry, R.J ., Werdon, M.B., Athey, J.E., Flynn, R.L., and Clautice, K.H., 2002, Bedrock geologic map of the Eagle A-1

Publications - GMC 388 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 388 Publication Details Title: Core photographs of the Cominco DDH-1 through DDH-4 boreholes the Cominco DDH-1 through DDH-4 boreholes, NAP Cu-Zn Prospect, Dillingham Quadrangle, Alaska: Alaska Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska

Geologic map of the Sappho Patera Quadrangle (V-20), Venus

USGS Publications Warehouse

McGill, George E.

2000-01-01

The Sappho Patera quadrangle (V–20) of Venus is bounded by 0° and 30° East longitude, 0° and 25° North latitude. It is one of 62 quadrangles covering the entire planet at a scale of 1:5,000,000. The quadrangle derives its name from Sappho Patera, a large rimmed depression (diameter about 225 km) lying on top of a shield-shaped mountain named Irnini Mons. Sappho, a noted Greek poet born about 612 B.C., spent most of her life on the island of Lesbos. All of her works were burned in 1073 by order of ecclesiastical authorities in Rome and Constantinople. What little survives was discovered in 1897 as parts of papier mâché coffins in the Fayum (Durant, 1939). The Sappho Patera quadrangle includes the central portion of Eistla Regio, an elongated, moderately elevated (relief ~1 km) region extending for about 7,500 km west-northwestward from the west end of Aphrodite Terra. It is generally interpreted to be the surface manifestation of one or more mantle plumes (Phillips and Malin, 1983; Stofan and Saunders, 1990; Kiefer and Hager, 1991; Senske and others, 1992; Grimm and Phillips, 1992; Solomon and others, 1992). Eistla Regio is dominated by several large volcanic features. All or parts of four of these occur within the Sappho Patera quadrangle: the eastern flank of Gula Mons, Irnini Mons, Anala Mons, and Kali Mons. The quadrangle also includes eight named coronae: Nehalennia, Sunrta, Libera, Belet-Ili, Gaia, Asomama, Rabzhima, and Changko. A major rift extends from Gula Mons in the northwestern corner of the quadrangle to Libera Corona near the east border. East of Irnini and Anala Montes this rift is named Guor Linea; west of the montes it is named Virtus Linea. In addition to these major features, the Sappho Patera quadrangle includes numerous smaller volcanic flows and constructs, several unnamed coronae and corona-like features, a complex array of faults, fractures, and wrinkle ridges, and extensive plains that are continuous with the regional plains that constitute about 80% of the surface of Venus (Masursky and others, 1980). This area is geologically interesting because it contains examples of most globally important types of features and deposits and is an excellent area to study the temporal and genetic relations among plains, rifts, coronae, and large shield volcanoes. The temporal relations displayed in this quadrangle can provide useful constraints on models for venusian tectonic style (McGill, 1994b).

Geologic map of the east half of the Lime Hills 1:250,000-scale quadrangle, Alaska

USGS Publications Warehouse

Gamble, Bruce M.; Reed, Bruce L.; Richter, Donald H.; Lanphere, Marvin A.

2013-01-01

This map is compiled from geologic mapping conducted between 1985 and 1992 by the U.S. Geological Survey as part of the Alaska Mineral Resource Assessment Program. That mapping built upon previous USGS work (1963–1988) unraveling the magmatic history of the Alaska–Aleutian Range batholith. Quaternary unit contacts depicted on this map are derived largely from aerial-photograph interpretation. K-Ar ages made prior to this study have been recalculated using 1977 decay constants. The east half of the Lime Hills 1:250,000-scale quadrangle includes part of the Alaska–Aleutian Range batholith and several sequences of sedimentary rocks or mixed sedimentary and volcanic rocks. The Alaska–Aleutian Range batholith contains rocks that represent three major igneous episodes, (1) Early and Middle Jurassic, (2) Late Cretaceous and early Tertiary, and (3) middle Tertiary; only rocks from the latter two episodes are found in this map area. The map area is one of very steep and rugged terrain; elevations range from a little under 1,000 ft (305 m) to 9,828 ft (2,996 m). Foot traverses are generally restricted to lowermost elevations. Areas suitable for helicopter landings can be scarce at higher elevations. Most of the area was mapped from the air, supplemented by direct examination of rocks where possible. This restricted access greatly complicates understanding some of the more complex geologic units. For example, we know there are plutons whose compositions vary from gabbro to granodiorite, but we have little insight as to how these phases are distributed and what their relations might be to each other. It is also possible that some of what we have described as compositionally complex plutons might actually be several distinct intrusions.

Geology and mineral resources of the Port Moller region, western Alaska Peninsula, Aleutian arc: A section in USGS research on mineral resources - 1989: Program and abstracts

USGS Publications Warehouse

Wilson, Frederic H.; White, Willis H.; Detterman, Robert L.

1988-01-01

Geologic mapping of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles was begun under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP) in 1983 . Two important mineral deposits are located in the Port Moller quadrangle; the Pyramid prospect is the largest copper porphyry system in the Aleutian Arc, and the Apollo Mine is the only gold mine to reach production status in the Aleutian Arc.

Bedrock geology and mineral resources of the Knoxville 1°x2° quadrangle, Tennessee, North Carolina, and South Carolina

USGS Publications Warehouse

Robinson, Gilpin R.; Lesure, Frank G.; Marlowe, J.I.; Foley, Nora K.; Clark, S.H.

1992-01-01

Vermiculite produced from a large deposit near Tigerville, S.C., in the Inner Piedmont. Deposit worked out and mine backfilled. Smaller deposits associated with ultramafic rocks in the east flank of the Blue Ridge are now uneconomic and have not been worked in the past 20 years. C. Metals: Copper in three deposits, the Fontana and Hazel Creek mines in the Great Smoky Mountains National Park in the Central Blue Ridge, and the Cullowhee mine in the east flank of the Blue Ridge. D. Organic fuels:  The rocks of the quadrangle contain no coal and probably lie outside the maximum range in thermal maturity permitting the survival of oil. The rocks in the Valley and Ridge and for a short distance eastward below the west flank of the Blue Ridge probably lie within a zone of thermal maturity permitting the survival of natural gas. Consequently the western part of the quadrangle is an area of high risk for hydrocarbon exploration. No exploration drilling has been done in this belt. 

Preliminary Geologic Map of the North-Central Part of the Alamosa 30' x 60' Quadrangle, Alamosa, Conejos and Costilla Counties, Colorado

USGS Publications Warehouse

Machette, Michael N.; Thompson, Ren A.; Brandt, Theodore R.

2008-01-01

This geologic map presents new polygon (geologic map unit contacts) and line (terrace and lacustrine spit/barrier bar) vector data for a map comprised of four 7.5' quadrangles in the north-central part of the Alamosa, Colorado, 30' x 60' quadrangle. The quadrangles include Baldy, Blanca, Blanca SE, and Lasauses. The map database, compiled at 1:50,000 scale from new 1:24,000-scale mapping, provides geologic coverage of an area of current hydrogeologic, tectonic, and stratigraphic interest. The mapped area is located primarily in Costilla County, but contains portions of Alamosa and Conejos Counties, and includes the town of Blanca in its northeastern part. The map area is mainly underlain by surficial geologic materials (fluvial and lacustrine deposits, and eolian sand), but Tertiary volcanic and volcaniclastic rocks crop out in the San Luis Hills, which are in the central and southern parts of the mapped area. The surficial geology of this area has never been mapped at any scale greater than 1:250,000 (broad reconnaissance), so this new map provides important data for ground-water assessments, engineering geology, and the Quaternary geologic history of the San Luis Basin. Newly discovered shoreline deposits are of particular interest (sands and gravels) that are associated with the high-water stand of Lake Alamosa, a Pliocene to middle Pleistocene lake that occupied the San Luis basin prior to its overflow and cutting of a river gorge through the San Luis Hills. After the lake drained, the Rio Grande system included Colorado drainages for the first time since the Miocene (>5.3 Ma). In addition, Servilleta Basalt, which forms the Basaltic Hills on the east margin of the map area, is dated at 3.79+or-0.17 Ma, consistent with its general age range of 3.67-4.84 Ma. This map provides new geologic information for better understanding ground-water flow paths in and adjacent to the Rio Grande system. The map abuts U.S. Geological Survey Open File Report 2005-1392 (a map of the northwestern part of the Alamosa 30' x 60' quadrangle map) to the west and U.S. Geological Survey Scientific Investigations Map 2965 (Fort Garland 7.5' quadrangle) to the east.

Publications - GMC 390 | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska DGGS GMC 390 Publication Details Title: Drill logs (1987) from the Cominco Upper Discovery DDH-1 and Lower Discovery DDH-1 through DDH-5 boreholes, Mt. Estelle Prospect, Tyonek Quadrangle, Alaska Authors

Publications - GMC 420 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 420 Publication Details Title: X-Ray fluorescence spectroscopy and 40Ar/39Ar analyses of core more information. Quadrangle(s): Ikpikpuk River; Umiat Bibliographic Reference Shimer, G., 2013, X-Ray

Publications - PIR 2009-7 | Alaska Division of Geological & Geophysical

Science.gov Websites

Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2009-7 Publication Details Title: Geologic map of the Kanayut River area, Chandler Lake ., and Burns, P.C., 2009, Geologic map of the Kanayut River area, Chandler Lake Quadrangle, Alaska

Preliminary Geological Map of the Ac-H-8 Nawish Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

NASA Astrophysics Data System (ADS)

Frigeri, A.; De Sanctis, M. C.; Carrorro, F. G.; Ammannito, E.; Williams, D. A.; Mest, S. C.; Buczkowski, D.; Preusker, F.; Jaumann, R.; Roatsch, T.; Scully, J. E. C.; Raymond, C. A.; Russell, C. T.

2015-12-01

Herein we present the geologic mapping of the Ac-H-8 Nawish Quadrangle of dwarf planet Ceres, produced on the basis of the Dawn spacecraft data. The Ac-H-08 Nawish quadrangle is located between -22°S and 22°N and between 144°E and 216°E. At the north-east border, a polygonal, 75km-wide crater named Nawish gives the name to the whole quadrangle. An unamed, partially degraded, 100km-diameter crater is evident in the lower central sector of the quadrangle. Bright materials have been mapped and are associated with craters. For example, bright materials occur in the central peak region of Nawish crater and in the ejecta of an unnamed crater, which is located in the nearby quadrangle Ac-H-09. The topography of the area obtained from stereo-processing of imagery shows an highland in the middle of the quadrangle. Topography is lower in the northern and southern borders, with a altitude span of about 9500 meters. At the time of this writing geologic mapping was performed on Framing Camera (FC) mosaics from the Approach (1.3 km/px) and Survey (415 m/px) orbits, including grayscale and color images and digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) images in January 2016. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA, and from the German and Italian Space Agencies.

Paleozoic strata of the Dyckman Mountain area, northeastern Medfra quadrangle, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

USGS Publications Warehouse

Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.

2000-01-01

Paleozoic rocks in the Dyckman Mountain area (northeastern Medfra quadrangle; Farewell terrane) include both shallowand deep-water lithologies deposited on and adjacent to a carbonate platform. Shallow-water strata, which were recognized by earlier workers but not previously studied in detail, consist of algal-laminated micrite and skeletal-peloidal wackestone, packstone, and lesser grainstone. These rocks are, at least in part, of Early and (or) Middle Devonian age but locally could be as old as Silurian; they accumulated in shallow subtidal to intertidal settings with periodically restricted water circulation. Deepwater facies, reported here for the first time, are thin, locally graded beds of micrite and calcisiltite and subordinate thick to massive beds of lime grainstone and conglomerate. Conodonts indicate an age of Silurian to Middle Devonian; the most tightly dated intervals are early Late Silurian (early to middle Ludlow). These strata formed as hemipelagic deposits, turbidites, and debris flows derived from shallow-water lithologies of the Nixon Fork subterrane. Rocks in the Dyckman Mountain area are part of a broader facies belt that is transitional between the Nixon Fork carbonate platform to the west and deeper water, basinal lithologies (Minchumina “terrane”) to the east. Transitional facies patterns are complex because of Paleozoic shifts in the position of the platform margin, Mesozoic shortening, and Late Cretaceous-Tertiary disruption by strike-slip faulting.

Publications - RDF 2012-1 | Alaska Division of Geological & Geophysical

Science.gov Websites

Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS RDF 2012-1 Publication Details Title: Palynological analysis of 228 outcrop samples from the ., 2012, Palynological analysis of 228 outcrop samples from the Kenai, Seldovia, and Tyonek quadrangles

Mineral resource assessment of the Dillon 1 degree x 2 degrees Quadrangle, Idaho and Montana

USGS Publications Warehouse

Pearson, Robert Carl; Trautwein, C.M.; Ruppel, E.T.; Hanna, W.F.; Rowan, L.C.; Loen, J.S.; Berger, B.R.

1992-01-01

The Dillon 1°x2° quadrangle in southwestern Montana and east-central Idaho was investigated as part of the U.S. Geological Survey's Conterminous United States Mineral Assessment Program (CUSMAP) to determine its mineral resource potential. An interdisciplinary study was made of geology, geochemistry, geophysics (gravity and aeromagnetics), remote sensing, and mineral deposits. The results of those studies, as well as mineral resource assessment of numerous mineraldeposit types, are published separately as a folio of maps. This report summarizes the studies, provides background information on them, and presents a selected bibliography relevant to the geology and mineral resources of the quadrangle. The quadrangle contains large resources of gold and substantial resources of talc and chlorite, all of which were being mined in the 1980's and early 1990's. Submarginal resources of molybdenum, copper, tungsten, and iron range from moderately large to large. Other commodities that may be present in significant amounts are chromite, lead, zinc, silver, barite, zeolite minerals, and various nonmetallic metamorphic minerals.

Stratiform zinc-lead mineralization in Nasina assemblage rocks of the Yukon-Tanana Upland in east-central Alaska

USGS Publications Warehouse

Dusel-Bacon, Cynthia; Bressler, Jason R.; Takaoka, Hidetoshi; Mortensen, James K.; Oliver, Douglas H.; Leventhal, Joel S.; Newberry, Rainer J.; Bundtzen, Thomas K.

1998-01-01

The Yukon-Tanana Upland of east-central Alaska and Yukon comprises thrust sheets of ductilely deformed metasedimentary and metaigneous rocks of uncertain age and origin that are overlain by klippen of weakly metamorphosed oceanic rocks of the Seventymile-Slide Mountain terrane, and intruded by post-kinematic Early Jurassic, Cretaceous and Tertiary granitoids. Metamorphosed continental margin strata in the Yukon-Tanana Upland of east-central Alaska are thought to be correlative, on the basis of stratigraphic similarities and sparse Mississippian U-Pb zircon and fossil ages (Mortensen, 1992), with middle Paleozoic metasedimentary and metavolcanic rocks in the eastern Alaska Range and in western and southeastern Yukon. Furthermore, rocks in the northern Yukon-Tanana Upland may correlate across the Tintina fault with unmetamorphosed counterparts in the Selwyn Basin (Murphy and Abbott, 1995). Volcanic-hosted (VMS) and sedimentary exhalative (sedex) massive sulfide occurrences are widely reported for these other areas (green-colored unit of fig. 1) but, as yet, have not been documented in the Alaskan part of the Yukon-Tanana Upland. Recent discoveries of VMS deposits in Devono-Mississippian metavolcanic rocks in the Finlayson Lake area of southeastern Yukon (Hunt, 1997) have increased the potential for finding VMS deposits in rocks of similar lithology and age in the Yukon-Tanana Upland of Alaska. Restoration of 450 km of early Tertiary dextral movement along the Tintina fault juxtaposes these two areas.

Publications - GMC 328 | Alaska Division of Geological & Geophysical

Science.gov Websites

Taylor Mountains A3 Quadrangle (Cass 84-4, Cass 84-6 and Cass 88-8) by Brett Resources Authors: Brett Prospect core of Taylor Mountains A3 Quadrangle (Cass 84-4, Cass 84-6 and Cass 88-8) by Brett Resources

Alaska Resource Data File, Nabesna quadrangle, Alaska

USGS Publications Warehouse

Hudson, Travis L.

2003-01-01

Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

Alaska Resource Data File, McCarthy quadrangle, Alaska

USGS Publications Warehouse

Hudson, Travis L.

2003-01-01

Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

Timber resource statistics of south-central Alaska, 2003.

Treesearch

Willem W.S. van Hees

2005-01-01

Estimates of timber resources for south-central Alaska are presented. Data collection began in 2000 and was completed in 2003. All forest lands over all ownerships were considered for sampling. The inventory unit was, roughly, the region between Icy Bay to the east and Kodiak Island to the west. Forest lands within national forest wilderness study areas and recommended...

Map showing distribution of copper in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of copper in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of barium in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of barium in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Geologic map of the Glen Canyon Dam 30’ x 60’ quadrangle, Coconino County, northern Arizona

USGS Publications Warehouse

Billingsley, George H.; Priest, Susan S.

2013-01-01

The Glen Canyon Dam 30’ x 60’ quadrangle is characterized by nearly flat lying to gently dipping Paleozoic and Mesozoic sedimentary strata that overlie tilted Proterozoic strata or metasedimentary and igneous rocks similar to those exposed at the bottom of Grand Canyon southwest of the quadrangle. Mississippian to Permian rocks are exposed in the walls of Marble Canyon; Permian strata and minor outcrops of Triassic strata form the surface bedrock of House Rock Valley and Marble Plateau, southwestern quarter of the quadrangle. The Paleozoic strata exposed in Marble Canyon and Grand Canyon south of the map are likely present in the subsurface of the entire quadrangle but with unknown facies and thickness changes. The Mesozoic sedimentary rocks exposed along the Vermilion and Echo Cliffs once covered the entire quadrangle, but Cenozoic erosion has removed most of these rocks from House Rock Valley and Marble Plateau areas. Mesozoic strata remain over much of the northern and eastern portions of the quadrangle where resistant Jurassic sandstone units form prominent cliffs, escarpments, mesas, buttes, and much of the surface bedrock of the Paria, Kaibito, and Rainbow Plateaus. Jurassic rocks in the northeastern part of quadrangle are cut by a sub-Cretaceous regional unconformity that bevels the Entrada Sandstone and Morrison Formation from Cummings Mesa southward to White Mesa near Kaibito. Quaternary deposits, mainly eolian, mantle much of the Paria, Kaibito, and Rainbow Plateaus in the northern and northeastern portion of the quadrangle. Alluvial deposits are widely distributed over parts of House Rock Valley and Marble Plateau in the southwest quarter of the quadrangle. The east-dipping strata of the Echo Cliffs Monocline forms a general north-south structural boundary through the central part of the quadrangle, separating Marble and Paria Plateaus west of the monocline from the Kaibito Plateau east of the monocline. The Echo Cliffs Monocline continues north of the quadrangle into southern Utah. The gentle north- and northeast-dipping Mesozoic strata on the Kaibito and Rainbow Plateaus are partly interrupted by northwest-trending, broad-based, ill-defined synclines and anticlines. These broad-based structures form mesas and buttes near anticlinal crests and deeply incised drainages in synclinal valleys. The 1,300-ft-thick (396-m-thick) Navajo Sandstone erodes into a maze of tributary slot canyons in the northeastern part of the quadrangle. Mesozoic strata in the extreme northeast corner of the quadrangle dip gently southwest due to the influence of the Monument Upwarp in southeastern Utah and by an intrusive uplift (laccolith) that forms Navajo Mountain, a prominent 10,388 ft (3,166 m) landmark just northeast of the quadrangle.

Publications - GMC 293 | Alaska Division of Geological & Geophysical

Science.gov Websites

exploratory hole, Healy A-6 Quadrangle, Alaska Authors: Kennecott Exploration Publication Date: 2000 Publisher Exploration, 2000, Geologic log of the Kennecott Exploration McCallie Creek MC-1 exploratory hole, Healy A-6

Alaska Interim Land Cover Mapping Program; final report

USGS Publications Warehouse

Fitzpatrick-Lins, Katherine; Doughty, E.F.; Shasby, Mark; Benjamin, Susan

1989-01-01

In 1985, the U.S. Geological Survey initiated a research project to develop an interim land cover data base for Alaska as an alternative to the nationwide Land Use and Land Cover Mapping Program. The Alaska Interim Land Cover Mapping Program was subsequently created to develop methods for producing a series of land cover maps that utilized the existing Landsat digital land cover classifications produced by and for the major land management agencies for mapping the vegetation of Alaska. The program was successful in producing digital land cover classifications and statistical summaries using a common statewide classification and in reformatting these data to produce l:250,000-scale quadrangle-based maps directly from the Scitex laser plotter. A Federal and State agency review of these products found considerable user support for the maps. Presently the Geological Survey is committed to digital processing of six to eight quadrangles each year.

Explanation of fields used in the Alaska Resource Data File of mines, prospects, and mineral occurrences in Alaska

USGS Publications Warehouse

,

1996-01-01

Descriptions of mines, prospects, and mineral occurrences in the Alaska Resource Data File (ARDF) are published for individual U.S. Geological Survey 1:250,000 scale quadrangles in Alaska (see accompanying map) and are available for downloading from USGS World Wide Web site: http://www-rnrs-ak.wr.usgs.gov/ardf.These descriptions are divided into a number of fields which describe features of each mine, prospect, or mineral occurrence. These descriptions were complied from published literature and from unpublished reports and data from industry, the U.S. Bureau of Mines, and the U.S. Geological Survey and other sources. Compilation of this database is an ongoing process and each report is essentially a progress report. The authors of the individual quadrangle reports would appreciate any corrections or additional information that users may be able to contribute.

Publications - GMC 330 | Alaska Division of Geological & Geophysical

Science.gov Websites

Prospect of the Taylor Mountains B6 Quadrangle (Mose #1-84, 112.5'; Mose #2-84, 201.7'; Mose #3-84, 103.6 Taylor Mountains B6 Quadrangle (Mose #1-84, 112.5'; Mose #2-84, 201.7'; Mose #3-84, 103.6'; Mose #4-84

New ages on intrusive rocks and altered zones in the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1977

USGS Publications Warehouse

Wilson, Frederic H.; Detterman, Robert L.; Silberman, Miles L.

1978-01-01

Preliminary potassium-argon dating of intrusive rocks and altered zones in the Chignik and Sutwik Island quadrangles of the Alaska Peninsula seems to indicate at least three and possibly four Tertiary ages of alteration and mineralization.

Merged aeroradiometric data for Alaska; a web site for distribution of gridded data and plot files

USGS Publications Warehouse

Saltus, R.W.; Riggle, F.E.; Clark, B.T.; Hill, P.L.

1999-01-01

The National Uranium Resource Evaluation (NURE) program was conducted by the U.S. Government between 1974 and 1983. The NURE program was administered by the Grand Junction, CO, office of the Department of Energy. The program included airborne gamma-ray spectrometry and magnetic data collection as well as extensive geochemical sample collection and processing. Aeroradiometric and aeromagnetic surveys of 98 1° by 3° quadrangles were flown in Alaska between 1975 and 1980. The data were flown in 15 surveys by Texas Instruments (T.I.), Lockwood, Kessler, and Bartlett (LKB), and AeroServices (Aero) under contract to the U.S. Government. A series of contractor reports document the surveys on a quadrangle by quadrangle basis. We list references to these reports on the detailed survey index pages accessible through the Survey Irfo page.

Geologic Map of the Niobe Planitia Quadrangle (V-23), Venus

USGS Publications Warehouse

Hansen, Vicki L.

2009-01-01

The Niobe Planitia quadrangle (V-23) encompasses approximately 8,000,000 km2 of the Venusian equatorial region extending from lat 0 deg to 25 deg N. and from long 90 deg to 120 deg E. (approximately 9,500 15-minute quadrangles on Earth). The map area lies along the north margin of the equatorial highland, Aphrodite Terra (V-35), and extends into the lowland region to the north, preserving a transition from southern highlands to northern lowlands (figs. 1, 2, map sheet). The northern parts of the crustal plateau, Ovda Regio and Haasttse-baad Tessera, mark the south margin of the map area; Niobe and Sogolon Planitiae make up the lowland region. The division between Niobe and Sogolon Planitiae is generally topographic, and Sogolon Planitia forms a relatively small elongate basin. Mesolands, the intermediate topographic level of Venus, are essentially absent or represented only by Gegute Tessera, which forms a slightly elevated region that separates Niobe Planitia from Llorona Planitia to the east (V-24). Lowlands within the map area host five features currently classified as coronae: Maya Corona (lat 23 deg N., long 97 deg E.) resides to the northwest and Dhisana, Allatu, Omeciuatl, and Bhumiya Coronae cluster loosely in the east-central area. Lowlands extend north, east, and west of the map area. Mapping the Niobe Planitia quadrangle (V-23) provides an excellent opportunity to examine a large tract of lowlands and the adjacent highlands with the express goal of clarifying the processes responsible for resurfacing this part of Venus and the resulting implications for Venus evolution. Although Venus lowlands are widely considered to have a volcanic origin, lowlands in the map area lack adjacent coronae or other obvious volcanic sources.

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Haines area, Juneau and Skagway quadrangles, southeast Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 212 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Chilkat, Klehini, Tsirku, and Takhin river drainages, as well as smaller drainages flowing into Chilkat and Chilkoot Inlets near Haines, Skagway Quadrangle, Southeast Alaska. Additionally some samples were also chosen from the Juneau gold belt, Juneau Quadrangle, Southeast Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Correlation of coal beds in the Fruitland Formation as interpreted from geophysical logs, east-central San Juan County, New Mexico

USGS Publications Warehouse

Sandberg, Dorothy T.

1986-01-01

Correlation of coal beds in the Fruitland Formation (Upper Cretaceous) in the subsurface, from interpretation of geophysical logs, is an outgrowth of unpublished studies of deep coal on the Navajo Reservation by the author in the Toadlena 30 x 60 minute quadrangle, New Mexico, and by W. J. Mapel in the Farmington 30 x 60 minute quadrangle, New Mexico.  The lines of sections of this report extend eastward from the reservation into east-central San Juan County, which is in the western part of the San Juan Basin.  In this area, the rocks dip gently northeast toward the central part of the basin.  The thick coal is less than 1,500 feet beneath the surface.  Of the 53 logs in the sections, 48 are from oil- and gas-test holes, and 5 are from coal-test holes (see table 1).  Stratigraphic relations of the Upper Cretaceous Lewis Shale, Pictured Cliffs Sandstone, and Fruitland Formation, shown on the cross sections and briefly reviewed below, have been previously described for this or other parts of the San Juan Basin by Hayes and Zapp (1955), Beaumont (1971), Fassett and hinds (1971), O;Sullivan and other (1972), and Molenaar (1983), among others.

Publications - GMC 373 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 373 Publication Details Title: 1964 Bear Creek Mining Company drill logs and assay records for and assay records for the Orange Hill Property, Nabesna Quadrangle, Alaska: Drill holes OH #1 and OH

Geologic Map of the Atlin Quadrangle, Southeastern Alaska

USGS Publications Warehouse

Brew, David A.; Himmelberg, Glen R.; Ford, Arthur B.

2009-01-01

This map presents the results of U.S. Geological Survey (USGS) geologic bedrock mapping studies in the mostly glacier covered Atlin 1:250,000-scale quadrangle, northern southeastern Alaska. These studies are part of a long-term systematic effort by the USGS to provide bedrock geologic and mineral-resource information for all of southeastern Alaska, covering all of the Tongass National Forest (including Wilderness Areas) and Glacier Bay National Park and Preserve. Some contributions to this effort are those concerned with southwesternmost part of the region, the Craig and Dixon Entrance quadrangles (Brew, 1994; 1996) and with the Wrangell-Petersburg area (Brew, 1997a-m; Brew and Grybeck, 1997; Brew and Koch, 1997). As shown on the index map (fig. 1), the study area is almost entirely in the northern Coast Mountains adjacent to British Columbia, Canada. No previous geologic map has been published for the area, although Brew and Ford (1985) included a small part of it in a preliminary compilation of the adjoining Juneau quadrangle; and Brew and others (1991a) showed the geology at 1:500,000 scale. Areas mapped nearby in British Columbia and the United States are also shown on figure 1. All of the map area is in the Coast Mountains Complex as defined by Brew and others (1995a). A comprehensive bibliography is available for this and adjacent areas (Brew, 1997n).

Geologic map and database of the Salem East and Turner 7.5-minute quadrangles, Marion County, Oregon: a digital database

USGS Publications Warehouse

Tolan, Terry L.; Beeson, Marvin H.; Digital Database by DuRoss, Christopher B.

2000-01-01

The Salem East and Turner 7.5-minute quadrangles are situated in the center of the Willamette Valley near the western margin of the Columbia River Basalt Group (CRBG) distribution. The terrain within the area is of low to moderate relief, ranging from about 150 to almost 1,100-ft elevation. Mill Creek flows northward from the Stayton basin (Turner quadrangle) to the northern Willamette Valley (Salem East quadrangle) through a low that dissects the Columbia River basalt that forms the Salem Hills on the west and the Waldo Hills to the east. Approximately eight flows of CRBG form a thickness of up to 700� in these two quadrangles. The Ginkgo intracanyon flow that extends from east to west through the south half of the Turner quadrangle is exposed in the hills along the southeast part of the quadrangle. Previous geologic mapping by Thayer (1939) and Bela (1981) while providing the general geologic framework did not subdivide the CRBG which limited their ability to delineate structural elements. Reconnaissance mapping of the CRBG units in the Willamette Valley indicated that these stratigraphic units could serve as a series of unique reference horizons for identifying post-Miocene folding and faulting (Beeson and others, 1985,1989; Beeson and Tolan, 1990). Crenna, et al. (1994) compiled previous mapping in the Willamette Valley in a study of the tectonics of the Salem area. The major emphasis of this study was to identify and map CRBG units within the Salem East and Turner Quadrangles and to utilize this detailed CRBG stratigraphy to identify and characterize structural features. Water well logs were used to provide better subsurface stratigraphic control. Three other quadrangles (Scotts Mills, Silverton, and Stayton NE) in the Willamette Valley have been mapped in this way (Tolan and Beeson, 1999). This area was a lowland area of weathered and eroded marine sedimentary when the Columbia River basalts encroached on this area approximately 15-16 m.y. ago. An incipient Coast Range apparently stopped or diverted the fluid lava flows from moving much farther westward toward the coast at this latitude. It is assumed also that an ancestral Willamette River flowed northward through this low-lying area so that water was present as streams and ponds along the flood plain.

Publications - PIR 2015-7 | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PIR 2015-7 Publication Details Title: Oil-stained sandstone in the Middle Jurassic lower information. Quadrangle(s): Iliamna Bibliographic Reference Wartes, M.A., and Herriott, T.M., 2015, Oil Jurassic; Oil Seeps; Oil and Gas; Paveloff Siltstone Member; Petroleum; Petrology; Provenance; Reservoir

Publications - RI 94-25 | Alaska Division of Geological & Geophysical

Science.gov Websites

-materials map of the Anchorage C-7 NW Quadrangle, Alaska, scale 1:25,000 (1.4 M) Digital Geospatial Data Digital Geospatial Data Anchorage C-7 NW Derivative materials Data File Format File Size Info Download

Publications - RI 94-26 | Alaska Division of Geological & Geophysical

Science.gov Websites

-materials map of the Anchorage C-8 NE Quadrangle, Alaska, scale 1:25,000 (3.8 M) Digital Geospatial Data Digital Geospatial Data Anchorage C-8 NE Derivative materials Data File Format File Size Info Download

Publications - RI 94-27 | Alaska Division of Geological & Geophysical

Science.gov Websites

-materials map of the Anchorage C-8 NW Quadrangle, Alaska, scale 1:25,000 (676.0 M) Digital Geospatial Data Digital Geospatial Data Anchorage C-8 NW Derivative materials Data File Format File Size Info Download

Publications - RI 94-24 | Alaska Division of Geological & Geophysical

Science.gov Websites

-materials map of the Anchorage C-7 NE Quadrangle, Alaska, scale 1:25,000 (2.4 M) Digital Geospatial Data Digital Geospatial Data Anchorage C-7 NE Derivative materials Data File Format File Size Info Download

Publications - RI 2005-1F | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2005-1F Publication Details Title: Surficial geologic map of the Council Area, Solomon D-4 ): Bendeleben; Solomon Bibliographic Reference Stevens, D.S.P., 2005, Surficial geologic map of the Council Area , Solomon D-4 and Bendeleben A-4 quadrangles, Seward Peninsula, Alaska: Alaska Division of Geological &

Geochemistry of surface-waters in mineralized and non-mineralized areas of the Yukon-Tanana Uplands

USGS Publications Warehouse

Wang, B.; Wanty, R.B.; Vohden, J.

2005-01-01

The U.S. Geological Survey (USGS) and Alaska Department of Natural Resources (ADNR) are continuing investigations on element mobility in mineralized and non-mineralized areas of the Yukon-Tanana Upland in east-central Alaska. The chemistry of stream water is evaluated in the context of regional bedrock geology and geologic structure. Sampling sites were located in the Big Delta B2 quadrangle, which includes the mineralized areas of the Pogo claim block. The area is typified by steep, subarctic-alpine, boreal forest catchment basins. Samples were collected from catchments that either cross structural features and lithologic contacts, or are underlain by a single lithology. Waters are generally dilute (< 213 mg/L TDS), and are classified as Ca2+ and Mg2+-HCO3- to Ca2+ and Mg2+-SO42- waters. Gneissic lithologies are more SO42- dominated than the intrusive units. The major-ion chemistry of the waters reflects a rock-dominated aqueous system. Trace-element concentrations in water are generally low; however, As and Sb are detected near mineralized areas but in most cases rapidly attenuated downstream and processes other than simple dilution are controlling the concentrations of these trace elements. There is a tendency toward increasing SO42- concentrations downstream in waters both proximal and distal to mineralized areas. More work is necessary to determine what proportion of the increase in SO42- could be derived from the oxidation of sulfide minerals as opposed to water influenced by the underlying gneissic units.

Publications - RDF 2015-15 v. 1.1 | Alaska Division of Geological &

Science.gov Websites

geochemical data from rocks collected in 2015 in the Tok area, Tanacross A-5, A-6, and parts of adjacent rocks collected in 2015 in the Tok area, Tanacross A-5, A-6, and parts of adjacent quadrangles, Alaska Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in

FACILITY 846, NORTHWEST END AND SOUTHWEST SIDE, QUADRANGLE J, OBLIQUE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FACILITY 846, NORTHWEST END AND SOUTHWEST SIDE, QUADRANGLE J, OBLIQUE VIEW FACING EAST. - Schofield Barracks Military Reservation, Quadrangles I & J Barracks Type, Between Wright-Smith & Capron Avenues near Williston Avenue, Wahiawa, Honolulu County, HI

Asbestos occurrence in the Eagle C-4 quadrangle, Alaska

USGS Publications Warehouse

Foster, Helen Laura

1969-01-01

An asbestos occurrence was discovered in a remote part of the Eagle quadrangle, Alaska, in the summer of 1968 during geologic reconnaissance in connection with the U.S. Geological Survey's Heavy Metals program. The exposed part of the deposit consists of large joint blocks of serpentine which are cut by closely spaced subparallel veins. Most of the veins are about ? inch thick, and they consist of cross-fiber chrysotile asbestos. The asbestos appears to be of commercial quality, but the total quantity is unknown. The asbestos occurs in a serpentinized ultramafic mass which appears to intrude metamorphic rocks. Many other serpentinized ultramafic masses are known in the Eagle quadrangle, but this is the first one in which considerable asbestos has been found. The deposit is of importance because it shows that geologic conditions are locally favorable for the formation of asbestos in the Yukon-Tanana Upland, and hope of finding commercial asbestos deposits thus seems possible.

Preliminary grid data and maps for an aeromagnetic survey of the Taylor mountains quadrangle and a portion of the Bethel quadrangle, Alaska

USGS Publications Warehouse

Saltus, R.W.; Milicevic, B.

2004-01-01

A preliminary data grid and maps are presented for an aeromagnetic survey of the Taylor Mountains and a portion of the Bethel quadrangles, Alaska. The aeromagnetic survey was flown by McPhar Geosurveys Ltd. for the U.S. Geological Survey (USGS). A flight-line spacing of 1,600 meters (1 mile) and nominal flight height of 305 meters (1,000 feet) above topography (draped) was used for the survey. The preliminary data grid has a grid cell size of 350 meters (1150 feet). Final data processing and quality control have not been applied to these data. The purpose of this preliminary data release is to allow prompt public access to these data, which are of interest for active mineral exploration in the region. A more complete data release and description will be published later once the final data processing is complete.

Reconnaissance geologic map of the Wadi Khulab Quadrangle, sheet 16/43 A, Kingdom of Saudi Arabia

USGS Publications Warehouse

Blank, Horace Richard; Gettings, Mark E.

1985-01-01

From west to east, the physiography of the mapped area consists of a portion of the Tiharmat Asir, or coastal plain, extending from the Jizan quadrangle to the west (Blank and Gettings, 1984), a northwest-trending hill range close to the western border of the quadrangle; a pediplain; and the foothills of the Red Sea escarpment. The top of the escarpment is about 50 km east of the mapped area, in the Yemen Arab Republic. Within Saudi Arabia, the highest elevation in the quadrangle about 77 m above sea level, is found at Tirf in the western range of hills.

The Alaska Mineral Resource Assessment Program; background information to accompany geologic and mineral-resource maps of the Cordova and Middleton Island quadrangles, southern Alaska

USGS Publications Warehouse

Winkler, Gary R.; Plafker, George; Goldfarb, R.J.; Case, J.E.

1992-01-01

report summarizes recent results of integrated geological, geochemical, and geophysical field and laboratory studies conducted by the U.S. Geological Survey in the Cordova and Middleton Island 1?x3 ? quadrangles of coastal southern Alaska. Published open-file reports and maps accompanied by descriptive and interpretative texts, tables, diagrams, and pertinent references provide background information for a mineral-resource assessment of the two quadrangles. Mines in the Cordova and Middleton Island quadrangles produced copper and byproduct gold and silver in the first three decades of the 20th century. The quadrangles may contain potentially significant undiscovered resources of precious and base metals (gold, silver, copper, zinc, and lead) in veins and massive sulfide deposits hosted by Cretaceous and Paleogene sedimentary and volcanic rocks. Resources of manganese also may be present in the Paleogene rocks; uranium resources may be present in Eocene granitic rocks; and placer gold may be present in beach sands near the mouth of the Copper River, in alluvial sands within the canyons of the Copper River, and in smaller alluvial deposits underlain by rocks of the Valdez Group. Significant coal resources are present in the Bering River area, but difficult access and structural complexities have discouraged development. Investigation of numerous oil and gas seeps near Katalla in the eastern part of the area led to the discovery of a small, shallow field from which oil was produced between 1902 and 1933. The field has been inactive since, and subsequent exploration and drilling onshore near Katalla in the 1960's and offshore near Middleton Island on the outer continental shelf in the 1970's and 1980's was not successful.

27 CFR 9.193 - Rattlesnake Hills.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Yakima East Quadrangle, Washington—Yakima Co., 1953, photorevised 1985; (2) Elephant Mountain Quadrangle... boundary line— (2) Proceeds straight eastward, crossing onto the Elephant Mountain map, to the 2,192-foot peak of Elephant Mountain, section 16, T12N/R20E; then (3) Continues straight east-southeast, crossing...

27 CFR 9.193 - Rattlesnake Hills.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Yakima East Quadrangle, Washington—Yakima Co., 1953, photorevised 1985; (2) Elephant Mountain Quadrangle... boundary line— (2) Proceeds straight eastward, crossing onto the Elephant Mountain map, to the 2,192-foot peak of Elephant Mountain, section 16, T12N/R20E; then (3) Continues straight east-southeast, crossing...

27 CFR 9.193 - Rattlesnake Hills.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Yakima East Quadrangle, Washington—Yakima Co., 1953, photorevised 1985; (2) Elephant Mountain Quadrangle... boundary line— (2) Proceeds straight eastward, crossing onto the Elephant Mountain map, to the 2,192-foot peak of Elephant Mountain, section 16, T12N/R20E; then (3) Continues straight east-southeast, crossing...

27 CFR 9.193 - Rattlesnake Hills.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Yakima East Quadrangle, Washington—Yakima Co., 1953, photorevised 1985; (2) Elephant Mountain Quadrangle... boundary line— (2) Proceeds straight eastward, crossing onto the Elephant Mountain map, to the 2,192-foot peak of Elephant Mountain, section 16, T12N/R20E; then (3) Continues straight east-southeast, crossing...

27 CFR 9.193 - Rattlesnake Hills.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Yakima East Quadrangle, Washington—Yakima Co., 1953, photorevised 1985; (2) Elephant Mountain Quadrangle... boundary line— (2) Proceeds straight eastward, crossing onto the Elephant Mountain map, to the 2,192-foot peak of Elephant Mountain, section 16, T12N/R20E; then (3) Continues straight east-southeast, crossing...

Publications - GMC 327 | Alaska Division of Geological & Geophysical

Science.gov Websites

drill holes of the Coal Creek tin property of the Talkeetna Mountains D-6 Quadrangle of the Alaska Range and assays of cores from 1980, 1981, and 1982 drill holes of the Coal Creek tin property of the

Geologic map of the Hogback Mountain quadrangle, Lewis and Clark and Meagher Counties, Montana

USGS Publications Warehouse

Reynolds, Mitchell W.

2003-01-01

The geologic map of the Hogback Mountain quadrangle, scale 1:24,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of an area in the geologically complex southern part of the Montana disturbed belt. In the Hogback Mountain area, rocks ranging in age from Middle Proterozoic through Cretaceous are strongly folded within and under thrust plates of equivalent rocks. Continental rocks of successive thrust plates have been telescoped eastward over a buttress of the stable continent. Erosional remnants of Oligocene andesitic basalt lie on highest surfaces eroded across the strongly deformed older rocks; younger erosion has dissected the terrain deeply, producing Late Tertiary and Quaternary deposits of alluvium, colluvium, and local landslide debris in the valleys and canyons. Different stratigraphic successions are exposed at different structural levels across the quadrangle. In the northeastern part of the quadrangle at the lowest structural level, rocks of the Upper Mississippian Big Snowy Group, including the Kibbey Formation and the undivided Otter and Heath Formations, the overlying Pennsylvanian Amsden and undivided Quadrant and Phosphoria Formations, the Ellis Group, and the Kootenai Formation, are folded and broken by thrust faults. The next higher structural level, the Avalanche Butte thrust plate, exposes strongly folded and, in places, attenuated strata of Cambrian (Flathead Sandstone, Wolsey Shale, Meagher Limestone, and undivided Pilgrim Formation and Park Shale), Devonian (Maywood Formation, Jefferson Formation, and most of the Three Forks Formation), and Mississippian (uppermost part of the Three Forks Formation and Lodgepole and Mission Canyon Limestones) ages. The overlying Hogback Mountain thrust plate contains strongly folded rocks ranging in age from the Middle Proterozoic Greyson Formation to the Upper and Lower Mississippian Mission Canyon Limestone and Cretaceous diorite sills. The highest structural level, the Moors Mountain thrust plate, contains the Middle Proterozoic Greyson and Newland Formations and discontinuous Upper Proterozoic diabase sills. Rocks are complexly folded and faulted across the quadrangle. At the lowest level in the northeastern part of the quadrangle, Upper Mississippian and younger strata are folded along northwest-trending axes and broken by thrust faults that at outcrop level displace the same rocks. The central core of the quadrangle is formed by the Avalanche Butte thrust plate, which contains recumbently folded and thrust faulted Paleozoic rocks. A succession of four tight recumbent folds within the plate have axial traces that trend northwest and north-northwest, and that are both arched and downfolded along east- and northeast-trending axes. Carbonate rocks of the Mission Canyon and Lodgepole Limestones in the upper part of the Avalanche Butte thrust plate exposed in the canyon of Trout Creek are folded and attenuated in stacked east-directed recumbent folds that developed as a succession of folded duplex thrust slices. The exposed remnant of the next higher structural level, the Hogback Mountain thrust plate, contains northeast- and east-trending folds that are inverted on the upper overturned limb of a younger northwest-trending recumbent fold. The Hogback Mountain thrust fault is itself folded and, in its northernmost exposures, is overturned to dip west beneath the overlying Moors Mountain thrust plate. During post-middle Tertiary deformation, the Hogback Mountain thrust fault moved as a normal fault, down on the east. The structurally highest Moors Mountain thrust plate rests on the Avalanche Butte thrust plate in the southwestern part of the quadrangle and across both the Avalanche Butte and Hogback Mountain thrust plates along the northwest edge of the quadrangle. In the central eastern part of the map area, the edge of a large klippen of the Moors Mounta

Preliminary integrated geologic map databases for the United States: Digital data for the generalized bedrock geologic map, Yukon Flats region, east-central Alaska

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Phillips, Jeffrey D.; Stanley, Richard G.; Crews, Jessie

2006-01-01

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Geological Map of the Fredegonde (V-57) Quadrangle, Venus

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Head, J. W.

2009-01-01

The area of V-57, the Fredegonde quadrangle (50-75degS, 60-120degE, Fig.1), is located within the eastern portion of Lada Terra within the topographic province of midlands (0-2 km above MPR [1,2]). Midlands form the most abundant portion of the surface of Venus and are characterized by diverse sets of units and structures [3-11]. The area of the Fredegonde quadrangle is in contact with the elevated portion of Lada Terra to the W and with the lowland of Aino Planitia to the NE. The transitions of the mid-lands to the lowlands and highlands are, thus, one of the main themes of the geology within the V-57 quadrangle. The character of the transitions and distribution and sequence of units/structures in the midlands are crucially important in understanding the time and modes of formation of this topographic province. The most prominent features in the map area are linear deformational zones consisting of swarms of grooves and graben and large coronae. The zones characterize the central and NW portions of the map area and represent regionally important, broad (up to 100s km wide) ridges that are 100s m high. Relatively small (100s km across, 100s m deep) equidimensional basins occur between the corona-groove-chains in the west and border the central chain from the east. Here we describe units that make up the surface within the V-57 quadrangle and present a summary of our geological map that shows the areal distribution of the major groups of units.

Tables showing analyses of semiquantitative spectrometry and atomic-absorption spectrophotometry of rock samples collected in the Ugashik, Bristol Bay, and western part of the Karluk quadrangles, Alaska

USGS Publications Warehouse

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

1987-01-01

The accompanying tables list chemical analyses of 337 rock samples that were collected in 1979, 1980, and 1981 in conjunction with geologic mapping in the Ugashik, Bristol Bay, and part of Karluk quadrangles. This work was conducted under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP). This report is to accompany Wilson and O'Leary (1986) which inadvertently is missing most of the data tables listed here. Together the two reports contain the complete data from all samples collected for the Ugashik AMRAP.

Publications - RI 2005-1E | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2005-1E Publication Details Title: Bedrock geologic map of the Council area, Solomon D-4 for more information. Quadrangle(s): Bendeleben; Solomon Bibliographic Reference Newberry, R.J ., Werdon, M.B., Athey, J.E., and Szumigala, D.J., 2005, Bedrock geologic map of the Council area, Solomon D

Publications - RDF 2001-1 | Alaska Division of Geological & Geophysical

Science.gov Websites

geochemical data from rocks collected in the Salcha River-Pogo area in 2000, Big Delta and northwestern Eagle more information. Quadrangle(s): Big Delta; Eagle Bibliographic Reference Werdon, M.B., Athey, J.E , and geochemical data from rocks collected in the Salcha River-Pogo area in 2000, Big Delta and

Geologic Map of the Weaverville 15' Quadrangle, Trinity County, California

USGS Publications Warehouse

Irwin, William P.

2009-01-01

The Weaverville 15' quadrangle spans parts of five generally north-northwest-trending accreted terranes. From east to west, these are the Eastern Klamath, Central Metamorphic, North Fork, Eastern Hayfork, and Western Hayfork terranes. The Eastern Klamath terrane was thrust westward over the Central Metamorphic terrane during early Paleozoic (Devonian?) time and, in Early Cretaceous time (approx. 136 Ma), was intruded along its length by the massive Shasta Bally batholith. Remnants of overlap assemblages of the Early Cretaceous (Hauterivian) Great Valley sequence and the Tertiary Weaverville Formation cover nearly 10 percent of the quadrangle. The base of the Eastern Klamath terrane in the Weaverville quadrangle is a peridotite-gabbro complex that probably is correlative to the Trinity ophiolite (Ordovician), which is widely exposed farther north beyond the quadrangle. In the northeast part of the Weaverville quadrangle, the peridotite-gabbro complex is overlain by the Devonian Copley Greenstone and the Mississippian Bragdon Formation. Where these formations were intruded by the Shasta Bally batholith, they formed an aureole of gneissic and other metamorphic rocks around the batholith. Westward thrusting of the Eastern Klamath terrane over an adjacent body of mafic volcanic and overlying quartzose sedimentary rocks during Devonian time formed the Salmon Hornblende Schist and the Abrams Mica Schist of the Central Metamorphic terrane. Substantial beds of limestone in the quartzose sedimentary unit, generally found near the underlying volcanic rock, are too metamorphosed for fossils to have survived. Rb-Sr analysis of the Abrams Mica Schist indicates a metamorphic age of approx. 380 Ma. West of Weavervillle, the Oregon Mountain outlier of the Eastern Klamath terrane consists mainly of Bragdon Formation(?) and is largely separated from the underlying Central Metamorphic terrane by serpentinized peridotite that may be a remnant of the Trinity ophiolite. The North Fork terrane is faulted against the west edge of the Central Metamorphic terrane, and its northerly trend is disrupted by major left-lateral offsets along generally west-northwest-trending faults. The serpentinized peridotite-gabbro complex that forms the western base of the terrane is the Permian North Fork ophiolite, which to the east is overlain by broken formation of mafic-volcanic rocks, red chert, siliceous tuff, argillite, minor limestone, and clastic sedimentary rocks. The chert and siliceous tuff contain radiolarians of Permian and Mesozoic ages, and some are as young as Early Jurassic (Pliensbachian). Similar Pliensbachian radiolarians are found in Franciscan rocks of the Coast Ranges. The Eastern Hayfork terrane is broken formation and melange of mainly chert, sandstone, argillite, and various exotic blocks. The cherts yield radiolarians of Permian and Triassic ages but none of clearly Jurassic age. Limestone bodies of the Eastern Hayfork terrane contain Permian microfaunas of Tethyan affinity. The Western Hayfork terrane, exposed only in a small area in the southwestern part of the quadrangle, consists dominantly of mafic tuff and dark slaty argillite. Sparse paleontologic data indicate a Mesozoic age for the strata. The terrane includes small bodies of diorite that are related to the nearby Wildwood pluton of Middle Jurassic age and probably are related genetically to the stratified rocks. The terrane is interpreted to be the accreted remnants of a Middle Jurassic volcanic arc. Shortly after intrusion by Shasta Bally batholith (approx. 136 Ma), much of the southern half of the Weaverville quadrangle was overlapped by Lower Cretaceous, dominantly Hauterivian, marine strata of the Great Valley sequence, and to a lesser extent later during Oligocene and (or) Miocene time by fluvial and lacustrine deposits of the Weaverville Formation. This map of the Weaverville Quadrangle is a digital rendition of U.S. Geological Survey Miscellaneous Field

Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

NASA Astrophysics Data System (ADS)

Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

2013-12-01

Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

Publications - RDF 2004-1 | Alaska Division of Geological & Geophysical

Science.gov Websites

, C-4, and B-5 quadrangles, Alaska Authors: Athey, J.E., Layer, P.W., and Drake, Jeff Publication Date ): Livengood Bibliographic Reference Athey, J.E., Layer, P.W., and Drake, Jeff, 2004, 40Ar/39Ar ages of rocks

Fossil locations and data for the Taylor Mountains, and parts of the Bethel, Goodnews, and Dillingham quadrangles, southwestern Alaska

USGS Publications Warehouse

Karl, Susan M.; Blodgett, R.B.; Labay, Keith A.; Box, S.E.; Bradley, D.C.; Miller, M.L.; Wallace, W.K.; Baichtal, J.F.

2011-01-01

Information about fossils collected by U.S. Geological Survey, State of Alaska, academic, and industry geologists that have been reported in literature or archived in reports from the former U.S. Geological Survey Branch of Paleontology and Stratigraphy are compiled on a plate and table in this report to provide comprehensive paleontologic age data for the Taylor Mountains quadrangle area in southwestern Alaska. The reports used to compile the table in this report were submitted by recognized paleontologic experts. Some of the information is derived from reports that date back almost 100 years. Many of the data are available in more detail in the Alaska Paleontological Database (http://www.alaskafossil.org/). The 287 entries in this table are shown on the accompanying plate, on which symbols representing the entries are color-coded by geologic age. This report represents the most comprehensive and most recently updated compilation of paleontologic data for this area.

Map showing distribution of gold in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, W.R.; Motooka, J.M.; McHugh, J.B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of gold in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the Selected References of this report. The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of silver in the nonmagnetic fraction of heavy-mineral concentrates, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of silver in the nonmagnetic fraction of heavy-mineral concentrates of drainage-sediment samples. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of thorium in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of thorium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of zinc in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of zinc in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of lead in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of lead in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of cadmium and antimony in the nonmagnetic fraction of heavy-mineral concentrates, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of cadmium and antimony in the nonmagnetic fraction of drainage-sediment samples. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of molybdenum in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of molybdenum in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of bismuth and cadmium in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of bismuth and cadimum in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of silver in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of silver in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of tin in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of tin in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Map showing distribution of uranium in stream-sediment samples, Richfield 1 degree by 2 degrees Quadrangle, Utah

USGS Publications Warehouse

Miller, William R.; Motooka, Jerry M.; McHugh, John B.

1990-01-01

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of uranium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

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

Huntsman, J.R.

Eastern slate belt lithologies in the central Flowers quadrangle consist of metavolcanic and metasedimentary rocks. Very fine-grained quartz-white mica phyllite containing narrow, discontinuous layers of thinly laminated chlorite-rich rock and fine-grained, thinly layered, feldspar crystal felsic metatuff comprise the dominant, mappable units consistent across the quadrangle. An increase in grain size accompanied by a replacement of chlorite-rich lithologies with biotite [+-] garnet assemblages suggest metamorphic grade increases towards the western half of the quadrangle (quartz-muscovite schist and biotite-quartz-muscovite-feldspar gneiss). An early, northeast-trending foliation (050[degree] to 060[degree]) dipping moderately to steeply southeast persists across the quadrangle and is axial planar tomore » tight to isoclinal, recumbent to moderately inclined folds. Later non-coaxial folding produced steeply plunging, northerly trending (000[degree] to 020[degree]), open, asymmetric structures verging towards the east/southeast. Shear zones formed locally along the axial trend of these later folds and produced protomylonitic to mylonitic ( ) fabrics. Map patterns and cross-sectional interpretations are best explained by modification of zig-zag fold interference patterns. Thin section examination reveals garnets growing across the early axial planar foliation. The observed increase in metamorphic grade across the quadrangle matches the regional Alleghanian prograde event and constrains relative timing of observed deformational fabrics. Noticeably absent are regional, late-stage upright folds.« less

Inter-population movements of steller sea lions in Alaska with implications for population separation.

PubMed

Jemison, Lauri A; Pendleton, Grey W; Fritz, Lowell W; Hastings, Kelly K; Maniscalco, John M; Trites, Andrew W; Gelatt, Tom S

2013-01-01

Genetic studies and differing population trends support the separation of Steller sea lions (Eumetopias jubatus) into a western distinct population segment (WDPS) and an eastern DPS (EDPS) with the dividing line between populations at 144° W. Despite little exchange for thousands of years, the gap between the breeding ranges narrowed during the past 15-30 years with the formation of new rookeries near the DPS boundary. We analyzed >22,000 sightings of 4,172 sea lions branded as pups in each DPS from 2000-2010 to estimate probabilities of a sea lion born in one DPS being seen within the range of the other DPS (either 'West' or 'East'). Males from both populations regularly traveled across the DPS boundary; probabilities were highest at ages 2-5 and for males born in Prince William Sound and southern Southeast Alaska. The probability of WDPS females being in the East at age 5 was 0.067 but 0 for EDPS females which rarely traveled to the West. Prince William Sound-born females had high probabilities of being in the East during breeding and non-breeding seasons. We present strong evidence that WDPS females have permanently emigrated to the East, reproducing at two 'mixing zone' rookeries. We documented breeding bulls that traveled >6,500 km round trip from their natal rookery in southern Alaska to the northern Bering Sea and central Aleutian Islands and back within one year. WDPS animals began moving East in the 1990s, following steep population declines in the central Gulf of Alaska. Results of our study, and others documenting high survival and rapid population growth in northern Southeast Alaska suggest that conditions in this mixing zone region have been optimal for sea lions. It is unclear whether eastward movement across the DPS boundary is due to less-optimal conditions in the West or a reflection of favorable conditions in the East.

Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska

USGS Publications Warehouse

Dusel-Bacon, Cynthia; Slack, John F.; Koenig, Alan E.; Foley, Nora K.; Oscarson, Robert L.; Gans, Kathleen D.

2011-01-01

This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of sulfide minerals determined by electron microprobe and laser ablation—inductively coupled plasma—mass spectrometry (LA-ICP-MS) techniques. The PDF consists of text, appendix explaining the analytical methods used for the analyses presented in the data tables, a sample location map, and seven data tables. The seven tables are also available as spreadsheets in several file formats. Descriptions and discussions of the Bonnifield deposits are given in Dusel-Bacon and others (2004, 2005, 2006, 2007, 2010).

Reconnaissance sedimentology of selected tertiary exposures in the upland region bordering the Yukon Flats basin, east-central Alaska

USGS Publications Warehouse

LePain, David L.; Stanley, Richard G.

2017-01-01

This report summarizes reconnaissance sedimentologic and stratigraphic observations made during six days of helicopter-supported fieldwork in 2002 on Tertiary sedimentary rocks exposed in the upland region around the flanks of the Yukon Flats basin in east-central Alaska (fig. 1). This project was a cooperative effort between the Alaska Division of Geological & Geophysical Surveys (DGGS) and the U.S. Geological Survey (USGS) to investigate the geology of the basin in preparation for an assessment of the undiscovered, technically recoverable hydrocarbon resources (Stanley and others, 2004). Field observations and interpretations summarized in this report are reconnaissance level. At most, no more than a few hours were spent on the ground at any location. Measured sections included in this report are sketch sec- tions and thicknesses shown are approximate. Relatively detailed observations were made by the authors at only three locations, including The Mudbank (Hodzana River), Rampart (east bank of the Yukon River), and Bryant Creek (along the Tintina fault near the Canada border). These three locations are described first in relative detail, then followed by general descriptions of other locations.

Nure aerial gamma-ray and magnetic reconnaissance survey: Chugach/Yakutat area, Alaska, Mt. Saint Elias Quadrangle

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

Not Available

1978-10-01

Volume II contains the following data on Mt. Saint Elias, Alaska: geologic base map, flight path map, anomaly maps (U, Th, K, UlTh, UlK, ThlK), radiometric multiple-parameter stacked profiles, magnetic and ancillary profile data, and statistical data. (LK)

Geologic map of the Alamosa 30’ × 60’ quadrangle, south-central Colorado

USGS Publications Warehouse

Thompson, Ren A.; Shroba, Ralph R.; Michael N. Machette,; Fridrich, Christopher J.; Brandt, Theodore R.; Cosca, Michael A.

2015-10-15

The Alamosa 30'× 60' quadrangle is located in the central San Luis Basin of southern Colorado and is bisected by the Rio Grande. The Rio Grande has headwaters in the San Juan Mountains of Colorado and ultimately discharges into the Gulf of Mexico 3,000 kilometers (km) downstream. Alluvial floodplains and associated deposits of the Rio Grande and east-draining tributaries, La Jara Creek and Conejos River, occupy the north-central and northwestern part of the map area. Alluvial deposits of west-draining Rio Grande tributaries, Culebra and Costilla Creeks, bound the Costilla Plain in the south-central part of the map area. The San Luis Hills, a northeast-trending series of flat-topped mesas and hills, dominate the landscape in the central and southwestern part of the map and preserve fault-bound Neogene basin surfaces and deposits. The Precambrian-cored Sangre de Cristo Mountains rise to an elevation of nearly 4,300 meters (m), almost 2,000 m above the valley floor, in the eastern part of the map area. In total, the map area contains deposits that record surficial, tectonic, sedimentary, volcanic, magmatic, and metamorphic processes over the past 1.7 billion years.

Off-platform Silurian sequences in the Ambler River quadrangle: A section in Geologic studies in Alaska by the U.S. Geological Survey during 1987

USGS Publications Warehouse

Dumoulin, Julie A.; Harris, Anita G.

1988-01-01

Lithofacies changes in coeval upper Paleozoic rocks have been used to unravel the tectonic history of northern Alaska (for example, Mayfield and others, 1983). Conodont biostratigraphy and detailed petrologic studies are now revealing facies differences in lower Paleozoic rocks that can also be used to constrain their tectono-sedimentary framework (Dumoulin and Harris, 1987). A basic element of basin analysis is the discrimination of shallow-water shelf and platform sequences from deeper water slope and basinal deposits. This report documents several new localities of deeper water, off-platform Silurian deposits in the Ambler River quadrangle and briefly outlines some of their paleogeographic implications.

Aerial gamma ray and magnetic survey: Nebraska/Texas survey, Texarkana Quadrangle of Texas, Oklahoma, Arkansas, and Louisiana. Final report

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

Not Available

The Texarkana quadrangle of eastern Texas and portions of three adjacent states lies within the northern Gulf Coastal Province. The area contains portions of the Ouachita Tectonic Belt and the East Texas-Athens Embayment. The Mexia-Talco Fault Zone strikes roughly east-west through the center of the quadrangle. North of the fault zone Cretaceous platform deposits dominate, whereas Eocene neritic sediments cover most of the area south of the zone. Examination of available literature shows no known uranium deposits (or occurrences) within the quadrangle. One hundred fifty-nine groups of uranium samples were defined as anomalies and discussed briefly in this report. Nonemore » were considered significant, and most appeared to be of cultural origin. Magnetic data in the quadrangle are dominantly low frequency/low amplitude wavelengths, which suggests that sources may be extremely deep.« less

Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska

USGS Publications Warehouse

Dusel-Bacon, Cynthia; Holm-Denoma, Christopher S.; Jones, James V.; Aleinikoff, John N.; Mortensen, James K.

2017-01-01

We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the Healy schist, all have dominant detrital zircon populations of 1.9–1.8 Ga and a subordinate population of 2.7–2.6 Ga. Three zircons from Totatlanika Schist yield the youngest age of ca. 780 Ma. The anomalous Healy schist sample has abundant 1.6–0.9 Ga detrital zircon, as well as populations at 2.0–1.8 Ga and 2.7–2.5 Ga that overlap the ages from the rest of our samples; it has a minimum age population of ca. 1007 Ma.Detrital zircon age populations from all but the anomalous sample are statistically similar to those from (1) other peri-Laurentian units in east-central Alaska; (2) the Snowcap assemblage in Yukon, basement of the allochthonous Yukon-Tanana terrane; (3) Neoproterozoic to Ordovician Laurentian passive margin strata in southern British Columbia, Canada; and (4) Proterozoic Laurentian Sequence C strata of northwestern Canada. Recycling of zircon from the Paleoproterozoic Great Bear magmatic zone in the Wopmay orogen and its Archean precursors could explain both the Precambrian zircon populations and arc trace element signatures of our samples. Zircon from the anomalous Healy schist sample resembles that in Nation River Formation and Adams Argillite in eastern Alaska, suggesting recycling of detritus in those units.

Geologic map of the Vashon 7.5' quadrangle and selected areas, King County, Washington

USGS Publications Warehouse

Booth, Derek B.; Troost, Kathy Goetz; Tabor, Rowland W.

2015-01-01

This map, the Vashon quadrangle and selected adjacent areas, encompasses most of Vashon Island, Maury Island, and Three Tree Point in the south-central Puget Sound. One small area in the Vashon quadrangle on the east side of Puget Sound is excluded from this map but included on the adjacent Seattle quadrangle (Booth and others, 2005). The map displays a wide variety of surficial geologic deposits, which reflect many geologic environments and processes. Multiple ice-sheet glaciations and intervening nonglacial intervals have constructed a complexly layered sequence of deposits that underlie both islands to a depth of more than 300 m below sea level. These deposits not only record glacial and nonglacial history but also control the flow and availability of ground water, determine the susceptibility of the slopes to landslides, and provide economic reserves of sand and gravel. The islands are surrounded by channels of Puget Sound, some as deep as the islands are high (>600 ft (~200 m)). The shorelines provide many kilometers of well-exposed coastal outcrops that reveal abundant lithologic and stratigraphic details not ordinarily displayed in the heavily vegetated Puget Lowland.

Geologic Map of the MTM -30262 and -30267 Quadrangles, Hadriaca Patera Region of Mars

USGS Publications Warehouse

Crown, David A.; Greeley, Ronald

2007-01-01

Introduction Mars Transverse Mercator (MTM) -30262 and -30267 quadrangles cover the summit region and east margin of Hadriaca Patera, one of the Martian volcanoes designated highland paterae. MTM -30262 quadrangle includes volcanic deposits from Hadriaca Patera and Tyrrhena Patera (summit northeast of map area) and floor deposits associated with the Dao and Niger Valles canyon systems (south of map area). MTM -30267 quadrangle is centered on the caldera of Hadriaca Patera. The highland paterae are among the oldest, central-vent volcanoes on Mars and exhibit evidence for explosive eruptions, which make a detailed study of their geology an important component in understanding the evolution of Martian volcanism. Photogeologic mapping at 1:500,000-scale from analysis of Viking Orbiter images complements volcanological studies of Hadriaca Patera, geologic investigations of the other highland paterae, and an analysis of the styles and evolution of volcanic activity east of Hellas Planitia in the ancient, cratered highlands of Mars. This photogeologic study is an extension of regional geologic mapping east of Hellas Planitia. The Martian highland paterae are low-relief, areally extensive volcanoes exhibiting central calderas and radial channels and ridges. Four of these volcanoes, Hadriaca, Tyrrhena, Amphitrites, and Peneus Paterae, are located in the ancient cratered terrains surrounding Hellas Planitia and are thought to be located on inferred impact basin rings or related fractures. Based on analyses of Mariner 9 images, Potter (1976), Peterson (1977), and King (1978) suggested that the highland paterae were shield volcanoes formed by eruptions of fluid lavas. Later studies noted morphologic similarities between the paterae and terrestrial ash shields and the lack of primary lava flow features on the flanks of the volcanoes. The degraded appearances of Hadriaca and Tyrrhena Paterae and the apparently easily eroded materials composing their low, broad shields further suggest that the highland paterae are composed predominantly of pyroclastic deposits. Analyses of eruption and flow processes indicate that the distribution of units at Hadriaca and Tyrrhena Paterae is consistent with emplacement by gravity-driven pyroclastic flows. Detailed geologic study of the summit caldera and flanks of Hadriaca Patera is essential to determine the types of volcanic materials exposed, the nature of the processes forming these deposits, and the role of volcanism in the evolution of the cratered highlands that are characteristic of the southern hemisphere of Mars.

Alaska Resource Data File: Chignik quadrangle, Alaska

USGS Publications Warehouse

Pilcher, Steven H.

2000-01-01

Descriptions of the mineral occurrences can be found in the report. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska. There is a website from which you can obtain the data for this report in text and Filemaker Pro formats

Transit traverse in Missouri, 1900-1937. Part 6, Northeastern Missouri, 1900-37

USGS Publications Warehouse

Staack, John George

1940-01-01

This bulletin, which for convenience is to be published in eight parts, contains the results of all transit traverse* done In Missouri through 1937 by the Geological Survey, United States Department of the Interior, including those heretofore published. (See page X.) Each of the parts deals with one of eight sections into which the State has been divided for this purpose and which have been designated northeastern, northwestern, southeastern, southwestern, central, east-central, south-central, and west-central Missouri. In each part descriptions of the points for which geodetic positions have been determined are listed according to the quadrangles in which the points occur. Results of transit traverse other than that done by the Geological Survey have not been included.Northeastern Missouri, as the term is used in this bulletin and as the subject of part 6 of the bulletin, is, as its name indicates, the north-easternmost section of the State. Its north and east boundaries are the boundaries of the State; its west and south boundaries are formed by a line that runs south along longitude 93°15' to latitude 39°30', thence east to longitude 92°00', thence south to latitude 39°15', thence east to the east boundary of the State.

Geochemical data for stream-sediment, heavy-mineral-concentrate and rock samples collected from the Fortyseven Creek gold-arsenic-antimony-tungsten prospect, southwestern Alaska

USGS Publications Warehouse

Gray, John E.; Lee, G.K.; O'Leary, R. M.; Theodorakos, P.M.

1999-01-01

In the summer of 1991, we conducted a reconnaissance geochemical survey around the Fortyseven Creek Au-As-Sb-W prospect that is located in the southwestern part of the Sleetmute quadrangle. At that time, this project was a small part of a more comprehensive Alaska Mineral Resource Assessment Program (AMRAP) study of the Sleemute quadrangle. AMRAP studies were conducted by the U.S. Geological Survey (USGS) to fulfill requirements of the Alaska National Interests Lands Conservation Act (Public Law 96-487, 1980) to survey certain federal lands to determine their mineral potential. Although AMRAP is no longer in operation, this study represents a small topical study that was conducted during the Sleetmute quadrangle AMRAP study. The objective of the Fortyseven Creek work was to characterize the geochemistry of samples collected downstream from the Fortyseven Creek prospect, as well as mineralized and altered rock samples collected from the prospect. In this report, we describe the samples collected in 1991, the methods used for the analysis of the samples, and the geochemical data for these samples. The data in this report are also available in digital form on computer diskette in Gray and others (1999). An interpretation of these data appears in Gray and others (1998).

New ichnological, paleobotanical and detrital zircon data from an unnamed rock unit in Yukon-Charley Rivers National Preserve (Cretaceous: Alaska): Stratigraphic implications for the region

USGS Publications Warehouse

Fiorillo, Anthony R.; Fanti, Federico; Hults, Chad; Hasiotis, Stephen T

2014-01-01

A paleontological reconnaissance survey on Cretaceous and Paleogene terrestrial units along the Yukon River drainage through much of east-central Alaska has provided new chronostratigraphic constraints, paleoclimatological data, and the first information on local biodiversity within an ancient, high-latitude ecosystem. The studied unnamed rock unit is most notable for its historic economic gold placer deposits, but our survey documents its relevance as a source rock for Mesozoic terrestrial vertebrates, invertebrates, and associated flora. Specifically, new U-Pb ages from detrital zircons combined with ichnological data are indicative of a Late Cretaceous age for at least the lower section of the studied rock unit, previously considered to be representative of nearly exclusively Paleogene deposition. Further, the results of our survey show that this sedimentary rock unit preserves the first record of dinosaurs in the vast east-central Alaska region. Lastly, paleobotanical data, when compared to correlative rock units, support previous interpretations that the Late Cretaceous continental ecosystem of Alaska was heterogeneous in nature and seasonal.

Geology and ground-water resources of northern Mercer County, Pennsylvania

USGS Publications Warehouse

Schiner, G.R.; Kimmel, G.E.

1976-01-01

The Shenango and Stoneboro 15-minute quadrangles are in northwestern Pennsylvania and are about 60 miles north of Pitts burgh. These two quadrangles comprise the following 7%-minute quadrangles: Greenville West, Greenville East, Sharpsville, Fredonia, Hadley, New Lebanon, Jackson Center, and Sandy Lake. The area covered by the two quadrangles includes the northern two thirds of Mercer County and a small amount of adjoining southern Crawford County.

Traces of Old Glaciations in East-central Alaska

NASA Astrophysics Data System (ADS)

Duk-Rodkin, A.; Barendregt, R. W.; Weber, F.

2001-12-01

The East-central Alaska record of glaciations is similar to that preserved in the west-central Yukon. Surficial geologic mapping of the Yukon-Tanana upland has indicated at least 5 glacial periods including at least one early Holocene. The two earliest glaciations are of pre-Mid Pleistocene age and followed regional erosion and renewed uplift ca.4 Ma. The earliest glaciation of west-central Yukon occurred between 2.6 and 2.9 Ma, forming a continuous carapace of ice covering all the mountain ranges except for a small part of the Dawson Range. This first glaciation was also the most extensive in the region, and resulted in the NW diversion of Yukon River into Alaska by the Cordilleran Ice Sheet. Stratigraphic evidence of 6 glaciations of pre-Mid Pleistocene age is preserved in the western Canadian sector of the Tintina Trench. The limits of these glaciations have been mapped in Yukon on the basis of glacial landforms and the distribution of erratics. Although morphological features of older glaciations (Plio-Pleistocene) are generally not well preserved, there is relatively good control on the distribution of glacial features for two of the older glaciations in Mt.Harper, Alaska. Stratigraphic evidence of at least 3 older glaciations is found in the Goodpastor River. An initial magnetostratigraphic study of three sites in east-central Alaska have yielded normal magnetic polarities only. The sites are:(1) a relatively weathered lowermost till outcropping along Goodpastor River on the Yukon-Tanana upland,(2) an extremely weathered high level moraine (609m) on the western side of the Gerstle River, near Granite Mt.in the Alaska Range and (3)ca.914m pediment containing glacial erratics and a luvisol at its surface, located on Tok River, Tanana Valley, Alaska Range. The normal polarity of the first site likely indicates a Brunhes age rather than a normal subchron within the Matuyama Reversed Chron based on the modest degree of weathering of the till and lack of any reversed overprint. The second site may be related to an older glacial event based on the high degree of clast weathering (>90%) and the presence of a luvisol over 1m depth. Clasts at the third site are better preserved suggesting the normal magnetization of these sediments may be Brunhes age. Deeply weathered clasts and red soils (Wounded Moose Paleosol)are found on pre-Mid Pleistocene glacial drift surfaces in west-central Yukon and appear also to be present on the older drift surfaces in east-central Alaska (for example, the well developed paleosol exposed in a borrow pit at the Tok town site). The presence of relatively old (early Brunhes) glacial deposits at high elevations (third site) could be explained by tectonic uplift, however a minimum of 300m of post depositional uplift would be required to account for the present elevation of these surfaces. Evidence for the diversion of the Yukon River by the first glaciation is seen near Circle, Alaska where lower fluvial gravels free of argillites of eastern (Ogilvie Mountains) provenance, are overlain by glacial outwash gravels containing approximately 8% argillites. The lower gravels are considered Late Pliocene (Gauss) based on plant macro fossils and normal polarity, and based on the absence of argillites, are clearly preglacial. Normally magnetized Late Pliocene pre-glacial fluvial gravels, the White Channel gravels, are found in the Tintina Trench and Klondike Plateau, which are conformably overlain by the Klondike outwash gravels associated with the first glaciation.

Geologic map of the Leadville North 7.5’ quadrangle, Eagle and Lake Counties, Colorado

USGS Publications Warehouse

Ruleman, Chester A.; Brandt, Theodore R.; Caffee, Marc W.; Goehring, Brent M.

2018-04-24

The Leadville North 7.5’ quadrangle lies at the northern end of the Upper Arkansas Valley, where the Continental Divide at Tennessee Pass creates a low drainage divide between the Colorado and Arkansas River watersheds. In the eastern half of the quadrangle, the Paleozoic sedimentary section dips generally 20–30 degrees east. At Tennessee Pass and Missouri Hill, the core of the Sawatch anticlinorium is mapped as displaying a tight hanging-wall syncline and foot-wall anticline within the basement-cored structure. High-angle, west-dipping, Neogene normal faults cut the eastern margin of the broad, Sawatch anticlinorium. Minor displacements along high-angle, east- and west-dipping Laramide reverse faults occurred in the core of the north-plunging anticlinorium along the western and eastern flanks of Missouri Hill. Within the western half of the quadrangle, Meso- and Paleoproterozoic metamorphic and igneous rocks are uplifted along the generally east-dipping, high-angle Sawatch fault system and are overlain by at least three generations of glacial deposits in the western part of the quadrangle. 10Be and 26Al cosmogenic nuclide ages of the youngest glacial deposits indicate a last glacial maximum age of about 21–22 kilo-annum and complete deglaciation by about 14 kilo-annum, supported by chronologic studies in adjacent drainages. No late Pleistocene tectonic activity is apparent within the quadrangle.

Preliminary Geologic Map of the Hemet 7.5' Quadrangle, Riverside County, California

USGS Publications Warehouse

Morton, Douglas M.; Matti, Jon C.

2005-01-01

The Hemet 7.5' quadrangle is located near the eastern edge of the Perris block of the Peninsular Ranges batholith. The northeastern corner of the quadrangle extends across the San Jacinto Fault Zone onto the edge of the San Jacinto Mountains block. The Perris block is a relatively stable area located between the Elsinore Fault Zone on the west and the San Jacinto Fault Zone on the east. Both of the fault zones are active; the San Jacinto being the seismically most active in southern California. The fault zone is obscured by very young alluvial deposits. The concealed location of the San Jacinto Fault Zone shown on this quadrangle is after Sharp, 1967. The geology of the quadrangle is dominated by Cretaceous tonalite formerly included in the Coahuila Valley pluton of Sharp (1967). The northern part of Sharp's Coahuila Valley pluton is separated out as the Hemet pluton. Tonalite of the Hemet pluton is more heterogeneous than the tonalite of the Coahuila Valley pluton and has a different sturctural pattern. The Coahuila Valley pluton consists of relatively homogeneous hornblende-biotite tonalite, commonly with readily visible large euhedral honey-colored sphene crystals. Only the tip of the adjacent Tucalota Valley pluton, another large tonalite pluton, extends into the quadrangle. Tonalite of the Tucalota Valley pluton is very similar to the tonalite of the Coahuila Valley pluton except it generally lacks readily visible sphene. In the western part of the quadrangle a variety of amphibolite grade metasedimentary rocks are informally referred to as the rocks of Menifee Valley; named for exposures around Menifee Valley west of the Hemet quadrangle. In the southwestern corner of the quadrangle a mixture of schist and gneiss marks a suture that separated low metamorphic grade metasedimentary rocks to the west from high metamorphic grade rocks to the east. The age of these rocks is interpreted to be Triassic and the age of the suturing is about 100 Ma, essentially the same age as the adjacent Coahuila Valley pluton. Rocks within the suture zone consist of a mixture of lithologies from both sides of the suture. Gneiss, schist, and anatectic gneiss are the predominate lithologies within the rocks on the east side of the suture. Lesser amounts of metalithic greywacke and lenticular masses of black amphibolite are subordinate rock types. Biotite, biotite-sillimanite and lesser amounts of garnet-biotite-sillimanite schist and metaquartzite-metalithic greywacke lithologies occur west of the suture. Pleistocene continental beds, termed the Bautista beds occur east of the San Jacinto Fault Zone in the northeast corner of the quadrangle. Most of the Bautista beds were derived from the San Jacinto pluton that is located just to the east of the sedimentary rocks. Along the northern part of the quadrangle is the southern part of a large Holocene-late Pleistocene fan emanating from Baustista Canyon. Sediments in the Bautista fan are characterized by their content of detritus derived from amphibolite grade metasedimentary rocks located in the Bautista Canyon drainage. Between the Holocene-late Pleistocene Bautista fan and the Santa Rosa Hills is the remnant of a much older Bautista Canyon alluvial fan. A pronounced Holocene-late Pleistocene channel was developed along the south fringe of the very old alluvial fan and the Santa Rosa Hill. A now dissected late to middle Pleistocene alluvial complex was produced by the coalesced fans of Goodhart, St. Johns, and Avery canyons, and Cactus Valley. Pleistocene continental beds, termed the Bautista beds occur east of the San Jacinto Fault Zone in the northeast corner of the quadrangle. Most of the Bautista beds were derived from the San Jacinto pluton that is located just to the east of the sedimentary rocks. Along the northern part of the quadrangle is the southern part of a large Holocene-late Pleistocene fan emanating from Baustista Canyon. Sediments in the Bautista fan are characterized by

Reconnaissance investigation of the Lisburne Group in the Cobblestone Creek area, Chandler Lake quadrangle, Alaska

USGS Publications Warehouse

Dumoulin, Julie A.; Whalen, Michael T.; Edited by Wartes, M. A.; Decker, P. L.

2015-01-01

A reconnaissance investigation of the Carboniferous Lisburne Group in the Cobblestone Creek area, Chandler Lake Quadrangle, yields insights into its resource potential and regional relations. Locally porous vuggy dolostone with hydrocarbon reservoir potential occurs in the lower Lisburne in the three most southerly of five thrust sheets, and contains traces of dead oil in two of these sheets. The dolostones are coarse crystalline, commonly cross-bedded, and at least in part of Osagean (late Early Mississippian) age; they have pelmatozoan grainstone protoliths that likely formed in sand shoals of the midramp to inner ramp. Similar, coeval porous dolostones occur in the Lisburne from Skimo Creek to Itkillik Lake, ~70 km west and 10 km east of the Cobblestone Creek area, respectively. We also examined the uppermost Lisburne Group at several localities in the Cobblestone Creek area, mainly in the northernmost thrust sheet where the rocks are as young as Morrowan (Early Pennsylvanian). Cobblestone sections contain more supportstone than equivalent strata at Skimo Creek, and overlying Permian successions also differ between the two areas. These lithologic contrasts may reflect different rates of tectonically controlled subsidence, and (or) changes in sediment input, along the late Paleozoic continental margin.

Radiometric age map of southcentral Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Turner, D.L.

1975-01-01

This map includes published, thesis, and open-file radiometric data available to us as of June, 1975. Some dates are not plotted because of inadequate location data in the original references.The map is divided into five sections, based on 1:1,000,000 scale enlargements of the National Atlas maps of Alaska. Within each section (e.g., southeastern Alaska), radiometric dates are plotted and keyed to 1:250,000 scale quadrangles. Accompanying each map section is table 1, listing map numbers and the sample identification numbers used in DGGS Special Report 10: Radiometric Dates from Alaska-A 1975 Compilation”. The reader is referred to Special Report 10 for more complete information on location, rock type, dating method, and literature references for each age entry. A listing of dates in Special Report lo which require correction or deletion is included S table 2. Corrected and additional entries are listed in table 3. The listings in tables 2 and 3 follow the format of Special Report 10. Table 4 is a glossary of abbreviations used for quadrangle name, rock type, mineral dated, and type of dating method used.

Radiometric age map of southwest Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Turner, D.L.

1975-01-01

This map includes published, thesis, and open-file radiometric data available to us as of June, 1975. Some dates are not plotted because of inadequate location data in the original references.The map is divided into five sections, based on 1:1,000,000 scale enlargements of the National Atlas maps of Alaska. Within each section (e.g., southeastern Alaska), radiometric dates are plotted and keyed to 1:250,000 scale quadrangles. Accompanying each map section is table 1, listing map numbers and the sample identification numbers used in DGGS Special Report 10: Radiometric Dates from Alaska-A 1975 Compilation”. The reader is referred to Special Report 10 for more complete information on location, rock type, dating method, and literature references for each age entry. A listing of dates in Special Report lo which require correction or deletion is included S table 2. Corrected and additional entries are listed in table 3. The listings in tables 2 and 3 follow the format of Special Report 10. Table 4 is a glossary of abbreviations used for quadrangle name, rock type, mineral dated, and type of dating method used.

Radiometric age map of southeast Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Turner, D.L.

1975-01-01

This map includes published, thesis, and open-file radiometric data available to us as of June, 1975. Some dates are not plotted because of inadequate location data in the original references.The map is divided into five sections, based on 1:1,000,000 scale enlargements of the National Atlas maps of Alaska. Within each section (e.g., southeastern Alaska), radiometric dates are plotted and keyed to 1:250,000 scale quadrangles. Accompanying each map section is table 1, listing map numbers and the sample identification numbers used in DGGS Special Report 10: Radiometric Dates from Alaska-A 1975 Compilation”. The reader is referred to Special Report 10 for more complete information on location, rock type, dating method, and literature references for each age entry. A listing of dates in Special Report lo which require correction or deletion is included S table 2. Corrected and additional entries are listed in table 3. The listings in tables 2 and 3 follow the format of Special Report 10. Table 4 is a glossary of abbreviations used for quadrangle name, rock type, mineral dated, and type of dating method used.

Radiometric age map of northern Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Turner, D.L.

1975-01-01

This map includes published, thesis, and open-file radiometric data available to us as of June, 1975. Some dates are not plotted because of inadequate location data in the original references.The map is divided into five sections, based on 1:1,000,000 scale enlargements of the National Atlas maps of Alaska. Within each section (e.g., southeastern Alaska), radiometric dates are plotted and keyed to 1:250,000 scale quadrangles. Accompanying each map section is table 1, listing map numbers and the sample identification numbers used in DGGS Special Report 10: Radiometric Dates from Alaska-A 1975 Compilation”. The reader is referred to Special Report 10 for more complete information on location, rock type, dating method, and literature references for each age entry. A listing of dates in Special Report lo which require correction or deletion is included S table 2. Corrected and additional entries are listed in table 3. The listings in tables 2 and 3 follow the format of Special Report 10. Table 4 is a glossary of abbreviations used for quadrangle name, rock type, mineral dated, and type of dating method used.

Paleobiogeographic affinities of emsian (late early devonian) gastropods from farewell terrane (west-central Alaska)

USGS Publications Warehouse

Fryda, J.; Blodgett, R.B.

2008-01-01

The vast majority of Emsian gastropods from Limestone Mountain, Medfra B-4 quadrangle, west-central Alaska (Farewell terrane) belong to species with lecithotrophic larval strategy. The present data show that there is no significant difference in the paleobiogeo-graphic distribution of Emsian gastropod genera with lecithotrophic and planktotrophic larval strategies. Numerical analysis of the faunal affinities of the Emsian gastropod fauna from the Farewell terrane reveals that this terrane has much stronger faunal connections to regions like Variscan Europe, eastern Australia, and the Alexander terrane of southeast Alaska than to cratonic North America (Laurentia). The Canadian Arctic Islands is the only region of cratonic North America (Laurentia) that shows significant faunal affinities to the Emsian gastropod faunas of the Farewell terrane. The analysis also indicates a close faunal link between the Farewell and Alexander terranes. Published paleontological and geological data suggest that the Farewell and Alexander terranes represents tectonic entities that have been rifted away from the Siberia, Baltica, or the paleo-Pacific margin of Australia. The results of the present numerical analysis are not in conflict with any of these possibilities. However, the principle of spatial continuity of the wandering path prefers Siberia as the most probable "parental" paleocontinent for the derivation of both the Farewell and Alexander terranes. ?? 2008 The Geological Society of America.

Inter-Population Movements of Steller Sea Lions in Alaska with Implications for Population Separation

PubMed Central

Jemison, Lauri A.; Pendleton, Grey W.; Fritz, Lowell W.; Hastings, Kelly K.; Maniscalco, John M.; Trites, Andrew W.; Gelatt, Tom S.

2013-01-01

Genetic studies and differing population trends support the separation of Steller sea lions (Eumetopias jubatus) into a western distinct population segment (WDPS) and an eastern DPS (EDPS) with the dividing line between populations at 144° W. Despite little exchange for thousands of years, the gap between the breeding ranges narrowed during the past 15–30 years with the formation of new rookeries near the DPS boundary. We analyzed >22,000 sightings of 4,172 sea lions branded as pups in each DPS from 2000–2010 to estimate probabilities of a sea lion born in one DPS being seen within the range of the other DPS (either ‘West’ or ‘East’). Males from both populations regularly traveled across the DPS boundary; probabilities were highest at ages 2–5 and for males born in Prince William Sound and southern Southeast Alaska. The probability of WDPS females being in the East at age 5 was 0.067 but 0 for EDPS females which rarely traveled to the West. Prince William Sound-born females had high probabilities of being in the East during breeding and non-breeding seasons. We present strong evidence that WDPS females have permanently emigrated to the East, reproducing at two ‘mixing zone’ rookeries. We documented breeding bulls that traveled >6,500 km round trip from their natal rookery in southern Alaska to the northern Bering Sea and central Aleutian Islands and back within one year. WDPS animals began moving East in the 1990s, following steep population declines in the central Gulf of Alaska. Results of our study, and others documenting high survival and rapid population growth in northern Southeast Alaska suggest that conditions in this mixing zone region have been optimal for sea lions. It is unclear whether eastward movement across the DPS boundary is due to less-optimal conditions in the West or a reflection of favorable conditions in the East. PMID:23940543

Geologic Map of the Frederick 30' x 60' Quadrangle, Maryland, Virginia, and West Virginia

USGS Publications Warehouse

Southworth, Scott; Brezinski, David K.; Drake, Avery Ala; Burton, William C.; Orndorff, Randall C.; Froelich, Albert J.; Reddy, James E.; Denenny, Danielle; Daniels, David L.

2007-01-01

The Frederick 30? ? 60? quadrangle lies within the Potomac River watershed of the Chesapeake Bay drainage basin. The map area covers parts of Montgomery, Howard, Carroll, Frederick, and Washington Counties in Maryland; Loudoun, Clarke, and Fairfax Counties in Virginia; and Jefferson and Berkeley Counties in West Virginia. Many geologic features (such as faults and folds) are named for geographic features that may or may not be shown on the 1:100,000-scale base map. The geology of the Frederick 30? ? 60? quadrangle, Maryland, Virginia, and West Virginia, was first mapped on the 32 1:24,000-scale 7.5-minute quadrangle base maps between 1989 and 1994. The geologic data were compiled manually at 1:100,000 scale in 1997 and were digitized between 1998 and 1999. The geologic map and database may be used to support activities such as land-use planning, soil mapping, groundwater availability and quality studies, identifying aggregate resources, and conducting engineering and environmental studies. The map area covers distinct geologic provinces and sections of the central Appalachian region that are defined by unique bedrock and resulting landforms. From west to east, the provinces include the Great Valley section of the Valley and Ridge province, the Blue Ridge province, and the Piedmont province; in the extreme southeastern corner, a small part of the Coastal Plain province is present. The Piedmont province is divided into several sections; from west to east, hey are the Frederick Valley synclinorium, the Culpeper and Gettysburg basins, the Sugarloaf Mountain anticlinorium, the Westminster terrane, and the Potomac terrane. The geology of the Frederick quadrangle is discussed by geologic province and sections; the geologic units within each province are discussed from oldest to youngest. Where applicable, the discussion includes information on tectonic origins. For more information concerning the report, please contact the author.

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.

Preliminary bedrock geologic map of the Seward Peninsula, Alaska, and accompanying conodont data

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Werdon, Melanie B.; Bleick, Heather A.

2010-01-01

This 1:500,000-scale geologic map depicts the bedrock geology of Seward Peninsula, western Alaska, on the North American side of the Bering Strait. The map encompasses all of the Teller, Nome, Solomon, and Bendeleben 1:250,000-scale quadrangles, and parts of the Shishmaref, Kotzebue, Candle, and Norton Bay 1:250,000-scale quadrangles (sheet 1; sheet 2). The geologic map is presented on Sheet 1. The pamphlet includes an introductory text, unit descriptions, tables of geochronologic data, and an appendix containing conodont (microfossil) data and a text about those data. Sheet 2 shows metamorphic and tectonic units, conodont color alteration indices, key metamorphic minerals, and locations of geochronology samples listed in the pamphlet.

Geologic map of the Skykomish River 30- by 60-minute quadrangle, Washington

USGS Publications Warehouse

Tabor, R.W.; Frizzell, D.A.; Booth, D.B.; Waitt, R.B.; Whetten, J.T.; Zartman, R.E.

1993-01-01

From the eastern-most edges of suburban Seattle, the Skykomish River quadrangle stretches east across the low rolling hills and broad river valleys of the Puget Lowland, across the forested foothills of the North Cascades, and across high meadowlands to the bare rock peaks of the Cascade crest. The Straight Creek Fault, a major Pacific Northwest structure which almost bisects the quadrangle, mostly separates unmetamorphosed and low-grade metamorphic Paleozoic and Mesozoic oceanic rocks on the west from medium- to high-grade metamorphic rocks on the east. Within the quadrangle the lower grade rocks are mostly Mesozoic melange units. To the east, the higher-grade terrane is mostly the Chiwaukum Schist and related gneisses of the Nason terrane and invading mid-Cretaceous stitching plutons. The Early Cretaceous Easton Metamorphic Suite crops out on both sides of the Straight Creek fault and records it's dextral displacement. On the south margin of the quadrangle, the fault separates the lower Eocene Swauk Formation on the east from the upper Eocene and Oligocene(?) Naches Formation and, farther north, it's correlative Barlow Pass Volcanics the west. Stratigraphically equivalent rocks ot the Puget Group crop out farther to the west. Rocks of the Cascade magmatic arc are mostly represented by Miocene and Oligocene plutons, including the Grotto, Snoqualmie, and Index batholiths. Alpine river valleys in the quadrangle record multiple advances and retreats of alpine glaciers. Multiple advances of the Cordilleran ice sheet, originating in the mountains of British Columbia, Canada, have left an even more complex sequence of outwash and till along the western mountain front, up these same alpine river valleys, and over the Puget Lowland.

Publications - GMC 329 | Alaska Division of Geological & Geophysical

Science.gov Websites

Bee Creek 1976 holes of Chignik C2 Quadrangle (B-1, 265'; B-2, 500'; B-3, 500'; B-4, 300' and B-5, 300 the Bee Creek 1976 holes of Chignik C2 Quadrangle (B-1, 265'; B-2, 500'; B-3, 500'; B-4, 300' and B-5

MC-13 Syrtis Major Region

NASA Technical Reports Server (NTRS)

1994-01-01

Mars digital-image mosaic merged with color of the MC-13 quadrangle, Syrtis Major region of Mars. The central part is dominated by dark dust and lava flows of the Syrtis Major Planitia region. These lava flows are partly bounded to the east by a large depression, Isidis basin, which contains smooth plains, and to the west and north by heavily cratered and moderately faulted highlands. Latitude range 0 to 30 degrees, longitude range -90 to -45 degrees.

FACILITY 847, DETAIL OF A CENTRAL STAIRWAY FROM COURTYARD, QUADRANGLE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FACILITY 847, DETAIL OF A CENTRAL STAIRWAY FROM COURTYARD, QUADRANGLE J, VIEW FACING NORTHEAST. - Schofield Barracks Military Reservation, Quadrangles I & J Barracks Type, Between Wright-Smith & Capron Avenues near Williston Avenue, Wahiawa, Honolulu County, HI

Geology and ore deposits of the Philipsburg quadrangle, Montana

USGS Publications Warehouse

Emmons, William Harvey; Calkins, Frank Cathcart

1913-01-01

Philipsburg lies about midway between the eastern and western limits of the Rocky Mountain system, if the term be used in the broad sense prevailing in the United States. In the general latitude of Montana the system as defined by American usage is bounded on the west by the Columbia River basalt plain and on the east by the Great Plains. The western limit is fairly definite, but on the east there is no very definite line between the plains and mountains; the mountains are fairly continuous west and north of the Philipsburg quadrangle, but to the east and southeast mountains alternate with broad stretches of semiarid lowland. The quadrangle therefore overlaps the line between two physiographic provinces, one characterized by isolated mountain groups, of which the Flint Creek Range is the most westerly, and the other by more continuous elevations, of which the Sapphire Mountains are an example.

Digital data base application to porphyry copper mineralization in Alaska; case study summary

USGS Publications Warehouse

Trautwein, Charles M.; Greenlee, David D.; Orr, Donald G.

1982-01-01

The purpose of this report is to summarize the progress in use of digital image analysis techniques in developing a conceptual model for assessing porphyry copper mineral potential. The study area consists of approximately the southern one-half of the 1? by 3? Nabesna quadrangle in east-central Alaska. The digital geologic data base consists of data compiled under the Alaskan Mineral Resource Assessment Program (AMRAP) as well as digital elevation data and Landsat spectral reflectance data from the Multispectral Scanner System. The digital data base used to develop and implement a conceptual model for porphyry-type copper mineralization consisted of 16 original data types and 18 derived data sets formatted in a grid-cell (raster) structure and registered to a map base in the Universal Transverse Mercator (UTM) projection. Minimum curvature and inverse distance squared interpolation techniques were used to generate continuous surfaces from sets of irregularly spaced data points. Processing requirements included: (1) merging or overlaying of data sets, (2) display and color coding of maps and images, (3) univariate and multivariate statistical analyses, and (4) compound overlaying operations. Data sets were merged and processed to create stereoscopic displays of continuous surfaces. The ratio of several data sets were calculated to evaluate relative variations and to enhance the display of surface alteration (gossans). Factor analysis and principal components analysis techniques were used to determine complex relationships and correlations between data sets. The resultant model consists of 10 parameters that identify three areas most likely to contain porphyry copper mineralization; two of these areas are known occurrences of mineralization and the third is not well known. Field studies confirmed that the three areas identified by the model have significant copper potential.

Geologic map of the Bernalillo NW quadrangle, Sandoval County, New Mexico

USGS Publications Warehouse

Koning, Daniel J.; Personius, Stephen F.

2002-01-01

The Bernalillo NW quadrangle is located in the northern part of the Albuquerque basin, which is the largest basin or graben within the Rio Grande rift. The quadrangle is underlain by poorly consolidated sedimentary rocks of the Santa Fe Group. These rocks are best exposed in the southwestern part of the quadrangle in the Rincones de Zia, a badland topography cut by northward-flowing tributary arroyos of the Jemez River. The Jemez River flows through the northern half of the quadrangle; extensive fluvial and eolian deposits cover bedrock units along the river. The structural fabric of the quadrangle is dominated by dozens of generally north striking, east and west-dipping normal faults and minor folds associated with the Neogene Rio Grande rift.

Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Blodgett, Robert B.; Blome, Charles D.; Mohadjer, Solmaz; Preller, Cindi C.; Klimasauskas, Edward P.; Gamble, Bruce M.; Coonrad, Warren L.

2017-03-03

The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

Preliminary geologic map of the Murrieta 7.5' quadrangle, Riverside County, California

USGS Publications Warehouse

Kennedy, Michael P.; Morton, Douglas M.

2003-01-01

The Murrieta quadrangle is located in the northern part of the Peninsular Ranges Province and includes parts of two structural blocks, or structural subdivisions of the province. The quadrangle is diagonally crossed by the active Elsinore fault zone, a major fault zone of the San Andreas fault system, and separates the Santa Ana Mountains block to the west from the Perris block to the east. Both blocks are relatively stable internally and within the quadrangle are characterized by the presence of widespread erosional surfaces of low relief. The Santa Ana Mountains block, in the Murrieta quadrangle, is underlain by undifferentiated, thick-layered, granular, impure quartzite and well-layered, fissile, phyllitic metamorphic rock of low metamorphic grade. Both quartzite and phyllitic rocks are Mesozoic. Unconformably overlying the metamorphic rocks are remnants of basalt flows having relatively unmodified flow surfaces. The age of the basalt is about 7-8Ma. Large shallow depressions on the surface of the larger basalt remnants form vernal ponds that contain an endemic flora. Beneath the basalt the upper part of the metamorphic rocks is deeply weathered. The weathering appears to be the same as the regional Paleocene saprolitic weathering in southern California. West of the quadrangle a variable thickness sedimentary rock, physically resembling Paleogene rocks, occurs between the basalt and metamorphic rock. Where not protected by the basalt, the weathered rock has been removed by erosion. The dominant feature on the Perris block in the Murrieta quadrangle is the south half of the Paloma Valley ring complex, part of the composite Peninsular Ranges batholith. The complex is elliptical in plan view and consists of an older ring-dike with two subsidiary short-arced dikes that were emplaced into gabbro by magmatic stoping. Small to large stoped blocks of gabbro are common within the ring-dikes. A younger ring-set of hundreds of thin pegmatite dikes occur largely within the central part of the complex. These pegmatite dikes were emplaced into a domal fracture system, apparently produced by cauldron subsidence, and include in the center of the complex, a number of flat-floored granophyre bodies. The granophyre is interpreted to be the result of pressure quenching of pegmatite magma. Along the eastern edge of the quadrangle is the western part of a large septum of medium metamorphic grade Mesozoic schist. A dissected basalt flow caps the Hogbacks northeast of Temecula, and represents remnants of a channel filling flow. Beneath the basalt is a thin deposit of stream gravel. Having an age of about 10Ma, this basalt is about 2-3Ma older than the basalt flows in the Santa Ana Mountains. The Elsinore fault zone forms a complex of pull-apart basins. The west edge of the fault zone, the Willard Fault, is marked by the high, steep eastern face of the Santa Ana Mountains. The east side of the zone, the Wildomar Fault, forms a less pronounced physiographic step. In the center of the quadrangle a major splay of the fault zone, the Murrieta Hot Springs Fault, strikes east. Branching of the fault zone causes the development of a broad alluvial valley between the Willard Fault and the Murrieta Hot Springs Fault. All but the axial part of the zone between the Willard and Wildomar Faults consist of dissected Pleistocene sedimentary units. The axial part of the zone is underlain by Holocene and latest Pleistocene sedimentary units.

Publications - GMC 318 | Alaska Division of Geological & Geophysical

Science.gov Websites

geochemical core data, Talkeetna Mountains A-5 quadrangle Authors: Unknown Publication Date: 2005 Publisher or please see our publication sales page for more information. Bibliographic Reference Unknown, 2005

Aeromagnetic and Aeroradiometric Data for the Conterminous United States and Alaska from the National Uranium Resource Evaluation (NURE) Program of the U.S. Department of Energy

USGS Publications Warehouse

Hill, Patricia L.; Kucks, Robert P.; Ravat, Dhananjay

2009-01-01

The National Uranium Resource Evaluation (NURE) program was initiated in 1973 with a primary goal of identifying uranium resources in the United States. The airborne program's main purpose was to collect radiometric data of the conterminous United States and Alaska. Magnetic data were also collected. After the program ended, most of the data were given to the U.S. Geological Survey (USGS). All areas were flown at about 400 feet above ground, the optimum height for collecting radiometric data, and the line spacing varied from 3 to 6 mile intervals. A few selected quadrangles or parts of quadrangles were flown at 1- or 2-mile line spacing. About forty smaller areas were targeted and flown at 0.25-mile to 1 mile line spacing.

Aerial radiometric and magnetic reconnaissance survey of the Eagle--Dillingham area, Alaska, Mt. Hayes Quadrangle

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

Not Available

1978-06-01

The results of a high-sensitivity aerial gamma-ray spectrometer and magnetometer survey of the Mt. Hayes Quadrangle, Alaska, are presented. Instrumentation and methods are described in Volume 1 of this final report. Statistical and geological analysis of the radiometric data revealed two uranium anomalies worthy of field checking as possible prospects. One is located near Mesozoic granite, which is believed to have the best potential for future economic uranium deposits. Another uranium anomaly is associated with Paleozoic-Precambrian rocks and may be caused by augen gneiss or possibly granitic intrusives. Two weakly uraniferous provinces merit study: one in the northwest, which maymore » be related to the Tertiary-Cretaceous coal-bearing unit, and a second in the northeast, which may be related to Mesozoic granites.« less

Bedrock geologic map of the Seward Peninsula, Alaska, and accompanying conodont data

USGS Publications Warehouse

Till, Alison B.; Dumoulin, Julie A.; Werdon, Melanie B.; Bleick, Heather A.

2011-01-01

This 1:500,000-scale geologic map depicts the bedrock geology of Seward Peninsula, western Alaska, on the North American side of the Bering Strait. The map encompasses all of the Teller, Nome, Solomon, and Bendeleben 1:250,000-scale quadrangles, and parts of the Shishmaref, Kotzebue, Candle, and Norton Bay 1:250,000-scale quadrangles (sh. 1; sh. 2). The geologic map is presented on Sheet 1. The pamphlet includes an introductory text, detailed unit descriptions, tables of geochronologic data, and an appendix containing conodont (microfossil) data and a text explaining those data. Sheet 2 shows metamorphic and tectonic units, conodont color alteration indices, key metamorphic minerals, and locations of geochronology samples listed in the pamphlet. The map area covers 74,000 km2, an area slightly larger than West Virginia or Ireland.

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Tonsina area, Valdez Quadrangle, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 128 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Tonsina area in the Chugach Mountains, Valdez quadrangle, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies

Reconnaissance geology of the Jabal Bitran quadrangle, Kingdom of Saudi Arabia

USGS Publications Warehouse

Kahr, Viktor P.; Overstreet, W.C.; Whitlow, J.W.; Ankary, A.O.

1972-01-01

The Jabal Bitten quadrangle covers an area of 2833 sq km in the eastern part of the Precambrian Shield in Saudi Arabia. The rocks in the quadrangle are divided geographically alone arcuate north-trending lines into an eastern area of granite intruded by a swarm of dikes of rhyolite and andesite, and a western area of dominantly pelitic chlorite-sericite schist, separated by the narrow central complex of the Idsas Range. This complex is composed of pyroclastic rocks, lava, conglomerate, marble, and plutonic mafic rocks that have been intricately modified by episodes of metamorphism, igneous intrusion, and faulting. The Idsas Range contains ancient gold and copper mines, and deposits of magnetite, copper, asbestos, and chromite. The rocks in the Jabal Bitten quadrangle are here interpreted to consist of three major sedimentary and volcanic groups, the lowermost of which was deposited unconformably on hornblende-biotite granite gneiss, and all of which are intruded by granite dikes and plutons. From oldest to youngest the layered rocks are called Halaban Group, Bi'r Khountina Group, and Murdama Group, A biotite-hornblende granite is older than uppermost Bi'r Khountina, and peralkalic granite is younger than Murdama. The layered rocks of these groups are generally metamorphosed to the greenschist facies. The metamorphic grade rises abruptly at the Idsas Range to the albite-epidote-amphibolite facies and lower subfacies of the amphibolite facies in parts of the Halaban Group; some skarn east of the range may be in the upper part of the amphibolite facies. Characteristically, the Halaban Group has the highest grade and the greatest range in metamorphic grade, and the Murdama Group has the lowest but most uniformly developed metamorphic grade. The metamorphism of the rocks was caused by three successive pulses of regional dynamothermal metamorphism plus contact metamorphism around the younger bodies of plutonic igneous rocks. Four major structural elements of the quadrangle are reflected in the geography and geologic units. These are a mantled gneiss dome on the east separated from a north-plunging synclinorium in rocks of the Murdama and Bi?r Khountina Groups on the west by a narrow dejective zone of the Halaban and lower Bi?r Khountina. The dejective zone is much modified by impricate overthrusts and accompanying tear faults. These major faults have pushed elements of the Halaban and Bi?r Khountina westward over Bi?r Khountina and Murdama, with the result that very complex fault patterns have evolved. Open geochemical reconnaissance of the area disclosed one positive anomaly for nickel and 40 threshold indications of several elements, principally nickel, chromium, copper, and tungsten. Heavy-mineral and radiometric reconnaissance showed 18 areas containing scheelite and/or powellite and four areas of anomalous radioactivity. Most of these features are in the dejective zone, as are five of the nine ancient workings, the massive and disseminated magnetite, most of the secondary copper minerals, and the traces of asbestos, magnesite, and chromite known in the quadrangle. The mantled gneiss dome and a complex of gabbro and amphibolite on its southwestern flank are the next most mineralized areas. Scant evidence of mineralization is present in the Murdama Group west of the dejective zone. Magnetite deposits at Jabal Idsas have the greatest potential of the mineral deposits in the Jabal Bitran quadrangle. Further study of gold at Fawara and Selib mines is recommended, as is investigation of a positive nickel anomaly that shows threshold cobalt and above background radioactivity. The garnetiferous skarn in the east-central part of the quadrangle should be examined for composition and abrasive character of the garnet and for the remote possibility of tungsten in scheelite and beryllium in helvite.

Geologic map of the Sand Creek Pass quadrangle, Larimer County, Colorado, and Albany County, Wyoming

USGS Publications Warehouse

Workman, Jeremiah B.; Braddock, William A.

2010-01-01

New geologic mapping within the Sand Creek Pass 7.5 minute quadrangle defines geologic relationships within the northern Front Range of Colorado along the Wyoming border approximately 35 km south of Laramie, Wyo. Previous mapping within the quadrangle was limited to regional reconnaissance mapping; Eaton Reservoir 7.5 minute quadrangle to the east (2008), granite of the Rawah batholith to the south (1983), Laramie River valley to the west (1979), and the Laramie 30' x 60' quadrangle to the north (2007). Fieldwork was completed during 1981 and 1982 and during 2007 and 2008. Mapping was compiled at 1:24,000-scale. Minimal petrographic work was done and no isotope work was done in the quadrangle area, but detailed petrographic and isotope studies were performed on correlative map units in surrounding areas as part of a related regional study of the northern Front Range. Stratigraphy of Proterozoic rocks is primarily based upon field observation of bulk mineral composition, macroscopic textural features, and field relationships that allow for correlation with rocks studied in greater detail outside of the map area. Stratigraphy of Phanerozoic rocks is primarily based upon correlation with similar rocks to the north in the Laramie Basin of Wyoming and to the east in the Front Range of Colorado.

Geologic map of the Tetilla Peak Quadrangle, Santa Fe and Sandoval counties, New Mexico

USGS Publications Warehouse

Sawyer, D.A.; Shroba, R.R.; Minor, S.A.; Thompson, R.A.

2002-01-01

This digital geologic map summarizes all available geologic information for the Tetilla Peak quadrangle located immediately southwest of Santa Fe, New Mexico. The geologic map consists of new polygon (geologic map units) and line (contact, fault, fold axis, dike, flow contact, hachure) data, as well as point data (locations for structural measurements, geochemical and geochronologic data, geophysical soundings, and water wells). The map database has been generated at 1:24,000 scale, and provides significant new geologic information for an area of the southern Cerros del Rio volcanic field, which sits astride the boundary of the Espanola and Santo Domingo basins of the Rio Grande rift. The quadrangle includes the west part of the village of La Cienega along its eastern border and includes the southeasternmost part of the Cochiti Pueblo reservation along its northwest side. The central part of the quadrangle consists of Santa Fe National Forest and Bureau of Land Management lands, and parts of several Spanish-era land grants. Interstate 25 cuts through the southern half of the quadrangle between Santa Fe and Santo Domingo Pueblo. Canada de Santa Fe, a major river tributary to the Rio Grande, cuts through the quadrangle, but there is no dirt or paved road along the canyon bottom. A small abandoned uranium mine (the La Bajada mine) is found in the bottom of the Canada de Santa Fe about 3 km east of the La Bajada fault zone; it has been partially reclaimed. The surface geology of the Tetilla Peak quadrangle consists predominantly of a thin (1-2 m generally, locally as thick as 10? m) layer of windblown surficial deposits that has been reworked colluvially. Locally, landslide, fluvial, and pediment deposits are also important. These colluvial deposits mantle the principal bedrocks units, which are (from most to least common): (1) basalts, basanites, andesite, and trachyte of the Pliocene (2.7-2.2 Ma) Cerros del Rio volcanic field; (2) unconsolidated deposits of the Santa Fe Group, mainly along the western border, in the hanging wall of the La Bajada fault zone, but locally extending 2-3 km east under the Cerros del Rio volcanic field; (3) older Tertiary volcanic and sedimentary rocks (Abiquiu?, Espinaso, and Galisteo Formations); (4) intrusive rocks of the Cerrillos intrusive center that are roughly coeval with the Espinaso volcanic rocks; and (5) Mesozoic sedimentary rocks ranging in age from the Upper Triassic Chinle Formation to the Upper Cretaceous Mancos Shale.

Radiometric age map of Aleutian Islands

USGS Publications Warehouse

Wilson, Frederic H.; Turner, D.L.

1975-01-01

This map includes published, thesis, and open-file radiometric data available to us as of June, 1975. Some dates are not plotted because of inadequate location data in the original references.The map is divided into five sections, based on 1:1,000,000 scale enlargements of the National Atlas maps of Alaska. Within each section (e.g., southeastern Alaska), radiometric dates are plotted and keyed to 1:250,000 scale quadrangles. Accompanying each map section is table 1, listing map numbers and the sample identification numbers used in DGGS Special Report 10: Radiometric Dates from Alaska-A 1975 Compilation”. The reader is referred to Special Report 10 for more complete information on location, rock type, dating method, and literature references for each age entry. A listing of dates in Special Report lo which require correction or deletion is included S table 2. Corrected and additional entries are listed in table 3. The listings in tables 2 and 3 follow the format of Special Report 10. Table 4 is a glossary of abbreviations used for quadrangle name, rock type, mineral dated, and type of dating method used.

Maps showing aeromagnetic survey and geologic interpretation of the Chignik and Sutwik Island quadrangles, Alaska

USGS Publications Warehouse

Case, J.E.; Cox, D.P.; Detra, D.E.; Detterman, R.L.; Wilson, Frederic H.

1981-01-01

An aeromagnetic survey over part of the Chignik and Sutwik Island quadrangles, on the southern Alaska Peninsula, was flown in 1977 as part of the Alaska mineral resource assessment program (AMRAP). Maps at scales 1:250,000 and 1:63,360 have been released on open-file (U.s. Geological Survey, 1978a, 1978b). This report includes the aeromagnetic map superimposed on the topographic base (sheet 1) and an interpretation map superimposed on the topographic and simplified geologic base (sheet 2). This discussion provides an interpretation of the aeromagnetic data with respect to regional geology, occurrence of ore deposits and prospects, and potential oil and gas resources. The survey was flown along northwest-southeast lines, spaced about 1.6 km apart, at a nominal elevation of about 300 m above the land surface. A proton-precession magnetometer was used for the survey, and the resulting digital data were computer contoured at intervals of 10 and 50 gammas (sheet 1). The International Geomagnetic Reference Field (IGRF) of 1965, updated to 1977, was removed from the total field data.

Geologic map of the Kechumstuk fault zone in the Mount Veta area, Fortymile mining district, east-central Alaska

USGS Publications Warehouse

Day, Warren C.; O’Neill, J. Michael; Dusel-Bacon, Cynthia; Aleinikoff, John N.; Siron, Christopher R.

2014-01-01

This map was developed by the U.S. Geological Survey Mineral Resources Program to depict the fundamental geologic features for the western part of the Fortymile mining district of east-central Alaska, and to delineate the location of known bedrock mineral prospects and their relationship to rock types and structural features. This geospatial map database presents a 1:63,360-scale geologic map for the Kechumstuk fault zone and surrounding area, which lies 55 km northwest of Chicken, Alaska. The Kechumstuk fault zone is a northeast-trending zone of faults that transects the crystalline basement rocks of the Yukon-Tanana Upland of the western part of the Fortymile mining district. The crystalline basement rocks include Paleozoic metasedimentary and metaigneous rocks as well as granitoid intrusions of Triassic, Jurassic, and Cretaceous age. The geologic units represented by polygons in this dataset are based on new geologic mapping and geochronological data coupled with an interpretation of regional and new geophysical data collected by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys. The geochronological data are reported in the accompanying geologic map text and represent new U-Pb dates on zircons collected from the igneous and metaigneous units within the map area.

Geologic map of the Sauk River 30- by 60-minute quadrangle, Washington

USGS Publications Warehouse

Tabor, R.W.; Booth, D.B.; Vance, J.A.; Ford, A.B.

2002-01-01

Summary -- The north-south-trending regionally significant Straight Creek Fault roughly bisects the Sauk River quadrangle and defines the fundamental geologic framework of it. Within the quadrangle, the Fault mostly separates low-grade metamorphic rocks on the west from medium- to high-grade metamorphic rocks of the Cascade metamorphic core. On the west, the Helena-Haystack melange and roughly coincident Darrington-Devils Mountain Fault Zone separate the western and eastern melange belts to the southwest from the Easton Metamorphic Suite, the Bell Pass melange, and rocks of the Chilliwack Group, to the northeast. The tectonic melanges have mostly Mesozoic marine components whereas the Chilliwack is mostly composed of Late Paleozoic arc rocks. Unconformably overlying the melanges and associated rocks are Eocene volcanic and sedimentary rocks, mostly infaulted along the Darrington-Devils Mountain Fault Zone. These younger rocks and a few small Eocene granitic plutons represent an extensional tectonic episode. East of the Straight Creek Fault, medium to high-grade regional metamorphic rocks of the Nason, Chelan Mountains, and Swakane terranes have been intruded by deep seated, Late Cretaceous granodioritic to tonalitic plutons, mostly now orthogneisses. Unmetamorphosed mostly tonalitic intrusions on both sides of the Straight Creek fault range from 35 to 4 million years old and represent the roots of volcanoes of the Cascade Magmatic Arc. Arc volcanic rocks are sparsely preserved east of the Straight Creek fault, but dormant Glacier Peak volcano on the eastern margin of the quadrangle is the youngest member of the Arc. Deposits of the Canadian Ice Sheet are well represented on the west side of the quadrangle, whereas alpine glacial deposits are common to the east. Roughly 5000 years ago lahars from Glacier Peak flowed westward filling major valleys across the quadrangle.

Preliminary geologic map of the northeast Dillingham quadrangle (D-1, D-2, C-1, and C-2), Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Hudson, Travis L.; Grybeck, Donald; Stoeser, Douglas B.; Preller, Cindi C.; Bickerstaff, Damon; Labay, Keith A.; Miller, Martha L.

2003-01-01

The Correlation of Map Units and Description of Map Units are in a format similar to that of the USGS Geologic Investigations Series (I-series) maps but have not been edited to comply with I-map standards. Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the Stratigraphic Nomenclature of the U.S. Geological Survey. ARC/INFO symbolsets (shade and line) as used for these maps have been made available elsewhere as part of Geologic map of Central (Interior) Alaska, published as a USGS Open-File Report (Wilson and others, 1998, http://geopubs.wr.usgs.gov/open-file/of98-133-a/). This product does not include the digital topographic base or land-grid files used to produce the map, nor does it include the AML and related ancillary key and other files used to assemble the components of the map.

Geologic map of the Pinedale quadrangle, McKinley County, New Mexico

USGS Publications Warehouse

Robertson, Jacques F.

2005-01-01

The 1:24,000-scale geologic map of the Pinedale 7.5' quadrangle lies in the western part of the Grants uranium mineral belt, which was mapped and studied under a cooperative agreement between the USGS and the U.S. Department of Energy. A spectacular panoramic view of the southern half of the Pinedale quadrangle is obtained looking northward from Interstate Highway 40, particularly from the New Mexico State travelers' rest stop near the Shell Oil Company's Ciniza Refinery, 28.5 kilometers (17.8 miles) east of Gallup. A west-trending escarpment, 200 meters high, of massive red sandstone, rises above a broad valley, its continuity broken only by a few deep and picturesque canyons in the western half of the quadrangle. The escarpment is formed by the eolian Entrada Sandstone of Late Jurassic age. The Entrada unconformably overlies the Chinle Formation of Late Triassic age, which occupies the valley below. The Chinle Formation consists of cherty mottled limestone and mudstone of the Owl Rock Member and underlying, poorly consolidated, red to purple fluvial siltstone, mudstone, and sandstone beds of the Petrified Forest Member. The pinyon- and juniper-covered bench that tops the escarpment is underlain by the Todilto Limestone. A quarry operation, located just north of the Indian community of Iyanbito in the southwestern part of the quadrangle, produces crushed limestone aggregate for highway construction and railroad ballast. Beyond the escarpment to the north and rising prominently above it, is the northwest-trending Fallen Timber Ridge. Near the west side of the quadrangle lie the peaks of Midget Mesa, and Mesa Butte, the latter of which has the highest altitude in the area at 2,635 meters (8,030 feet) above sea level. The prominences are capped by buff-colored resistant beds of the Dakota Sandstone of Late Cretaceous age, containing some interbedded coal. These beds unconformably overlie the uranium-bearing Morrison Formation, which consists of red, green, and gray shale, orange feldspathic sandstone, and green tuffaceous mudstone, deposited in ancient lakes, alluvial fans, and rivers during the Upper Jurassic Period. Thick, crossbedded, white beds of the Cow Springs Sandstone, derived from ancient windblown desert sands, underlie the Morrison. In the northern part of the quadrangle, the Dakota Sandstone is overlain by gray Mancos Shale and yellowish-gray Two Wells and Gallup Sandstones that were deposited in Late Cretaceous seas. Unconsolidated deposits of Quaternary age are found throughout the quadrangle in talus, slope wash, fans, valley alluviums, pediments, and as windblown sands in dunes and blanket deposits. The strata conform to the regional dip of about three degrees to north, except where they are down-folded some 200 meters along the Pinedale monocline, whose limbs follow a sinuous west-northwest trend across the northern half of the quadrangle. The monocline is beautifully exposed at Pinedale, where it shows as much as 20 degrees dip on the pine-studded bare rock slope of the Two Wells Sandstone. A north-plunging broad anticline and accompanying syncline is developed in the east-central part of the quadrangle but dies out against the monocline. A minor fault, with barely 3 meters of vertical displacement, extends several kilometers westward across the Todilto Limestone bench. A large landslide mass, 1.5 kilometers long by 0.7 kilometers wide occurs in the Mancos Shale west of Pinedale. Exploration drilling for uranium in the Morrison Formation has been extensive in the quadrangle, particularly north of the monocline, which adjoins the Old Church Rock mine area, west northwest of the quadrangle.

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C.

USGS Publications Warehouse

Lyttle, Peter T.; Aleinikoff, John N.; Burton, William C.; Crider, E. Allen; Drake, Avery A.; Froelich, Albert J.; Horton, J. Wright; Kasselas, Gregorios; Mixon, Robert B.; McCartan, Lucy; Nelson, Arthur E.; Newell, Wayne L.; Pavlides, Louis; Powars, David S.; Southworth, C. Scott; Weems, Robert E.

2018-01-02

The Washington West 30’ × 60’ quadrangle covers an area of approximately 4,884 square kilometers (1,343 square miles) in and west of the Washington, D.C., metropolitan area. The eastern part of the area is highly urbanized, and more rural areas to the west are rapidly being developed. The area lies entirely within the Chesapeake Bay drainage basin and mostly within the Potomac River watershed. It contains part of the Nation's main north-south transportation corridor east of the Blue Ridge Mountains, consisting of Interstate Highway 95, U.S. Highway 1, and railroads, as well as parts of the Capital Beltway and Interstate Highway 66. Extensive Federal land holdings in addition to those in Washington, D.C., include the Marine Corps Development and Education Command at Quantico, Fort Belvoir, Vint Hill Farms Station, the Naval Ordnance Station at Indian Head, the Chesapeake and Ohio Canal National Historic Park, Great Falls Park, and Manassas National Battlefield Park. The quadrangle contains most of Washington, D.C.; part or all of Arlington, Culpeper, Fairfax, Fauquier, Loudoun, Prince William, Rappahannock, and Stafford Counties in northern Virginia; and parts of Charles, Montgomery, and Prince Georges Counties in Maryland.The Washington West quadrangle spans four geologic provinces. From west to east these provinces are the Blue Ridge province, the early Mesozoic Culpeper basin, the Piedmont province, and the Coastal Plain province. There is some overlap in ages of rocks in the Blue Ridge and Piedmont provinces. The Blue Ridge province, which occupies the western part of the quadrangle, contains metamorphic and igneous rocks of Mesoproterozoic to Early Cambrian age. Mesoproterozoic (Grenville-age) rocks are mostly granitic gneisses, although older metaigneous rocks are found as xenoliths. Small areas of Neoproterozoic metasedimentary rocks nonconformably overlie Mesoproterozoic rocks. Neoproterozoic granitic rocks of the Robertson River Igneous Suite intruded the Mesoproterozoic rocks. The Mesoproterozoic rocks are nonconformably overlain by Neoproterozoic metasedimentary rocks of the Fauquier and Lynchburg Groups, which in turn are overlain by metabasalt of the Catoctin Formation. The Catoctin Formation is overlain by Lower Cambrian clastic metasedimentary rocks of the Chilhowee Group. The Piedmont province is exposed in the east-central part of the map area, between overlapping sedimentary units of the Culpeper basin on the west and those of the Coastal Plain province on the east. In this area, the Piedmont province contains Neoproterozoic and lower Paleozoic metamorphosed sedimentary, volcanic, and plutonic rocks. Allochthonous mélange complexes on the western side of the Piedmont are bordered on the east by metavolcanic and metasedimentary rocks of the Chopawamsic Formation, which has been interpreted as part of volcanic arc. The mélange complexes are unconformably overlain by metasedimentary rocks of the Popes Head Formation. The Silurian and Ordovician Quantico Formation is the youngest metasedimentary unit in this part of the Piedmont. Igneous rocks include the Garrisonville Mafic Complex, transported ultramafic and mafic inclusions in mélanges, monzogranite of the Dale City pluton, and Ordovician tonalitic and granitic plutons. Jurassic diabase dikes are the youngest intrusions. The fault boundary between rocks of the Blue Ridge and Piedmont provinces is concealed beneath the Culpeper basin in this area but is exposed farther south. Early Mesozoic rocks of the Culpeper basin unconformably overlie those of the Piedmont and Blue Ridge provinces in the central part of the quadrangle. The north-northeast-trending extensional basin contains Upper Triassic to Lower Jurassic nonmarine sedimentary rocks. Lower Jurassic sedimentary strata are interbedded with basalt flows, and both Upper Triassic and Lower Jurassic strata are intruded by diabase of Early Jurassic age. The Bull Run Mountain fault, a major Mesozoic normal fault characterized by down-to-the-east displacement, separates rocks of the Culpeper basin from those of the Blue Ridge province on the west. On the east, the contact between rocks of the Culpeper basin and those of the Piedmont province is an unconformity, which has been locally disrupted by normal faults. Sediments of the Coastal Plain province unconformably overlie rocks of the Piedmont province along the Fall Zone and occupy the eastern part of the quadrangle. Lower Cretaceous deposits of the Potomac Formation consist of fluvial-deltaic gravels, sands, silts, and clays. Discontinuous fluvial and estuarine terrace deposits of Pleistocene and middle- to late-Tertiary age flank the modern Potomac River valley unconformable capping these Cretaceous strata and the crystalline basement where the Cretaceous has been removed by erosion. East of the Potomac River, the Potomac Formation is onlapped and unconformably overlain by a westward thinning wedge of marine sedimentary deposits of Late Cretaceous and early- and late-Tertiary age. Basement rooted Coastal Plain faults of Tertiary to Quaternary age occur along the Fall Zone and this part of the inner Coastal Plain. These Coastal Plain faults have geomorphic expression that appear to influence river drainage patterns.The geologic map of the Washington West quadrangle is intended to serve as a foundation for applying geologic information to problems involving land use decisions, groundwater availability and quality, earth resources such as natural aggregate for construction, assessment of natural hazards, and engineering and environmental studies for waste disposal sites and construction projects. This 1:100,000-scale map is mainly based on more detailed geologic mapping at a scale of 1:24,000.

Offset of Tertiary arcs on the Alaska Peninsula: A section in Geological Survey research, fiscal year 1981

USGS Publications Warehouse

,

1984-01-01

Geologic mapping and potassium-argon dating by R. L. Detterman, F. H. Wilson, J. E. Case, and Nora Shew in the Ugashik and western part of the Karluk quadrangles have shown that the Eocene and Oligocene volcanic arc continues into these quadrangles from the south in the Chignik and Sutwik Island quadrangles. Surface exposures of the arc extend northward to approximately 57°30'N., or midway through the Ugashik quadrangle, but none are observed north of that point. Subsurface drill-hole data (Brockway and others, 1975) indicate continuation of the arc, possibly offset to the northwest of the northernmost known surface exposures.In the extreme northern part of the Ugashik and Karluk quadrangles, volcanic rocks again become important. These volcanic rocks are as yet undated; however, they may be related to the Katmai late Tertiary volcanic centers.Like the early Tertiary volcanic arc, the present-day Aleutian arc is also offset to the northwest in the northern part of the Ugashik and Karluk quadrangles. No major offset of the Mesozoic rocks is indicated through the offset zone; this fact suggests a change in the Tertiary tectonic regime in the area of the offset.

Geologic Map of the Cedargrove Quadrangle, Dent and Shannon Counties, Missouri

USGS Publications Warehouse

Weary, David J.

2008-01-01

The Cedargrove 7.5-minute quadrangle is located in south-central Missouri within the Salem Plateau region of the Ozark Plateaus physiographic province. Most of the land in the quadrangle is privately owned and used primarily for grazing cattle and horses and growing timber. The map area has topographic relief of about 565 feet (ft), with elevations ranging from about 760 ft at Akers Ferry on the central-southern edge of the map to about 1,325 ft near the town of Jadwin in the north-central part of the map area. The most prominent physiographic features in the quadrangle are the valleys of the Current River and Big Creek in the southwestern part of the map area, and the valley of Gladden Creek, which transects the eastern part of the quadrangle from north to south.

Digital data base of lakes on the North Slope, Alaska

USGS Publications Warehouse

Walker, Kim-Marie; York, James; Murphy, Dennis; Sloan, C.E.

1986-01-01

The National Mapping Division and Water Resources Division of the U.S. Geological Survey have produced a digital data base of approximately 23,330 lakes on the North Slope of Alaska. The inventoried region consists of the area north of the 69th parallel and is composed of sixteen 1° x 3° quadrangles. The data base includes (1) locations of lake centers in latitude and longitude, (2) a unique number for each lake within a quadrangle, and (3) acreage for water classes (deep, shallow or turbid, and ice) within each lake and lake total. The digital data base is an easily accessible storage and retrieval system that will allow for rapid identification of a particular lake or region of lakes and its characteristics. The data base is designed to accommodate field study data such as lake depth, water quality, volume of water, ice thickness, and other pertinent information.

Publications - PDF 94-40 | Alaska Division of Geological & Geophysical

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content DGGS PDF 94-40 Publication Details Title: Geology of the Gagaryah River area, Lime Hills C-5 and C ., Clautice, K.H., and Harris, E.E., 1994, Geology of the Gagaryah River area, Lime Hills C-5 and C-6 Sheet 1 Geologic map of the Gagaryah River Area, Lime Hills C-5 and C-6 quadrangles, Southwestern Alaska

Perspective View of Venus (Center Latitude 45 Degrees N., Center Longitude 11 Degrees E.)

NASA Technical Reports Server (NTRS)

1992-01-01

This perspective view of Venus, generated by computer from Magellan data and color-coded with emissivity, shows part of the lowland plains in Sedna Planitia. Circular depressions with associated fracture patterns called 'coronae' are apparently unique to the lowlands of Venus, and tend to occur in linear clusters along the planet's major tectonic belts. Coronae differ greatly in size and detailed morphology: the central depression may or may not lie below the surrounding plains, and may or may not be surrounded by a raised rim or a moat outside the rim. The corona shown here is relatively small (100 km in diameter and 1 km deep) and is of the subtype known as an 'arachnoid' because of the spider-like configuration of concentric (body) and radial (legs) fractures. Coronae are thought to be caused by localized 'hot spot' magmatic activity in Venus' subsurface. Intrusion of magma into the crust first pushes up the surface, after which cooling and contraction create the central depression and generate a pattern of concentric fractures. In some cases, lava may be extruded onto the surface. The fractured ridge at the left is classified as a 'nova' or 'stellate fracture center' and is believed to represent an early phase of corona formation, in which subsidence due to cooling has not yet created the central depression, and the fracture pattern is still entirely radial. Magellan MIDR quadrangle* containing this image: C1-45N011. Image resolution (m): 225. Size of region shown (E-W x N-S, in km): 439 x 474. Range of emissivities from violet to red: 0.82 -- 0.88. Vertical exaggeration: 100. Azimuth of viewpoint (deg clockwise from East): 150. Elevation of viewpoint (km): 600. *Quadrangle name indicates approximate center latitude (N=north, S=south) and center longitude (East).

Database for the geologic map of the Bend 30- x 60-minute quadrangle, central Oregon

USGS Publications Warehouse

Koch, Richard D.; Ramsey, David W.; Sherrod, David R.; Taylor, Edward M.; Ferns, Mark L.; Scott, William E.; Conrey, Richard M.; Smith, Gary A.

2010-01-01

The Bend 30- x 60-minute quadrangle has been the locus of volcanism, faulting, and sedimentation for the past 35 million years. It encompasses parts of the Cascade Range and Blue Mountain geomorphic provinces, stretching from snowclad Quaternary stratovolcanoes on the west to bare rocky hills and sparsely forested juniper plains on the east. The Deschutes River and its large tributaries, the Metolius and Crooked Rivers, drain the area. Topographic relief ranges from 3,157 m (10,358 ft) at the top of South Sister to 590 m (1,940 ft) at the floor of the Deschutes and Crooked Rivers where they exit the area at the north-central edge of the map area. The map encompasses a part of rapidly growing Deschutes County. The city of Bend, which has over 70,000 people living in its urban growth boundary, lies at the south-central edge of the map. Redmond, Sisters, and a few smaller villages lie scattered along the major transportation routes of U.S. Highways 97 and 20. This geologic map depicts the geologic setting as a basis for structural and stratigraphic analysis of the Deschutes basin, a major hydrologic discharge area on the east flank of the Cascade Range. The map also provides a framework for studying potentially active faults of the Sisters fault zone, which trends northwest across the map area from Bend to beyond Sisters. This digital release contains all of the information used to produce the geologic map published as U.S. Geological Survey Geologic Investigations Series I-2683 (Sherrod and others, 2004). The main component of this digital release is a geologic map database prepared using ArcInfo GIS. This release also contains files to view or print the geologic map and accompanying descriptive pamphlet from I-2683.

Geologic map of the Lazy Y Point Quadrangle, Moffat County Colorado

USGS Publications Warehouse

Van Loenen, R. E.; Selner, G.I.; Bryant, W.A.

1999-01-01

The Lazy Y Point quadrangle is in northwestern Colorado a few miles north of Rangely. The prominent structural feature of the Lazy Y Point quadrangle is the Skull Creek monocline. Pennsylvanian rocks are exposed along the axis of the monocline while hogbacks along its southern flank expose rocks that are from Permian to Upper Cretaceous in age. The Wolf Creek monocline and the Wolf Creek thrust fault, which dissects the monocline, are salient structural features in the northern part of the quadrangle. Little or no mineral potential exists within the quadrangle. A geologic map of the Skull Creek quadrangle, which is adjacent to the Lazy Y Point quadrangle on the east, is also available (Geologic Investigations Series I-2647). This companian map shows similar geologic features, including the eastern half of the Skull Creek monocline. The geology of this quadrangle was mapped because of its proximity to Dinosaur National Monument. It is adjacent to quadrangles previously mapped to display the geology of this very scenic and popular National Monument. The Lazy Y Point quadrangle includes parts of the Willow and Skull Creek Wilderness Study Areas, which were assessed for their mineral resource potential.

Geologic map of the Santa Ana Pueblo quadrangle, Sandoval County, New Mexico

USGS Publications Warehouse

Personius, Stephen F.

2002-01-01

The Santa Ana Pueblo quadrangle is located in the northern part of the Albuquerque basin, which is the largest basin or graben within the Rio Grande rift. The quadrangle is underlain by poorly consolidated sedimentary rocks of the Santa Fe Group and is dominated by Santa Ana Mesa, a volcanic tableland underlain by basalt flows of the San Felipe volcanic field. The San Felipe volcanic field is the largest area of basaltic lavas exposed in the Albuquerque basin. The structural fabric of the quadrangle is dominated by dozens of generally north striking, east- and west-dipping normal faults associated with the Neogene Rio Grande rift.

Map and table showing isotopic age data in Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Shew, Nora B.; DuBois, G.D.

1994-01-01

The source of the data reported here is a compilation of radiometric ages maintained in conjunction with the Alaska Mineral Resource Assessment Program (AMRAP) studies for Alaska. The symbol shape plotted at each location is coded for rock type, whether igneous, metamorphic, or other; the color of the symbol shows the geologic era or period for the Sample(s) at each locale. A list of references for each quadrangle is given to enable the user to find specific information including analytical data for each sample dated within a particular quadrangle. At the scale of this map, the very large number of Samples and the clustering of the samples in limited areas prevented the showing of individual sample numbers on the map.Synthesis and interpretation of any data set requires the user to evaluate the reliability or value of each component of the data set with respect to his or her intended use of the data. For geochronological data, this evaluation must be based on both analytical and geological criteria. Most age determinations are published with calculated estimates of analytical precision, Replicate analyses are infrequently performed; therefore, reported analytical precision is based on estimates of the precision of various components of the analysis and often on an intuitive factor to cover components that may have not been considered. Analytical accuracy is somewhat more difficult to determine; it is not only dependent on the actual measurement, it is also concerned with uncertainties in decay and abundance constants, uncertainties in the isotopic composition and size of the tracer for conventional K-Ar ages, and uncertainties in the Original isotopic composition of the sample, Geologic accuracy of a date is Variable; the interpretation of the meaning of an age determination, is important in the evaluation of its geologic accuracy. Potassium-argon, rubidium-strontium, and uranium-lead age determinations on a single sample can differ widely yet none or all may be wrong Given that the basic Conditions of each dating method were met, each method determines an age based on the equilibration of its particular isotopic system, yet these are different systems and they react to heat, pressure, and recrystallization in different ways.This map is a compilation and not a synthesis or interpretation. Its purpose is to help the user determine the dating coverage of areas of Alaska and gain access to the available data for the state or a project area. Interpretation of that data and evaluation of its suitability for use with any particular project is left to the user. Compilations, with sample data, have been published for much of the state; and are as follows: Wilson, and others (1979), southeastern Alaska; Wilson (1981), Aleutian Islands and Alaska Peninsula, Shew and Wilson (1981), southwestern Alaska; Wilson and others (1985), Yukon Crystalline terrane; Grybeck and others (1977), northern Alaska; Dadisman (1980), south-central Alaska.

A transect of metamorphic rocks along the Copper River, Cordova and Valdez Quadrangles, Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1982

USGS Publications Warehouse

Miller, Marti L.; Dumoulin, Julie A.; Nelson, S.W.

1984-01-01

The lower Tertiary Orca Group is juxtaposed against the Upper Cretaceous Valdez Group along the Contact fault system (Winkler and Plafker, 1974, 198; Plafker and others, 1977)(fig. 33). In both groups, turbidites are the dominant rock type, with lesser mafic volcanic rocks (table 10). The Valdez Group, on the north, has traditionally been considered to be of higher metamorphic grade than the Orca Group (Moffit, 1954; Tysdal and Case, 1979; Winkler and Plafker, 198; Winkler and others, 1981). In 1982, we made a transect across the regional strike of the rocks and the contact between the two groups. The transect area follows the Copper River for 85 km from the Cordova quadrangle north into the Valdez quadrangle and extends for about 25 km on either side of the river (fig. 33). We planned, by systematic sampling of the area, to examine the metamorphic differences between the Orca and Valdez Groups. We found, however, that a strong thermal metamorphic event has overprinted and obscured regional metamorphic relations. We believe intrusion of Tertiary granite (fig. 33) to be responsible for this metamorphism. (Figures 33 and 34 and tables follow this article.)

Geologic map of the Lada Terra quadrangle (V-56), Venus

USGS Publications Warehouse

Kumar, P. Senthil; Head, James W.

2013-01-01

This publication provides a geological map of Lada Terra quadrangle (V–56), a portion of the southern hemisphere of Venus that extends from lat 50° S. to 70° S. and from long 0° E. to 60° E. V–56 is bordered by Kaiwan Fluctus (V–44) and Agnesi (V–45) quadrangles in the north and by Mylitta Fluctus (V–61), Fredegonde (V–57), and Hurston (V–62) quadrangles in the west, east, and south, respectively. The geological map of V–56 quadrangle reveals evidence for tectonic, volcanic, and impact processes in Lada Terra in the form of tesserae, regional extensional belts, coronae, and volcanic plains. In addition, the map also shows relative age relations such as overlapping or cross-cutting relations between the mapped geologic units. The geology observed within this quadrangle addresses (1) how coronae evolved in association with regional extensional belts and (2) how tesserae, regional plains, and impact craters, which are also significant geological units observed in Lada Terra quadrangle, were formed.

Analysis of Shublik Formation rocks from Mt. Michelson quadrangle, Alaska

USGS Publications Warehouse

Detterman, Robert L.

1970-01-01

Analysis of 88 samples from the Shublik formation on Fire Creek, Mt. Michelson Quadrangle, Alaska, are presented in tabular form. The results include the determination of elements by semiquantitative spectrographic analysis, phosphate by X-ray fluorescence, carbon dioxide by acid decomposable carbonate, total carbon by induction furnace, carbonate carbon by conversion using the conversion factor of 0.2727 for amount of carbon in carbon dioxide, and organic carbon by difference. A seven- cycle semilogarithmic chart presents the data graphically and illustrates the range, mode, and mean for some of the elements. The chart shows, also, the approximate concentration of the same elements in rocks similar to the black shale and limestone of the Shublik Formation. Each sample represents 5 feet of section and is composed of rock chips taken at 1 - foot intervals. The samples are keyed into a stratigraphic column of the formation. Rocks of the Shublik Formation contain anomalously high concentrations of some of the elements. These same elements might be expected to be high in some of the petroleum from northern Alaska if the Shublik Formation is a source for this petroleum. Several of the stratigraphic intervals may represent, also, a low-grade phosphate deposit.

Map showing abundance and distribution of chromium in stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

USGS Publications Warehouse

Whittington, Charles L.; Grimes, David J.; Leinz, Reinhard W.

1985-01-01

The Medford quadrangle is located in mountainous southwestern Oregon adjacent to the California border and a short distance east of the Pacific coast. Various parts of this area lie in different geologic provinces. Most of the western half of the quadrangle is underlain by pre-Tertiary rocks of the Klamath Mountains province. However, the Coast Range province is represented by the Tertiary sedimentary rocks in the northwest corner. Much of the eastern half of the quadrangle lies in the Cascade Range. In Oregon, because of differences in physiographic expression and age of rocks, this province is commonly divided into the more rugged High Cascade Range on the east and the more subdued Western Cascade Range on the west. This division is approximated on the map by the contact between the Quaternary and Tertiary volcanic rocks of the High Cascade Range and the Tertiary volcanic rocks of the Western Cascade Range. The geology shown is generalized from a more detailed compilation by Smith and others (1982).

Map showing abundance and distribution of silver in stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

USGS Publications Warehouse

Whittington, Charles L.; Grimes, David J.; Leinz, Reinhard W.

1985-01-01

The Medford quadrangle is located in mountainous southwestern Oregon adjacent to the California border and a short distance east of the Pacific coast. Various parts of this area lie in different geologic provinces. Most of the western half of the quadrangle is underlain by pre-Tertiary rocks of the Klamath Mountains province. However, the Coast Range province is represented by the Tertiary sedimentary rocks in the northwest corner. Much of the eastern half of the quadrangle lies in the Cascade Range. In Oregon, because of differences in physiographic expression and age of rocks, this province is commonly divided into the more rugged High Cascade Range on the east and the more subdued Western Cascade Range on the west. This division is approximated on the map by the contact between the Quaternary and Tertiary volcanic rocks of the High Cascade Range and the Tertiary volcanic rocks of the Western Cascade Range. The geology shown is generalized from a more detailed compilation by Smith and others (1982).

Publications - PIR 2004-3B | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PIR 2004-3B Publication Details Title: Bedrock geologic map of the Livengood SW C-3 and SE C ., Newberry, R.J., Werdon, M.B., and Hicks, S.A., 2004, Bedrock geologic map of the Livengood SW C-3 and SE C geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska, scale 1

Geologic Map and Engineering Properties of the Surficial Deposits of the Tok Area, East-Central Alaska

USGS Publications Warehouse

Carrara, Paul E.

2007-01-01

The Tok area 1:100,000-scale map, through which the Alaska Highway runs, is in east-central Alaska about 160 km west of the Yukon border. The surficial geologic mapping in the map area 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 Tok map area contains parts of three physiographic provinces, the Alaska Range, the Yukon-Tanana Upland, and the Northway-Tanana Lowland. The high, rugged, glaciated landscape of the eastern Alaska Range dominates the southwestern map area. The highest peak, an unnamed summit at the head of Cathedral Rapids Creek No. 2, rises to 2166 m. The gently rolling hills of the Yukon-Tanana Upland, in the northern map area, rise to about 1000 m. The Northway-Tanana Lowland contains the valley of the westerly flowing Tanana River. Elevations along the floor of the lowland generally range between 470 and 520 m. The dominant feature within the map is the Tok fan, which occupies about 20 percent of the map area. This large (450 km2), nearly featureless fan contains a high percentage of volcanic clasts derived from outside the present-day drainage of the Tok River. Because the map area is dominated by various surficial deposits, the map depicts 26 different surficial units consisting of man-made, alluvial, colluvial, eolian, lacustrine, organic, glaciofluvial, glacial, and periglacial deposits. The accompanying table provides information concerning the various units including their properties, characteristics, resource potential, and associated hazards in this area of the upper Tanana valley.

National Uranium Resource Evaluation: Aztec quadrangle, New Mexico and Colorado

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

Green, M.W.

1982-09-01

Areas and formations within the Aztec 1/sup 0/ x 2/sup 0/ Quadrangle, New Mexico and Colorado considered favorable for uranium endowment of specified minimum grade and tonnage include, in decreasing order of favorability: (1) the Early Cretaceous Burro Canyon Formation in the southeastern part of the Chama Basin; (2) the Tertiary Ojo Alamo Sandstone in the east-central part of the San Juan Basin; and (3) the Jurassic Westwater Canyon and Brushy Basin Members of the Morrison Formation in the southwestern part of the quadrangle. Favorability of the Burro Canyon is based on the presence of favorable host-rock facies, carbonaceous materialmore » and pyrite to act as a reductant for uranium, and the presence of mineralized ground in the subsurface of the Chama Basin. The Ojo Alamo Sandstone is considered favorable because of favorable host-rock facies, the presence of carbonaceous material and pyrite to act as a reductant for uranium, and the presence of a relatively large subsurface area in which low-grade mineralization has been encountered in exploration activity. The Morrison Formation, located within the San Juan Basin adjacent to the northern edge of the Grants mineral belt, is considered favorable because of mineralization in several drill holes at depths near 1500 m (5000 ft) and because of favorable facies relationships extending into the Aztec Quadrangle from the Grants mineral belt which lies in the adjacent Albuquerque and Gallup Quadrangles. Formations considered unfavorable for uranium deposits of specified tonnage and grade include the remainder of sedimentary and igneous formations ranging from Precambrian to Quaternary in age. Included under the unfavorable category are the Cutler Formation of Permian age, and Dakota Sandstone of Late Cretaceous age, and the Nacimiento and San Jose Formations of Tertiary age.« less

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.

Field guide to the Mesozoic accretionary complex along Turnagain Arm and Kachemak Bay, south-central Alaska

USGS Publications Warehouse

Bradley, Dwight C.; Kusky, Timothy M.; Karl, Susan M.; Haeussler, Peter J.

1997-01-01

Turnagain Arm, just east of Anchorage, provides a readily accessible, world-class cross section through a Mesozoic accretionary wedge. Nearly continuous exposures along the Seward Highway, the Alaska Railroad, and the shoreline of Turnagain Arm display the two main constituent units of the Chugach terrane: the McHugh Complex and Valdez Group. In this paper we describe seven bedrock geology stops along Turnagain Arm, and two others in the Chugach Mountains just to the north (Stops 1-7 and 9), which will be visited as part of the May, 1997 field trip of the Alaska Geological Society. Outcrops along Turnagain Arm have already been described in two excellent guidebook articles (Clark, 1981; Winkler and others 1984), both of which remain as useful and valid today as when first published. Since the early 1980's, studies along Turnagain Arm have addressed radiolarian ages of chert and conodont ages of limestone in the McHugh Complex (Nelson and others, 1986, 1987); geochemistry of basalt in the McHugh Complex (Nelson and Blome, 1991); post-accretion brittle faulting (Bradley and Kusky, 1990; Kusky and others, 1997); and the age and tectonic setting of gold mineralization (Haeussler and others, 1995). Highlights of these newer findings will described both in the text below, and in the stop descriptions.Superb exposures along the southeastern shore of Kachemak Bay show several other features of the McHugh Complex that are either absent or less convincing along Turnagain Arm. While none of these outcrops can be reached via the main road network, they are still reasonably accessible - all are within an hour by motorboat from Homer, seas permitting. Here, we describe seven outcrops along the shore of Kachemak Bay that we studied between 1989 and 1993 during geologic mapping of the Seldovia 1:250,000- scale quadrangle. These outcrops (Stops 61-67) will not be part of the 1997 itinerary, but are included here tor the benefit of those who may wish to visit them later.

Geomorphic domains and linear features on Landsat images, Circle Quadrangle, Alaska

USGS Publications Warehouse

Simpson, S.L.

1984-01-01

A remote sensing study using Landsat images was undertaken as part of the Alaska Mineral Resource Assessment Program (AMRAP). Geomorphic domains A and B, identified on enhanced Landsat images, divide Circle quadrangle south of Tintina fault zone into two regional areas having major differences in surface characteristics. Domain A is a roughly rectangular, northeast-trending area of relatively low relief and simple, widely spaced drainages, except where igneous rocks are exposed. In contrast, domain B, which bounds two sides of domain A, is more intricately dissected showing abrupt changes in slope and relatively high relief. The northwestern part of geomorphic domain A includes a previously mapped tectonostratigraphic terrane. The southeastern boundary of domain A occurs entirely within the adjoining tectonostratigraphic terrane. The sharp geomorphic contrast along the southeastern boundary of domain A and the existence of known faults along this boundary suggest that the southeastern part of domain A may be a subdivision of the adjoining terrane. Detailed field studies would be necessary to determine the characteristics of the subdivision. Domain B appears to be divisible into large areas of different geomorphic terrains by east-northeast-trending curvilinear lines drawn on Landsat images. Segments of two of these lines correlate with parts of boundaries of mapped tectonostratigraphic terranes. On Landsat images prominent north-trending lineaments together with the curvilinear lines form a large-scale regional pattern that is transected by mapped north-northeast-trending high-angle faults. The lineaments indicate possible lithlogic variations and/or structural boundaries. A statistical strike-frequency analysis of the linear features data for Circle quadrangle shows that northeast-trending linear features predominate throughout, and that most northwest-trending linear features are found south of Tintina fault zone. A major trend interval of N.64-72E. in the linear feature data, corresponds to the strike of foliations in metamorphic rocks and magnetic anomalies reflecting compositional variations suggesting that most linear features in the southern part of the quadrangle probably are related to lithologic variations brought about by folding and foliation of metamorphic rocks. A second important trend interval, N.14-35E., may be related to thrusting south of the Tintina fault zone, as high concentrations of linear features within this interval are found in areas of mapped thrusts. Low concentrations of linear features are found in areas of most igneous intrusives. High concentrations of linear features do not correspond to areas of mineralization in any consistent or significant way that would allow concentration patterns to be easily used as an aid in locating areas of mineralization. The results of this remote sensing study indicate that there are several possibly important areas where further detailed studies are warranted.

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential.The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska.For this report, DGGS funded reanalysis of 105 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Zane Hills area in the Hughes and Shungnak quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, Northern Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Bird, Kenneth J.

2003-01-01

A revised stratigraphic nomenclature is proposed for Cretaceous and Tertiary geologic units of the central and western North Slope of Alaska. This revised nomenclature is a simplified and broadly applicable scheme suitable for a suite of digital geologic quadrangle maps being prepared jointly by the U.S. Geological Survey and the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas. This revised nomenclature scheme is a simplification of a complex stratigraphic terminology that developed piecemeal during five decades of geologic investigations of the North Slope. It is based on helicopter-supported geologic field investigations incorporating information from high-resolution aerial photography, satellite imagery, paleontology, reflection seismic records, and sequence stratigraphic concepts. This revised nomenclature proposes the abandonment of the Colville Group; demotion of the Nanushuk Group to formation status; abandonment of six formations (Kukpowruk, Tuktu, Grandstand, Corwin, Chandler, and Ninuluk); revision of four formations (Sagavanirktok, Prince Creek, Schrader Bluff, and Seabee); elevation of the Tuluvak Tongue of the Prince Creek Formation to formation status; revision of two members (Franklin Bluffs Member and Sagwon Member of the Sagavanirktok Formation); abandonment of eight members or tongues (Kogosukruk, Rogers Creek, Barrow Trail, Sentinel Hill, Ayiyak, Shale Wall, Niakogon, and Killik); and definition of one new member (White Hills Member of the Sagavanirktok Formation).

Preliminary isostatic residual gravity map of the Newfoundland Mountains 30' by 60' quadrangle and east part of the Wells 30' by 60' quadrangle, Box Elder County, Utah

USGS Publications Warehouse

Langenheim, Victoria; Athens, N.D.; Churchel, B.A.; Willis, H.; Knepprath, N.E.; Rosario, Jose J.; Roza, J.; Kraushaar, S.M.; Hardwick, C.L.

2013-01-01

A new isostatic residual gravity map of the Newfoundland Mountains and east of the Wells 30×60 quadrangles of Utah is based on compilation of preexisting data and new data collected by the Utah and U.S. Geological Surveys. Pronounced gravity lows occur over Grouse Creek Valley and locally beneath the Great Salt Lake Desert, indicating significant thickness of low-density Tertiary sedimentary rocks and deposits. Gravity highs coincide with exposures of dense pre-Cenozoic rocks in the Newfoundland, Silver Island, and Little Pigeon Mountains. Gravity values measured on pre-Tertiary basement to the north in the Bovine and Hogup Mountains are as much as 10mGal lower. Steep, linear gravity gradients may define basin-bounding faults concealed along the margins of the Newfoundland, Silver Island, and Little Pigeon Mountains, Lemay Island and the Pilot Range.

High-pressure amphibolite facies dynamic metamorphism and the Mesozoic tectonic evolution of an ancient continental margin, east- central Alaska

USGS Publications Warehouse

Dusel-Bacon, C.; Hansen, V.L.; Scala, J.A.

1995-01-01

Ductilely deformed amphibolite facies tectonites comprise two adjacent terranes in east-central Alaska: the northern, structurally higher Taylor Mountain terrane and the southern, structurally lower Lake George subterrane of the Yukon-Tanana terrane. The pressure, temperature, kinematic and age data are interpreted to indicate that the metamorphism of the Taylor Mountain terrane and Lake George subterrane took place during different phases of a latest Palaeozoic through early Mesozoic shortening episode resulting from closure of an ocean basin now represented by klippen of the Seventymile-Slide Mountain terrane. High- to intermediate-pressure metamorphism of the Taylor Mountain terrane took place within a SW-dipping (present-day coordinates) subduction system. High- to intermediate-pressure metamorphism of the Lake George subterrane and the structural contact zone occurred during NW-directed overthrusting of the Taylor Mountain, Seventymile-Slide Mountain and Nisutlin terranes, and imbrication of the continental margin in Jurassic time. -from Authors

27 CFR 9.61 - El Dorado.

Code of Federal Regulations, 2012 CFR

2012-04-01

....” (“Tunnel Hill” and “Slate Mountain” Quadrangles); (5) Thence east along the range line to its intersection with the range line “R. 12 E./R. 13 E.” (“Slate Mountains” and “Pollock Pines” Quadrangles); (6) Thence...,” 1952 (photorevised 1973); (7) “Tunnel Hill, California,” 1950 (photorevised 1973); (8) “Slate Mountain...

27 CFR 9.61 - El Dorado.

Code of Federal Regulations, 2013 CFR

2013-04-01

....” (“Tunnel Hill” and “Slate Mountain” Quadrangles); (5) Thence east along the range line to its intersection with the range line “R. 12 E./R. 13 E.” (“Slate Mountains” and “Pollock Pines” Quadrangles); (6) Thence...,” 1952 (photorevised 1973); (7) “Tunnel Hill, California,” 1950 (photorevised 1973); (8) “Slate Mountain...

27 CFR 9.61 - El Dorado.

Code of Federal Regulations, 2014 CFR

2014-04-01

....” (“Tunnel Hill” and “Slate Mountain” Quadrangles); (5) Thence east along the range line to its intersection with the range line “R. 12 E./R. 13 E.” (“Slate Mountains” and “Pollock Pines” Quadrangles); (6) Thence...,” 1952 (photorevised 1973); (7) “Tunnel Hill, California,” 1950 (photorevised 1973); (8) “Slate Mountain...

Publications - PDF 93-47 | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS PDF 93-47 Publication Details Title: Geologic map of the Sleetmute C-7, D-7, C-8, and D-8 ., Harris, E.E., Kline, J.T., and Miller, M.L., 1993, Geologic map of the Sleetmute C-7, D-7, C-8, and D-8 Sleetmute C-7, C-8, D-7 and D-8 quadrangles, Horn Mountain Area, southwest Alaska, scale 1:63,360 (34.0 M

Reconnaissance geology of the Thaniyah Quadrangle, sheet 20/42 C, Kingdom of Saudi Arabia

USGS Publications Warehouse

Greene, Robert C.

1983-01-01

The Thaniyah quadrangle, sheet 20/42 C, is located in the transition zone between the Hijaz Mountains and the Najd Plateau of southwestern Saudi Arabia between lat 20?00' and 20?30' N., long 42?00' to 42?30' E. The quadrangle is underlain by Precambrian metavolcanic, metasedimentary, plutonic, and dike rocks. Metavolcanic rocks consist of metamorphosed basalt and andesite with minor dacite and rhyolite and underlie three discontinuous northwest-trending belts. Metasedimentary rocks are confined to small areas underlain by quartzite, metasandstone, marble, and calc-silicate rock. Plutonic rocks include an extensive unit of tonalite and quartz diorite and a smaller unit of diorite and quartz diorite, which occupy much of the central part of the quadrangle. A small body of diorite and gabbro and a two-part zone of tonalite gneiss are also present. All of these plutonic rocks are assigned to the An Nimas batholith. Younger plutonic rocks include extensive graphic granite and rhyolite in the northeastern part of the quadrangle and several smaller bodies of granitic rocks and of gabbro. The metavolcanic rocks commonly have strong foliation with northwest strike and steep to vertical dip. Diorite and quartz diorite are sheared and brecciated and apparently syntectonic. Tonalite and quartz diorite are both foliate and nonfoliate and were intruded in episodes both preceding and following shearing. The granitic rocks and gabbro are post-tectonic. Trends of faults and dikes are mostly related to the Najd faulting episode. Radiometric ages, mostly from adjacent quadrangles, suggest that the An Nimas batholith is 835 to 800 Ma, gabbro and granite, except the graphic granite and rhyolite unit, are about 640 to 615 Ma, and the graphic granite and rhyolite 575 to 565 Ma old. Metavolcanic rocks similar to those hosting copper and gold mineralization in the Wadi Shuwas mining district adjacent to the southwestern part of the quadrangle are abundant. An ancient copper mine was discovered at the edge of the tonalite gneiss belt east of Wadi Ranyah. Granite and gabbro have economic potential as building stone.

Geologic map of the Harvard Lakes 7.5' quadrangle, Park and Chaffee Counties, Colorado

USGS Publications Warehouse

Kellogg, Karl S.; Lee, Keenan; Premo, Wayne R.; Cosca, Michael A.

2013-01-01

The Harvard Lakes 1:24,000-scale quadrangle spans the Arkansas River Valley in central Colorado, and includes the foothills of the Sawatch Range on the west and Mosquito Range on the east. The Arkansas River valley lies in the northern end of the Rio Grande rift and is structurally controlled by Oligocene and younger normal faults mostly along the west side of the valley. Five separate pediment surfaces were mapped, and distinctions were made between terraces formed by the Arkansas River and surfaces that formed from erosion and alluviation that emanated from the Sawatch Range. Three flood deposits containing boulders as long as 15 m were deposited from glacial breakouts just north of the quadrangle. Miocene and Pliocene basin-fill deposits of the Dry Union Formation are exposed beneath terrace or pediment deposits in several places. The southwestern part of the late Eocene Buffalo Peaks volcanic center, mostly andesitic breccias and flows and ash-flow tuffs, occupy the northeastern corner of the map. Dated Tertiary intrusive rocks include Late Cretaceous or early Paleocene hornblende gabbro and hornblende monzonite. Numerous rhyolite and dacite dikes of inferred early Tertiary or Late Cretaceous age also intrude the basement rocks. Basement rocks are predominantly Mesoproterozoic granites, and subordinately Paleoproterozoic biotite gneiss and granitic gneiss.

FACILITY 847, DETAIL OF A CENTRAL STAIRWELL BETWEEN SECOND AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FACILITY 847, DETAIL OF A CENTRAL STAIRWELL BETWEEN SECOND AND THIRD FLOORS, QUADRANGLE J, VIEW FACING SOUTHEAST. - Schofield Barracks Military Reservation, Quadrangles I & J Barracks Type, Between Wright-Smith & Capron Avenues near Williston Avenue, Wahiawa, Honolulu County, HI

Reconnaissance geology of the Al Mukhul Quadrangle, sheet 26/42 B, Kingdom of Saudi Arabia

USGS Publications Warehouse

Du Bray, E.A.

1984-01-01

Mineral potential in the quadrangle is low. At a very small prospect pit in the north-central part of the quadrangle, massive, milky quartz veins cutting weakly metamorphosed volcanogenic sedimentary rocks are stained blue and green by copper minerals. A previously reported mine site in the southern part of the quadrangle was not relocated.

Uranium hydrogeochemical and stream sediment reconnaissance of the Philip Smith Mountains NTMS quadrangle, Alaska

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

Not Available

1981-09-01

Results of a hydrogeochemical and stream sediment reconnaissance of the Philip Smith Mountains NTMS quadrangle, Alaska are presented. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. In this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data were subsetted by onemore » of the Los Alamos National Laboratory (LANL) sorting programs into groups of stream sediment and lake sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report.« less

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).

8. LOOKING EAST FROM TOP OF WATER TOWER: VIEW SHOWS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. LOOKING EAST FROM TOP OF WATER TOWER: VIEW SHOWS BUILDING #626 AND PORTION OF QUADRANGLE - Fort Sam Houston, San Antonio Depot, Water-Watch Tower, Grayson Street & New Braunfels Avenue, San Antonio, Bexar County, TX

Biogeochemical characterization of an undisturbed highly acidic, metal-rich bryophyte habitat, east-central Alaska, U.S.A.

USGS Publications Warehouse

Gough, L.P.; Eppinger, R.G.; Briggs, P.H.; Giles, S.

2006-01-01

We report on the geochemistry of soil and bryophyte-laden sediment and on the biogeochemistry of willows growing in an undisturbed volcanogenic massive sulfide deposit in the Alaska Range ecoregion of east-central Alaska. We also describe an unusual bryophyte assemblage found growing in the acidic metal-rich waters that drain the area. Ferricrete-cemented silty alluvial sediments within seeps and streams are covered with the liverwort Gymnocolea inflata whereas the mosses Polytrichum commune and P. juniperinum inhabit the area adjacent to the water and within the splash zone. Both the liverwort-encrusted sediment and Polytrichum thalli have high concentrations of major and trace metal cations (e.g., Al, As, Cu, Fe, Hg, La, Mn, Pb, and Zn). Soils in the area do not reflect the geochemical signature of the mineral deposit and we postulate they are influenced by the chemistry of eolian sediments derived from outside the deposit area. The willow, Salix pulchra, growing mostly within and adjacent to the larger streams, has much higher concentrations of Al, As, Cd, Cr, Fe, La, Pb, and Zn when compared to the same species collected in non-mineralized areas of Alaska. The Cd levels are especially high and are shown to exceed, by an order of magnitude, levels demonstrated to be toxic to ptarmigan in Colorado. Willow, growing in this naturally occurring metal-rich Red Mountain alteration zone, may adversely affect the health of browsing animals. ?? 2006 Regents of the University of Colorado.

Geologic map and digital database of the Apache Canyon 7.5' quadrangle, Ventura and Kern counties, California

USGS Publications Warehouse

Stone, Paul; Cossette, P.M.

2000-01-01

The Apache Canyon 7.5-minute quadrangle is located in southwestern California about 55 km northeast of Santa Barbara and 65 km southwest of Bakersfield. This report presents the results of a geologic mapping investigation of the Apache Canyon quadrangle that was carried out in 1997-1999 as part of the U.S. Geological Survey's Southern California Areal Mapping Project. This quadrangle was chosen for study because it is in an area of complex, incompletely understood Cenozoic stratigraphy and structure of potential importance for regional tectonic interpretations, particularly those involving the San Andreas fault located just northwest of the quadrangle and the Big Pine fault about 10 km to the south. In addition, the quadrangle is notable for its well-exposed sequences of folded Neogene nonmarine strata including the Caliente Formation of Miocene age from which previous workers have collected and described several biostratigraphically significant land-mammal fossil assemblages. During the present study, these strata were mapped in detail throughout the quadrangle to provide an improved framework for possible future paleontologic investigations. The Apache Canyon quadrangle is in the eastern part of the Cuyama 30-minute by 60-minute quadrangle and is largely part of an erosionally dissected terrain known as the Cuyama badlands at the east end of Cuyama Valley. Most of the Apache Canyon quadrangle consists of public lands in the Los Padres National Forest.

Color Shaded-Relief and Surface-Classification Maps of the Fish Creek Area, Harrison Bay Quadrangle, Northern Alaska

USGS Publications Warehouse

Mars, John L.; Garrity, Christopher P.; Houseknecht, David W.; Amoroso, Lee; Meares, Donald C.

2007-01-01

Introduction The northeastern part of the National Petroleum Reserve in Alaska (NPRA) has become an area of active petroleum exploration during the past five years. Recent leasing and exploration drilling in the NPRA requires the U.S. Bureau of Land Management (BLM) to manage and monitor a variety of surface activities that include seismic surveying, exploration drilling, oil-field development drilling, construction of oil-production facilities, and construction of pipelines and access roads. BLM evaluates a variety of permit applications, environmental impact studies, and other documents that require rapid compilation and analysis of data pertaining to surface and subsurface geology, hydrology, and biology. In addition, BLM must monitor these activities and assess their impacts on the natural environment. Timely and accurate completion of these land-management tasks requires elevation, hydrologic, geologic, petroleum-activity, and cadastral data, all integrated in digital formats at a higher resolution than is currently available in nondigital (paper) formats. To support these land-management tasks, a series of maps was generated from remotely sensed data in an area of high petroleum-industry activity (fig. 1). The maps cover an area from approximately latitude 70?00' N. to 70?30' N. and from longitude 151?00' W. to 153?10' W. The area includes the Alpine oil field in the east, the Husky Inigok exploration well (site of a landing strip) in the west, many of the exploration wells drilled in NPRA since 2000, and the route of a proposed pipeline to carry oil from discovery wells in NPRA to the Alpine oil field. This map area is referred to as the 'Fish Creek area' after a creek that flows through the region. The map series includes (1) a color shaded-relief map based on 5-m-resolution data (sheet 1), (2) a surface-classification map based on 30-m-resolution data (sheet 2), and (3) a 5-m-resolution shaded relief-surface classification map that combines the shaded-relief and surface-classification data (sheet 3). Remote sensing datasets that were used to compile the maps include Landsat 7 Enhanced Thematic Mapper+ (ETM+), and interferometric synthetic aperture radar (IFSAR) data. In addition, a 1:250,000-scale geologic map of the Harrison Bay quadrangle, Alaska (Carter and Galloway, 1985, 2005) was used in conjunction with ETM+ and IFSAR data.

Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks

USGS Publications Warehouse

Dusel-Bacon, C.; Lanphere, M.A.; Sharp, W.D.; Layer, P.W.; Hansen, V.L.

2002-01-01

We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the Yukon-Tanana Upland, Alaska. Integration of our data with published 40Ar/39Ar, kinematic, and metamorphic pressure (P) and temperature (T) data confirms and refines the complex interaction of metamorphism and tectonism proposed for the region. The oldest metamorphic episode(s) postdates Middle Permian magmatism and predates the intrusion of Late Triassic (215-212 Ma) granitoids into the Fortymile River assemblage (Taylor Mountain assemblage of previous papers). In the eastern Eagle quadrangle, rapid and widespread Early Jurassic cooling is indicated by ???188-186 Ma 40Ar/39Ar plateau ages for hornblende from plutons that intrude the Fortymile River assemblage, and for metamorphic minerals from the Fortymile River assemblage and the structurally underlying Nasina assemblage. We interpret these Early Jurassic ages to represent cooling resulting from northwest-directed contraction that emplaced the Fortymile River assemblage onto the Nasina assemblage to the north as well as the Lake George assemblage to the south. This cooling was the final stage of a continuum of subduction-related contraction that produced crustal thickening, intermediate- to high-P metamorphism within both the Fortymile River assemblage and the structurally underlying Lake George assemblage, and Late Triassic and Early Jurassic plutonism in the Fortymile River and Nasina assemblages. Although a few metamorphic samples from the Lake George assemblage yield Jurassic 40Ar/39Ar cooling ages, most yield Early Cretaceous 40Ar/39Ar ages: hornblende ???135-115 Ma, and muscovite and biotite ???110-108 Ma. We interpret the Early Cretaceous metamorphic cooling, in most areas, to have resulted from regional extension and exhumation of the lower plate, previously tectonically thickened during Early Jurassic and older convergence.

Mineral-resource assessments in Alaska; background information to accompany maps and reports about the geology and undiscovered-mineral-resource potential of the Mount Katmai Quadrangle and adjacent parts of the Naknek and Afognak quadrangles, Alaska Peninsula

USGS Publications Warehouse

Riehle, J.R.; Church, S.E.; Detterman, R.L.; Miller, J.W.

1994-01-01

Geologic and geochemical field studies were carded out from 1983 to 1987 in the Mount Katmai l?x2 ? quadrangle and adjoining region, at the northeast end of the Alaska Peninsula. The region is nearly entirely within Katmai National Park and Preserve and has had almost no mineral production, so prior to this study there were few data by which to assess the mineral potential of the region. This report describes the folio of publications that have resulted from the study: geologic maps, geochemical results, fossil identifications, radiometric rock ages, and an assessment of the undiscovered-mineral-resource potential of the region. The Katmai region is inferred to potentially have three types of undiscovered mineral deposits: porphyry copper (molybdenum), precious-metal vein, and hot-springs gold. These deposit types occur elsewhere on the Alaska Peninsula in similar geologic units. Evidence suggesting their occurrence in the Katmai region is the presence of trace amounts of metals typically associated with these kinds of deposits in bedrock of certain tracts and in sediments of streams draining those tracts. Magma to provide heat, fractures to provide pathways for mineralizing fluids, and altered rock are required by genetic models of these deposit types. Such features do occur in the Katmai tracts. Confirmation of any mineral deposit in the Katmai region requires detailed follow-up sampling and acquisition of subsurface information, which is beyond the scope of this study. However, producing porphyry deposits are unknown elsewhere on the Alaska Peninsula in similar rocks, so if any such deposits occur in the Katmai region, they are likely to be few in number. Conversely, vein deposits are typically small in size so there may be several of such deposits. The properties and thermal history of the sedimentary rocks that could serve as reservoirs for oil or gas are unfavorable in adjacent regions. Thus the potential of the Katmai region for producible quantities of fossil fuels is low. In theory the region has shallow concentrations of geothermal fluids, but specific evidence for their presence is obscured by heavy precipitation and cold young rocks or deposits. Small volumes of coal occur at tidewater sites on the Pacific coast.

Transit traverse in Missouri, 1900-1937. Part 7, Central Missouri, 1902-37

USGS Publications Warehouse

Staack, John George

1940-01-01

This bulletin, which for convenience is to be published in eight parts, contains the results of all transit traverse* done In Missouri through 1937 by the Geological Survey, United States Department of the Interior, including those heretofore published. (See page X.) Each of the parts deals with one of eight sections into which the State has been divided for this purpose and which have been designated northeastern, northwestern, southeastern, southwestern, central, east-central, south-central, and west-central Missouri. In each part descriptions of the points for which geodetic positions have been determined are listed according to the quadrangles in which the points occur. Results of transit traverse other than that done by the Geological Survey have not been included.Central Missouri, as the term is used in this bulletin and as the subject of part 7 of the bulletin, is that section of the State lying between latitudes 36°00' and 39°30' and between longitudes 92°00' and 93°30'.

Transit traverse in Missouri, 1900-1937. Part 8, West-central Missouri, 1906-37

USGS Publications Warehouse

Staack, John G.

1940-01-01

This bulletin, which for convenience is to be published in eight parts, contains the results of all transit traverse* done In Missouri through 1937 by the Geological Survey, United States Department of the Interior, including those heretofore published. (See page X.) Each of the parts deals with one of eight sections into which the State has been divided for this purpose and which have been designated northeastern, northwestern, southeastern, southwestern, central, east-central, south-central, and west-central Missouri. In each part descriptions of the points for which geodetic positions have been determined are listed according to the quadrangles in which the points occur. Results of transit traverse other than that done by the Geological Survey have not been included.West-central Missouri, as the term is used in this bulletin and as the subject of part 8 of the bulletin, is that section of the State lying between latitudes 38°00' and 39°30' and west of longitude 93°30'.

Geologic maps of the eastern Alaska Range, Alaska (1:63,360 scale)

USGS Publications Warehouse

Nokleberg, Warren J.; Aleinikoff, John N.; Bond, Gerard C.; Ferrians, Oscar J.; Herzon, Paige L.; Lange, Ian M.; Miyaoka, Ronny T.; Richter, Donald H.; Schwab, Carl E.; Silva, Steven R.; Smith, Thomas E.; Zehner, Richard E.

2015-01-01

This report provides a description of map units for a suite of 44 inch-to-mile (1:63,360-scale) geologic quadrangle maps of the eastern Alaska Range. This report also contains a geologic and tectonic summary and a comprehensive list of references pertaining to geologic mapping and specialized studies of the region. In addition to the geologic maps of the eastern Alaska Range, this package includes a list of map units and an explanation of map symbols and abbreviations. The geologic maps display detailed surficial and bedrock geology, structural and stratigraphic data, portrayal of the active Denali fault that bisects the core of the east–west-trending range, and portrayal of other young faults along the north and south flanks of the range.

Publications - GMC 364 | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska: Drew Pt #1, East Simpson Test Well #1, East Simpson #2, Ikpikpuk #1, J.W. Dalton #1, Seabee #1 , Topogoruk Test #1, and W. Dease #1 Authors: Talisman Energy Inc., and Core Laboratories Publication Date Properties Study on Core samples from 8 wells in Alaska: Drew Pt #1, East Simpson Test Well #1, East Simpson

Reconnaissance geologic map of the Dubakella Mountain 15 quadrangle, Trinity, Shasta, and Tehama Counties, California

USGS Publications Warehouse

Irwin, William P.; Yule, J. Douglas; Court, Bradford L.; Snoke, Arthur W.; Stern, Laura A.; Copeland, William B.

2011-01-01

The Dubakella Mountain 15' quadrangle is located just south of the Hayfork quadrangle and just east of the Pickett Peak quadrangle. It spans a sequence of four northwest-trending tectonostratigraphic terranes of the Klamath Mountains geologic province that includes, from east to west, the Eastern Hayfork, Western Hayfork, Rattlesnake Creek, and Western Jurassic terranes, as well as, in the southwest corner of the quadrangle, part of a fifth terrane, the Pickett Peak terrane of the Coast Ranges geologic province. The Eastern Hayfork terrane is a broken formation and melange of volcanic and sedimentary rocks that include blocks of limestone and chert. The limestone contains late Permian microfossils of Tethyan faunal affinity. The chert contains radiolarians of Mesozoic age, mostly Triassic, but none clearly Jurassic. The Western Hayfork terrane is an andesitic volcanic arc that consists mainly of agglomerate, tuff, argillite, and chert, and includes the Wildwood pluton. That pluton is related to the Middle Jurassic (about 170 Ma) Ironside Mountain batholith that is widely exposed farther north beyond the Dubakella Mountain quadrangle. The Rattlesnake Creek terrane is a highly disrupted ophiolitic melange of probable Late Triassic or Early Jurassic age. Although mainly ophiolitic, the melange includes blocks of plutonic rocks (about 200 Ma) of uncertain genetic relation. Some scattered areas of well-bedded mildly slaty detrital rocks of the melange appear similar to Galice Formation (unit Jg) and may be inliers of the nearby Western Jurassic terrane. The Western Jurassic terrane consists mainly of slaty to phyllitic argillite, graywacke, and stretched-pebble conglomerate and is correlative with the Late Jurassic Galice Formation of southwestern Oregon. The Pickett Peak terrane, the most westerly of the succession of terranes of the Dubakella Mountain quadrangle, is mostly fine-grained schist that includes the blueschist facies mineral lawsonite and is of Early Cretaceous (about 120 Ma) metamorphic age. Remnants of the Great Valley sequence of dominantly Cretaceous marine sedimentary strata, which once covered much of the southern fringe of the Klamath Mountains, are present at three places in the Dubakella Mountain quadrangle. Mineral production in the quadrangle has included small amounts of gold, chromite, and manganese. This map of the Dubakella Mountain 15' quadrangle is a digital rendition of U.S. Geological Survey Miscellaneous Field Studies Map MF-1808, with various improvements and additions.

Summary mineral resource appraisal of the Richfield 1 degree x 2 degrees Quadrangle, west-central Utah

USGS Publications Warehouse

Steven, Thomas August; Morris, Hal T.

1987-01-01

The mineral resource potential of the Richfield 1? x 2? quadrangle, Utah, has been appraised using geological, geophysical, geochemical, and remote-sensing techniques. These studies have led to many publications giving basic data and interpretations; of these, a series of 18 maps at 1:250,000 and 1:500,000 scales summarizing aspects of the geology, geophysics, geochemistry, and remote sensing is designated the CUSMAP (Conterminous United States Mineral Appraisal Program) folio. This circular uses the data shown on these maps to appraise the mineral resource potential of the quadrangle. The oldest rocks exposed in the Richfield quadrangle are small patches of Early Proterozoic (1.7 billion years old) gneiss and schist on the west side of the Mineral Mountains. These rocks presumably formed the basement on which many thousands of meters of Late Proterozoic, Paleozoic, and lower Mesozoic sedimentary strata were deposited. These rocks were deformed during the Late Cretaceous Sevier orogeny when Precambrian and Paleozoic strata in the western part of the quadrangle were thrust relatively eastward across Paleozoic and Mesozoic strata in the eastern part of the quadrangle. Late Cretaceous and early Tertiary highlands above the overthrust belt were eroded and much of the debris was deposited in broad basins east of the belt. Volcanism in Oligocene and earliest Miocene time formed an east-northeast-trending belt of calcalkalic volcanoes across the southern half of the quadrangle. In early Miocene time, the composition of the volcanic rocks changed to a bimodal assemblage of mafic rocks and high-silica alkali rhyolite that has been erupted episodically ever since. Syngenetic mineral resources developed during formation of both sedimentary and volcanic rocks. These include limestone and dolomite, silica-rich sandstone, metalliferous black shale, evaporite deposits, zeolite deposits, pumice, cinders and scoria, and evaporitic or diagenetic deposits in playa environments. Most of these deposits need to have markets established, or extraction and fabrication techniques developed, for them to be utilized. Most epigenetic deposits are of volcanogenic-hydrothermal origin. Deposits associated with calc-alkalic igneous activity largely contain Cu, Pb, Zn, Au, and Ag, and occur in a variety of types zoned around core intrusions. Younger deposits are mostly associated with silicic igneous centers belonging to the bimodal mafic-silicic igneous association. Resources associated with this latter group are likely to contain one or more of the elements Mo, W, U, Sn, Be, and F, as well as Pb, Zn, Au, and Ag. Alunite and kaolinite deposits are found at many mineralized centers. Most epigenetically mineralized areas expose only the upper, near-surface parts of the different hydrothermal systems; most of whatever mineral deposits formed in these systems probably still exist at depth, awaiting discovery. Our conclusion is that many mineralized areas have excellent possibilities for the occurrence of mineral resources. Each of the many identified centers of mineralization is discussed briefly in this report and an estimate made of its resource potential.

DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

EPA Science Inventory

This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

Map showing geologic terranes of the Hailey 1 degree x 2 degrees quadrangle and the western part of the Idaho Falls 1 degree x 2 degrees quadrangle, south-central Idaho

USGS Publications Warehouse

Worl, R.G.; Johnson, K.M.

1995-01-01

The paper version of Map Showing Geologic Terranes of the Hailey 1x2 Quadrangle and the western part of the Idaho Falls 1x2 Quadrangle, south-central Idaho was compiled by Ron Worl and Kate Johnson in 1995. The plate was compiled on a 1:250,000 scale topographic base map. TechniGraphic System, Inc. of Fort Collins Colorado digitized this map under contract for N.Shock. G.Green edited and prepared the digital version for publication as a geographic information system database. The digital geologic map database can be queried in many ways to produce a variety of geologic maps.

Ocean plateau-seamount origin of basaltic rocks, Angayucham terrane, central Alaska

USGS Publications Warehouse

Barker, F.; Jones, D.L.; Budahn, J.R.; Coney, P.J.

1988-01-01

The Angayucham terrane of north-central Alaska (immediately S of the Brooks Range) is a large (ca. 500 km E-W), allochthonous complex of Devonian to Lower Jurassic pillow basalt, diabase sills, gabbro plutons, and chert. The mafic rocks are transitional normal-to-enriched, mid-ocean-ridge (MORB) type tholeiites (TiO2 1.2-3.4%, Nb 7-23 ppm, Ta 0.24-1.08 ppm, Zr 69-214 ppm, and light REE's slightly depleted to moderately enriched). Geologic and geochemical constraints indicate that Angayucham terrane is the upper "skin' (ca. 3-4 km thick) of a long-lived (ca. 170-200 ma) oceanic plateau whose basaltic-gabbroic rocks are like those of seamounts of the East Pacific Rise. -Authors

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska

USGS Publications Warehouse

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 653 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering portions of the Inmachuk, Kugruk, Kiwalik, and Koyuk river drainages, Granite Mountain, and the northern Darby Mountains, located in the Bendeleben, Candle, Kotzebue, and Solomon quadrangles of eastern Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Preliminary geologic map of the Townsend 30' x 60' quadrangle, Montana

USGS Publications Warehouse

Reynolds, Mitchell W.; Brandt, Theodore R.

2006-01-01

The geologic map of the Townsend quadrangle, scale 1:100,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of this geologically complex area in west-central Montana. The quadrangle encompasses about 4,200 square km (1,640 square mi).

Principal Facts for 463 Gravity Stations in the Vicinity of Tangle Lakes, East-Central Alaska

USGS Publications Warehouse

Morin, Robert L.; Glen, Jonathan M.G.

2002-01-01

During the summer of 2001, a gravity survey was conducted in the vicinity of Tangle Lakes, east-central Alaska. Measurements of 87 gravity stations were made. The Tangle Lakes area is located about 25 km west of Paxson and north of the Denali Highway. The gravity survey is located on the southwest corner of the Mt. Hayes and the northwest corner of the Gulkana 1:250,000 scale USGS topographic maps. The boundaries of the study area are 62 deg 30' to 63 deg 30' N. latitude and 145 deg 30' to 147 deg 00' W. longitude. A map showing the location of the study area is shown in figure 1. One gravity base station was used for control for this survey. This base station, TLIN is located at the Tangle Lakes Inn. The observed gravity of this station was calculated based on multiple ties to base stations ANCU in Anchorage, PALH in Palmer, BD27 in Gulkana, and base stations D42, and D57 along the Denali Highway.

Geologic map of the Dillon quadrangle, Summit and Grand Counties, Colorado

USGS Publications Warehouse

Kellogg, Karl S.

2002-01-01

New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale Dillon quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, 1999), part of the northernmost reaches of the Rio Grande rift, a major late Oligocene to recent zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault, the western structural margin of the Colorado Front Range, cuts through the center of the quadrangle, although is mostly covered by surficial deposits. The oldest rocks in the quadrangle underlie the Williams Fork Mountains and the ridge immediately east of South Fork Middle Fork River, and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite that are intruded by granite inferred to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, 1987). The oldest exposed sedimentary unit is the Upper Jurassic Morrison Formation, but Pennsylvanian Maroon Formation, a sequence of red sandstone, conglomerate, and interbedded shale, underlies the southern part of the quadrangle. The thickest sequence of sedimentary rocks is Cretaceous in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. Surficial deposits include (1) an old, deeply dissected landslide deposit, possibly as old as Pliocene, on the west flank of the Williams Fork Mountains, (2) deeply weathered, very coarse gravel deposits underlying a mesa in the southwest part of the quadrangle (the Mesa Cortina subdivision. The gravels are gold bearing and were mined by hydraulic methods in the 1800s), (3) moderately to deeply weathered, widespread, bouldery material that is a combination of till of the Bull Lake glaciation, debris-flow deposits, landslide deposits, and possibly pre-Bull Lake till, (4) glacial deposits of both Bull Lake (middle Pleistocene) and Pinedale (late Pleistocene)glaciations, (5) recent landslide deposits, and (6)extensive colluvial and alluvial deposits.

Geologic map of the Dillon quadrangle, Summit and Grand Counties, Colorado

USGS Publications Warehouse

Kellogg, Karl S.

1997-01-01

New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale Dillon quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, 1999), part of the northernmost reaches of the Rio Grande rift, a major late Oligocene to recent zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault, the western structural margin of the Colorado Front Range, cuts through the center of the quadrangle, although is mostly covered by surficial deposits. The oldest rocks in the quadrangle underlie the Williams Fork Mountains and the ridge immediately east of South Fork Middle Fork River, and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite that are intruded by granite inferred to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, 1987). The oldest exposed sedimentary unit is the Upper Jurassic Morrison Formation, but Pennsylvanian Maroon Formation, a sequence of red sandstone, conglomerate, and interbedded shale, underlies the southern part of the quadrangle. The thickest sequence of sedimentary rocks is Cretaceous in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. Surficial deposits include (1) an old, deeply dissected landslide deposit, possibly as old as Pliocene, on the west flank of the Williams Fork Mountains, (2) deeply weathered, very coarse gravel deposits underlying a mesa in the southwest part of the quadrangle (the Mesa Cortina subdivision. The gravels are gold bearing and were mined by hydraulic methods in the 1800s), (3) moderately to deeply weathered, widespread, bouldery material that is a combination of till of the Bull Lake glaciation, debris-flow deposits, landslide deposits, and possibly pre-Bull Lake till, (4) glacial deposits of both Bull Lake (middle Pleistocene) and Pinedale (late Pleistocene)glaciations, (5) recent landslide deposits, and (6)extensive colluvial and alluvial deposits.

The mineral resource potential of the Thaniyah and Al Ufayriyah quadrangles, sheets 20/42 C and 20/42 A, Kingdom of Saudi Arabia

USGS Publications Warehouse

Fenton, Michael D.

1983-01-01

Areas with mineral resource potential in the Thaniyah and Al Ufayriyah quadrangles in the central Precambrian Shield of Saudi Arabia have been identified by reconnaissance rock geochemistry and inspection of ancient prospects. Locally anomalous areas in plutonic terrane have been defined as possible sources of tin, molybdenum, or base metal mineralization. The survey over layered volcanic terrane identified several areas of anomalous copper and zinc. One ancient copper prospect with gossan in the west-central part of the Thaniyah quadrangle merits additional study.

Principal facts for gravity stations in the Dry Valley area, west-central Nevada and east-central California

USGS Publications Warehouse

Sanger, Elizabeth A.; Ponce, David A.

2003-01-01

In June, 2002, the U.S. Geological Survey (USGS) established 143 new gravity stations and 12 new rock samples in the Dry Valley area, 30 miles north of Reno, Nevada, on the California - Nevada border (see fig. 1). This study reports on gravity, magnetic, and physical property data intended for use in modeling the geometry and depth of Dry Valley for groundwater analysis. It is part of a larger study that aims to characterize the hydrologic framework of several basins in Washoe County. Dry Valley is located south of the Fort Sage Mountains and south-east of Long Valley, on USGS 7.5’ quadrangles Constantia and Seven Lakes (fig. 2). The Cretaceous granitic rocks and Tertiary volcanic rocks that bound the sediment filled basin (fig. 3) may be especially important to future modeling because of their impact on groundwater flow. The granitic and volcanic rocks of Dry Valley exhibit densities and magnetic susceptibilities higher than the overlaying sediments, and create a distinguishable pattern of gravity and magnetic anomalies that reflect these properties.

Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese

USGS Publications Warehouse

Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.

2013-01-01

We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during autumn, winter, and spring. Temporal and spatial differences in migratory behavior may allow management practices that accommodate potential demographic differences between taiga and tundra populations.

Aerial gamma ray and magnetic survey: Nebraska/Texas survey, Waco quadrangle of Texas

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

Not Available

1980-02-01

The Waco quadrangle of eastern Texas lies within the northern Gulf Coastal Province. The area contains portions of the Ouachita Tectonic Belt, and the East Texas-Athens Embayment. The Mexia-Talco Fault Zone strikes NNW through the center of the area. West of the fault zone, Eocene neritic sediments are dominant, whereas Cretaceous platform deposits cover most of the area west of the zone. Examination of available literature shows no known uranium deposits (or occurrences) within the quadrangle. One hundred forty-four groups of uranium samples were defined as anomalous and discussed briefly in this report. None are considered significant. Most appear tomore » be of cultural origin. Magnetic data in the quadrangle are dominantly low frequency/low amplitude wavelengths, which suggest that sources may be extremely deep.« less

Geologic Map of the Umiat Quadrangle, Alaska

USGS Publications Warehouse

Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

2004-01-01

This geologic map of the Umiat quadrangle is a compilation of previously published USGS geologic maps and unpublished mapping done for the Richfield Oil Corporation. Geologic mapping from these three primary sources was augmented with additional unpublished map data from British Petroleum Company. This report incorporates recent revisions in stratigraphic nomenclature. Stratigraphic and structural interpretations were revised with the aid of modern high-resolution color infrared aerial photographs. The revised geologic map was checked in the field during the summers of 2001 and 2002. The geologic unit descriptions on this map give detailed information on thicknesses, regional distributions, age determinations, and depositional environments. The paper version of this map is available for purchase from the USGS Store.

Water and Sediment Chemical Data and Data Summary for Samples Collected in 1999 and 2001 in the Goodpaster River Basin, Big Delta B-2 Quadrangle, Alaska

USGS Publications Warehouse

Wang, Bronwen; Gough, Larry; Wanty, Richard; Vohden, Jim; Crock, Jim; Day, Warren

2006-01-01

We report the chemical analysis for water and sediment collected from the Big Delta B-2 quadrangle. These data are part of a study located in the Big Delta B-2 quadrangle that focused on the integration of geology and bedrock geochemistry on with the biogeochemistry of water, sediments, soil, and vegetation. The discovery of the Pogo lode gold deposit in the northwest corner of the quadrangle was the impetus for this study. The study objectives were to create a geologic map, evaluate the bedrock geochemical influence on the geochemical signature of the surficial environment, and define landscape-level predevelopment geochemical baselines. Important to baseline development is an evaluation of what, if any, geochemical difference exists between the mineralized and non-mineralized areas within a watershed or between mineralized and non-mineralized watersheds. The analytic results for the bedrock, soils, and vegetation are reported elsewhere. Presented here, with minimal interpretation, is the analytic data for the water and sediment samples collected in the summers of 1999 and 2001, and a summary statistics of these analyses.

Reconnaissance geology of the Jibal Matalli Quadrangle, sheet 27/40 D, Kingdom of Saudi Arabia

USGS Publications Warehouse

Ekren, E.B.

1984-01-01

Two northeast-trending buried right-lateral faults are inferred in the quadrangle; one in the southeast and one in the northwest. The one in the northwest probably offsets the comendite dike swarm about 3 km. This fault appears to be part of a broad right-lateral fault and flexure zone that juxtaposes the Hadn formation on the west against the Hulayfah group on the east.

Uranium hydrogeochemical and stream sediment reconnaissance of the Durango NTMS quadrangle, Colorado, including concentrations of forty-two additional elements

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

Shannon, S.S. Jr.

1980-05-01

Uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Durango National Topographic Map Series (NTMS) quadrangle, Colorado, by the Los Alamos Scientific Laboratory (LASL) are reported herein. The LASL is responsible for conducting the HSSR primarily in the states of New Mexico, Colorado, Wyoming, Montana, and Alaska. This study was conducted as part of the United States Department of Energy's National Uranium Resource Evaluation (NURE), which is designed to provide improved estimates of the availability and economics of nuclear fuel resources and to make available to industry information for use in exploration andmore » development of uranium resources. The HSSR data will ultimately be integrated with other NURE data (e.g., airborne radiometric surveys and geological investigations) to complete the entire NURE program. This report is a supplement to the HSSR uranium evaluation report for the Durango quadrangle which presented the field and uranium data for the 1518 water and 1604 sediment samples collected from 1804 locations in the quadrangle. The earlier report contains an evaluation of the uranium concentrations of the samples as well as descriptions of the geology, hydrology, climate, and uranium occurrences of the quadrangle. This supplement presents the sediment field and uranium data again and the analyses of 42 other elements in the sediments.« less

Database for the Geologic Map of the Skykomish River 30-Minute by 60-Minute Quadrangle, Washington (I-1963)

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Booth, D.B.; Waitt, R.B.; Whetten, J.T.; Zartman, R.E.

2006-01-01

This digital map database has been prepared from the published geologic map of the Skykomish River 30- by 60-minute quadrangle by the senior author. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the bedrock geology at 1:100,000 scale, but compiled Quaternary units at 1:24,000 scale. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. From the eastern-most edges of suburban Seattle, the Skykomish River quadrangle stretches east across the low rolling hills and broad river valleys of the Puget Lowland, across the forested foothills of the North Cascades, and across high meadowlands to the bare rock peaks of the Cascade crest. The Straight Creek Fault, a major Pacific Northwest structure which almost bisects the quadrangle, mostly separates unmetamorphosed and low-grade metamorphic Paleozoic and Mesozoic oceanic rocks on the west from medium- to high-grade metamorphic rocks on the east. Within the quadrangle the lower grade rocks are mostly Mesozoic melange units. To the east, the higher-grade terrane is mostly the Chiwaukum Schist and related gneisses of the Nason terrane and invading mid-Cretaceous stitching plutons. The Early Cretaceous Easton Metamorphic Suite crops out on both sides of the Straight Creek fault and records it's dextral displacement. On the south margin of the quadrangle, the fault separates the lower Eocene Swauk Formation on the east from the upper Eocene and Oligocene(?) Naches Formation and, farther north, its correlative Barlow Pass Volcanics the west. Stratigraphically equivalent rocks of the Puget Group crop out farther to the west. Rocks of the Cascade magmatic arc are mostly represented by Miocene and Oligocene plutons, including the Grotto, Snoqualmie, and Index batholiths. Alpine river valleys in the quadrangle record multiple advances and retreats of alpine glaciers. Multiple advances of the Cordilleran ice sheet, originating in the mountains of British Columbia, Canada, have left an even more complex sequence of outwash and till along the western mountain front, up these same alpine river valleys, and over the Puget Lowland. This database and accompanying plot files depict the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains new information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Geologic map of outcrop areas of sedimentary units in the eastern part of the Hailey 1 degree x 2 degrees quadrangle and part of the southern part of the Challis 1 degree x 2 degrees quadrangle, south-central Idaho

USGS Publications Warehouse

Link, P.K.; Mahoney, J.B.; Bruner, D.J.; Batatian, L.D.; Wilson, Eric; Williams, F.J.C.

1995-01-01

The paper version of the Geologic map of outcrop areas of sedimentary units in the eastern part of the Hailey 1x2 Quadrangle and part of the southern part of the Challis 1x2 Quadrangle, south-central Idaho was compiled by Paul Link and others in 1995. The plate was compiled on a 1:100,000 scale topographic base map. TechniGraphic System, Inc. of Fort Collins Colorado digitized this map under contract for N.Shock. G.Green edited and prepared the digital version for publication as a GIS database. The digital geologic map database can be queried in many ways to produce a variety of geologic maps.

Constraints on the age and provenance of the Chugach accretionary complex from detrital zircons in the Sitka Graywacke near Sitka, Alaska

USGS Publications Warehouse

Haeussler, Peter J.; Gehrels, George E.; Karl, Susan M.

2006-01-01

The Sitka Graywacke is the westernmost and youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on seven typical samples of Sitka Graywacke turbidites, which were collected in a transect across much of the unit near Sitka, Alaska. Individual grains range in age from 66 to 1,802 m.y. The youngest peak ages on relative-probability plots of the western four samples (74, 72, 74, and 74 m.y., from west to east) are distinctly younger than the youngest peak ages of the eastern three samples (105, 103, and 97 m.y., from west to east). These youngest peak ages set maximum depositional ages for each sample. We suggest that these peak ages are not significantly older (within ~5 m.y.) than the depositional age of the Sitka Graywacke because the deposits accumulated in a trench along a convergent margin, where magmatic sources likely continuously introduced juvenile zircons. The differences in the youngest cluster of detrital-zircon ages between the eastern and western sample localities is likely due to both a change in provenance and a fault. The similarity of the youngest peak ages in the Sitka Graywacke to fossil ages in the Valdez Group, in Prince William Sound, implies that the western part of the Sitka Graywacke is correlative with the Valdez Group, as previously inferred. However, the eastern part of the Sitka Graywacke has youngest detrital-zircon ages older than fossil ages in the Valdez Group and younger than fossil ages in the McHugh Complex, which in south-central Alaska is the oldest part of the accretionary complex. The age distribution of zircons in the older, eastern sequence suggests sources along the British Columbia margin. The detrital-zircon ages in the younger, western sequence are similar to igneous ages from south-central Alaska to southern British Columbia. Right-lateral strike slip on various fault systems inboard of the Sitka Graywacke implies that it lay to the south when it was deposited and offscraped. Thus, although source areas as far north as the St. Elias Mountains and south-central Alaska are possible, they were most likely in coastal and interior British Columbia.

Single-edition quadrangle maps

USGS Publications Warehouse

,

1998-01-01

In August 1993, the U.S. Geological Survey's (USGS) National Mapping Division and the U.S. Department of Agriculture's Forest Service signed an Interagency Agreement to begin a single-edition joint mapping program. This agreement established the coordination for producing and maintaining single-edition primary series topographic maps for quadrangles containing National Forest System lands. The joint mapping program saves money by eliminating duplication of effort by the agencies and results in a more frequent revision cycle for quadrangles containing national forests. Maps are revised on the basis of jointly developed standards and contain normal features mapped by the USGS, as well as additional features required for efficient management of National Forest System lands. Single-edition maps look slightly different but meet the content, accuracy, and quality criteria of other USGS products. The Forest Service is responsible for the land management of more than 191 million acres of land throughout the continental United States, Alaska, and Puerto Rico, including 155 national forests and 20 national grasslands. These areas make up the National Forest System lands and comprise more than 10,600 of the 56,000 primary series 7.5-minute quadrangle maps (15-minute in Alaska) covering the United States. The Forest Service has assumed responsibility for maintaining these maps, and the USGS remains responsible for printing and distributing them. Before the agreement, both agencies published similar maps of the same areas. The maps were used for different purposes, but had comparable types of features that were revised at different times. Now, the two products have been combined into one so that the revision cycle is stabilized and only one agency revises the maps, thus increasing the number of current maps available for National Forest System lands. This agreement has improved service to the public by requiring that the agencies share the same maps and that the maps meet a common standard, as well as by significantly reducing duplication of effort.

Geologic map of the Lower Valley quadrangle, Caribou County, Idaho

USGS Publications Warehouse

Oberlindacher, H. Peter; Hovland, R. David; Miller, Susan T.; Evans, James G.; Miller, Robert J.

2018-04-05

The Lower Valley 7.5-minute quadrangle, located in the core of the Southeast Idaho Phosphate Resource Area, includes Mississippian to Triassic marine sedimentary rocks, Pliocene to Pleistocene basalt, and Tertiary to Holocene surficial deposits. The Mississippian to Triassic marine sedimentary sequence was deposited on a shallow shelf between an emergent craton to the east and the Antler orogenic belt to the west. The Meade Peak Phosphatic Shale Member of the Permian Phosphoria Formation hosts high-grade deposits of phosphate that were the subject of geologic studies through much of the 20th century. Open-pit mining of the phosphate has been underway within and near the Lower Valley quadrangle for several decades.

Preliminary Geologic Map of the Sanchez Reservoir Quadrangle and Eastern Part of the Garcia Quadrangle, Costilla County, Colorado

USGS Publications Warehouse

Thompson, Ren A.; Machette, Michael N.; Drenth, Benjamin J.

2007-01-01

This geologic map is based entirely on new mapping by Thompson and Machette, whereas the geophysical data and interpretations were supplied by Drenth. The map area includes most of San Pedro Mesa, a basalt covered mesa that is uplifted as a horst between the Southern Sangre de Cristo fault zone (on the west) and the San Luis fault zone on the east. The map also includes most of the Sanchez graben, a deep structural basin that lies between the San Luis fault zone (on the west) and the Central Sangre de Cristo fault zone on the east. The oldest rocks in the map area are Proterozoic granites and Paleozoic sedimentary rocks, which are only exposed in a small hill on the west-central part of the mesa. The low hills that rise above San Pedro mesa are comprised of middle(?) Miocene volcanic rocks that are undated, but possibly correlative with mapped rocks to the east of Sanchez Reservoir. The bulk of the map area is comprised of the Servilleta Basalt, a regional series of flood basalts of Pliocene age. The west, north, and northeast margins of the mesa are covered by extensive landslide deposits that rest on poorly exposed sediment of the Santa Fe Group. Rare exposures of the sediment are comprised of siltstones, sandstones, and minor fluvial conglomerates. Most of the low ground surrounding the mesa is covered by surficial deposits of Quaternary age. The piedmont alluvium is subdivided into three Pleistocene units, and three Holocene units. The oldest Pleistocene gravel (unit Qao) forms an extensive coalesced alluvial fan and piedmont surface that is known as the Costilla Plains. This surface extends west from San Pedro Mesa to the Rio Grande. The primary geologic hazards in the map are are from earthquakes and landslides. There are three major fault zones in the area (as discussed above), and they all show evidence for late Pleistocene to possible Holocene movement. Two generations of landslides are mapped (younger and older), and both may have seismogenic origins.

Postglacial vegetation history of the Kachemak Bay area, Cook Inlet, south-central Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

USGS Publications Warehouse

Ager, Thomas A.

2000-01-01

Pollen records from two sites on the north shore of Kachemak Bay, south-central Alaska, provide the first radiocarbon-dated histories of postglacial vegetation development for southern Cook Inlet. During the late Wisconsin glacial interval, glaciers covered most of Cook Inlet. Deglaciation of Kachemak Bay began prior to 13,000 yr B.P. Pollen evidence indicates that a pioneering herbaceous tundra began to develop by 12,800 yr B.P., but was soon replaced by a shrub tundra of dwarf birch (Betula), Ericales (Ericaceae and Empetrum) and willows (Salix).By 9,500 yr B.P., a shrub-dominated vegetation of alders (Alnus) and willows, with some deciduous trees (Populus spp.) quickly developed and persisted until late Holocene time. By about 4,000–3,800 yr B.P., spruce trees (Picea glauca and (or) P. mariana) from the interior boreal forests reached the northern Kachemak Bay area from upper Cook Inlet and began to displace the alder-dominated vegetation. A coastal forest of Sitka spruce (Picea sitchensis) began to colonize Kachemak Bay more recently, about 1,650 yr B.P. (minimum age), apparently from sources in Prince William Sound to the east. Where Sitka spruce came into proximity with boreal white spruce (Picea glauca), hybridization occurred, ultimately influencing the spruce forests over a large area of the Kenai Lowland. Some key findings of this study are: (1) the Kachemak Bay-area pollen records do not display persuasive evidence for a “Younger Dryas” cold, dry interval ca. 11,000–10,000 yr B.P. that has been reported from pollen records on Kodiak Island (Gulf of Alaska) and Pleasant Island (southeastern Alaska); (2) at least one species of alder may have survived in refugia in south-central Alaska during the last glacial interval; (3) coastal forests appear to be still migrating west along the coast of south-central Alaska, but their spread northward is being limited by drier, colder winter climates; (4) the mountainous topography of south-central Alaska, coupled with varying degrees of maritime climate influence, create complex patterns of climates and vegetation in the region, in both the past and present.

Petrology of the Plutonic Rocks of west-central Alaska

USGS Publications Warehouse

Miller, Thomas P.

1970-01-01

A series of plutons in west-central Alaska defines the Hogatza plutonic belt which extends for about 200 miles in an east-west direction from the northeastern Seward Peninsula to the Koyukuk River. The plutonic rocks have an aggregate area of about 1,200 square miles and their composition, distribution, and possible petrogenesis are discussed for the first time in this report. Field, petrographic and chemical data supported by K/Ar age dating indicate the plutonic rocks are divisible into two suites differing in age, location, and composition. The western plutons are mid-Cretaceous (~100 m.y.) in age and consist of a heterogeneous assemblage of monzonite, syenite, quartz monzonite. Associated with these granitic rocks is a group of alkaline sub-silicic rocks that forma belt of intrusive complexes extending for a distance of at least 180 miles from west-central Alaska to the Bering Sea. The complex at Granite Mountain shows a rare example of zoning from an alkaline rim to a quartz-bearing core. The occurrence of a similar complex at Cape Dezhnev on the easternmost tip of Siberia suggests the alkaline province may extend into Siberia. The easternmost plutons are Late Cretaceous (180 m.y.) in age and composed primarily of granodiorite and quartz monzonite similar to calc-alkaline plutons found throughout the North America Cordillera. The plutons are epizonal and intrude deformed but unmetamorphosed Lower Cretaceous andesitic volcanics and volcanic graywacke which constitute the highly mobile Yukon-Koyukuk volcanogenic province of west-central Alaska. No older rocks have been found within the confines of this vast tract; the occurrence of a bounding ophiolite sequence has lead to the suggestion that the province was formed by large-scale rifting and is underlain by oceanic crust. The possibility of no juvenile sialic crust over much of the area suggests that the potassium-rich magma now represented by the alkaline rocks originated in the mantle. The distribution of the alkaline rocks appears to be related to regional structural features, particularly the boundary between the Mesozoic volcanogenic province of west-central Alaska and the thrust-faulted province of metamorphic-plutonic and sedimentary rocks of Paleozoic and Precambrian age that forms the eastern Seward Peninsula. This boundary may have been a zone of structural weakness along which alkaline magma was generated. Modal and chemical trends suggest that the potassium-rich magma influenced the composition of more granitic magmas forming at higher levels. The latter may have been forming as a result of anatexis of andesite and mixing of mantle-derived mafic magma. The result is the heterogeneous assemblage of generally potassium-rich plutonic rocks that forms the west end of the Hogataza plutonic belt. The loci of magmatism in west-central Alaska shifted east in Late Cretaceous time and the eastern plutons show only local signs of potassium enrichment. They are compositionally homogeneous and differences within plutons appear due to local contamination.

Bedrock geologic map of the Lisbon quadrangle, and parts of the Sugar Hill and East Haverhill quadrangles, Grafton County, New Hampshire

USGS Publications Warehouse

Rankin, Douglas W.

2018-04-20

The bedrock geologic map of the Lisbon quadrangle, and parts of the Sugar Hill and East Haverhill quadrangles, Grafton County, New Hampshire, covers an area of approximately 73 square miles (189 square kilometers) in west-central New Hampshire. This map was created as part of a larger effort to produce a new bedrock geologic map of Vermont through the collection of field data at a scale of 1:24,000. A large part of the map area consists of the Bronson Hill anticlinorium, a post-Early Devonian structure that is cored by metamorphosed Cambrian to Devonian sedimentary, volcanic, and plutonic rocks.The Bronson Hill anticlinorium is the apex of the Middle Ordovician to earliest-Silurian Bronson Hill magmatic arc that contains the Ammonoosuc Volcanics, Partridge Formation, and Oliverian Plutonic Suite, and extends from Maine, through western New Hampshire (down the eastern side of the Connecticut River), through southern New England to Long Island Sound. The deformed and partially eroded arc is locally overlain by a relatively thin Silurian section of metasedimentary rocks (Clough Quartzite and Fitch Formation) that thickens to the east. The Silurian section near Littleton is disconformably overlain by a thicker, Lower Devonian section that includes mostly metasedimentary and minor metavolcanic rocks of the Littleton Formation. The Bronson Hill anticlinorium is bisected by a series of northeast-southwest trending Mesozoic normal faults. Primarily among them is the steeply northwest-dipping Ammonoosuc fault that divides older and younger units (lower and upper sections) of the Ammonoosuc Volcanics. The Ammonoosuc Volcanics are lithologically complex and predominantly include interlayered and interfingered rhyolitic to basaltic volcanic and volcaniclastic rocks, as well as lesser amounts of slate, phyllite, ironstone, chert, sandstone, and pelite. The Albee Formation underlies the Ammonoosuc Volcanics and is predominantly composed of interbedded metamorphosed sandstone, siltstone, and phyllite.During the Late Ordovician, a series of arc-related plutons intruded the Ammonoosuc Volcanics including the Moody Ledge pluton and the Scrag granite of Billings (1937). Subsequent plutonism related to the Acadian orogeny occurred after volcanism and deposition resulted in the Littleton Formation during the Late Devonian, including the intrusion of the Haverhill pluton and French Pond Granite found in the southern part of the map.This report consists of a geologic map and an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, and structural geologic information. The geologic map is intended to serve as a foundation for applying geologic information to problems involving land use decisions, groundwater availability and quality, earth resources such as natural aggregate for construction, assessment of natural hazards, and engineering and environmental studies for waste disposal sites and construction projects.

Geologic Map of the Goleta Quadrangle, Santa Barbara County, California

USGS Publications Warehouse

Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Brandt, Theodore R.

2007-01-01

This map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying those parts of the Santa Barbara coastal plain and adjacent southern flank of the Santa Ynez Mountains within the Goleta 7 ?? quadrangle at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. The Goleta map overlaps an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002) that provided coverage within the coastal, central parts of the Goleta and contiguous Santa Barbara quadrangles. In addition to new mapping in the northern part of the Goleta quadrangle, geologic mapping in other parts of the map area has been revised from the preliminary map compilation based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units are described in detail in the accompanying map pamphlet. Abundant biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault-kinematic observations (including slip-sense determinations) are embedded in the digital map database. The Goleta quadrangle is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The Santa Barbara coastal plain surface, which spans the central part of the quadrangle, includes several mesas and hills that are geomorphic expressions of underlying, potentially active folds and partly buried oblique and reverse faults of the Santa Barbara fold and fault belt (SBFFB). Strong earthquakes have occurred offshore within 10 km of the Santa Barbara coastal plain in 1925 (6.3 magnitude), 1941 (5.5 magnitude) and 1978 (5.1 magnitude). These and numerous smaller seismic events located beneath and offshore of the coastal plain, likely occurred on reverse-oblique-slip faults that are similar to, or continuous with, Quaternary reverse faults crossing the coastal plain. Thus, faults of the SBFFB pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. In addition, numerous Quaternary landslide deposits along the steep southern flank of the Santa Ynez Mountains indicate the potential for continued slope failures and mass movements in developed areas. Folded, faulted, and fractured sedimentary rocks in the subsurface of the coastal plain and adjacent Santa Barbara Channel are sources and form reservoirs for economic deposits of oil and gas, some of which are currently being extracted offshore. Shallow, localized sedimentary aquifers underlying the coastal plain provide limited amounts of water for the urban areas, but the quality of some of this groundwater is compromised by coastal salt-water contamination. The present map compilation provides a set of uniform geologic digital coverages that can be used for analysis and interpretation of these and other geologic hazards and resources in the Goleta region.

Maps showing mineralogical data for nonmagnetic heavy-mineral concentrates in the Talkeetna Quadrangle, Alaska

USGS Publications Warehouse

Tripp, R.B.; Karlson, R.C.; Curtin, G.C.

1978-01-01

Reconnaissance geochemical and mineralogical sampling was done in the Talkeetna Quadrangle during 1975 and 1976 as part of the Alaska Mineral Resource Assessment Program (AMRAP). These maps show the distribution of gold, scheelite, chalcopyrite, arsenopyrite, galena, fluorite, cinnabar, and malachite in the nonmagnetic fraction of heavy-mineral concentrates. Heavy-mineral concentrate samples were collected at 812 sites from active stream channels. The heavy-mineral concentrates were obtained by panning stream sediment in the field to remove most of the light minerals. The panned samples were then sieved through a 20-mesh (0.8 mm) sieve in the laboratory, and the minus-20-mesh fraction was further separated with bromoform (specific gravity, 2.86) to remove any remaining light-mineral grains. Magnetite and other strongly magnetic heavy minerals were removed from the heavy-mineral fraction by use of a hand magnet. The remaining sample was passed through a Frantz Isodynamic Separator and a nonmagnetic fraction was examined for its mineralogical content with the aid of a binocular microscope and an x-ray diffractometer. The nonmagnetic concentrates primarily contain phyllite fragments, muscovite, sphene, zircon, apatite, tourmaline, rutile, and anatase. Most ore and ore-related minerals also occur in this fraction.

Identification of geostructures of continental crust, particularly as they relate to mineral resource evaluation

NASA Technical Reports Server (NTRS)

Gryc, G. (Principal Investigator); Lathram, E. H.

1973-01-01

The author has identified the following significant results. The southeastward continuation of a fault that has been mapped in the vicinity of Dan Creek, Alaska, shows up as a lineament on ERTS-1 image 1043-20163 that can be traced for more than 50 miles southeastward to beyond the Alaska-Canada boundary. The lineament probably reflects a major fault that is significant in understanding the complicated tectonics of the Wrangell Mountains-Saint Elias Mountains complex. From a study of the ERTS-1 image, low level vertical photography, and limited field work in the largely unmapped region, E.M. Mackevett, Jr., speculates that the eastern part of the fault may mark the southern boundary of a mild-Paleozoic metamorphic terrane that constitutes the westernmost known extent of the Alexander terrane of Berg, Jones, and Richter (1972) and correlates with the Kaskawulsh Group in Canada. This terrane, which consists dominantly of marble, was recognized during 1972 reconnaissance mapping in the eastcentral part of the McCarthy quadrangle by MacKevett, D.L. Jones, and D.H. Richter and contrasts strongly with the dominantly volcanic and volcanoclastic terrane of Pennsylvanian and Permian age that forms the basement in most of the McCarthy quadrangle.

Geologic map of the Vail East quadrangle, Eagle County, Colorado

USGS Publications Warehouse

Kellogg, Karl S.; Bryant, Bruce; Redsteer, Margaret H.

2003-01-01

New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of the State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale Vail East quadrangle straddles the Gore fault system, the western structural boundary of the Gore Range. The Gore fault system is a contractional structure that has been recurrently active since at least the early Paleozoic and marks the approximate eastern boundary of the Central Colorado trough, a thick late Paleozoic depocenter into which thousands of meters of clastic sediment were deposited from several uplifts, including the ancestral Front Range. The Gore fault was active during both the late Paleozoic and Upper Cretaceous-lower Tertiary (Laramide) deformations. In addition, numerous north-northwest faults that cut the crystalline rocks of the Gore Range were active during at least 5 periods, the last of which was related to Neogene uplift of the Gore Range and formation of the northern Rio Grande rift. Early Proterozoic crystalline rocks underlie the high Gore Range, north and east of the Gore fault system. These rocks consist predominantly of migmatitic biotite gneiss intruded by mostly granitic rocks of the 1.667-1.750 Ma Cross Creek batholith, part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, 1987). Southwest of the Gore fault, a mostly gently south-dipping sequence of Pennsylvanian Mimturn Formation, as thick as 1,900 m, and the Permian and Pennsylvanian Maroon Formation (only the basal several hundred meters are exposed in the quadrangle)were shed from the ancestral Front Range and overlie a thin sequence of Devonian and Cambrian rocks. The Minturn Formation is a sequence of interlayered pink, maroon, and gray conglomerate, sandstone, shale, and marine limestone. The Maroon Formation is mostly reddish conglomerate and sandstone. Glacial till of both the middle Pleistocene Bull Lake and late Pleistocene Pinedale glaciations are well exposed along parts of the Gore Creek valley and its tributaries, although human development has profoundly altered the outcrop patterns along the Gore Creek valley bottom. Landslides, some of which are currently active, are also mapped.

Summary terrane, mineral deposit, and metallogenic belt maps of the Russian Far East, Alaska, and the Canadian Cordillera

USGS Publications Warehouse

Nokleberg, Warren J.; West, Timothy D.; Dawson, Kenneth M.; Shpikerman, Vladimir I.; Bundtzen, Thomas K.; Parfenov, Leonid M.; Monger, James W.; Ratkin, Vladimir V.; Baranov, Boris V.; Byalobzhesky, Stanislauv G.; Diggles, Michael F.; Eremin, Roman A.; Fujita, Kazuya; Gordey, Steven P.; Gorodinskiy, Mary E.; Goryachev, Nikolai A.; Feeney, Tracey D.; Frolov, Yuri F.; Grantz, Arthur; Khanchuk, Alexander I.; Koch, Richard D.; Natal'in, Boris A.; Natapov, Lev M.; Norton, Ian O.; Patton, William W.; Plafker, George; Pozdeev, Anany I.; Rozenblum, Ilya S.; Scholl, David W.; Sokolov, Sergei D.; Sosunov, Gleb M.; Stone, David B.; Tabor, Rowland W.; Tsukanov, Nickolai V.; Vallier, Tracy L.

1998-01-01

This report is part of a project on the major mineral deposits, metallogenesis, and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. The project is to provide critical information for collaborators and customers on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for the Russian Far East, Alaska, and the Canadian Cordillera.

Geologic map and digital database of the Cougar Buttes 7.5' quadrangle, San Bernardino County, California

USGS Publications Warehouse

Powell, R.E.; Matti, J.C.; Cossette, P.M.

2000-01-01

The Southern California Areal Mapping Project (SCAMP) of Geologic Division has undertaken regional geologic mapping investigations in the Lucerne Valley area co-sponsored by the Mojave Water Agency and the San Bernardino National Forest. These investigations span the Lucerne Valley basin from the San Bernardino Mountains front northward to the basin axis on the Mojave Desert floor, and from the Rabbit Lake basin east to the Old Woman Springs area. Quadrangles mapped include the Cougar Buttes 7.5' quadrangle, the Lucerne Valley 7.5' quadrangle (Matti and others, in preparation b), the Fawnskin 7.5' quadrangle (Miller and others, 1998), and the Big Bear City 7.5' quadrangle (Matti and others, in preparation a). The Cougar Buttes quadrangle has been mapped previously at scales of 1:62,500 (Dibblee, 1964) and 1:24,000 (Shreve, 1958, 1968; Sadler, 1982a). In line with the goals of the National Cooperative Geologic Mapping Program (NCGMP), our mapping of the Cougar Buttes quadrangle has been directed toward generating a multipurpose digital geologic map database. Guided by the mapping of previous investigators, we have focused on improving our understanding and representation of late Pliocene and Quaternary deposits. In cooperation with the Water Resources Division of the U.S. Geological Survey, we have used our mapping in the Cougar Buttes and Lucerne Valley quadrangles together with well log data to construct cross-sections of the Lucerne Valley basin (R.E. Powell, unpublished data, 1996-1998) and to develop a hydrogeologic framework for the basin. Currently, our mapping in these two quadrangles also is being used as a base for studying soils on various Quaternary landscape surfaces on the San Bernardino piedmont (Eppes and others, 1998). In the Cougar Buttes quadrangle, we have endeavored to represent the surficial geology in a way that provides a base suitable for ecosystem assessment, an effort that has entailed differentiating surficial veneers on piedmont and pediment surfaces and distinguishing the various substrates found beneath these veneers.

Mapping Vesta Equatorial Quadrangle V-8EDL: Various Craters and Giant Grooves

NASA Astrophysics Data System (ADS)

Le Corre, L.; Nathues, A.; Reddy, V.; Buczkowski, D.; Denevi, B. W.; Gaffey, M.; Williams, D. A.; Garry, W. B.; Yingst, R.; Jaumann, R.; Pieters, C. M.; Russell, C. T.; Raymond, C. A.

2011-12-01

NASA's Dawn spacecraft arrived at the asteroid 4Vesta on July 15, 2011, and is now collecting imaging, spectroscopic, and elemental abundance data during its one-year orbital mission. As part of the geological analysis of the surface, a series of 15 quadrangle maps are being produced based on Framing Camera images (FC: spatial resolution: ~65 m/pixel) along with Visible & Infrared Spectrometer data (VIR: spatial resolution: ~180 m/pixel) obtained during the High-Altitude Mapping Orbit (HAMO). This poster presentation concentrates on our geologic analysis and mapping of quadrangle V-8EDL located between -22 and 22 degrees latitude and 144 and 216 degrees East longitude. This quadrangle is dominated by old craters (without any ejecta visible in the clear and color bands), but one small recent crater can be seen with bright ejecta blanket and rays. The latter has some small, dark units outside and inside the crater rim that could be indicative of impact melt. This quadrangle also contains a set of giant linear grooves running almost parallel to the equator that might have formed subsequent to a big impact. We will use FC mosaics with clear images and false color composites as well as VIR spectroscopy data in order to constrain the geology and identify the nature of each unit present in this quadrangle.

Geologic Map of the Eaton Reservoir Quadrangle, Larimer County, Colorado and Albany County, Wyoming

USGS Publications Warehouse

Workman, Jeremiah B.

2008-01-01

New geologic mapping of the Eaton Reservoir 7.5' quadrangle defines geologic relationships in the northern Front Range along the Colorado/Wyoming border approximately 35 km south of Laramie, Wyo. Previous mapping within the quadrangle was limited to regional reconnaissance mapping (Tweto, 1979; Camp, 1979; Burch, 1983) and some minor site-specific studies (Carlson and Marsh, 1986; W. Braddock, unpub. mapping, 1982). Braddock and others (1989) mapped the Diamond Peak 7.5' quadrangle to the east, Burch (1983) mapped rocks of the Rawah batholith to the south, W. Braddock (unpub. mapping, 1981) mapped the Sand Creek Pass 7.5' quadrangle to the west, and Ver Ploeg and Boyd (2000) mapped the Laramie 30' x 60' quadrangle to the north. Field work was completed during 2005 and 2006 and the mapping was compiled at a scale of 1:24,000. Minimal petrographic work and isotope dating was done in connection with the present mapping, but detailed petrographic and isotope studies were carried out on correlative map units in surrounding areas as part of a related regional study of the northern Front Range. Classification of Proterozoic rocks is primarily based upon field observation of bulk mineral composition, macroscopic textural features, and field relationships that allow for correlation with rocks studied in greater detail outside of the map area.

Geologic Map of the Piedmont Hollow Quadrangle, Oregon County, Missouri

USGS Publications Warehouse

Weary, David J.

2008-01-01

The Piedmont Hollow 7.5-min quadrangle is located in south-central Missouri within the Salem Plateau region of the Ozark Plateaus physiographic province (Fenneman, 1938; Bretz, 1965) (fig. 1). Almost all of the land in the quadrangle north of the Eleven Point River is part of the Mark Twain National Forest. Most of the land immediately adjoining the river is part of the Eleven Point National Scenic River, also administered by the U.S. Forest Service. South of the Eleven Point River, most of the land is privately owned and used primarily for grazing cattle and horses. The quadrangle has topographic relief of about 480 feet (ft), with elevations ranging from 550 ft on the Eleven Point River at the eastern edge of the quadrangle to 1,030 ft on a hilltop about a mile to the west-northwest. The most prominent physiographic feature in the quadrangle is the valley of the Eleven Point River, which traverses the quadrangle from west to northeast.

Publications - GMC 172 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Texaco Inc. East Kurupa Unit #1 well Authors: Pawlewicz, Mark Publication Date: 1990 Publisher: Alaska , Vitrinite reflectance data of cuttings (800'-12610') from the Texaco Inc. East Kurupa Unit #1 well: Alaska

Structure and thermochronology of the metamorphic core of the Brooks Range, Alaska

NASA Astrophysics Data System (ADS)

Toro, Jaime

1999-11-01

Detailed field studies were undertaken in two key areas of the Central Belt of the Brooks Range: (1) the north flank of Mt. Igikpak in the Survey Pass Quadrangle and (2) in the Shishakshinovik Pass area in the eastern Ambler River Quadrangle. In both areas structural, stratigraphic, petrologic, 40Ar/39Ar, apatite fission-track and U-Pb data were used to constrain the kinematic and thermal history of metamorphic rocks of those areas. North of the Mt. Igikpak massif a crustal section ˜15 km thick is exposed. There are upper greenschist facies rocks in the deeper portions, and very low grade metamorphic rocks at higher structural levels. Two foliations are found: a higher grade relict S1 fabric and a lower grade S 2 fabric that controls the metamorphic layering. 40Ar/ 39Ar analyses from S1 white mica in the low-grade rocks at the northern end of the transect indicate that peak M1 metamorphism occurred before ˜112 Ma. We ascribe M1 to shortening that occurred during collision of an island arc against the Arctic Alaska margin. S 2 involved the retrogression of earlier assemblages. Kinematic indicators on S2 are top-to-the-north. A rapid cooling event from 500 +/- 50°C to 300 +/- 50°C took place between ˜98 and ˜90 Ma. The driving mechanism for ductile deformation during S2, and for rapid cooling documented by our thermochronologic data, was probably the gravitational collapse of the core of the orogen, over-thickened during the preceding collision. At Shishakshinovik Pass there are Mississippian Lisburne Group strata surrounded by metamorphic rocks typical of the Central Belt of the Brooks Range. All the rocks at Shishakshinovik Pass are intensely deformed, so that one cannot distinguish between an autochthonous and an allochthonous sequence. Furthermore the Mississippian rocks, instead of being attached to the underlying basement, are in the hanging wall of a northwest dipping shear zone. Based on the variations in metamorphic grade and the 40Ar/ 39Ar thermochronology, we argue that this shear zone was an extensional structure active during the mid-Cretaceous orogenic collapse of the Brooks Range. A consequence of this structural interpretation is that the Endicott Mountains allochthon need not be restored south of the Shishakshinovik orthogneiss.

KSC-05pd2449

NASA Image and Video Library

2005-11-07

KENNEDY SPACE CENTER, FLA. - A Long-Eared Owl is spotted on Launch Complex 41 at Cape Canaveral Air Force Station in Florida. This one holds a typical stance for protecting its young. These owls range from Alaska and Canada to the Gulf states and Mexico, as far east as Central Florida. Their habitat is deciduous and evergreen forests. They nest in deserted nests of crows, hawks or squirrels.

KSC-05pd2448

NASA Image and Video Library

2005-11-07

KENNEDY SPACE CENTER, FLA. - A Long-Eared Owl is spotted on Launch Complex 41 at Cape Canaveral Air Force Station in Florida. This one holds a typical stance for protecting its young. These owls range from Alaska and Canada to the Gulf states and Mexico, as far east as Central Florida. Their habitat is deciduous and evergreen forests. They nest in deserted nests of crows, hawks or squirrels.

NURE aerial gamma-ray and magnetic reconnaissance survey: NE Washington area, Okanogan NM 11-10, Sandpoint NM 11-11 Quadrangles. Volume I. Narrative report

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

Not Available

1979-08-01

As part of the Department of Energy (DOE) National Uranium Resource Evaluation (NURE) Program, LKB Resources, Inc. has performed a rotary-wing, reconnaissance high sensitivity radiometric and magnetic survey in north-east Washington. Three 1:250,000 scale NTMS quadrangles (Spokane, Sandpoint, and Okanogan) were surveyed. A total of 14,421 line miles (23,203 kilometers) of data were collected utilizing a Sikorsky S58T helicopter. Traverse lines were flown in an east-west direction at 1.0 and 3.0 mile (1.6 and 4.8 kilometers) spacing, with tie lines flown in a north-south direction at 12 mile (20 kilometer) spacing. The data were digitally recorded at 1.0 second intervals.more » The NaI terrestrial detectors used in this survey had a total volume of 2,154 cubic inches. The magnetometer employed was a modified ASQ-10 fluxgate system. This report covers only the Okanogan and Sandpoint 1:250,000 scale NTMS quadrangles. Spokane 1:250,000 scale NTMS quadrangle is covered in a separate report. The radiometric data were normalized to 400 feet terrain clearance. The data are presented in the form of computer listings on microfiche and as stacked profile plots. Profile plots are contained in Volume II of this report. A geologic interpretation of the radiometric and magnetic data is included as part of this report.« less

Sedna Planitia (Right Member of a Synthetic Stereo Pair)

NASA Technical Reports Server (NTRS)

1992-01-01

This perspective view of Venus, generated by computer from Magellan data and color-coded with emissivity, shows part of the lowland plains in Sedna Planitia. Circular depressions with associated fracture patterns, called 'coronae', are apparently unique to the lowlands of Venus, and tend to occur in linear clusters along the planet's major tectonic belts, as seen in this image. Coronae differ greatly in size and detailed morphology: the central depression may or may not lie below the surrounding plains, and may or may not be surrounded by a raised rim or a moat outside the rim. Coronae are thought to be caused by localized 'hot spot' magmatic activity in Venus' subsurface. Intrusion of magma into the crust first pushes up the surface, after which cooling and contraction create the central depression and generate a pattern of concentric fractures. In some cases, lava may be extruded onto the surface, as seen here as bright flows in the foreground. This image is the right member of a synthetic stereo pair; the other image is PIA00313. To view the region in stereo, download the two images, arrange them side by side on the screen or in hardcopy, and view this image with the right eye and the other with the left. For best viewing, use a stereoscope or size the images so that their width is close to the interpupillary distance, about 6.6 cm (2.6 inches). Magellan MIDR quadrangle* containing this image: C1- 45N011. Image resolution (m): 225. Size of region shown (E-W x N-S, in km): 1900 x 120 at front edge. Range of emissivities from violet to red: 0.82 -- 0.88. Vertical exaggeration: 20. Azimuth of viewpoint (deg clockwise from East): 13. Elevation of viewpoint (km): 300. *Quadrangle name indicates approximate center latitude (N=north, S=south) and center longitude (East).

Sedna Planitia (Left Member of a Synthetic Stereo Pair)

NASA Technical Reports Server (NTRS)

1992-01-01

This perspective view of Venus, generated by computer from Magellan data and color-coded with emissivity, shows part of the lowland plains in Sedna Planitia. Circular depressions with associated fracture patterns, called 'coronae', are apparently unique to the lowlands of Venus, and tend to occur in linear clusters along the planet's major tectonic belts, as seen in this image. Coronae differ greatly in size and detailed morphology: the central depression may or may not lie below the surrounding plains, and may or may not be surrounded by a raised rim or a moat outside the rim. Coronae are thought to be caused by localized 'hot spot' magmatic activity in Venus' subsurface. Intrusion of magma into the crust first pushes up the surface, after which cooling and contraction create the central depression and generate a pattern of concentric fractures. In some cases, lava may be extruded onto the surface, as seen here as bright flows in the foreground. This image is the left member of a synthetic stereo pair; the other image is PIA00314. To view the region in stereo, download the two images, arrange them side by side on the screen or in hardcopy, and view this image with the left eye and the other with the right. For best viewing, use a stereoscope or size the images so that their width is close to the interpupillary distance, about 6.6 cm (2.6 inches). Magellan MIDR quadrangle* containing this image: C1-45N011. Image resolution (m): 225. Size of region shown (E-W x N-S, in km): 1900 x 120 at front edge. Range of emissivities from violet to red: 0.82 -- 0.88. Vertical exaggeration: 20. Azimuth of viewpoint (deg clockwise from East): 13. Elevation of viewpoint (km): 300. *Quadrangle name indicates approximate center latitude (N=north, S=south) and center longitude (East).

A Summary of the History and Achievements of the Alaska Volcano Observatory.

NASA Astrophysics Data System (ADS)

Smith, R. W.

2008-12-01

Volcanoes of the Aleutian Islands, Kamchatka and the Kurile Islands present a serious threat to aviation on routes from North America to the Far East. On March 27, 1986, an eruption of Augustine Volcano deposited ash over Anchorage and disrupted air traffic in south-central Alaska. The consequences of the colocation of an active volcano and the largest city in Alaska were clearly evident. That event led to a three-way partnership between the US Geological Survey, the University of Alaska Geophysical Institute and the Alaska State Division of Geological and Geophysical Surveys that now maintains a continuous watch through ground instrumentation and satellite imagery providing data from which warnings of eruptions can be issued to airline operators and pilots. The eruption of Redoubt Volcano in December 1989 was AVO's first big test. It spewed volcanic ash to a height of 14,000 m (45,000 feet) and managed to catch KLM 867, a Boeing 747 aircraft in its plume under dark conditions while approaching Anchorage Airport. Further details of the early days of the Alaska Volcano Observatory will be described, along with its recent successes and challenges.

Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus

USGS Publications Warehouse

Ivanov, Mikhail A.; Head, James W.

2008-01-01

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the Venusian atmosphere on October 12, 1994. Magellan Mission objectives included (1) improving the knowledge of the geological processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving the knowledge of the geophysics of Venus by analysis of Venusian gravity. The Meskhent Tessera quadrangle is in the northern hemisphere of Venus and extends from lat 50 degrees to 75 degrees N. and from long 60 degrees to 120 degrees E. In regional context, the Meskhent Tessera quadrangle is surrounded by extensive tessera regions to the west (Fortuna and Laima Tesserae) and to the south (Tellus Tessera) and by a large basinlike lowland (Atalanta Planitia) on the east. The northern third of the quadrangle covers the easternmost portion of the large topographic province of Ishtar Terra (northwestern map area) and the more localized upland of Tethus Regio (northeastern map area).

Reconnaissance geology of the Wadi Wassat quadrangle, Kingdom of Saudi Arabia

USGS Publications Warehouse

Overstreet, William C.; Rossman, D.L.

1970-01-01

The Wadi Wassat quadrangle covers an area of 2926 sq km in the southwestern part of the Kingdom of Saudi Arabia. The west half of the quadrangle is underlain by crystalline rocks of the Arabian Shield, but in the eastern half of the quadrangle the Precambrian rocks are covered by Permian or older sandstone which is succeeded farther east by aeolian sands of Ar Rub' al Khali. The Shield consists of a sequence of unmetamorphosed to metamorphosed interlayered volcanic and sedimentary rocks intruded by igneous rocks ranging in composition from gabbro to syenite and in age from Precambrian to Cambrian(?). The volcanic rocks range in composition from andesite to rhyolite and in texture from agglomerate to thick, massive flows and lithic tuff. They are interlayered with conglomerate, fine-grained graywacke sandstone, calcareous graywacke, siltstone, tuffaceous laminated shale, pyritiferous sediment, carbonaceous shale, limestone, and dolomite. Most clastic debris is derived from andesite. In places the rocks are polymetamorphosed; elsewhere they are unmetamorphosed. The rocks on which this volcano-sedimentary eugeosynclinal sequence was deposited are not exposed in the area of the quadrangle. Reglonal dynamothermal metamorphism was .the dominant process affecting the volcanic-sedimentary rocks in the western part of the quadrangle. In the eastern part of the Precambrian area the chief metamorphic effect results from contact action along the walls of intrusive plutons. The oldest igneous rock to intrude the volcanic-sedimentary sequence, after the dikes and sills of the sequence itself, is granite gneiss and gneissic granodiorite. The gneiss is sparsely present in the quadrangle, but northwest of the quadrangle it forms an immense batholith which is one of the major geologic features of southwestern Arabia. However, the most common intrusive rocks of the quadrangle are a magnetic differentiation sequence that ranges in composition from gabbro and diorite to granite, rhyolite, and syenite. The siliceous members of the differentiation sequence commonly contain aluminous pyroxene or amphibole, and to the sequence the name peralkalic magma series has been given. Plutonic rocks of the series are widely intruded by hypabyssal rocks of the series. In most places, the older hypabyssal rocks tend to form interior dikes in the plutonic rocks, and the younger hypabyssal rocks commonly form the exterior dike swarms outside the plutonic rocks of the magma series. Many exterior dike swarms are concentrated in roof pendants of volcano-sedimentary rocks over the plutonic members of the magma series. Isotopic ages of rocks in the peralkalic magma series range from 598 +/-24 m.y. to 509 +/-15 m.y. by K/Ar and Rb/Sr methods. A profound angular unconformity exists between the Precambrian and Cambrian(?) crystalline rocks and the Permian or older sandstone which laps onto the Shield from the east and south. This sandstone, is reddish-brown, yellow, tan, and white called Wajid Sandstone, crossbedded sandstone with ferruginous cement and concretions in some layers. Locally, the rocks underlying the Wajid Sandstone are deeply weathered. Poorly sorted alluvial sand and gravel mantle the wadi floors. In the northeastern and southwestern parts of the quadrangle well-sorted aeolian sand is common. The volcanic and sedimentary rocks of the quadrangle are part of the east limb of an immense synclinorium(?) that closes south-westward around a batholitic core of gneissic granite and granodiorite. These layered rocks were isoclinally folded along northerly and north-northeasterly trending axes prior to the intrusion of the peralkalic magma series. During intrusion, the layered rocks were again folded as they were pushed aside, and major old regional northerly faults were reactivated with persistent left-lateral displacement. Reconnaissance geochemical sampling disclosed several notable groupings of threshold and anomalous elements with spe

Mineral and energy resource assessment maps of the Mount Katmai, Naknek, and western Afognak quadrangles, Alaska

USGS Publications Warehouse

Church, S.E.; Riehle, J.R.; Magoon, L.B.; Campbell, D.L.

1992-01-01

Coal seams as much as several meters in aggregate thickness crop out in Tertiary rocks in the Geographic Harbor area. Since these coal beds occur within withdrawn Federal lands, there has been no incentive to evaluate them as coal resources. Given different land accessibility and a local market, these beds could constitute a small marketable coal resource.

Revision of Primary Series Maps

USGS Publications Warehouse

,

2000-01-01

In 1992, the U.S. Geological Survey (USGS) completed a 50-year effort to provide primary series map coverage of the United States. Many of these maps now need to be updated to reflect the construction of new roads and highways and other changes that have taken place over time. The USGS has formulated a graphic revision plan to help keep the primary series maps current. Primary series maps include 1:20,000-scale quadrangles of Puerto Rico, 1:24,000- or 1:25,000-scale quadrangles of the conterminous United States, Hawaii, and U.S. Territories, and 1:63,360-scale quadrangles of Alaska. The revision of primary series maps from new collection sources is accomplished using a variety of processes. The raster revision process combines the scanned content of paper maps with raster updating technologies. The vector revision process involves the automated plotting of updated vector files. Traditional processes use analog stereoplotters and manual scribing instruments on specially coated map separates. The ability to select from or combine these processes increases the efficiency of the National Mapping Division map revision program.

K-Ar geochronology of the Survey Pass, Ambler River and Eastern Baird Mountains quadrangles, southwestern Brooks Range, Alaska

USGS Publications Warehouse

Turner, Donald L.; Forbes, R.B.; Mayfield, C.F.

1978-01-01

We report 76 previously unpublished K-Ar mineral ages from 47 metamorphic and igneous rocks in the southwestern Brooks Range. The pattern of radiometric ages is complex, reflecting the complex geologic history of this area. Local and regional radiometric evidence suggests that the southern Brooks Range schist belt has, at least in part, undergone a late Precambrian metamorphism and that the parent sedimentary and igneous rocks for the metamorphic rocks dated as late Precambrian are at least this old (Precambrian Z). This schist terrane experienced a major thermal event in mid-Cretaceous time, causing widespread resetting of nearly all K-Ar mica ages. A series of apparent ages intermediate between late Precambrian and mid-Cretaceous are interpreted as indicating varying amounts of partial argon loss from older rocks during the Cretaceous event. The schist belt is characterized by dominant metasediments and subordinate metabasites and metafelsites. Blueschists occur within the schist belt from the Chandalar quadrangle westward to the Baird Mountains quadrangle, but geologic evidence does not support the existence of a fossil subduction zone.

Publications - GMC 302 | Alaska Division of Geological & Geophysical

Science.gov Websites

following northern Alaska exploratory wells: Husky Oil NPRA Operations (U.S. Navy) East Teshekpuk #1 (7090 -7180), and Husky Oil NPRA Operations (U.S. Navy) West Fish Creek #1 (5520-5780) and (7460-7580 northern Alaska exploratory wells: Husky Oil NPRA Operations (U.S. Navy) East Teshekpuk #1 (7090-7180), and

Dike rocks of the Apishapa Quadrangle, Colorado

USGS Publications Warehouse

Cross, Whitman

1915-01-01

The Apishapa quadrangle, the geographic relations of which are shown by Plate IV, is situated on the plains south of Arkansas River, in Colorado, about 24 miles east of the mountain front. The geology of the Pueblo, Walsenburg, Spanish Peaks, and Elmoro quadrangles, adjoining it on the northwest, west, southwest, and south, respectively, has been described in folios of the Geologic Atlas. G. K. Gilbert, assisted by F. P. Gulliver and G. W. Stose, took up the survey of the Apishapa area in 1894. The Apishapa folio was completed by Stose and was issued in 1913. The rocks to be described in this paper were collected by Gilbert and his assistants, the present writer never having visited the area. The following description of the occurrence of the has been kindly furnished by Mr. Stose.

Aerial gamma ray and magnetic survey: Nebraska/Texas survey, Tyler quadrangle of Texas and Louisiana. Final report

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

Not Available

The Tyler quadrangle of eastern Texas and westernmost Louisiana lies within the northern Gulf Coastal Province. The area contains portions of the East Texas-Athens Embayment, and the Sabine Uplift which strikes NW through the NW corner of the area. Eocene neritic sediments are dominant, though Cretaceous platform deposits are exposed in the extreme NW corner. Available literature shows no known uranium deposits (or occurrences) within the quadrangle. One hundred thirty-six groups of uranium samples were defined as anomalous and discussed briefly in this report. None are considered significant. Most appear to be of cultural origin. Magnetic data in the quadranglemore » are dominantly low frequency/low amplitude wavelengths, which suggests that sources may be extremely deep.« less

Aqueous geochemical data from the analysis of stream-water samples collected in June and July 2006-Taylor Mountains 1:250,00-scale quadrangle, Alaska

USGS Publications Warehouse

Wang, Bronwen; Mueller, Seth; Stetson, Sarah; Bailey, Elizabeth; Lee, Greg

2011-01-01

We report on the chemical analysis of water samples collected from the Taylor Mountains 1:250,000-scale quadrangle, Alaska. Parameters for which data are reported include pH, conductivity, water temperature, major cation and anion concentrations, trace-element concentrations, and dissolved organic-carbon concentrations. Samples were collected as part of a multiyear U.S. Geological Survey project entitled ?Geologic and Mineral Deposit Data for Alaskan Economic Development.? Data presented here are from samples collected in June and July 2006. The data are being released at this time with minimal interpretation. This is the third release of aqueous geochemical data from this project; aqueous geochemical data from samples collected in 2004 and 2005 were published previously. The data in this report augment but do not duplicate or supersede the previous data release. Site selection was based on a regional sampling strategy that focused on first- and second-order drainages. Water sample site selection was based on landscape parameters that included physiography, wetland extent, lithological changes, and a cursory field review of mineralogy from pan concentrates. Stream water in the Taylor Mountains quadrangle is dominated by bicarbonate (HCO3-), although in a few samples more than 50 percent of the anionic charge can be attributed to sulfate (SO42-). The major-cation chemistry ranges from Ca2+/Mg2+ dominated to a mix of Ca2+/Mg2+/Na++K+. Generally, good agreement was found between the major cations and anions in the duplicate samples. Many trace elements in these samples were at or near the analytical method detection limit, but good agreement was found between duplicate samples for elements with detectable concentrations. All field blank major-ion and trace-element concentrations were below detection.

Mines, prospects, and occurrences of nonmetallic mineral commodities in the Greenville 1 degree by 2 degrees Quadrangle, South Carolina, Georgia, and North Carolina

USGS Publications Warehouse

D'Agostino, John P.; O'Connor, Bruce J.; Zupan, Alan J.W.; Maybin, Arthur H.

1994-01-01

Mines, prospects, and occurrences of nonmetal mineral commodities in the Greenville 1° x 2° quadrangle are tabulated in this report. There are 488 symbols representing 579 mines, prospects, and occurrences located in the quadrangle. There are 379 symbols used for 466 features in Georgia, 106 symbols for 110 features in South Carolina, and 3 symbols for 3 features in North Carolina. The table lists, in consecutive orders for each county (fig. 1), the map number of each feature, which correlates and locates the item on the accompanying Greenville 1° x 2° quadrangle map. Also listed are the known name of the feature; the 7.5 topographic map on which the commodity site is located; the Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5’ topographic map; the commodity; remarks; and references. Some locations are known, but many sites are not verified and their locations are only approximate. Reference are listed in References Cited and referred to by number to save space. The generalized tectonic framework for the quadrangle is shown in figure 2.

Digital geologic map of the Nevada Test Site and vicinity, Nye, Lincoln, and Clark Counties, Nevada, and Inyo County, California

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

Slate, J.L.; Berry, M.E.; Rowley, P.D.

2000-03-08

This digital geologic map of the Nevada Test Site (NTS) and vicinity, as well as its accompanying digital geophysical maps, are compiled at 1:100,000 scale. The map area covers two 30 {times} 60-minute quadrangles-the Pahute Mesa quadrangle to the north and the Beatty quadrangle to the south-plus a strip of 7 1/2-minute quadrangles on the east side. In addition to the NTS, the map area includes the rest of the southwest Nevada volcanic field, part of the Walker Lane, most of the Amargosa Desert, part of the Funeral and Grapevine Mountains, some of Death Valley, and the northern Spring Mountains.more » This geologic map improves on previous geologic mapping of the same area by providing new and updated Quaternary and bedrock geology, new geophysical interpretations of faults beneath the basins, and improved GIS coverages. This publication also includes a new isostatic gravity map and a new aeromagnetic map. The primary purpose of the three maps is to provide an updated geologic framework to aid interpretation of ground-water flow through and off the NTS. The NTS is centrally located within the area of the Death Valley regional ground-water flow system of southwestern Nevada and adjacent California. During the last 40 years, DOE and its predecessor agencies have conducted about 900 nuclear tests on the NTS, of which 100 were atmospheric tests and the rest were underground tests. More than 200 of the tests were detonated at or beneath the water table, which commonly is about 500 to 600 m below the surface. Because contaminants introduced by these test may move into water supplies off the NTS, rates and directions of ground-water flow must be determined. Knowledge about the ground water also is needed to properly appraise potential future effects of the possible nuclear waste repository at Yucca Mountain, adjacent to the NTS.« less

Structural and kinematic evolution of the Yukon-Tanana upland tectonites, east-central Alaska: A record of late Paleozoic to Mesozoic crustal assembly

USGS Publications Warehouse

Hansen, V.L.; Dusel-Bacon, C.

1998-01-01

The Yukon-Tanana terrane, the largest tectonostratigraphic terrane in the northern North American Cordillera, is polygenetic and not a single terrane. Lineated and foliated (L-S) tectonites, which characterize the Yukon-Tanana terrane, record multiple deformations and formed at different times. We document the polyphase history recorded by L-S tectonites within the Yukon-Tanana upland, east-central Alaska. These upland tectonites compose a heterogeneous assemblage of deformed igneous and metamorphic rocks that form the Alaskan part of what has been called the Yukon-Tanana composite terrane. We build on previous kinematic data and establish the three-dimensional architecture of the upland tectonites through kinematic and structural analysis of more than 250 oriented samples, including quartz c-axis fabric analysis of 39 samples. Through this study we distinguish allochthonous tectonites from parautochthonous tectonites within the Yukon-Tanana upland. The upland tectonites define a regionally coherent stacking order: from bottom to top, they are lower plate North American parautochthonous attenuated continental margin; continentally derived marginal-basin strata; and upper plate ocean-basin and island-arc rocks, including some continental basement rocks. We delineate three major deformation events in time, space, and structural level across the upland from the United States-Canada border to Fairbanks, Alaska: (1) pre-Early Jurassic (>212 Ma) northeast-directed, apparent margin-normal contraction that affected oceanic rocks; (2) late Early to early Middle Jurassic (>188-185 Ma) northwest-directed, apparent margin-parallel contraction and imbrication that resulted in juxtaposition of the allochthonous tectonites with parautochthonous continental rocks; and (3) Early Cretaceous (135-110 Ma) southeast-directed crustal extension that resulted in exposure of the structurally deepest, parautochthonous continental rocks. The oldest event represents deformation within a west-dipping (present coordinates) Permian-Triassic subduction zone. The second event records Early to Middle Jurassic collision of the arc and subduction complex with North American crust, and the third event reflects mid-Cretaceous southeast-directed crustal extension. Events one and two can be recognized and correlated through southern Yukon, even though this region was affected by mid-Cretaceous dextral shear along steep northwest-striking faults. Our data support a model of crustal assembly originally proposed by D. Tempelman-Kluit in which previously deformed allochthonous rocks were thrust over parautochthonous rocks of the attenuated North American margin in Middle Jurassic time. Approximately 50 m.y. after tectonic accretion, east-central Alaska was dissected by crustal extension, exposing overthrust parautochthonous strata.

Conodont and Radiolarian Data from the De Long Mountains Quadrangle and Adjacent Areas, Northern Alaska

USGS Publications Warehouse

Dumoulin, Julie A.; Harris, Anita G.; Blome, Charles D.; Young, Lorne E.

2006-01-01

INTRODUCTION This report presents biostratigraphic data from 289 collections at 189 localities in the De Long Mountains, Misheguk Mountain, and Noatak quadrangles (fig. 1); most of these data have never been previously published. The collections were made during studies of the Red Dog massive sulfide deposit in 1998?2004 and in support of regional mapping projects in 1979, 1981, 1983, and 1997?98. The collections?mostly conodonts and some radiolarians?tightly constrain the age of many stratigraphic units of Devonian through Triassic age exposed within the study area, and provide additional data on the depositional environments and thermal history of these rocks. The data are presented in a series of tables, organized by fossil type, stratigraphic unit, and location. Tables 1?12 contain conodont data, mostly from the De Long Mountains quadrangle. All of these collections were initially examined, or were reevaluated, from 1997 through 2004, and complete faunal lists are given for all samples. Table 13 lists ages and conodont color alteration indices (CAIs) of 27 collections from 24 localities in the Noatak quadrangle; updated faunal lists were not prepared for these samples. Radiolarian data?all from the De Long Mountains quadrangle?are given in table 14; these collections were analyzed between 1998 and 2003. Collection localities are shown in four maps (sheets 1, 2). Map 1 (sheet 1) shows all outcrop samples from the De Long Mountains and western Misheguk Mountain quadrangle (locs. 1-121). Maps 2?4 (sheets 1, 2) show all drill hole sample localities; samples come from the Su-Lik deposit and in and around the Anarraaq deposit (map 2, locs. 122?135), in and adjacent to the Red Dog deposits (Paalaaq, Aqqaluk, Main, and Qanaiyaq) (map 3, locs. 136?158), and from drill holes along the Port Road in the Noatak quadrangle (map 4, locs. 159?160). Map 4 (sheet 2) also shows all outcrop samples from the Noatak quadrangle (locs. 161?189). The text summarizes the lithofacies, age, and biofacies of the Paleozoic and Mesozoic stratigraphic units that produced the fossil collections presented in the tables. Many of the data for the Lisburne Group are taken from Dumoulin and others (2004). Plates 1?4 illustrate important conodonts from the collections listed herein, as well as from coeval collections in the Howard Pass quadrangle; information about the Howard Pass conodonts is given in Table 15.

Applying Low Temperature Thermochronology to Constrain Exhumation Patterns along the Eastern Denali Fault Corner, Alaska

NASA Astrophysics Data System (ADS)

Warfel, T. S.; Fitzgerald, P. G.; Benowitz, J.; Ridgway, K.; Allen, W. K.

2017-12-01

The Denali Fault (DF) constitutes a long ( 2000 km), arcuate, dextrally transpressive intracontinental fault system sketching across south-central Alaska. Strain-partitioning along the DF is accommodated as slip on the fault and fault-normal motion on a series of thrusts located north and south of the fault itself. High topography in the central and eastern Alaska Range, also locations of the greatest exhumation along the fault, are associated with restraining bends in those regions. East of the Richardson Highway, along the eastern Denali fault corner (or east-central segment of the DF), thrust faults south of the DF, including the McCallum thrust have accommodated the fault-normal component of motion along the DF. The aim of this project is to better understand what controls exhumation along large strike-slip faults, in particular the DF. Previous work along the DF in the central and eastern Alaska Range (to the west of this region) indicate the importance of fault geometry and rheological contrasts between terranes that have been juxtaposed against one another in controlling the location of exhumation. Our area of interest is a largely unstudied section along the Denali Fault (eastern DF corner) located between the DF/Hines Creek fault intersection and the Totschunda/DF intersection. We are applying a combination of apatite fission track thermochronology and apatite (U-Th)/He dating to samples collected north and south of the DF, and across thrust faults south of the DF. Thermochronology is being applied to bedrock samples, collected in vertical profiles and/or hanging wall - footwall pairs. Cobbles were also collected within a stratigraphic framework (constrained by tephras), from Miocene sediments in inverted basins south of the DF. Thermochronologic data from these cobbles; using lag-time analyses and inverse thermal models, will constrain the exhumation history of the hinterland. Assuming modern rates for slip along the DF will allow constraints to be placed on spatial and temporal patterns of exhumation and hence, help constrain the underlying control on exhumation patterns. Preliminary results indicate older AFT and AHe ages (up to 50 Ma) away from the DF but yield apatite (U-Th)/He ages as young as 2 Ma for a sample from the footwall of the closest thrust south of the DF.

27 CFR 9.184 - Trinity Lakes.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Provisional Edition 1986; (2) Whisky Bill Peak, Calif. Provisional Edition 1986; (3) Damnation Peak, Calif...) Proceed due east on township line T37N/T36N onto the Whisky Bill Peak, California quadrangle map to the...

27 CFR 9.184 - Trinity Lakes.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Provisional Edition 1986; (2) Whisky Bill Peak, Calif. Provisional Edition 1986; (3) Damnation Peak, Calif...) Proceed due east on township line T37N/T36N onto the Whisky Bill Peak, California quadrangle map to the...

Recurring middle Pleistocene outburst floods in east-central Alaska

USGS Publications Warehouse

Froese, D.G.; Smith, D.G.; Westgate, J.A.; Ager, T.A.; Preece, S.J.; Sandhu, A.; Enkin, R.J.; Weber, F.

2003-01-01

Recurring glacial outburst floods from the Yukon-Tanana Upland are inferred from sediments exposed along the Yukon River near the mouth of Charley River in east-central Alaska. Deposits range from imbricate gravel and granules indicating flow locally extending up the Yukon valley, to more distal sediments consisting of at least 10 couplets of planar sands, granules, and climbing ripples with up-valley paleocurrent indicators overlain by massive silt. An interglacial organic silt, occurring within the sequence, indicates at least two flood events are associated with an earlier glaciation, and at least three flood events are associated with a later glaciation which postdates the organic silt. A minimum age for the floods is provided by a glass fission track age of 560,000 ?? 80,000 yr on the GI tephra, which occurs 8 m above the flood beds. A maximum age of 780,000 yr for the floods is based on normal magnetic polarity of the sediments. These age constraints allow us to correlate the flood events to the early-middle Pleistocene. And further, the outburst floods indicate extensive glaciation of the Yukon-Tanana Upland during the early-middle Pleistocene, likely representing the most extensive Pleistocene glaciation of the area. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Areal geology of the Little Cone quadrangle, Colorado

USGS Publications Warehouse

Bush, A.L.; Marsh, O.T.; Taylor, R.B.

1960-01-01

The Little Cone quadrangle includes an area of about 59 square miles in eastern San Miguel County in southwestern Colorado. The quadrangle contains features characteristic of both the Colorado Plateaus physiographic province and the San Juan Mountains, and it has been affected by geologic events and processes of two different geologic environments. The continental sedimentary rocks of the Cutler formation of Permian age are the oldest rocks exposed in the quadrangle. Deposition of the Cutler was followed by a long period of erosion and peneplanation. There is no marked angular discordance between the Cutler and the overlying Dolores formation in the Little Cone quadrangle, but there is in areas some tens of miles east and west of the quadrangle where some crustal warping took place. The continental sedimentary rocks of the Dolores formation of Late Triassic age are red beds that are similar in gross lithology to those of the Cutler. The Dolores formation is subdivided into five general units that persist throughout the quadrangle and for some tens of miles to the north, south, and east. A second long period of erosion followed deposition of the Dolores. The Entrada sandstone of Late Jurassic age overlies the Dolores formation, and is in turn overlain by the Wanakah formation, also of Late Jurassic age. The Wanakah consists of the Pony Express limestone member at the base, the Bilk Creek sandstone'member near the center, and a "marl" member at the top. The Morrison formation, which overlies the Wanakah, consists of the Salt Wash sandstone member in the lower part and the Brushy Basin shale member in the upper part. A period of erosion, probably of relatively short duration, followed deposition of the Brushy Basin member. The Burro Canyon formation of Early Cretaceous age occurs as discontinuous bodies that fill channels cut in the top of the Morrison formation. Deposition of the Burro Canyon formation was followed by another period of erosion, which in turn ended with deposition of the Dakota sandstone of Late Cretaceous age. The Dakota sandstone grades upward into the Mancos shale, also of Late Cretaceous age.The Paleozoic and Mesozoic formations were broadly folded during Laramide time as part of an orogeny of regional extent, and the San Juan Mountains area was uplifted as a broad dome. Extensive erosion followed deformation, and the Cretaceous rocks in the area of the Little Cone quadrangle and the Mesozoic and Paleozoic rocks eastward from the quadrangle were successively bevelled. The Telluride conglomerate of Oligocene(?) age was laid down on this surface. In the Little Cone quadrangle several hundred feet of the Telluride was deposited upon a considerable thickness (probably 3,000 feet or more) of the Mancos shale. At Telluride, about 12 miles east of the quadrangle, the Telluride conglomerate lies upon the Dolores formation. Volcanic rocks of Miocene (?) and Miocene age were deposited widely upon the Telluride conglomerate; at one time they had a thickness of probably 1,000 feet or more in the quadrangle. They have been eroded completely from the quadrangle, but are present in the San Miguel Mountains a few miles to the south and southeast.During the middle Tertiary, probably during the Miocene, the sedimentary rocks were cut by many igneous bodies. Four major rock types are represented; in decreasing order of abundance they are granogabbro, granodidrite, rhyolite(?), and microgabbro. The granogabbro is by far the most abundant, and it forms the Flat Top Peak plug, the Little Cone laccolith, several sills in the Dakota sandstone and the Mancos shale, and a few dikes. The granodiorite forms sills in the Dakota sandstone and the Mancos shale, and the rhyolite(?) forms a single major sill in the Dakota. The microgabbro forms dikes that cut rocks as young as the Mancos shale. Metamorphic effects adjacent to the intrusive bodies generally are restricted to baking that extends only a few feet out into the enclosing rocks; in many places no metamorphic effects are evident. The rocks in the Little Cone quadrangle were displaced along numerous faults in middle Tertiary time, probably after the igneous rocks were injected. All of the faults are normal, and have vertical or very steep dips. In part, the faults form two long and narrow northward- and northwestward-trending grabens that extend into the adjoining Placerville quadrangle to the north. The graben faults form two systems, one trending northward to northwestward, and the other trending northwestward, that are probably contemporaneous. Other faults trend eastward to northeastward; some of these appear to be related to the intrusion of the igneous rocks. At the end of the Tertiary, probably in the early Pleistocene, the general area was again uplifted and subjected to extensive erosion. The Mancos shale was stripped from the northern part of the Little Cone quadrangle, and in this part of the area, the upland surfaces formed on top of the Dakota sandstone were largely controlled by the geologic structure. During the Quaternary a basalt flow was erupted on Specie Mesa on a surface that cuts both the Mancos and the Dakota. The surface preserved beneath the flow has virtually the same position and slope as the adjacent present-day surfaces. Pleistocene deposits consist of (a) high-level or older drift that is unrelated to the present drainage systems and is correlated with the Cerro glacial stage of early Pleistocene age, and (b) younger drift and valley fill within the valleys of the present drainage systems that are correlated with the Durango or Wisconsin glacial stages and may represent both. Recent surficial, landslide, and spring deposits are also present. Within the Little Cone quadrangle and in the Placerville quadrangle to the north and the Gray Head quadrangle to the east, the Entrada sandstone of Late Jurassic age contains vanadium deposits with which are associated large but low-grade amounts of uranium. These deposits form a practically continuous layer about 10 miles long and 1 to 1% miles wide, and possibly a second layer of smaller dimensions. Placer gold deposits in terrace gravel and valley fill of Pleistocene age and in alluvium of Recent age contain the only other ores.

Active Tectonics of the Far North Pacific Observed with GPS

NASA Astrophysics Data System (ADS)

Elliott, J.; Freymueller, J. T.; Jiang, Y.; Leonard, L. J.; Hyndman, R. D.; Mazzotti, S.

2017-12-01

The idea that the tectonics of the northeastern Pacific is defined by relatively discrete deformation along the boundary between the Pacific and North American plates has given way to a more complex picture of broad plate boundary zones and distributed deformation. This is due in large part to the Plate Boundary Observatory and several focused GPS studies, which have greatly increased the density of high-quality GPS data throughout the region. We will present an updated GPS velocity field in a consistent reference frame as well as a new, integrated block model that sheds light on regional tectonics and provides improved estimates of motion along faults and their potential seismic hazard. Crustal motions in southern Alaska are strongly influenced by the collision and flat-slab subduction of the Yakutat block along the central Gulf of Alaska margin. In the area nearest to the collisional front, small blocks showing evidence of internal deformation are required. East of the front, block motions show clockwise rotation into the Canadian Cordillera while west of the front there are counterclockwise rotations that extend along the Alaska forearc, suggesting crustal extrusion. Farther from the convergent margin, the crust appears to move as rigid blocks, with uniform motion over large areas. In western Alaska, block motions show a southwesterly rotation into the Bering Sea. Arctic Alaska displays southeasterly motions that gradually transition into easterly motion in Canada. Much of the southeastern Alaska panhandle and coastal British Columbia exhibit northwesterly motions. Although the relative plate motions are mainly accommodated along major faults systems, including the Fairweather-Queen Charlotte transform system, the St. Elias fold-and-thrust belt, the Denali-Totschunda system, and the Alaska-Aleutian subduction zone, a number of other faults accommodate lesser but still significant amounts of motion in the model. These faults include the eastern Denali/Duke River system, the Castle Mountain fault, the western Denali fault, the Kaltag fault, and the Kobuk fault. Based on the expanded GPS data set, locked or partially locked sections of the Alaska subduction zone may extend as far north and east as the eastern Alaska Range.

Teleseismic P and S wave attenuation constraints on temperature and melt of the upper mantle in the Alaska Subduction Zone.

NASA Astrophysics Data System (ADS)

Soto Castaneda, R. A.; Abers, G. A.; Eilon, Z.; Christensen, D. H.

2017-12-01

Recent broadband deployments in Alaska provide an excellent opportunity to advance our understanding of the Alaska-Aleutians subduction system, with implications for subduction processes worldwide. Seismic attenuation, measured from teleseismic body waves, provides a strong constraint on thermal structure as well as an indirect indication of ground shaking expected from large intermediate-depth earthquakes. We measure P and S wave attenuation from pairwise amplitude and phase spectral ratios for teleseisms recorded at 204 Transportable Array, Alaska Regional, and Alaska Volcano Observatory, SALMON (Southern Alaska Lithosphere & Mantle Observation Network) and WVLF (Wrangell Volcanics & subducting Lithosphere Fate) stations in central Alaska. The spectral ratios are inverted in a least squares sense for differential t* (path-averaged attenuation operator) and travel time anomalies at every station. Our preliminary results indicate a zone of low attenuation across the forearc and strong attenuation beneath arc and backarc in the Cook Inlet-Kenai region where the Aleutian-Yakutat slab subducts, similar to other subduction zones. This attenuation differential is observed in both the volcanic Cook Inlet segment and amagmatic Denali segments of the Aleutian subduction zone. By comparison, preliminary results for the Wrangell-St. Elias region past the eastern edge of the Aleutian slab show strong attenuation beneath the Wrangell Volcanic Field, as well as much further south than in the Cook Inlet-Kenai region. This pattern of attenuation seems to indicate a short slab fragment in the east of the subduction zone, though the picture is complex. Results also suggest the slab may focus or transmit energy with minimal attenuation, adding to the complexity. To image the critical transition between the Alaska-Aleutian slab and the region to its east, we plan to incorporate new broadband data from the WVLF array, an ongoing deployment of 37 PASSCAL instruments installed in 2016. These stations have 10-20 km spacing, spanning the edge of the subducting slab, and so will provide a zone of increased resolution in the region where slab behavior is poorly understood. We will discuss these data in the context of enigmatic Wrangell volcanism and its relationship to the eastern end of the Alaska-Aleutian Wadati-Benioff zone.

The mineral resource potential of the Harrat Nawasif, sheet 21/42 C, Ranyah, sheet 21/42 D, and Jabal Dalfa, sheet 21/43 C quadrangles, Kingdom of Saudi Arabia

USGS Publications Warehouse

Fenton, Michael D.

1983-01-01

Areas with mineral resource potential in the Harrat Nawasif, Ranyah, and Jabal Dalfa quadrangles in the central Precambrian Shield of Saudi Arabia have been identified by reconnaissance rock geochemistry and inspection of ancient prospects. Locally anomalous areas in perthitic, alkalic granite terrane in the Ranyah quadrangle possibly contain niobium, zirconium, thorium, fluorite, rare-earth, tin, molybdenum, or copper mineralization. The reconnaissance rock geochemical survey in layered volcanic and volcaniclastic terrane in the Jabal Dalfa quadrangle identified a zinc anomaly in quartzite and a nickel-copper zone that is an extension of the Jabal Judayr prospect, where a low-grade, nickel-copper sulfide deposit is known. The Precambrian terrane in the Harrat Nawasif quadrangle has no known mineral resource potential.

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.

Isostatic Gravity Map of the Battle Mountain 30 x 60 Minute Quadrangle, North Central Nevada

USGS Publications Warehouse

Ponce, D.A.; Morin, R.L.

2000-01-01

Introduction Gravity investigations of the Battle Mountain 30 x 60 minute quadrangle were begun as part of an interagency effort by the U.S. Geological Survey (USGS) and the Bureau of Land Management to help characterize the geology, mineral resources, hydrology, and ecology of the Humboldt River Basin in north-central Nevada. The Battle Mountain quadrangle is located between 40?30' and 41?N. lat. and 116? and 117?W. long. This isostatic gravity map of the Battle Mountain quadrangle was prepared from data from about 1,180 gravity stations. Most of these data are publicly available on a CD-ROM of gravity data of Nevada (Ponce, 1997) and in a published report (Jewel and others, 1997). Data from about 780 gravity stations were collected by the U.S. Geological Survey since 1996; data from about 245 of these are unpublished (USGS, unpub. data, 1998). Data collected from the 400 gravity stations prior to 1996 are a subset of a gravity data compilation of the Winnemucca 1:250,000-scale quadrangle described in great detail by Wagini (1985) and Sikora (1991). This detailed information includes gravity meters used, dates of collection, sources, descriptions of base stations, plots of data, and a list of principal facts. A digital version of the entire data set for the Battle Mountain quadrangle is available on the World Wide Web at: http://wrgis.wr.usgs.gov/docs/gump/gump.html

Geologic map of the Jam Up Cave and Pine Crest quadrangles, Shannon, Texas, and Howell Counties, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.; Repetski, John E.

2013-01-01

The Jam Up Cave and Pine Crest 7.5-minute quadrangles are located in south-central Missouri within the Salem Plateau region of the Ozark Plateaus physiographic province. About 2,400 to 3,100 feet (ft) of flat-lying to gently dipping Lower Paleozoic sedimentary rocks, mostly dolomite, chert, sandstone, and orthoquartzite, overlie Mesoproterozoic igneous basement rocks. Unconsolidated residuum, colluvium, terrace deposits, and alluvium overlie the sedimentary rocks. Numerous karst features, such as sinkholes, caves, and springs, have formed in the carbonate rocks. Many streams are spring fed. The topography is a dissected karst plain with elevations ranging from about 690 ft where the Jacks Fork River exits the northeastern corner of the Jam Up Cave quadrangle to about 1,350 ft in upland areas along the north-central edge and southwestern corner of the Pine Crest quadrangle. The most prominent physiographic feature is the valley of the Jacks Fork River. This reach of the upper Jacks Fork, with its clean, swiftly-flowing water confined by low cliffs and bluffs, provides one of the most beautiful canoe float trips in the nation. Most of the land in the quadrangles is privately owned and used primarily for grazing cattle and horses and growing timber. A large minority of the land within the quadrangles is publicly owned by the Ozark National Scenic Riverways of the National Park Service. Geologic mapping for this investigation was conducted in 2005 and 2006.

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.

1:6000 Scale (6K) Quadrangles developed by USEPA to Support Reconnaissance, and Tactical and Strategic Planning for Emergency Responses and Homeland Security Events (Region 9 Extract)

EPA Pesticide Factsheets

Reference quads for emergency response reconnaissance developed for use by the US Environmental Protection Agency. Grid cells are based on densification of the USGS Quarterquad (1:12,000 scale or 12K) grids for the continental United States, Alaska, Hawaii and Puerto Rico and are roughly equivalent to 1:6000 scale (6K) quadrangles approximately 2 miles long on each side. Note: This file is a regional subset that has been extracted from a national file 6K quad file. Each regional extract includes a 20 mile buffer of tiles around each EPA Region. To access the national layer (size is greater than 80MB), go to https://edg.epa.gov/data/Public/OLEM/6kquads_epa.zip.

Geology of the Lake Mary quadrangle, Iron County, Michigan

USGS Publications Warehouse

Bayley, Richard W.

1959-01-01

The Lake Mary quadrangle is in eastern Iron County, in the west part of the Upper Peninsula of Michigan. The quadrangle is underlain by Lower and Middle Precambrian rocks, formerly designated Archean and Algonkian rocks, and is extensively covered by Pleistocene glacial deposits. A few Upper Precambrian (Keweenawan) diabase dikes and two remnants of sandstone and dolomite of early Paleozoic age are also found in the area. The major structural feature is the Holmes Lake anticline, the axis of which strikes northwest through the northeast part of the quadrangle. Most of the quadrangle, therefore, is underlain by rock of the west limb of the anticline. To the northwest along the fold axis, the Holmes Lake anticline is separated from the Amasa oval by a saddle of transverse folds in the vicinity of Michigamme Mountain in the Kiernan quadrangle. The Lower Precambrian rocks are represented by the Dickinson group and by porphyritic red granite whose relation to the Dickinson group is uncertain, but which may be older. The rocks of the Dickinson group are chiefly green to black metavolcanic schist and red felsite, some of the latter metarhyolite. The dark schist is commonly magnetic. The Dickinson group underlies the core area of the Holmes Lake anticline, which is flanked by steeply dipping Middle Precambrian formations of the Animikie series. A major unconformity separates the Lower Precambrian rocks from the overlying Middle Precambrian rocks. In ascending order the formations of the Middle Precambrian are the Randville dolomite, the Hemlock formation, which includes the Mansfield iron-bearing slate member, and the Michigamme slate. An unconformity occurs between the Hemlock formation and Michigamme slate. The post-Hemlock unconformity is thought to be represented in the Lake Mary quadrangle by the absence of iron-formation of the Amasa formation, which is known to lie between the Hemlock and the Michigamme to the northwest of the Lake Mary quadrangle in the Crystal Falls quadrangle. Post-Hemlock erosion may account also for the absence of iron-formation of the Fence River formation on the east limb of the Holmes Lake anticline within the Lake Mary quadrangle. The Randville dolomite is not exposed and is known only from diamond drilling in the northeast part of the area where it occurs in the east and west limbs of the Holmes Lake anticline. The formation has a maximum thickness of about 2,100 feet; this includes a lower arkosic phase, some of which is quartz pebble conglomerate, a medial dolomitic phase, and an upper slate phase. The triad is gradational. Included within the formation are a few beds of chloritic schist thought to be of volcanic origin. An unconformity between the Randville and the succeeding Hemlock is not indicated in the quadrangle, but is probably present. The Hemlock formation is best exposed in the northwest and south-central parts of the area. The apparent thickness of the formation is 10,000- 17,000 feet. It is composed mainly of mafic metavolcanic rocks and intercalated slate and iron-formation. In the north part of the quadrangle the volcanic rocks are greenstone, which includes altered basaltic flow rocks, volcanic breccia, tuff, and slate. Pillow structures are common in the metabasalt. It is not certain if any Hemlock rocks are present in the east limb of the Holmes Lake anticline. In the south part of the quadrangle, the rocks of the Hemlock are chiefly chlorite and hornblende schist and hornfels. Pyroxene hornfels is sparingly present. At least two sedimentary slate belts are included in the Hemlock formation. One of these, the Mansfield iron-bearing slate member, includes in its upper part an altered chert-siderite iron-formation 30 to over 150 feet thick from which iron ore has been mined at the Mansfield location. The position of the iron-bearing rocks has been determined magnetically, and past explorations for iron ore are discussed. Though probably; unconformable, the contact between the Hemlock and the Michigamme formations appears conformable. The Michigamme slate consists of at least 4,000 feet of interbedded mica schist and granulite, the altered equivalents of the slate and graywacke characteristic of the Michigamme in adjacent areas. The Michigamme rocks are best exposed in the south part of the quadrangle in the vicinity of Peavy Pond. Two periods of regional metamorphism have resulted in the alteration of almost all of the rocks of the quadrangle. The Lower Precambrian rocks underwent at least one period of metamorphism, uplift, and erosion before the deposition of the Randville dolomite. After the deposition of the Michigamme slate, a post-Middle Precambrian period of regional metamorphism occurred with attending deformation and igneous intrusion. The grade of metamorphism rises toward the south in the area. The rocks in the northern two-thirds of the quadrangle are representative of greenschist facies of regional metamorphism, whereas the rocks in the southern onethird of the quadrangle are representative of the albite-epidote-amphibolite, the amphibolite, and the pyroxene hornfels facies, the metamorphic node centering about the intrusive Peavy Pond complex in the Peavy Pond area. The Precambrian sedimentary and volcanic rocks are cut by intrusive igneous rocks of different types and several different ages. Gabbroic sills and dikes invaded the Hemlock rocks at some time after the Hemlock was deposited and before the post-Middle Precambrian orogeny and metamorphism. Some contact metamorphism attended the intrusion of the major sills. One of the sills, the West Kiernan sill, is well differentiated. A syntectonic igneous body, composed of gabbro and minor ultramafic parts and fringed with intermediate and felsic differentiates and hybrids, the Peavy; Pond complex, was intruded into the Hemlock and Michigamme formations during the post-Middle Precambrian orogeny. The complex is situated in the Peavy Pond area at the crest of the regional metamorphic node. Contact-altered sedimentary and volcanic rocks margin the complex. The effects of regional metamorphism have been superposed on the contact metamorphic rocks peripheral to the complex and on the igneous rocks of the complex as well. The mafic augite-bearing rocks of the complex emplaced early in the orogeny were deformed by granulation at the peak of the deformation and subsequently metamorphosed to hornblende rocks. Some of the intermediate and felsic rocks of the complex were foliated by the deformation, while the more fluid, felsic parts of the complex were intruded under orogenic stress and crystallized after the peak of deformation. The deformation culminated in major faulting during which the formations were dislocated, and some of the granite of the complex was extremely brecciated. A few diabase dikes, probably of Keweenawan age, have intruded the deformed and altered Animikie rocks. The only known metallic resource is iron ore. The Mansfield mine produced 1¥2 million tons of high-grade iron ore between the years 1890 and 1913. Sporadic exploration since 1913 has failed to reveal other ore deposits of economic importance.

The complex Chukchi Borderland region as part of the Arctic Alaska extended margin

NASA Astrophysics Data System (ADS)

Saltus, R.; Hutchinson, D. R.; Miller, E. L.

2017-12-01

The Chukchi Borderland region (CBR; includes the Chukchi Plateau and its surrounding component elevations) is a physiographically complex and somewhat enigmatic seafloor high adjacent to the broad Chukchi Shelf in the Alaska/Chukotka quadrant of the Amerasian Basin beneath the Arctic Ocean. The CBR includes several physiographic sub-components including the relatively high-standing Northwind Ridge and Northwind Plain as well as a lower-standing northern region (here called the North Chukchi Component Elevation or NCCE) that consists of several un-named knolls, ramps, and benches. The CBR shows numerous N-S physiographic features including ridges and escarpments related to extension. The CBR adjoins the Chukchi Shelf to the south, abuts the Canada Basin to the east, and is separated on the west and north from the Mendeleev and Alpha Ridges by the Chukchi Plain, the Mendeleev Plain, and the Nautilus Basin. Available geophysical data, comparative physiography/geomorphology, and geologic analysis show that the CBR is continuous with Arctic Alaska and the adjoining Chukchi Shelf. CBR, Arctic Alaska, and the Chukchi Shelf share common early Paleozoic basement elements as well as Ellesmerian and younger cover sequences. The CBR owes its complex physiographic and structural character to its central location relative to the multiple extensional domains associated with the multi-stage rift formation of the Amerasian Basin, large igneous province-influenced volcanism associated with the Alpha and Mendeleev regions on the north and west, and hyper-extension of continental crust to the east in the deep Canada Basin. The CBR is often portrayed as an independent tectonic element within Arctic tectonic reconstructions, but we argue that models for the formation of the Amerasian Basin should include the CBR as an integral component of the Arctic Alaska microplate.

Aerial gamma ray and magnetic survey: Mississippi and Florida airborne survey, Russellville quadrangle, Arkansas

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

Not Available

1980-09-01

The Russellville quadrangle in north central Arkansas overlies thick Paleozoic sediments of the Arkoma Basin. These Paleozoics dominate surface exposure except where covered by Quaternary alluvial materials. Examination of available literature shows no known uranium deposits (or occurrences) within the quadrangle. Eighty-eight groups of uranium samples were defined as anomalies and are discussed briefly. None were considered significant, and most appeared to be of cultural origin. Magnetic data show character that suggest structural and/or lithologic complexity, but imply relatively deep-seated sources.

Geologic map and map database of the Spreckels 7.5-minute Quadrangle, Monterey County, California

USGS Publications Warehouse

Clark, Joseph C.; Brabb, Earl E.; Rosenberg, Lewis I.; Goss, Heather V.; Watkins, Sarah E.

2001-01-01

Introduction The Spreckels quadrangle lies at the north end of the Sierra de Salinas and extends from the Salinas Valley on the northeast across Los Laurelles Ridge south to Carmel Valley, an intermontane valley that separates the Santa Lucia Range from the Sierra de Salinas (fig. 1). The Toro Regional Park occupies the east-central part of the quadrangle, whereas the former Fort Ord Military Reservation covers the northwestern part of the area and is the probable locus of future development. Subdivisions largely occupy the older floodplain of Toro Creek and the adjacent foothills, with less dense development along the narrower canyons of Corral de Tierra and San Benancio Gulch to the south. The foothills southwest of the Salinas River are the site of active residential development. Geologically, the study area has a crystalline basement of Upper Cretaceous granitic rocks of the Salinian block and older metasedimentary rocks of the schist of the Sierra de Salinas of probable Cretaceous age. Resting nonconformably upon these basement rocks is a sedimentary section that ranges in age from middle Miocene to Holocene and has a composite thickness of as much as 1,200 m. One of the purposes of the present study was to investigate the apparent lateral variation of the middle to upper Miocene sections from the typical porcelaneous and diatomaceous Monterey Formation of the Monterey and Seaside quadrangles to the west (Clark and others, 1997) to a thick marine sandstone section in the eastern part of the Spreckels quadrangle. Liquefaction, which seriously affected the Spreckels area in the 1906 San Francisco earthquake (Lawson, 1908), and landsliding are the two major geological hazards of the area. The landslides consist mainly of older large slides in the southern and younger debris flows in the northern part of the quadrangle. This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (skmf.txt, skmf.pdf, or skmf.ps), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

Preliminary volcano-hazard assessment for Akutan Volcano east-central Aleutian Islands, Alaska

USGS Publications Warehouse

Waythomas, Christopher F.; Power, John A.; Richter, Donlad H.; McGimsey, Robert G.

1998-01-01

Akutan Volcano is a 1100-meter-high stratovolcano on Akutan Island in the east-central Aleutian Islands of southwestern Alaska. The volcano is located about 1238 kilometers southwest of Anchorage and about 56 kilometers east of Dutch Harbor/Unalaska. Eruptive activity has occurred at least 27 times since historical observations were recorded beginning in the late 1700?s. Recent eruptions produced only small amounts of fine volcanic ash that fell primarily on the upper flanks of the volcano. Small amounts of ash fell on the Akutan Harbor area during eruptions in 1911, 1948, 1987, and 1989. Plumes of volcanic ash are the primary hazard associated with eruptions of Akutan Volcano and are a major hazard to all aircraft using the airfield at Dutch Harbor or approaching Akutan Island. Eruptions similar to historical Akutan eruptions should be anticipated in the future. Although unlikely, eruptions larger than those of historical time could generate significant amounts of volcanic ash, fallout, pyroclastic flows, and lahars that would be hazardous to life and property on all sectors of the volcano and other parts of the island, but especially in the major valleys that head on the volcano flanks. During a large eruption an ash cloud could be produced that may be hazardous to aircraft using the airfield at Cold Bay and the airspace downwind from the volcano. In the event of a large eruption, volcanic ash fallout could be relatively thick over parts of Akutan Island and volcanic bombs could strike areas more than 10 kilometers from the volcano.

Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

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

Not Available

1981-05-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. Amore » total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.« less

Airborne gamma-ray spectrometer and magnetometer survey, Medford Quadrangle Oregon. Final report

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

Not Available

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Medford, Oregon, map area. Traverse lines were flown in an east-west direction at a line spacing of three miles. Tie lines were flown north-south approximately twelve miles apart. A total ofmore » 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 2925 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.« less

Geologic Mapping of the Guinevere Planitia Quadrangle of Venus

NASA Technical Reports Server (NTRS)

Crown, David A.; Stofan, Ellen R.; Bleamaster, Leslie F., III

2008-01-01

The Guinevere Planitia quadrangle of Venus (0-25degN, 300-330deg) covers a lowland region east of Beta Regio and west of Eistla Regio, including parts of Guinevere and Undine Planitiae. The V-30 quadrangle is dominated by low-lying plains interpreted to be of volcanic origin and exhibiting numerous wrinkle ridges. Using Pioneer Venus, Goldstone, and Arecibo data, previous investigators have described radar bright, dark, and mottled plains units in the Guinevere Planitia region, as well as arcuate fracture zones and lineament belt segments that define the Beta-Eistla deformation zone [1-5]. Magellan SAR images show that volcanic landforms compose the majority of the surface units in V-30 [6-7]. The quadrangle contains parts of four major volcanoes: Atanua (9degN, 307deg), Rhpisunt (3degN, 302deg), Tuli (13degN, 314deg), and Var (3degN, 316deg) Montes, and three coronae: Hulda (12degN, 308deg), Madderakka (9degN, 316deg), and Poloznitsa (1degN, 303deg). Seymour crater, located at 18degN, 327deg, is associated with extensive crater outflow deposits.

Digital Geologic Map of the Nevada Test Site and Vicinity, Nye, Lincoln, and Clark Counties, Nevada, and Inyo County, California

USGS Publications Warehouse

Slate, Janet L.; Berry, Margaret E.; Rowley, Peter D.; Fridrich, Christopher J.; Morgan, Karen S.; Workman, Jeremiah B.; Young, Owen D.; Dixon, Gary L.; Williams, Van S.; McKee, Edwin H.; Ponce, David A.; Hildenbrand, Thomas G.; Swadley, W.C.; Lundstrom, Scott C.; Ekren, E. Bartlett; Warren, Richard G.; Cole, James C.; Fleck, Robert J.; Lanphere, Marvin A.; Sawyer, David A.; Minor, Scott A.; Grunwald, Daniel J.; Laczniak, Randell J.; Menges, Christopher M.; Yount, James C.; Jayko, Angela S.

1999-01-01

This digital geologic map of the Nevada Test Site (NTS) and vicinity, as well as its accompanying digital geophysical maps, are compiled at 1:100,000 scale. The map compilation presents new polygon (geologic map unit contacts), line (fault, fold axis, metamorphic isograd, dike, and caldera wall) and point (structural attitude) vector data for the NTS and vicinity, Nye, Lincoln, and Clark Counties, Nevada, and Inyo County, California. The map area covers two 30 x 60-minute quadrangles-the Pahute Mesa quadrangle to the north and the Beatty quadrangle to the south-plus a strip of 7.5-minute quadrangles on the east side-72 quadrangles in all. In addition to the NTS, the map area includes the rest of the southwest Nevada volcanic field, part of the Walker Lane, most of the Amargosa Desert, part of the Funeral and Grapevine Mountains, some of Death Valley, and the northern Spring Mountains. This geologic map improves on previous geologic mapping of the same area (Wahl and others, 1997) by providing new and updated Quaternary and bedrock geology, new geophysical interpretations of faults beneath the basins, and improved GIS coverages. Concurrent publications to this one include a new isostatic gravity map (Ponce and others, 1999) and a new aeromagnetic map (Ponce, 1999).

Geologic map of the Puye Quadrangle, Los Alamos, Rio Arriba, Sandoval, and Santa Fe Counties, New Mexico

USGS Publications Warehouse

Dethier, David P.

2003-01-01

The Puye quadrangle covers an area on the eastern flank of the Jemez Mountains, north of Los Alamos and west of Espanola, New Mexico. Most of the quadrangle consists of a dissected plateau that was formed on the resistant caprock of the Bandelier Tuff, which was erupted from the Valles caldera approximately 1 to 2 million years ago. Within the canyons of the east-flowing streams that eroded this volcanic tableland, Miocene and Pliocene fluvial deposits of the Puye Formation and Santa Fe Group are exposed beneath the Bandelier Tuff. These older units preserve sand and gravel that were deposited by streams and debris flows flowing from source areas located mostly north and northeast of the Puye quadrangle. The landscape of the southeastern part of the quadrangle is dominated by the valley of the modern Rio Grande, and by remnants of piedmont-slope and river-terrace deposits that formed during various stages of incision of the Rio Grande drainage on the landscape. Landslide deposits are common along the steep canyon walls where broad tracts of the massive caprock units have slumped toward the canyons on zones of weakness in underlying strata, particularly on silt/clay-rich lacustrine beds within the Puye Formation.

27 CFR 9.199 - Jahant.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the Mokelumne River to its intersection with New Hope Road, about 0.7 mile north of the village of Thornton, T5N, R5E (Thornton Quadrangle); then (2) Proceed north then east for 3 miles on New Hope Road to...

Geologic map of the Yacolt quadrangle, Clark County, Washington

USGS Publications Warehouse

Evarts, R.C.

2006-01-01

The Yacolt 7.5' quadrangle is situated in the foothills of the western Cascade Range of southwestern Washington approximately 35 km northeast of Portland, Oregon. Since late Eocene time, the Cascade Range has been the locus of an active volcanic arc associated with underthrusting of oceanic lithosphere beneath the North American continent along the Cascadia Subduction Zone. Volcanic and shallow-level intrusive rocks emplaced early in the history of the arc underlie most of the Yacolt quadrangle, forming a dissected and partly glaciated terrain with elevations between 250 and 2180 ft (75 and 665 m). The bedrock surface slopes irregularly but steeply to the southwest, forming the eastern margin of the Portland Basin, and weakly consolidated Miocene and younger basin-fill sediments lap up against the bedrock terrain in the southern part of the map area. A deep canyon, carved by the East Fork Lewis River that flows westward out of the Cascade Range, separates Yacolt and Bells Mountains, the two highest points in the quadrangle. Just west of the quadrangle, the river departs from its narrow bedrock channel and enters a wide alluvial floodplain. Bedrock of the Yacolt quadrangle consists of near-horizontal strata of Oligocene volcanic and volcaniclastic rocks that comprise early products of the Cascade volcanic arc. Basalt and basaltic andesite flows predominate. Most were emplaced on the flanks of a large mafic shield volcano and are interfingered with crudely bedded sections of volcanic breccia of probable lahar origin and a variety of well bedded epiclastic sedimentary rocks. At Yacolt Mountain, the volcanogenic rocks are intruded by a body of Miocene quartz diorite that is compositionally distinct from any volcanic rocks in the map area. The town of Yacolt sits in a north-northwest-trending valley apparently formed within a major fault zone. Several times during the Pleistocene, mountain glaciers moved down the Lewis River valley and spread southward into the map area. The largest glacier(s) covered the entire map area north of the East Fork Lewis River except for the summit of Yacolt Mountain. As the ice receded, it left behind a sculpted bedrock topography thickly mantled by drift, and deposited outwash in the fault-bounded valley at Yacolt and along the East Fork Lewis River valley. This map is a contribution to a program designed to improve geologic knowledge of the Portland Basin region of the Pacific Northwest urban corridor, the densely populated Cascadia forearc region of western Washington and Oregon. More detailed information on the bedrock and surficial geology of the basin and its surrounding area is necessary to refine assessments of seismic risk, ground-failure hazards and resource availability in this rapidly growing region.

Overview of environmental and hydrogeologic conditions at Fort Yukon, Alaska

USGS Publications Warehouse

Nakanishi, Allan S.; Dorava, Joseph M.

1994-01-01

The village of Fort Yukon along the Yukon River in east-central Alaska has long cold winters and short summers. The Federal Aviation Administration operates and supports some airport facilities in Fort Yukon and is evaluating the severity of environmental contamination and options for remediation of such contamination at their facilites. Fort Yukon is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available from local surface-water bodies or from presently unidentified confined aquifers.

Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation

USGS Publications Warehouse

Ager, T.A.; Matthews, J.V.; Yeend, W.

1994-01-01

Gravels deposited by the ancestral Yukon River are preserved in terrace remnants on the margins of the Yukon River valley near the village of Circle in east-central Alaska. Plant fossils recovered from sandy silt lenses within these gravels include cones and needles of Picea and Larix and a variety of seeds. Seed types include several taxa which no longer grow in Alaska, such as Epipremnum, Prunus and Weigela. Pollen types recovered from these deposits represent tree and shrub taxa that grow in interior Alaska today, such as Picea, Larix, Betula and Alnus, as well as several taxa that no longer grow in interior Alaska today, such as Pinus, Tsuga, Abies and Corylus. Pollen of herb taxa identified include Gramineae, Cyperaceae, Caryophyllaceae, Compositae, Polemonium and Epilobium. The fossil flora from the gravels near Circle are similar and probably age-equivalent to the flora recovered from the Nenana Gravel in the Alaska Range 250 km to the south. Palynological and tectonic evidence summarized in this paper now suggests that the Nenana Gravel was deposited during the early and middle Pliocene. The presence of plant fossils of Tsuga, Abies, Pinus, Weigela and Prunus suggests that the mean annual temperature (MAT) of eastern interior Alaska during the early and middle Pliocene was perhaps 7-9??C warmer and less continental than today's MAT of -6.4??C. ?? 1994.

Geologic map of the Storm King Mountain quadrangle, Garfield County, Colorado

USGS Publications Warehouse

Bryant, Bruce; Shroba, Ralph R.; Harding, Anne E.; Murray, Kyle E.

2002-01-01

New 1:24,000-scale geologic mapping in the Storm King Mountain 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new data on the structure on the south margin of the White River uplift and the Grand Hogback and on the nature, history, and distribution of surficial geologic units. Rocks ranging from Holocene to Proterozoic in age are shown on the map. The Canyon Creek Conglomerate, a unit presently known to only occur in this quadrangle, is interpreted to have been deposited in a very steep sided local basin formed by dissolution of Pennsylvanian evaporite late in Tertiary time. At the top of the Late Cretaceous Williams Fork Formation is a unit of sandstone, siltstone, and claystone from which Late Cretaceous palynomorphs were obtained in one locality. This interval has been mapped previously as Ohio Creek Conglomerate, but it does not fit the current interpretation of the origin of the Ohio Creek. Rocks previously mapped as Frontier Sandstone and Mowry Shale are here mapped as the lower member of the Mancos Shale and contain beds equivalent to the Juana Lopez Member of the Mancos Shale in northwestern New Mexico. The Pennsylvanian Eagle Valley Formation in this quadrangle grades into Eagle Valley Evaporite as mapped by Kirkham and others (1997) in the Glenwood Springs area. The Storm King Mountain quadrangle spans the south margin of the White River uplift and crosses the Grand Hogback monocline into the Piceance basin. Nearly flat lying Mississippian through Cambrian sedimentary rocks capping the White River uplift are bent into gentle south dips and broken by faults at the edge of the uplift. South of these faults the beds dip moderately to steeply to the south and are locally overturned. These dips are interrupted by a structural terrace on which are superposed numerous gentle minor folds and faults. This terrace has an east-west extent similar to that of the Canyon Creek Conglomerate to the north. We interpret that the terrace formed by movement of Eagle Evaporite from below in response to dissolution and diapirism in the area underlain by the conglomerate. A low-angle normal fault dipping gently north near the north margin of the quadrangle may have formed also in response to diapirism and dissolution in the area of the Canyon Creek Conglomerate. Along the east edge of the quadrangle Miocene basalt flows are offset by faults along bedding planes in underlying south-dipping Cretaceous rocks, probably because of diapiric movement of evaporite into the Cattle Creek anticline (Kirkham and Widmann, 1997). Steep topography and weak rocks combine to produce a variety of geologic hazards in the quadrangle.

Magnetic susceptibility and relation to initial 87Sr/86Sr for granitoids of the central Sierra Nevada, California

USGS Publications Warehouse

Bateman, P.C.; Dodge, F.C.W.; Kistler, R.W.

1991-01-01

Measurement of the magnetic susceptibility of more than 6000 samples of granitic rock from the Mariposa 1?? by 2?? quadrangle, which crosses the central part of the Sierra Nevada batholith between 37?? and 38??N latitude, shows that magnetic susceptibility values are above 10-2 SI units in the east and central parts of the batholith and drop abruptly to less than 10-3 SI units in the western foothills. In a narrow transitional zone, intermediate values (10-3 to 10-2) prevail. Magnetic susceptibility appears to decrease slightly westward within the zones of both high and low values. Magnetic susceptibility in plutonic rocks is chiefly a function of the abundance of magnetite, which depends, in turn, on the total iron content of the rocks and their oxidation ratio. Correlations of magnetic susceptibility with initial 87Sr/86Sr suggest that oxidation ratios have been inherited from the source regions for the magmas from which the rocks crystallized. Reduction of Fe3+ to Fe2+ by organic carbon or other reducing substances may also have affected magnetic susceptibility. -from Authors

Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus: Evidence for Early Formation and Preservation of Regional Topography

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Head, James W.

2008-01-01

The area of the Meskhent Tessera quadrangle (V-3, 50-75degN, 60-120degE, Fig. 1) corresponds to a transition zone from the uplands of Ishtar Terra to the west to the lowlands of Atalanta Planitia to the east. The topographic configuration, gravity signature, and presence of large tesserae in Ishtar Terra are consistent with extensive areas of thickened crust and tectonically stabilized lithosphere representing ancient and now extinct regimes of mantle convection. The gravity and topographic characteristics of Atalanta Planitia have been cited as evidence for large-scale mantle downwelling. Thus, the region of Meskhent Tessera quadrangle represents an important sample for the study of the regional history of long-wavelength topography (highlands, midlands, and lowlands), interaction between the downwelling and areas of thickened crust/lithosphere, formation of associated tectonic features, and emplacement of volcanic plains.

Gold occurrences in the Greenville 1 degree by 2 degrees Quadrangle, South Carolina, Georgia, and North Carolina

USGS Publications Warehouse

D'Agostino, John P.; Mason, George T.; Zupan, Alan J.W.; Maybin, Arthur H.; German, Jerry M.; Abrams, Charlotte E.

1994-01-01

All of the gold mines, prospects, placers, and occurrences known in the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order by county (fig. 1), the map number of each feature, which is located either on the accompanying Greenville 1° x 2° quadrangle map or figure 2. The known name of the feature; the 7.5' topographic map on the which the gold site is located (if known, within 25 ft or 7.6 m), the Universal Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5' topographic map; the commodity; remarks; and references are also listed. Some locations are known, but many sites are not verified and their locations are only approximate. References are listed in References Cited and referred to by number to save space.

Geologic map of the Masters 7.5' quadrangle, Weld and Morgan Counties, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Slate, Janet L.; Paces, James B.; Hanson, Paul R.; Brandt, Theodore R.

2015-09-28

The Masters 7.5' quadrangle is located along the South Platte River corridor on the semiarid plains of eastern Colorado and contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated in concert with environmental changes from Pleistocene to present time. The South Platte River, originating high in the Colorado Front Range, has played a major role in shaping the surficial geology of the quadrangle, which is situated downstream of where the last of the major headwater tributaries (St. Vrain, Big Thompson, and Cache la Poudre) join the river. Recurrent glaciation (and deglaciation) of basin headwaters affected river discharge and sediment supply far downstream, influencing deposition of alluvium and terrace formation in the Masters quadrangle. Kiowa and Bijou Creeks, unglaciated tributaries originating in the Colorado Piedmont east of the Front Range and joining the South Platte River just downstream of the Masters quadrangle, also have played a major role by periodically delivering large volumes of sediment to the river during flood events, which may have temporarily dammed the river. Eolian sand deposits of the Greeley (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of prolonged drought. With the onset of irrigation and damming during historical times, the South Platte River has changed from a broad, shallow sandy braided river with highly seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge. Along the reach of river in the Masters quadrangle, the river has incised into Upper Cretaceous Pierre Shale, which, although buried by alluvial deposits here, is locally exposed downstream along the South Platte River bluff near the Bijou Creek confluence, in some of the larger draws, and along Wildcat Creek.

Use of LANDSAT imagery for wildlife habitat mapping in northeast and east central Alaska

NASA Technical Reports Server (NTRS)

Lent, P. C. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Two scenes were analyzed by applying an iterative cluster analysis to a 2% random data sample and then using the resulting clusters as a training set basis for maximum likelihood classification. Twenty-six and twenty-seven categorical classes, respectively resulted from this process. The majority of classes in each case were quite specific vegetation types; each of these types has specific value as moose habitat.

Geologic map of Ophir and central Candor Chasmata (MTM -05072) of Mars

USGS Publications Warehouse

Lucchitta, Baerbel K.

1999-01-01

The geologic map of Ophir and central Candor Chasmata is one of a series of 1:500,000 scale maps prepared for areas on Mars that are of particular scientific interest and may serve as potential future landing sites. This map is also part of a set that includes east Candor Chasma, west Candor Chasma, and Melas Chasma. The geologic interpretations are based dominantly on medium- and high-resolution Viking images, many of them stereoscopic, and supplemented by lower resolution apoapsis and other color images. A strip of very high resolution stereoscopic images (~20 m/pixel) crosses the central part of the quadrangle from northwest to southeast and served to clarify detailed relations not obvious on other images. A topographic map with contour intervals of 200 m was also used, as were multidirectional oblique images derived from merged image mosaics and topography (see fig. 1) (Bertolini and McEwen, 1990). Geologic relations and interpretations are based on the entire central Valles Marineris map set. The map area is included in the Valles Marineris map of Witbeck and others (1991), but units were defined independently. Age assignments, however, were integrated with those by Witbeck and others and Scott and Tanaka (1986).

Arctic Storms and Their Influence on Surface Climate in the Chukchi-Beaufort Seas

NASA Astrophysics Data System (ADS)

Yang, Y.; Zhang, X.; Rinke, A.; Zhang, J.

2017-12-01

Increases in the frequency and intensity of Arctic storms and resulting weather hazards may endanger the offshore environment, coastal community, and energy infrastructure in the Arctic as sea ice retreats. Advancing ability to identify fine-scale variations in surface climate produced by progressively stronger storm would be extremely helpful to resources management and sustainable development for coastal community. In this study, we analyzed the storms and their impacts on surface climate over the Beaufort-Chukchi seas by employing the date sets from both the hindcast simulations of the coupled Arctic regional climate model HIRHAM-NAOSIM and the recently developed Chukchi-Beaufort High-resolution Atmospheric Reanalysis (CBHAR). Based on the characteristics of spatial pattern and temporal variability of the Arctic storm activity, we categorized storms to three groups with their different origins: the East Siberia Sea, Alaska and the central Arctic Ocean. The storms originating from the central Arctic Ocean have the strongest intensity in winter with relatively less storm number. Storms traveling from Alaska to the Beaufort Sea most frequently occurred in autumn with weaker intensity. A large portion of storms originated from the East Siberia Sea region in summer. Further statistical analysis suggests that increase in surface air temperature and wind speed could be attributed to the increased frequency of storm occurrence in autumn (September to November) along the continental shelf in the Beaufort Sea.

Geologic map of the Alley Spring quadrangle, Shannon County, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.

2012-01-01

The Alley Spring 7.5-minute quadrangle is located in south-central Missouri within the Salem Plateau region of the Ozark Plateaus physiographic province. About 1,990 feet (ft) of flat-lying to gently dipping Lower Paleozoic sedimentary rocks, mostly dolomite, chert, sandstone, and orthoquartzite, overlie Mesoproterozoic volcanic rocks. A small exposure of the volcanic rocks exists near the eastern edge of the quadrangle. Unconsolidated residuum, colluvium, terrace deposits, and alluvium overlie the sedimentary rocks. Karst features, such as sinkholes, caves, and springs, have formed in the carbonate rocks. Many streams are spring fed. Alley Spring, the largest karst spring in the quadrangle, has an average discharge of 81 million gallons per day. The topography is a dissected karst plain with elevation ranging from 630 ft where the Jacks Fork River exits the quadrangle to more than 1,140 ft at numerous places in the northern half of the quadrangle. The most prominent physiographic feature is the valley of the Jacks Fork River. Most of the land in the quadrangle is privately owned and used primarily for grazing cattle and horses and growing timber. A large minority of the land within the quadrangle is publicly owned, either by the Missouri State Forests or by the Ozark National Scenic Riverways of the National Park Service. Geologic mapping for this investigation was conducted in 2003 and 2004.

Geologic map of the Valdez D-1 and D-2 quadrangles (Mount Wrangell Volcano), Alaska

USGS Publications Warehouse

Richter, D.H.; McGimsey, R.G.; Labay, Keith A.; Lanphere, M.A.; Moore, R.B.; Nye, C.J.; Rosenkrans, D.S.; Winkler, G.R.

2016-04-29

This study was directed toward Mount Wrangell volcano and the older Wrangell volcanic field rocks that underlie the volcano. These older lavas include the Chetaslina lavas (867 ka–1,650 ka) and a basaltic andesite–dacite center (1,590 ka–1,640 ka) whose source areas are not well defined. Older Paleozoic and Mesozoic sedimentary, igneous, and metamorphic rocks of the Wrangellia terrane underlie the entire Wrangell volcanic field.

Publications - RI 98-12 | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 98-12 Publication Details Title: Geology of the Sleetmute C-7, C-8, D-7, and D-8 ., Miller, M.L., Layer, P.W., and Laird, G.M., 1999, Geology of the Sleetmute C-7, C-8, D-7, and D-8 ; Other Oversized Sheets Sheet 1 Geologic map of the Sleetmute C-7, C-8, D-7 and D-8 quadrangles, Horn

Major- and Trace-Element Concentrations in Rock Samples Collected in 2006 from the Taylor Mountains 1:250,000-scale Quadrangle, Alaska

USGS Publications Warehouse

Klimasauskas, Edward P.; Miller, Marti L.; Bradley, Dwight C.

2007-01-01

Introduction The Kuskokwim mineral belt of Bundtzen and Miller (1997) forms an important metallogenic region in southwestern Alaska that has yielded more than 3.22 million ounces of gold and 400,000 ounces of silver. Precious-metal and related deposits in this region associated with Late Cretaceous to early Tertiary igneous complexes extend into the Taylor Mountains 1:250,000-scale quadrangle. The U.S. Geological Survey is in the process of conducting a mineral resource assessment of this region. This report presents analytical data collected during the third year of this multiyear study. A total of 138 rock geochemistry samples collected during the 2006 field season were analyzed using the ICP-AES/MS42, ICP-AES10, fire assay, and cold vapor atomic absorption methods described in more detail below. Analytical values are provided in percent (% or pct: 1 gram per 100 grams), parts per million (ppm: 1 gram per 1,000,000 grams), or parts per billion (ppb: 1 gram per 1,000,000,000 grams) as indicated in the column heading of the data table. Data are provided for download in Excel (*.xls), comma delimited (*.csv), dBase 4 (*.dbf) and as a point coverage in ArcInfo interchange (*.e00) formats available at http://pubs.usgs.gov/of/2007/1386/.

The length of the glaciers in the world - a straightforward method for the automated calculation of glacier center lines

NASA Astrophysics Data System (ADS)

Machguth, H.; Huss, M.

2014-05-01

Glacier length is an important measure of glacier geometry but global glacier inventories are mostly lacking length data. Only recently semi-automated approaches to measure glacier length have been developed and applied regionally. Here we present a first global assessment of glacier length using a fully automated method based on glacier surface slope, distance to the glacier margins and a set of trade-off functions. The method is developed for East Greenland, evaluated for the same area as well as for Alaska, and eventually applied to all ∼200 000 glaciers around the globe. The evaluation highlights accurately calculated glacier length where DEM quality is good (East Greenland) and limited precision on low quality DEMs (parts of Alaska). Measured length of very small glaciers is subject to a certain level of ambiguity. The global calculation shows that only about 1.5% of all glaciers are longer than 10 km with Bering Glacier (Alaska/Canada) being the longest glacier in the world at a length of 196 km. Based on model output we derive global and regional area-length scaling laws. Differences among regional scaling parameters appear to be related to characteristics of topography and glacier mass balance. The present study adds glacier length as a central parameter to global glacier inventories. Global and regional scaling laws might proof beneficial in conceptual glacier models.

Extending Alaska's plate boundary: tectonic tremor generated by Yakutat subduction

USGS Publications Warehouse

Wech, Aaron G.

2016-01-01

The tectonics of the eastern end of the Alaska-Aleutian subduction zone are complicated by the inclusion of the Yakutat microplate, which is colliding into and subducting beneath continental North America at near-Pacific-plate rates. The interaction among these plates at depth is not well understood, and further east, even less is known about the plate boundary or the source of Wrangell volcanism. The drop-off in Wadati-Benioff zone (WBZ) seismicity could signal the end of the plate boundary, the start of aseismic subduction, or a tear in the downgoing plate. Further compounding the issue is the possible presence of the Wrangell slab, which is faintly outlined by an anemic, eastward-dipping WBZ beneath the Wrangell volcanoes. In this study, I performed a search for tectonic tremor to map slow, plate-boundary slip in south-central Alaska. I identified ∼11,000 tremor epicenters, which continue 85 km east of the inferred Pacific plate edge marked by WBZ seismicity. The tremor zone coincides with the edges of the downgoing Yakutat terrane, and tremors transition from periodic to continuous behavior as they near the aseismic Wrangell slab. I interpret tremor to mark slow, semicontinuous slip occurring at the interface between the Yakutat and North America plates. The slow slip region lengthens the megathrust interface beyond the WBZ and may provide evidence for a connection between the Yakutat slab and the aseismic Wrangell slab.

Preliminary Geological Map of the Ac-H-2 Coniraya Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

NASA Astrophysics Data System (ADS)

Hiesinger, H.; Pasckert, J. H.; Williams, D. A.; Crown, D. A.; Mest, S. C.; Buczkowski, D.; Schenk, P.; Scully, J. E. C.; Jaumann, R.; Roatsch, T.; Preusker, F.; Platz, T.; Nathues, A.; Hoffmann, M.; Marchi, S.; De Sanctis, M. C.; Russell, C. T.; Raymond, C. A.

2015-12-01

To better understand the geologic history of dwarf planet Ceres, the surface has been divided into 15 quadrangles that are systematically mapped on the basis of images obtained by NASA's Dawn spacecraft, which began orbiting Ceres in April 2015. We will report on preliminary mapping results for the Ac-H-2 Coniraya Quadrangle based on Framing Camera (FC) mosaics from the Dawn Approach (1.3 km/px) and Survey (415 m/px) orbits. This quadrangle is located between 21-66°N and 0-90°E and is dominated by mostly highly degraded impact craters of diameters between 50 and 200 km and clusters of small- to midsize impact craters. Color data show that this quadrangle is generally darker than most regions of the southern hemisphere. Two prominent impact craters in this quadrangle have been named Coniraya and Gaue crater, respectively. Coniraya is the largest more or less intact impact crater with a diameter of 136 km, centered at 65.8°N/40.5°E. It appears shallow and its crater rim is heavily degraded but still continuous. At the current image resolution, textural differences between the interior and exterior of the crater are not visible. With a diameter of 84 km, Gaue crater appears to be the freshest large impact crater in this quadrangle. It is located at the eastern border of the Coniraya Quadrangle with a small central peak at 30°N/85.7°E. The crater rim is quite sharp and the ejecta blanket can be traced around the crater to a distance of ~200km from the crater center. Most of the crater floor around the central peak is covered by a smooth uniform unit with a lower impact crater population than the surrounding surfaces. Color data show that this smooth unit is darker than the surrounding surfaces. A similar unit can be found on the floor of a complex cluster of 10-56 km diameter craters at 32°N/40°E. With upcoming higher resolution data we will refine our geologic map and will specifically investigate possible formation processes of these smooth units.

Geologic map of the Mount Sherman 7.5' quadrangle, Lake and Park Counties, Colorado

USGS Publications Warehouse

Bohannon, Robert G.; Ruleman, Chester A.

2013-01-01

The Mount Sherman 7.5- minute quadrangle is located along the crest of the Mosquito Range in between Leadville and Fairplay, Colorado. There are eleven 13,000-foot peaks and one fourteener, Mount Sherman, within the quadrangle. General elevations range from 10,400–14,036 feet (3,200–4,278 meters). The western half of the quadrangle primarily consists of Proterozoic granitic rocks reverse faulted over Paleozoic sedimentary rocks during the Laramide orogeny of late Cretaceous and Paleocene time. Coeval to this contractional event, sills and laccoliths of the White porphyry group (which probably includes rocks equivalent to the Pando Porphyry) were emplaced in the surrounding country rocks. Igneous activity continued into the Late Eocene with the emplacement of the Sacramento Porphyry (about 43.9 Ma) and the Gray porphyry group (about 36.7 Ma), and as young as 29 Ma to the north within the Climax quadrangle. With the inception of the Rio Grande rift within the region, the Paleozoic sedimentary rocks and Late Cretaceous to early Oligocene igneous rocks were extensionally faulted and tilted to the east. This resulted in the present 20–30 degree dip-slope of these rocks on top of Proterozoic basement rocks within the eastern half of the quadrangle. This extensional regime has continued well into the Pliocene. Within the southwestern quadrant, suspicious lineaments, alignment of springs, and continuous, measureable escarpments provide reasonable evidence for Quaternary tectonic activity along the western flank of the range. Pleistocene glaciers have dramatically sculpted the region, providing exceptional exposure of the region’s bedrock and structure.

Digital image processing techniques for detecting surface alteration - An application on the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983

USGS Publications Warehouse

York, James; Wilson, Frederic H.; Gamble, Bruce M.

1985-01-01

The tectonic evolution of the Alaska Peninsula makes it a likely area for the discovery of significant mineral deposits. However, because of problems associated with remoteness and poor weather, little detailed mineral exploration work has been carried on there. This study focuses on using Landsat multispectral scanner data for the Port Moller, Stepovak Bay, and Simeon of Island Quadrangles to detect surface alteration, probably limonitic (iron oxide staining) and(or) argillic (secondary clay minerals) in character, that could be indicative of mineral deposits. The techniques used here are useful for mapping deposits that have exposed surface alteration of at least an hectare, the approximate spatial resolution of the Landsat data. Virtually cloud-free Landsat coverage was used, but to be detected, the alteration area must also be unobscured by vegetation. Not all mineral deposits will be associated with surface alteration, and not all areas of surface alteration will have valuable mineral deposits.

Airborne gamma-ray spectrometer and magnetometer survey: Chico quadrangle, California. Final report

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

Not Available

1981-05-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Chico, California, map area. Traverse lines were flown in an east-west direction at a line spacing of three. Tie lines were flown north-south approximately twelve miles apart. A total of 16,880.5more » line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 3026.4 line miles are in the quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.« less

Preliminary geologic map of the San Guillermo Mountain Quadrangle, Ventura County, California

USGS Publications Warehouse

Minor, S.A.

1999-01-01

New 1:24,000-scale geologic mapping in the Cuyama 30' x 60' quadrangle, in support of the USGS Southern California Areal Mapping Project (SCAMP), is contributing to a more complete understanding of the stratigraphy, structure, and tectonic evolution of the complex junction area between the NW-striking Coast Ranges and EW-striking western Transverse Ranges. The 1:24,000-scale geologic map of the San Guillermo Mountain quadrangle is one of six contiguous 7 1/2' quadrangle geologic maps in the eastern part of the Cuyama map area being compiled for a more detailed portrayal and reevaluation of geologic structures and rock units shown on previous geologic maps of the area (e.g., Dibblee, 1979). The following observations and interpretations are based on the new San Guillermo Mountain geologic compilation: (1) The new geologic mapping in the northern part of the San Guillermo Mountain quadrangle allows for reinterpretation of fault architecture that bears on potential seismic hazards of the region. Previous mapping had depicted the eastern Big Pine fault (BPF) as a northeast-striking, sinistral strike-slip fault that extends for 30 km northeast of the Cuyama River to its intersection with the San Andreas fault (SAF). In contrast the new mapping indicates that the eastern BPF is a thrust fault that curves from a northeast strike to an east strike, where it is continuous with the San Guillermo thrust fault, and dies out further east about 15 km south of the SAF. This redefined segment of the BPF is a south-dipping, north-directed thrust, with dominantly dip slip components (rakes > 60 deg.), that places Middle Eocene marine rocks (Juncal and Matilija Formations) over Miocene through Pliocene(?) nonmarine rocks (Caliente, Quatal, and Morales Formations). Although a broad northeast-striking fault zone, exhibiting predominantly sinistral components of slip (rakes < 45 deg.), extends to the SAF as previously mapped, the fault zone does not connect to the southwest with the BPF but instead curves into a southwest-directed thrust fault system a short distance north of the BPF. Oligocene to Pliocene(?) nonmarine sedimentary and volcanic rocks of the Plush Ranch, Caliente, and Morales(?) Formations are folded on both sides of this fault zone (informally named the Lockwood Valley fault zone [LVFZ] on the map). South-southeast of the LVFZ overturned folds have southward vergence. Several moderate-displacement (< 50 m), mainly northwest-dipping thrust and reverse faults, exhibiting mostly sinistral-oblique slip, flank and strike parallel to the overturned folds. The fold vergence and thrust direction associated with the LVFZ is opposite to that of the redefined BPF, providing further evidence that the two faults are distinct structures. These revised fault interpretations bring into question earlier estimates of net sinistral strike-slip displacement of as much as 13 km along the originally defined eastern BPF, which assumed structural connection with the LVFZ. Also, despite sparse evidence for repeated Quaternary movement on the LVFZ (e.g., Dibblee, 1982), the potential for a large earthquake involving coseismic slip on both the LVFZ and the central BPF to the southwest may not be as great as once believed. (2) Several generations of Pleistocene and younger dissected alluvial terrace and fan deposits sit at various levels above modern stream channels throughout the quadrangle. These deposits give testimony to the recent uplift and related fault deformation that has occurred in the area. (3) A vast terrane of Eocene marine sedimentary rocks (Juncal and Matilija Formations and Cozy Dell Shale) exposed south of the Big Pine fault forms the southern two-thirds of the San Guillermo Mountain quadrangle. Benthic foraminifers collected from various shale intervals within the Juncal Formation indicate a Middle Eocene age (Ulatisian) for the entire formation (K. McDougall, unpub. data, 1998) and deposition at paleodepths as great as 2,000 m (i.e., lowe

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

Nakamura, K.; Jacob, K.

Flank eruptions of polygenetic volcanoes are regarded as surface expressions of radial dikes. Therefore, the approximate pattern of radial dikes is revealed by the distribution of sites of flank eruptions. Bending of radial dikes into a preferred orientation reveals the maximum horizontal compressive stress axis. The Aleutian and Alaskan volcanoes are studied using this concept and 28 orientations of the maximum horizontal compressive stress axis are obtained. Combined with the orientation of similar quality obtained from active faults in central Alaska the trajectories of the maximum horizontal stress for the entire area during recent 10,000 to 100,000 years or longermore » is depicted. Along the Aleutian-Alaska volcanic belt, the maximum horizontal compression parallels the direction of relative motion between the North American and Pacific plates. Seven roughly east-westerly orientations are obtained from west Alaskan and Bering Sea volcanoes. In central Alaska, the trajectories spread north-westward in a fan shape with axis of symmetry in a N25/sup 0/W direction passing through the easternmost part of the Aleutian trench. The trajectories continue westward onto the Bering Sea shelf with a generally westerly trend. The overall pattern of orientations of maximum horizontal compressive stresses seems to be explained by the convergent plate motions along. An exception is the high--angle relationship between the maximum horizontal stress orientation in the central Aleutians and the immediate back-arc region, which suggests that in the back-arc region the tectonic stress system has a different origin probably at considerable depth beneath the crust.« less

Detrital zircon geochronology of some neoproterozoic to triassic rocks in interior alaska

USGS Publications Warehouse

Bradley, D.C.; McClelland, W.C.; Wooden, J.L.; Till, A.B.; Roeske, S.M.; Miller, M.L.; Karl, Susan M.; Abbott, J.G.

2007-01-01

We report 777 U-Pb SHRIMP detrital zircon ages from thirteen sandstones and metasandstones in interior Alaska. About sixty grains per sample were analyzed; typically, half to three-fourths of these were concordant within ?? 10%. Farewell terrane. Two quartzites were collected from Ruby quadrangle and a third from Taylor Mountains quadrangle. All three are interpreted to represent a low stratigraphic level in the Nixon Fork platform succession; the samples from Ruby quadrangle are probably late Neoproterozoic, and the sample from Taylor Mountains quadrangle is probably Cambrian in age. The youngest detrital zircon in any of the three is 851 Ma. The two Ruby quadrangle samples area almost identical: one has a major age cluster at 1980-2087 and minor age clusters at 944-974 and 1366-1383 Ma; the other has a major age cluster at 1993-2095 Ma and minor age clusters at 912-946 and 1366-1395 Ma. The Taylor Mountains sample shows one dominant peak at 1914-2057 Ma. Notably absent are zircons in the range 1800-1900 Ma, which are typical of North American sources. The detrital zircon populations are consistent with paleontological evidence for a peri- Siberian position of the Farewell terrane during the early Paleozoic. Mystic subterrane of the Farewell terrane. Three graywackes from flysch of the Mystic subterrane, Talkeetna quadrangle, were sampled with the expectation that all three were Pennsylvanian. Asample from Pingston Creek is Triassic (as revealed by an interbedded ash dated at ca. 223 Ma) and is dominated by age clusters of 341-359 and 1804-1866 Ma, both consistent with a sediment source in the Yukon-Tanana terrane. Minor age clusters at 848-869 and 1992-2018 Ma could have been sourced in the older part of the Farewell terrane. Still other minor age clusters at 432-461, 620-657, 1509-1536, and 1627-1653 Ma are not readily linked to sources that are now nearby. Asample from Surprise Glacier is mid-Mississippian or younger. Adominant age cluster at 1855-1883 and a minor one at 361-367 Ma could have been sourced in the Yukon-Tanana terrane. Other age clusters at 335-336, 457-472, 510-583, and 1902-1930 have no obvious nearby source. A sample from Ripsnorter Creek is Silurian or younger. The dominant age cluster at 937-981 Ma and a minor one at 2047-2077 Ma could have been sourced in the Farewell terrane. Minor age clusters at 1885-1900 and 2719-2770 Ma could have been sourced in the Yukon-Tanana terrane. Other age clusters at 429 490, 524-555, 644-652, 1023-1057, 1131-1185, and 1436-1445 Ma have no obvious nearby source. The so-called Mystic subterrane is structurally complex and would appear to include more than one Phanerozoic turbidite succession; more mapping and detrital zircon geochronology are needed. Wickersham and Yukon-Tanana terranes. A grit from Wickersham terrane in Tanana quadrangle and a grit from Yukon-Tanana terrane in Talkeetna quadrangle have similar, exclusively Precambrian detrital zircon populations, supporting previous correlations. The Wickersham sample has major age clusters at 1776-1851 and 1930-1964 Ma, and the youngest grain is 1198 Ma. The Yukon-Tanana grit has a major age cluster at 1834-1867 Ma, and the youngest grain is 1789 Ma. A North American source has been previously proposed, and this seems likely based on detrital zircon data. Ruby terrane and Minook Complex. Detrital zircons from quartzites in the Ruby terrane show two quite different age patterns. Asample from the Bear Creek area of Tanana quadrangle has detrital zircon ages that are similar to those from the Wickersham and Yukon-Tanana grits. The dominant age clusters are 1823-1856 and 1887-1931 Ma. In contrast, a quartzite from nearby Senatis Mountain (Tanana quadrangle) yielded a completely different detrital zircon age spectrum, featuring a broad peak with no significant gaps from 1024 to 1499 Ma and a minor age cluster at 1671-1695 Ma. The youngest concordant zircon is 1024 ?? 6 Ma. Aquartzite from the Minook Complex, a sliver along t

The Conterminous United States Mineral Appraisal Program; background information to accompany folio of geologic, geochemical, geophysical, and mineral resources maps of the Tonopah 1 by 2 degree Quadrangle, Nevada

USGS Publications Warehouse

John, David A.; Nash, J.T.; Plouff, Donald; Whitebread, D.H.

1991-01-01

The Tonopah 1 ? by 2 ? quadrangle in south-central Nevada was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The selected bibliography lists references to the geology, geochemistry, geophysics, and mineral deposits of the Tonopah 1 ? by 2 ? quadrangle.

Geologic map of the Wenatchee 1:100,000 Quadrangle, central Washington

USGS Publications Warehouse

Tabor, R.W.; Waitt, R.B.; Frizzell, V.A.; Swanson, D.A.; Byerly, G.R.; Bentley, R.D.

1982-01-01

The rocks and deposits within the Wenatchee quadrangle can be grouped into six generalized units: (1) Precambrian(?) Swakane Biotite Gneiss in the northeastern part of the quadrangle and the probable Jurassic low-grade metamorphic suite, mostly composed of the Easton Schist, in the southwestern part; (2) the Mesozoic Ingalls Tectonic Complex; (3) the Mesozoic Mount Stuart batholith; (4) lower and middle Tertiary nonmarine sedimentary and volcanic rocks; (5) Miocene basalt flows and interbedded epiclastic rocks constituting part of the Columbia River Basalt Group and interbedded silicic volcaniclastic rocks of the Ellensburg Formation; and (6) Pliocene to Holocene alluvium, glacial, flood, and mass-wastage deposits.

27 CFR 9.156 - Diablo Grande.

Code of Federal Regulations, 2013 CFR

2013-04-01

... section 8, Township 6 South, Range 7 East (T. 6S., R. 7E.) on the Patterson Quadrangle U.S.G.S. map. (1... proceed due south past Copper Mountain in section 16, T. 6S., R. 6E., to Mikes Peak in section 4, T. 7S...

27 CFR 9.156 - Diablo Grande.

Code of Federal Regulations, 2012 CFR

2012-04-01

... section 8, Township 6 South, Range 7 East (T. 6S., R. 7E.) on the Patterson Quadrangle U.S.G.S. map. (1... proceed due south past Copper Mountain in section 16, T. 6S., R. 6E., to Mikes Peak in section 4, T. 7S...

27 CFR 9.156 - Diablo Grande.

Code of Federal Regulations, 2014 CFR

2014-04-01

... section 8, Township 6 South, Range 7 East (T. 6S., R. 7E.) on the Patterson Quadrangle U.S.G.S. map. (1... proceed due south past Copper Mountain in section 16, T. 6S., R. 6E., to Mikes Peak in section 4, T. 7S...

50 CFR 18.122 - In what specified geographic region does this subpart apply?

Code of Federal Regulations, 2010 CFR

2010-10-01

..., Alaska, and includes all Alaska coastal areas, State waters, and Outer Continental Shelf waters east of that line to the Canadian border and an area 25 miles inland from Barrow on the west to the Canning River on the east. The Arctic National Wildlife Refuge is not included in the area covered by this...

Implementing Global Studies Curriculum through International School-to-School Partnerships.

ERIC Educational Resources Information Center

Parrett, William H.; Hartsock, Jerry

Alaska's geographic position at the crossroads between East and West and heavy trade with Japan have sparked widespread interest among Alaskans in education about Pacific Rim countries. In 1985 the Alaska Sister Schools Network was formed by the Alaska Department of Education and the University of Alaska, Fairbanks, to create opportunities for…

77 FR 41754 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... program in the Southeast Alaska purse seine salmon fishery. NMFS conducted a referendum to approve the..., Chief, Financial Services Division, NMFS, Attn: SE Alaska Purse Seine Salmon Buyback, 1315 East-West...

Publications - PIR 2008-1G | Alaska Division of Geological & Geophysical

Science.gov Websites

Wartes, M.A., and Decker, P.L., eds., Preliminary results of recent geologic field investigations in the Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2008-1G Publication Details Title: Turonian-Campanian strata east of the Trans-Alaska

Bedrock geologic map of the Uxbridge quadrangle, Worcester County, Massachusetts, and Providence County, Rhode Island

USGS Publications Warehouse

Walsh, Gregory J.

2014-01-01

The bedrock geology of the 7.5-minute Uxbridge quadrangle consists of Neoproterozoic metamorphic and igneous rocks of the Avalon zone. In this area, rocks of the Avalon zone lie within the core of the Milford antiform, south and east of the terrane-bounding Bloody Bluff fault zone. Permian pegmatite dikes and quartz veins occur throughout the quadrangle. The oldest metasedimentary rocks include the Blackstone Group, which represents a Neoproterozoic peri-Gondwanan marginal shelf sequence. The metasedimentary rocks are intruded by Neoproterozoic arc-related plutonic rocks of the Rhode Island batholith. This report presents mapping by G.J. Walsh. The complete report consists of a map, text pamphlet, and GIS database. The map and text pamphlet are available only as downloadable files (see frame at right). The GIS database is available for download in ESRI™ shapefile and Google Earth™ formats, and includes contacts of bedrock geologic units, faults, outcrops, structural geologic information, geochemical data, and photographs.

Mines, prospects, and occurrences of metallic (excluding gold), pegmatite, and rare-earth mineral commodities in the Greenville 1 degree by 2 degrees Quadrangle, South Carolina, Georgia, and North Carolina

USGS Publications Warehouse

D'Agostino, John P.; Zupan, Alan Jon; Maybin, Arthur H.; Abrams, Charlotte E.; German, Jerry M.

1994-01-01

All of the known mines, prospects, and occurrences of metallic (excluding gold, pegmatite, and rare-earth mineral commodities for the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order for each county (fig. 1), the map number of each item, which correlates and locates the item on the accompanying Greenville 1° x 2° quadrangle map. The known name of the feature; the 7.5' topographic map on the which the commodity site is located; the Universal Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5' topographic map; the commodity; remarks; and references are also listed. Some locations are known, but many sites are not verified and their locations are only approximate. References are listed in References Cited and referred to by number to save space.

Geologic framework and evidence for neotectonism in the epicentral area of the 2011 Mineral, Virginia, earthquake

USGS Publications Warehouse

Burton, William C.; Harrison, Richard W.; Spears, David B.; Evans, Nicholas H.; Mahan, Shannon

2015-01-01

The epicenters of the main shock and associated aftershocks of the 2011 moment magnitude, Mw 5.8 Mineral, Virginia (USA), earthquake, and the updip projection of the possible fault plane that triggered the quakes, are contained in the areas of 2 adjoining 7.5′ quadrangles in the central Virginia Piedmont. These quadrangles have therefore been the focus of concentrated geologic study in the form of bedrock and surficial mapping and near-surface trenching in order to identify potential seismogenic structures. Bedrock mapping has outlined a series of northeast-southwest–trending lithologic belts that include the Ordovician Chopawamsic and Quantico Formations, the narrow neck of the Late Ordovician Ellisville pluton, and mélange zone III of the Mine Run Complex. The region was affected by at least two ductile deformational events, one in the early Paleozoic that was broadly synchronous with the intrusion of the pluton, and one later in the Paleozoic. The earlier deformation produced the Quantico synclinorium and other regional folds, and the later deformation produced faults with associated high-strain zones. Two of these faults have been trenched at their intersection along the east-dipping eastern contact of the Ellisville neck, near where the causative fault for the earthquake projects to the surface. The trenches have exposed abundant evidence of post-Paleozoic fracturing and faulting, including brecciated quartz-tourmaline veins, slickensided thrust and strike-slip faults, and clay-filled fractures. Fluvial and colluvial gravels that overlie these brittle structures have yielded optically stimulated luminescence ages ranging from ca. 27 to 10 ka. These structures are likely representative of surface features associated with Quaternary earthquakes in the Central Virginia seismic zone.

Aerial gamma ray and magnetic survey: Powder River II Project, Gillette Quadrangle, Wyoming. Final report

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

Not Available

1979-04-01

The Gillette quadrangle in northeastern Wyoming and western South Dakota contains approximately equal portions of the Powder River Basin and the Black Hills Uplift. In these two structures, a relatively thick sequence of Paleozoic and Mesozoic strata represent nearly continuous deposition over the Precambrian basement complex. The Powder River Basin also contains a thick sequence of early Tertiary rocks which cover about 50% of the surface. A stratigraphic sequence from Upper Cretaceous to Precambrian is exposed in the Black Hills Uplift to the east. Magnetic data apparently illustrate the relative depth to the Precambrian crystalline rocks, but only weakly definemore » the boundary between the Powder River Basin and the Black Hills Uplift. The positions of some small isolated Tertiary intrusive bodies in the Black Hills Uplift are relatively well expressed. The Gillette quadrangle has been productive in terms of uranium mining, but its current status is uncertain. The producing uranium deposits occur within the Lower Cretaceous Inyan Kara Group and the Jurassic Morrison Formation in the Black Hills Uplift. Other prospects occur within the Tertiary Wasatch and Fort Union Formations in the Pumpkin Buttes - Turnercrest district, where it extends into the quadrangle from the Newcastle quadrangle to the south. These four formations, all predominantly nonmarine, contain all known uranium deposits in the Gillette quadrangle. A total of 108 groups of sample responses in the uranium window constitute anomalies as defined in Volume I. The anomalies are most frequently found in the Inyan Kara-Morrison, Wasatch and Fort Union Formations. Many anomalies occur over known mines or prospects. Others may result from unmapped uranium mines or areas where material other than uranium is mined. The remainder may relate to natural geologic features.« less

Geologic map of the Orchard 7.5' quadrangle, Morgan County, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Slate, Janet L.; Hanson, Paul R.; Brandt, Theodore R.

2015-01-01

The Orchard 7.5' quadrangle is located along the South Platte River corridor on the semi-arid plains of eastern Colorado, and contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated through environmental changes from the Pleistocene to the present. The South Platte River, originating high in the Colorado Front Range, has played a major role in shaping the geology of the quadrangle, which is situated downstream of where the last of the major headwater tributaries (St. Vrain, Big Thompson, and Cache la Poudre) join the river. Recurrent glaciation (and deglaciation) of basin headwaters affected river discharge and sediment supply far downstream, influencing alluvium deposition and terrace formation in the Orchard quadrangle. Kiowa and Bijou Creeks, unglaciated tributaries originating east of the Front Range also have played a major role by periodically delivering large volumes of sediment to the river during flood events, which may have temporarily dammed the river. Eolian sand deposits of the Greeley (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of drought. With the onset of irrigation during historic times, the South Platte River has changed from a broad, shallow, and sandy braided river with highly seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge. Along this reach, the river has incised into Upper Cretaceous Pierre Shale, which, although buried by alluvial deposits in Orchard quadrangle, is locally exposed downstream along the South Platte River bluff near the Bijou Creek confluence, in some of the larger draws, and along Wildcat Creek.

Geochemical map of the North Fork John Day River Roadless Area, Grant County, Oregon

USGS Publications Warehouse

Evans, James G.

1986-01-01

The North Fork John Day River Roadless Area comprised 21,210 acres in the Umatilla and Wallowa-Whitman National Forests, Grant County, Oregon, about 30 miles northwest of Baker, Oregon. The irregularly shaped area extends for about 1 mile on both sides of a 25-mile segment of the North Fork John Day River from Big Creek on the west to North Fork John Day Campground on the east. Most of the roadless area is in the northern half of the Desolation Butte 15-minute quadrangle. The eastern end of the area is in parts of the Granite and Trout Meadows 7½-minute quadrangles.

Publications - GMC 412 | Alaska Division of Geological & Geophysical

Science.gov Websites

Spectrometer) data of core from the East Simpson Test Well #1, Ikpikpuk Test Well #1, Inigok Test Well #1, and Peard Test Well #1 wells Authors: Gottlieb, E. Publication Date: Nov 2012 Publisher: Alaska Division of , LaserChron (Nu Instruments High Resolution ICP Mass Spectrometer) data of core from the East Simpson Test

Geologic map of the Cook Inlet region, Alaska, including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale quadrangles

USGS Publications Warehouse

Wilson, Frederic H.; Hults, Chad P.; Schmoll, Henry R.; Haeussler, Peter J.; Schmidt, Jeanine M.; Yehle, Lynn A.; Labay, Keith A.

2012-01-01

In 1976, L.B. Magoon, W.L. Adkinson, and R.M. Egbert published a major geologic map of the Cook Inlet region, which has served well as a compilation of existing information and a guide for future research and mapping. The map in this report updates Magoon and others (1976) and incorporates new and additional mapping and interpretation. This map is also a revision of areas of overlap with the geologic map completed for central Alaska (Wilson and others, 1998). Text from that compilation remains appropriate and is summarized here; many compromises have been made in strongly held beliefs to allow construction of this compilation. Yet our willingness to make interpretations and compromises does not allow resolution of all mapping conflicts. Nonetheless, we hope that geologists who have mapped in this region will recognize that, in incorporating their work, our regional correlations may have required some generalization or lumping of map units. Many sources were used to produce this geologic map and, in most cases, data from available maps were combined, without generalization, and new data were added where available. A preliminary version of this map was published as U.S. Geological Survey Open-File Report 2009–1108. The main differences between the versions concern revised mapping of surfical deposits in the northern and eastern parts of the map area. Minor error corrections have been made also.

Geologic map of southwestern Sequoia National Park, Tulare County, California

USGS Publications Warehouse

Sisson, Thomas W.; Moore, James G.

2013-01-01

This map shows the geology of 675 km2 (260 mi2) on the west slope of the Sierra Nevada, California, mainly in Sequoia National Park and Sequoia National Forest. It was produced by the U.S. Geological Survey (USGS) at the request of the National Park Service to complete the geologic map coverage of Kings Canyon and Sequoia National Parks. The area includes the Mineral King 15’ topographic quadrangle (sheet 1) and strips along the east and northeast edges of the Kaweah 15’ topographic quadrangle (sheet 2), both in Tulare County. Mapping was performed mainly on the 1:24,000-scale Mineral King, Silver City, Quinn Peak, Moses Mountain, Case Mountain, and Dennison Peak 7.5’ topographic quadrangle bases. Rocks within the study area are chiefly Cretaceous granites and granodiorites of the Sierra Nevada batholith that intruded coherent masses of Mesozoic metasedimentary and metavolcanic rocks. Quaternary till and talus are the principal surficial deposits, with the exception of a large bouldery alluvial apron near the southwest corner of the map area. The study area includes the headwaters of the Kaweah River (East and South Forks), Tule River (North Fork and North Fork of the Middle Fork), and the Little Kern River. Relief is considerable, with elevations spanning from 1,500 feet along the Middle Fork Kaweah River to 12,432 feet at the summit of Florence Peak along the crest of the Great Western Divide.

Geologic map of the Valley Mountain 15’ quadrangle, San Bernardino and Riverside Counties, California

USGS Publications Warehouse

Howard, Keith A.; Bacheller, John; Fitzgibbon, Todd T.; Powell, Robert E.; Allen, Charlotte M.

2013-01-01

The Valley Mountain 15’ quadrangle straddles the Pinto Mountain Fault, which bounds the eastern Transverse Ranges in the south against the Mojave Desert province in the north. The Pinto Mountains, part of the eastern Transverse Ranges in the south part of the quadrangle expose a series of Paleoproterozoic gneisses and granite and the Proterozoic quartzite of Pinto Mountain. Early Triassic quartz monzonite intruded the gneisses and was ductiley deformed prior to voluminous Jurassic intrusion of diorite, granodiorite, quartz monzonite, and granite plutons. The Jurassic rocks include part of the Bullion Mountains Intrusive Suite, which crops out prominently at Valley Mountain and in the Bullion Mountains, as well as in the Pinto Mountains. Jurassic plutons in the southwest part of the quadrangle are deeply denuded from midcrustal emplacement levels in contrast to supracrustal Jurassic limestone and volcanic rocks exposed in the northeast. Dikes inferred to be part of the Jurassic Independence Dike Swarm intrude the Jurassic plutons and Proterozoic rocks. Late Cretaceous intrusion of the Cadiz Valley Batholith in the northeast caused contact metamorphism of adjacent Jurassic plutonic rocks. The Tertiary period saw emplacement of basanitoid basalt at about 23 Ma and deposition of Miocene and (or) Pliocene ridge-capping gravels. An undated east-dipping low-angle normal fault zone in the Pinto Mountains drops hanging-wall rocks eastward and may account for part of the contrast in uplift history across the quadrangle. The eastern Transverse Ranges are commonly interpreted as severely rotated clockwise tectonically in the Neogene relative to the Mojave Desert, but similar orientations of Jurassic dike swarms suggest that any differential rotation between the two provinces is small in this quadrangle. The late Cenozoic Pinto Mountain Fault and other strike-slip faults cut Quaternary deposits in the quadrangle, with two northwest-striking faults cutting Holocene deposits. Geographic Information System and metadata on most geologic features are available on the Geologic map of the Sheep Hole Mountains 30’ by 60’ quadrangle, U.S. Geological Survey map MF–2234, scale 1:100,000, available at http://pubs.usgs.gov/mf/2002/2344/.

Seasonal movements of the Short-eared Owl (Asio flammeus) in western North America as revealed by satellite telemetry

USGS Publications Warehouse

Johnson, James A.; Booms, Travis L.; DeCicco, Lucas H.; Douglas, David C.

2017-01-01

The Short-eared Owl (Asio flammeus) is a widespread raptor whose abundance and distribution fluctuates in response to the varying amplitudes of its prey, which are predominately microtines. Previous efforts to describe the seasonal movements of Short-eared Owls have been hindered by few band recoveries and the species' cryptic and irruptive behavior. We attached satellite transmitters to adult Short-eared Owls at breeding areas in western and interior Alaska in June 2009 and July 2010, and tracked their movements for up to 19 mo. Owls initiated long-distance southward movements from Alaska and most followed a corridor east of the Rocky Mountains into the Prairie provinces and Great Plains states. Four owls followed a coastal route west of the Rocky Mountains, including one owl that crossed the Gulf of Alaska. Completed autumn migration distances ranged from 3205–6886 km (mean = 4722 ± 1156 km [SD]). Wintering areas spanned 21° of latitude from central Montana to southern Texas, and 24° of longitude from central California to western Kansas. Subsequent seasonal migrations were generally northward in spring and southward in autumn; these movements were comparatively short-distance (mean = 767.5 ± 517.4 km [SD]) and the owls exhibited low site fidelity. The Short-eared Owls we tracked from two relatively local breeding areas in Alaska used a patchwork of diverse open habitats across a large area of North America, which highlights that effective conservation of this species requires a collaborative, continental-scale focus.

Elevations and distances in the United States

USGS Publications Warehouse

,

1991-01-01

The information in this booklet was compiled to answer inquiries received by the U.S. Geological Survey from students; teachers; writers; editors; publishers of encyclopedias, almanacs, and other reference books; and people in many other fields of work. The elevations of features and distances between points in the United States were determined from surveys and topographic maps of the U.S. Geological Survey or obtained from other sources. In most cases, the elevations were determined from surveys and from 1:24,000- and 1:25,000-scale, 7.5-minute topographic quadrangle maps. In Alaska, information was taken from 1:63,360-scale, 15-minute topographic quadrangle maps. In a few cases, data were obtained from older, 1:62,500-scale, 15-minute maps; these maps are being replaced with larger-scale 7.5-minute coverage. Further information about U.S. Geological Survey products can be obtained from: U.S. Geological Survey, Earth Science Information Center, 507 National Center, Reston, VA 22092 or phone 703-860-6045.

Publications - RI 2013-2 | Alaska Division of Geological & Geophysical

Science.gov Websites

content DGGS RI 2013-2 Publication Details Title: Surficial-geologic map of the Livengood area, central Burns, P.A.C., 2013, Surficial-geologic map of the Livengood area, central Alaska: Alaska Division of Sheet 1 Surficial-geologic map of the Livengood area, central Alaska, scale 1:50,000 (30.0 M) Digital

Preliminary geologic map of the Winchester 7.5' quadrangle, Riverside County, California

USGS Publications Warehouse

Morton, Douglas M.

2003-01-01

The Winchester quadrangle is located in the northern part of the Peninsular Ranges Province within the central part of the Perris block, a relatively stable, rectangular in plan view, area located between the Elsinore and San Jacinto fault zones (see location map). The quadrangle is underlain by Cretaceous and older basement rocks. Cretaceous plutonic rocks are part of the composite Peninsular Ranges batholith, which indicates wide variety of granitic rocks, ranging from granite to gabbro. Parts of three major plutonic complexes are within the quadrangle, the Lakeview Mountains pluton, the Domenigoni Valley pluton and the Paloma Valley ring complex. In the northern part of the quadrangle is the southern part of the Lakeview Mountains pluton, a large composite body, most of which lies in the quadrangle to the north. In the center part of the quadrangle is the eastern part of the Domenigoni Valley pluton, which consists of massive biotite-hornblende granodiorite and tonalite; some tonalite in the southern part of the pluton has a relatively pronounced foliation produced by oriented biotite and hornblende. Common to abundant equant-shaped, mafic inclusions occur through out the pluton except in the outermost part where inclusions are absent. The pluton was passively emplaced by piecemeal stoping of a variety of older rocks and the eastern contact is well exposed in the quadrangle. Associated with the Domenigoni Valley pluton is a swarm of latite dikes; the majority of these dikes occur in the Winchester quadrangle, but they extend into the Romoland quadrangle to the west. The latite dikes intrude both the pluton and adjacent metamorphic rocks, most are foliated, and most have a well developed lineation defined by oriented biotite and/or hornblende crystals. Dikes intruding the pluton were emplaced in northwest striking joints; and dikes intruding the metamorphic rocks were emplaced along foliation planes. In the eastern part of the quadrangle a Cretaceous age suture juxtaposes low-metamorphic grade Mesozoic rocks against high-metamorphic grade gneissic-textured Mesozoic rocks. Juxtaposition occurred when the high-metamorphic grade rocks were at upper amphibolite grade temperatures, and produced a steep thermal gradient in the low-metamorphic grade Mesozoic rocks. Age of suturing and attendant metamorphism, based on metamorphic mineral ages, is about 100 Ma (L. Snee, personal communication, 2002). The suture zone appears to vary in thickness, and includes within it a number of metadunite bodies and related rocks. Prebatholithic rocks of Mesozoic age include a wide variety of sedimentary rocks of greenschist or lower metamorphic grade, in the western and central part of the quadrangle, and upper amphibolite grade near the eastern edge of the quadrangle. The metamorphic grade increases from greenschist to upper amphibolite grade over a distance of less than two miles; andalusite and sillimanite isograds are closely spaced near the suture. Metamorphism was Buchan type of relatively high temperature and relatively low pressure (Schwarcz, 1969). Common lithologies of the low metamorphic grade suite include phyllite, lithic greywacke, impure quartzite, meta-arkose, and interlayered quartzite and phyllite. Most of the layering and foliation in the metamorphic rocks is the result of intense structural transposition. Relic bedding appears to be restricted to very local occurrences in hinges of slip folds. The upper amphibolite grade, gneissic-textured Mesozoic rocks consist of sillimanite-biotite gneiss, black amphibolite, and impure quartzite. Anatectic gneiss containing igneous textured segregations of quartz and feldspar is commonly inter leaved with biotite gneiss.

Environmental geochemical study of Red Mountain--an undisturbed volcanogenic massive sulfide deposit in the Bonnifield District, Alaska range, east-central Alaska: Chapter I in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

Eppinger, Robert G.; Briggs, Paul H.; Dusel-Bacon, Cynthia; Giles, Stuart A.; Gough, Larry P.; Hammarstrom, Jane M.; Hubbard, Bernard E.

2007-01-01

Water samples with the lowest pH values, highest specific conductances, and highest major- and trace-element concentrations are from springs and streams within the quartz-sericite-pyrite alteration zone. Aluminum, As, Cd, Co, Cu, Fe, Mn, Ni, Pb, Y, and particularly Zn and the REEs are all found in high concentrations, ranging across four orders of magnitude. Waters collected upstream from the alteration zone have near-neutral pH values, lower specific conductances, lower metal concentrations, and measurable alkalinities. Water samples collected downstream of the alteration zone have pH values and metal concentrations intermediate between these two extremes. Stream sediments are anomalous in Zn, Pb, S, Fe, Cu, As, Co, Sb, and Cd relative to local and regional background abundances. Red Mountain Creek and its tributaries do not support, and probably never have supported, significant megascopic faunal aquatic life.

27 CFR 9.169 - Red Hills Lake County.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-foot contour line with the section 17 east boundary line, and continue for about 0.45 miles along the...-foot elevation line (Kelseyville Quadrangle); then (18) Proceed about 1.35 miles straight easterly to... 4, T12N, R7W, proceed approximately 0.1 miles due south along the common section line to its...

27 CFR 9.169 - Red Hills Lake County.

Code of Federal Regulations, 2010 CFR

2010-04-01

... intersection with the 1,400-foot contour line, section 3, T12N, R7W (Clearlake Highlands Quadrangle); then (2) Proceed east-southeasterly along the meandering 1,400-foot contour line onto the Lower Lake map south of Anderson Flat, then reverse direction with the contour line and continue westerly, leaving the Lower Lake...

27 CFR 9.169 - Red Hills Lake County.

Code of Federal Regulations, 2011 CFR

2011-04-01

... intersection with the 1,400-foot contour line, section 3, T12N, R7W (Clearlake Highlands Quadrangle); then (2) Proceed east-southeasterly along the meandering 1,400-foot contour line onto the Lower Lake map south of Anderson Flat, then reverse direction with the contour line and continue westerly, leaving the Lower Lake...

Geological Map of the Fredegonade (V-57) Quadrangle, Venus: Status Report

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Head, J. W.

2010-01-01

The Fredegonde quadrangle (V-57; 50-75degS, 60-120degE, Fig. 1) corresponds to the northeastern edge of Lada Terra and covers a broad area of the topographic province of midlands (0-2 km above MPR [1,2]). This province is most abundant on Venus and displays a wide variety of units and structures [3-11]. The sequence of events that formed the characteristic features of the midlands is crucially important in understanding of the timing and modes of evolution of this topographic province. Topographically, the Fredegonde quadrangle is within a transition zone between the elevated portion of Lada Terra to the west (Quetzalpetlatl-Boala Coronae rise, approx.3.5 km) and the lowland of Aino Planitia to the north and northeast (approx.-0.5 km). This transition is one of the key features of the V-57 quadrangle. In this respect the quadrangle resembles the region of V-4 quadrangle [12] that shows transition between the midlands and the lowlands of Atalanta Planitia. One of the main goals of our mapping within the V-57 quadrangle is comparison of this region with the other transitional topographic zones such as quadrangles V-4 and V-3 [13]. The most prominent features in the V-57 quadrangle are linear deformational zones of grooves and large coronae. The zones characterize the central and NW portions of the map area and represent broad (up to 100s of km wide) ridges that are 100s of m high. Morphologically and topographically, these zones are almost identical to the groove belt/corona complexes at the western edge of Atalanta Planitia [12]. Within the Fredegonde area, however, the zones are oriented at high angles to the general trend of elongated Aino Planitia, whereas within the V-4 quadrangle they are parallel to the edge of Atalanta Planitia. Relatively small (100s of km across, 100s of m deep) equidimensional basins occur between the corona-groove-chains in the area of V-57 quadrangle. These basins are similar to those that populate the area of the V-3 quadrangle [13]. Broad regional plains cover the surface of the basins in both regions. In contrast to Fredegonde, the area of the V-3 quadrangle displays a greater diversity of units and features [13]. Here we describe units that make up the surface within the V-57 quadrangle and present a summary of our geological map that shows the areal distribution of the major groups of units.

The Conterminous United States Mineral Assessment Program; background information to accompany folio of geologic, geochemical, remote sensing, and mineral resources maps of the Butte 1 degree x 2 degrees Quadrangle, Montana

USGS Publications Warehouse

Elliott, James E.; Trautwein, C.M.; Wallace, C.A.; Lee, G.K.; Rowan, L.C.; Hanna, W.F.

1993-01-01

The Butte 1?x2 ? quadrangle in west-central Montana was investigated as part of the U.S. Geological Survey's Conterminous United States Mineral Assessment Program (CUSMAP). These investigations included geologic mapping, geochemical surveys, gravity and aeromagnetic surveys, examinations of mineral deposits, and specialized geochronologic and remote-sensing studies. The data collected during these studies were compiled, combined with available published and unpublished data, analyzed, and used in a mineral-resource assessment of the quadrangle. The results, including data, interpretations, and mineral-resource assessments for nine types of mineral deposits, are published separately as a folio of maps. These maps are accompanied by figures, tables, and explanatory text. This circular provides background information on the Butte quadrangle, summarizes the studies and published maps, and lists a selected bibliography of references pertinent to the geology, geochemistry, geophysics, and mineral resources of the quadrangle. The Butte quadrangle, which includes the world-famous Butte mining district, has a long history of mineral production. Many mining districts within the quadrangle have produced large quantities of many commodities; the most important in dollar value of production were copper, gold, silver, lead, zinc, manganese, molybdenum, and phosphate. At present, mines at several locations produce copper, molybdenum, gold, silver, lead, zinc, and phosphate. Exploration, mainly for gold, has indicated the presence of other mineral deposits that may be exploited in the future. The results of the investigations by the U.S. Geological Survey indicate that many areas of the quadrangle are highly favorable for the occurrence of additional undiscovered resources of gold, silver, copper, molybdenum, tungsten, and other metals in several deposit types.

Geologic map of the Montauk quadrangle, Dent, Texas, and Shannon Counties, Missouri

USGS Publications Warehouse

Weary, David J.

2015-04-30

The Montauk 7.5-minute quadrangle is located in south-central Missouri within the Salem Plateau region of the Ozark Plateaus physiographic province. About 2,000 feet (ft) of flat-lying to gently dipping lower Paleozoic sedimentary rocks, mostly dolomite, chert, sandstone, and orthoquartzite, overlie Mesoproterozoic igneous basement rocks. Unconsolidated residuum, colluvium, terrace deposits, and alluvium overlie the sedimentary rocks. Numerous karst features, such as caves, springs, and sinkholes, have formed in the carbonate rocks. Many streams are spring fed. The topography is a dissected karst plain with elevations ranging from approximately 830 ft where the Current River exits the middle-eastern edge of the quadrangle to about 1,320 ft in sec. 16, T. 31 N., R. 7 W., in the southwestern part of the quadrangle. The most prominent physiographic features within the quadrangle are the deeply incised valleys of the Current River and its major tributaries located in the center of the map area. The Montauk quadrangle is named for Montauk Springs, a cluster of several springs that resurge in sec. 22, T. 32 N., R. 7 W. These springs supply clean, cold water for the Montauk Fish Hatchery, and the addition of their flow to that of Pigeon Creek produces the headwaters of the Current River, the centerpiece of the Ozark National Scenic Riverways park. Most of the land in the quadrangle is privately owned and used primarily for grazing cattle and horses and growing timber. A smaller portion of the land within the quadrangle is publicly owned by either Montauk State Park or the Ozark National Scenic Riverways (National Park Service). Geologic mapping for this investigation was conducted in 2007 and 2009.

Major- and Trace-Element Concentrations in Rock Samples Collected in 2005 from the Taylor Mountains 1:250,000-scale Quadrangle, Alaska

USGS Publications Warehouse

Klimasauskas, Edward P.; Miller, Marti L.; Bradley, Dwight C.; Bundtzen, Tom K.; Hudson, Travis L.

2006-01-01

The data consist of major- and minor-element concentrations for rock samples collected during 2005 by the U.S. Geological Survey. Samples were analyzed by fire assay (Au, Pd, Pt), cold vapor atomic absorption spectroscopy (Hg), and the inductively coupled plasma mass spectrometry (ICPMS) 10 and 42 element methods. For details of sample preparation and analytical techniques see USGS Open File Report 02-0223 (Analytical methods for chemical analysis of geologic and other materials, U.S. Geological Survey), available at .

Terrain Data of Mount Hayes D-4 Quadrangle, Fort Greely, Alaska

DTIC Science & Technology

1974-08-01

sampled. Common herbs are grasses, sedge, Linnaea, and Peliia, a leathery liverwort . Black spruce forests (Fig;. 18) sampled grew on terrace, moraine...Mss - 80 ___2_ icegauca ___4_ 24- -8- -Lichen -- 10 1 14 Picea-mariana j 2 24 8 Pellia -_ - 30- ----- Lea* f li t t er 20 V1.1 E’CA~kC1ON TYPE Salix...Iledum aroenlandicum - 2 10 3 Sedge 30 8 Ledwa dccunbcns 1__ 10 5 2 Lu21nlus 30____ 8___ Arctostophylos al ims- 5 4 2 Asttau- Salix 2 4 2 Pellia

Analytical results, geology, and sample locality map of mercury-sulfur-gypsum mineralization at Crater, Inyo County, California

USGS Publications Warehouse

Erickson, M.S.; Marsh, S.P.; Roemer, T.A.

1984-01-01

The Crater mercury-su l fur-gypsum ~ineral ized area is located in east-central California along the crest of the Last Chance Range, west of the north end of Death Valley (fig. 1). The area is in the northwest quarter of the Last Chance Range 15-minute quadrangle and occupies the area between 117 39 and 117 45 longitude and 37 10 and 37 15 latitudP.. The area studied lies between 5000 ( 1525 m) and 6000 ( 1830 m) feet above sea level. Relief isgenerally moderate but can be extreme in some places, as at Hanging Rock Canyon (plate 1). The climate is arid, and there are no active streams in the area. The range fronts east and west of the area are precipitous and incised by many steep canyons, whereas the range crest has relatively low relief. The old abandoned town and mine site of Crater 1 ie in this area of low relief. Access to the Crater area is by paved and dirt roads from Big Pine to the west or from the north end of the Death Valley National Monument to the southeast.

General geology and mines of the East Tintic mining district, Utah and Juab counties, Utah, with sections on the geology of the Burgin mine and the geology of the Trixie mine

USGS Publications Warehouse

Morris, H.T.; Lovering, Thomas Seward; Mogensen, A.P.; Shepard, W.M.; Perry, L.I.; Smith, S.M.

1979-01-01

This report is a study of the rocks, geologic structures, and mines of a highly productive silver, gold, and base-metal mining district in the east-central Great Basin. The East Tintic mining district is in the east-central part of the East Tintic Mountains, near the east margin of the Basin and Range province in Utah and Juab Counties, Utah. The district occupies the northeastern part of the Eureka quadrangle and is about 5 mi (8 km) wide and 6 mi (9.7 km) long. Officially it is within the designated boundaries of the Tintic mining district, but it generally though erroneously has been regarded as a separate district since the late 1800's.Prospecting was first undertaken in East Tintic in 1870; although small quantities of ore were produced in 1899 and from 1909 to 1913, the district first achieved prominence in 1916 with the discovery of the totally concealed Central ore body of the Tintic Standard mine. Within a few years of this discovery, the Tintic Standard became one of the most productive silver mines in the world. Additional discoveries of important concealed ore deposits have continued to be made in the district, including the North Lily mine in 1927, the Eureka Lilly and Eureka Standard mines in 1928, the Burgin mine in 1958, and the Trixie mine in 1969.To December 31, 1975, the East Tintic mining district has yielded approximately 4.83 million short tons (4.38 million tonnes) of silver, gold, and base-metal ores, largely from concealed deposits overlain by many hundreds of feet of barren rocks. These ores have a gross valuation of approximately $231 million. The district first achieved prominence in 1916 with the discovery of the ore bodies of the Tintic Standard mine, which for a time was the world's richest silver producer (Lindgren, 1933, p. 588). By 1946 this deposit and a number of other deposits discovered and developed nearby had been exhausted, and the district became dormant. A dramatic revival of, mining activities in the East Tintic district began in 1956 after the discovery and subsequent development of the concealed Burgin ore bodies in an area 1 mile (1.6 km) southeast of the Tintic Standard that previously had been only superficially prospected. As in the earlier history of the district, the Burgin development has led to the discovery of other concealed deposits, focusing international attention on the revitalization of a nearly abandoned mining district by the application of geologic and geochemical techniques.

Hydrologic indices for nontidal wetlands

USGS Publications Warehouse

Lent, Robert M.; Weiskel, Peter K.; Lyford, Forest P.; Armstrong, David S.

1997-01-01

Two sets of hydrologic indices were developed to characterize the water-budget components of nontidal wetlands. The first set consisted of six water-budget indices for input and output variables, and the second set consisted of two hydrologic interaction indices derived from the water-budget indices. The indices then were applied to 19 wetlands with previously published water-budget data. Two trilinear diagrams for each wetland were constructed, one for the three input indices and another for the three output indices. These two trilinear diagrams then were combined with a central quadrangle to form a Piper-type diagram, with data points from the trilinear diagrams projected onto the quadrangle. The quadrangle then was divided into nine fields that summarized the water-budget information. Two quantitative "interaction indices" were calculated from two of the six water-budget indices (precipitation and evapotranspiration). They also were obtained graphically from the water-budget indices, which were first projected to the central quadrangle of a Piper-type diagram from the flanking trilinear plots. The first interaction index (l) defines the strength of interaction between a wetland and the surrounding ground- and surface-water system. The second interaction index (S) defines the nature of the interaction between the wetland and the surrounding ground- and surface-water system (source versus sink). Evaluation of these indices using published wetland water-budget data illustrates the usefulness of the technique.

Arctic reconstruction from an Alaskan viewpoint

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

Crane, R.C.

1985-04-01

Field, seismic, structural, and stratigraphic data were used to reconstruct the geologic history of the Arctic in 10-m.y. time slices from the present to mid-Jurassic - the initial opening of the Arctic Ocean. A basic assumption is that Lomonosov Ridge, Alpha Ridge, Mendeleyev Ridge, and Chukchi Plateau are all foundered continental plates. Opening of the Arctic occurs in two stages: Late Jurassic - Cretaceous for the Canada basin and Neogene for the Eurasian basin. Opening is facilitated by two subparallel transform shears - the Arctic (Kaltag-Porcupine) on the east and the Chukchi on the west. Deformation is essentially tensional onmore » the Barents side of the Arctic and shear-compressional on the Alaska side. The development of Chutkoya, North Slope, Brooks Range, north-west Canada, Seward Peninsula, and central Alaska can be sequentially related to Arctic opening, modified by impingement on the northern terrane of allochthonous terranes arriving from the south - the Pacific plates of Tintina, Denali, Orca (Prince William-Chugach-Yakutat), Anadyr, Khatyrka, Kolyman, and other minor terranes. The North Slope of Alaska, a passive, rifted, subsided margin, is restored to line up with a similar margin on Alpha Ridge. Northeastern Alaska (the Romanzof Mountain area) lines up opposite the north end of the Sverdrup Rim, near Prince Patrick and Borden Islands.« less

Assessing forest roads and their edge effects on burn severity patterns using satellite data and geospatial analysis

NASA Astrophysics Data System (ADS)

Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

2011-12-01

Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

Geologic Map of the Sulphur Mountain Quadrangle, Park County, Colorado

USGS Publications Warehouse

Bohannon, Robert G.; Ruleman, Chester A.

2009-01-01

The main structural element in the Sulphur Mountain quadrangle is the Elkhorn thrust. This northwest-trending fault is the southernmost structure that bounds the west side of the Late Cretaceous and early Tertiary Front Range basement-rock uplift. The Elkhorn thrust and the Williams Range thrust that occurs in the Dillon area north of the quadrangle bound the west flank of the Williams Range and the Front Range uplift in the South Park area. Kellogg (2004) described widespread, intense fracturing, landsliding, and deep-rooted scarps in the crystalline rocks that comprise the upper plate of the Williams Range thrust. The latter thrust is also demonstrably a low-angle structure upon which the fractured bedrock of the upper plate was translated west above Cretaceous shales. Westward thrusting along the border of the Front Range uplift is probably best developed in that area. By contrast, the Elkhorn in the Sulphur Mountain quadrangle is poorly exposed and occurs in an area of relatively low relief. The thrust also apparently ends in the central part of the quadrangle, dying out into a broad area of open, upright folds with northwest axes in the Sulphur Mountain area.

Early Stages Of Biome Shift in Boreal Alaska: Climate Sensitivity of Tree Growth and Accelerated Tree Mortality

NASA Astrophysics Data System (ADS)

Juday, G. P.; Grant, T.; Alix, C. M.; Spencer, D. L.; Beck, P. S.

2012-12-01

The boreal forest region of Alaska is characterized by a major east-west climate gradient, in addition to a widely appreciated north-south gradient. Low elevations of the eastern and central Interior experience warm summer temperatures and low annual precipitation, while coastal western Alaska has cool summer temperatures and greater precipitation. In the Interior the four dominant tree species of white and black spruce, aspen, and Alaska birch on low elevation sites nearly all register a strong negative radial growth relationship to summer temperatures, concentrated in May and July. Precipitation, particularly in late winter and midsummer, plays a supplemental role as a positive factor in growth. Floodplain white spruce along the Yukon and Kuskokwim Rivers transition from negative temperature response to positive response in western Alaska near the tree limit. Populations of white spruce on treeline sites display both negative growth response to July temperature and positive response to spring temperatures, with the negative response dominant in the east and the positive response dominant in the west. Across boreal Alaska summer temperatures increased abruptly in 1974, and have remained at historically high levels since. Correspondingly, climatic favorability for radial growth of Interior trees on most low elevation sites has been at extreme low levels particularly in the 21st century. Satellite-based NDVI coverage confirms that forest growth reduction is widespread in boreal Alaska since the 1980s. Defoliating and wood boring insects have reached outbreak population levels across most of boreal Alaska, partly from release of direct temperature control on the insects and partly from increased tree host susceptibility. Major outbreak species include aspen leaf miner, spruce engraver beetle, and spruce budworm. About a dozen tall willow species have been subjected to widespread attack by willow leaf blotch miner, and a new disease and defoliating insect have spread rapidly in alder shrubs, so nearly all woody species face health challenges. Temperatures and precipitation on many Interior sites are now at or beyond tolerance limits for white spruce, aspen, and Alaska birch. Two episodes of acute drought injury were widespread in birch during the last decade. Deficits in climate predicted tree growth are synchronous with the major insect outbreaks as recorded in insect trapping records and aerial surveys of area affected. Over the past 25 years tree mortality of 50% or more occurred in nearly all long-term monitoring plots in mature stands on productive sites in the Interior, but to date trees have successfully regenerated on most disturbed sites. These environmental changes and tree responses, including opposite responses, are coherent, and consistent with early stages of a biome shift eliminating boreal forest on dry Interior sites, and emergence of a new climate optimum zone in western Alaska currently only sparsely populated with forest.

77 FR 67580 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Jig Gear in the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-13

... Vessels Using Jig Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... vessels using jig gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t...

78 FR 10102 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent... pot gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hours, Alaska local time (A...

77 FR 65640 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-30

... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... vessels using pot gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t...

78 FR 54592 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher/Processors Using...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... Catcher/Processors Using Trawl Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National... (C/Ps) using trawl gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hours, Alaska local time (A.l.t...

76 FR 45217 - Fisheries of the Exclusive Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

..., management, safety, and economic gains realized under the Rockfish Pilot Program and viability of the Gulf of...-BA97 Fisheries of the Exclusive Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program... available for public review and comment. The groundfish fisheries in the exclusive economic zone of Alaska...

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

Reconnaissance geology of the Precambrian rocks in the Ayn Qunay quadrangle, Kingdom of Saudi Arabia

USGS Publications Warehouse

Overstreet, William C.; Whitlow, Jesse William; Ankary, Abdullah O.

1972-01-01

The Aya Qunay quadrangle covers an area of 2833 sq km in central Saudi Arabia, Only the western edge of the quadrangle is underlain by Precambrian rocks, which were the subject of this investigation. Toward the east the Precambrian rocks are unconformably overlain by Permian and younger sedimentary rocks. The Permian rocks at the west edge of the Ayn Qunay quadrangle consist mainly of a granitic intrusive complex of batholithic dimensions. Parts of the eastern edge of the granitic complex are exposed just west of the overlying Khuff Formation of Permian age, where biotite-hornblende granite of the complex intrudes chlorite-sericite schist of the Precambrian Bi'r Khountina Group. The biotite-hornblende granite of the complex also intrudes plutons of diorite, gabbro, and pyroxenite and is itself intruded by granite porphyry, thereby indicating some difference in age between the granitic rocks in the complex. A sequence of metamorphosed volcanic rocks composed mainly of andesite, rhyolite, and kindred rocks, and called the Halaban Group, is older than the Bi'r Khountina Group. Relations between the Halaban and a gray hornblende-biotite granite gneiss are uncertain, but the gneiss may be older than the Halaban. The few observed contacts disclosed parallel foliation in the two units, but the foliation may have been imposed after the Halaban was deposited on the granite gneiss. Two major left-lateral faults extend west-northwest across the Precambrian rocks but are not in the Permian rocks. These faults parallel to the Najd fault zone found farther south. Seemingly they correlate in time with early movements on the Najd fault zone, but not with the latest. Saprolitic material-of variable thickness is present on the upper surface of the Precambrian rocks beneath the Khuff Formation at many places. Where the Khuff Formation has been removed by erosion, the saprolite is also stripped away. The weathering probably took place in pre-Khuff time. No ancient mines or prospects were seen in the Precambrian rocks; however, a notable positive anomaly for tungsten in concentrates is associated with a small prominence of granite porphyry 35 km southwest of Ayn Qunay. Further investigation of the porphyry should be undertaken to learn the amount of scheelite at this locality.

Geologic Map of the Estes Park 30' x 60' Quadrangle, North-Central Colorado

USGS Publications Warehouse

Cole, James C.; Braddock, William A.

2009-01-01

The rocks and landforms of the Estes Park 30 x 60 minute quadrangle display an exceptionally complete record of geologic history in the northern Front Range of Colorado. The Proterozoic basement rocks exposed in the core of the range preserve evidence of Paleoproterozoic marine sedimentation, volcanism, and regional soft-sediment deformation, followed by regional folding and gradational metamorphism. The metasedimentary rocks of the Estes Park quadrangle are distinct within northern Colorado for preserving the complete metamorphic zonation from low-grade chlorite-muscovite phyllites, through middle greenschist-grade rocks with sequential aluminous porphyroblasts, to partially melted gneisses that contain high-grade cordierite and garnet in the non-melted residues. Regional and textural evidence shows that the widespread metamorphism was essentially concurrent with intrusion of the Boulder Creek Granodiorite and related magmas and with the peak of deformation in the partially melted high-grade rocks. The metamorphic thermal pulse arrived later following the peak of deformation in the physically higher, cooler, low-grade terrane. Mesoproterozoic time was marked by intrusion of biotite granite in the Longs Peak-St Vrain batholith, a complex, irregular body that occupies nearly half of the core of the Front Range in this quadrangle. The magma was dry and viscous as it invaded the metamorphic rocks and caused wholesale plastic folding of the wall rock structure. Steep metamorphic foliation that resulted from the Paleoproterozoic deformations was bowed upward and re-oriented into flat-lying attitudes as the crystal-rich magma rose buoyantly and spread out in the middle crust. Magma invaded the schists and gneisses along weak foliation planes and produced a characteristic sill-upon-sill intrusive fabric, particularly in the higher parts of the batholith. Broad, open arches and swales that are defined by the flow-aligned feldspar foliation of the granite, as well as by compositional banding in the intruded and included metamorphic rocks, formed late during batholith emplacement due to rising, buoyant magma and sinking, dense wall rocks. The Longs Peak-St Vrain batholith was intruded into crust that was structurally neutral or moderately extending in an east-northeast direction. A broad zone of mylonite, the Moose Mountain shear zone, formed within the batholith during the final stages of consolidation as a result of differential buoyancy between the magma and dense wall rock, not as a result of regional tectonic deformation.

27 CFR 9.169 - Red Hills Lake County.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-foot contour line with the section 17 east boundary line, and continue for about 0.45 miles along the... continue straight north 0.25 miles on Wilkinson Road to its intersection with the 1,600-foot elevation line...-foot elevation line, section 19, T13N, R8W (Kelseyville Quadrangle); then (20) Proceed about 3.0 miles...

27 CFR 9.169 - Red Hills Lake County.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-foot contour line with the section 17 east boundary line, and continue for about 0.45 miles along the... continue straight north 0.25 miles on Wilkinson Road to its intersection with the 1,600-foot elevation line...-foot elevation line, section 19, T13N, R8W (Kelseyville Quadrangle); then (20) Proceed about 3.0 miles...

Three-dimensional perspective views of Venusian Terrains composed of reduced resolution left-looking synthetic-aperture radar images merged with altimetry data from the Magellan spacecraft.

NASA Image and Video Library

1998-06-03

The view from NASA's Magellan spacecraft shows most of Galindo V-40 quadrangle looking east; Atete Corona, in the foreground, is a 600-km-long and about 450-km-wide, circular volcano-tectonic feature. http://photojournal.jpl.nasa.gov/catalog/PIA00096

Inventory of wetlands and agricultural land cover in the upper Sevier River Basin, Utah

NASA Technical Reports Server (NTRS)

Jaynes, R. A.; Clark, L. D., Jr.; Landgraf, K. F. (Principal Investigator)

1981-01-01

The use of color infrared aerial photography in the mapping of agricultural land use and wetlands in the Sevier River Basin of south central utah is described. The efficiency and cost effectiveness of utilizing LANDSAT multispectral scanner digital data to augment photographic interpretations are discussed. Transparent overlays for 27 quadrangles showing delineations of wetlands and agricultural land cover were produced. A table summarizing the acreage represented by each class on each quadrangle overlay is provided.

Detrital zircon geochronology of the Adams Argillite and Nation River Formation, east-central Alaska, U.S.A

USGS Publications Warehouse

Gehrels, G.E.; Johnsson, M.J.; Howell, D.G.

1999-01-01

The Cambrian Adams Argillite and the Devonian Nation River Formation are two sandstone-bearing units within a remarkably complete Paleozoic stratigraphic section in east-central Alaska. These strata, now foreshortened and fault-bounded, were originally contiguous with miogeoclinal strata to the east that formed as a passive-margin sequence along the northwestern margin of the North American continent. Seventy-five detrital zircon grains from the Adams Argillite and the Nation River Formation were analyzed in an effort to provide constraints on the original sources of the grains, and to generate a detrital zircon reference for miogeoclinal strata in the northern Cordillera. Thirty-five single zircon grains from a quartzite in the Adams Argillite yield dominant age clusters of 1047-1094 (n = 6), 1801-1868 (n = 10), and 2564-2687 (n = 5) Ma. Forty zircons extracted from a sandstone in the Nation River Formation yield clusters primarily of 424-434 (n = 6), 1815-1838 (n = 6), 1874-1921 (n = 7), and 2653-2771 (n = 4) Ma. The Early Proterozoic and Archean grains in both units probably originated in basement rocks in a broad region of the Canadian Shield. In contrast, the original igneous sources for mid-Protcrozoic grains in the Adams Argillite and ??? 430 Ma grains in the Nation River Formation are more difficult to identify. Possible original sources for the mid-Proterozoic grains include: (1) the Grenville Province of eastern Laurentia, (2) the Pearya terrane along the Arctic margin, and (3) mid-Proterozoic igneous rocks that may have been widespread along or outboard of the Cordilleran margin. The ??? 430 Ma grains may have originated in: (1) arc-type sources along the Cordilleran margin, (2) the Caledonian orogen, or (3) a landmass, such as Pearya, Siberia, or crustal fragments now in northern Asia, that resided outboard of the Innuitian orogen during mid-Paleozoic time. Copyright ?? 1999, SEPM (Society for Sedimentary Geology).

Uranium hydrogeochemical and stream sediment reconnaissance of the Solomon NTMS quadrangle, Alaska

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

Langfeldt, S.L.; Youngquist, C.A.; D'Andrea, R.F. Jr.

This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Solomon NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form through the Grand Junction Office Information System at Oak Ridge National Laboratory. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendices A and B describe the sample media andmore » summarize the analytical results for each medium. The data were subdivided by one of the Los Alamos National Laboratory (LANL) sorting programs of Zinkl and others into groups of stream sediment and stream water samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report. In addition, maps showing results of multivariate statistical analyses have been included. Further information about the HSSR program in general, or about the LANL portion of the program in particular, can be obtained in quarterly or semiannual program progress reports on open-file at DOE's Technical Library in Grand Junction. Information about the field and analytical procedures used by LANL during sample collection and analysis may be found in any HSSR data release prepared by the LANL and will not be included in this report.« less

Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system

USGS Publications Warehouse

Haeussler, Peter J.; Matmon, Ari; Schwartz, David P.; Seitz, Gordon G.

2017-01-01

The neotectonics of southern Alaska (USA) are characterized by a several hundred kilometers–wide zone of dextral transpressional that spans the Alaska Range. The Denali fault system is the largest active strike-slip fault system in interior Alaska, and it produced a Mw 7.9 earthquake in 2002. To evaluate the late Quaternary slip rate on the Denali fault system, we collected samples for cosmogenic surface exposure dating from surfaces offset by the fault system. This study includes data from 107 samples at 19 sites, including 7 sites we previously reported, as well as an estimated slip rate at another site. We utilize the interpreted surface ages to provide estimated slip rates. These new slip rate data confirm that the highest late Quaternary slip rate is ∼13 mm/yr on the central Denali fault near its intersection with the eastern Denali and the Totschunda faults, with decreasing slip rate both to the east and west. The slip rate decreases westward along the central and western parts of the Denali fault system to 5 mm/yr over a length of ∼575 km. An additional site on the eastern Denali fault near Kluane Lake, Yukon, implies a slip rate of ∼2 mm/yr, based on geological considerations. The Totschunda fault has a maximum slip rate of ∼9 mm/yr. The Denali fault system is transpressional and there are active thrust faults on both the north and south sides of it. We explore four geometric models for southern Alaska tectonics to explain the slip rates along the Denali fault system and the active fault geometries: rotation, indentation, extrusion, and a combination of the three. We conclude that all three end-member models have strengths and shortcomings, and a combination of rotation, indentation, and extrusion best explains the slip rate observations.

Geologic Map of the Greenaway Quadrangle (V-24), Venus

USGS Publications Warehouse

Lang, Nicholas P.; Hansen, Vicki L.

2010-01-01

The Greenaway quadrangle (V-24; lat 0 degrees -25 degrees N., long 120 degrees -150 degrees E.), Venus, derives its name from the impact crater Greenaway, centered at lat 22.9 degrees N., long 145.1 degrees E., in the northeastern part of the quadrangle. Greenaway was a well-noted writer and illustrator of children`s books in Britain during the nineteenth century. In Greenaway`s honor, the Library Association of Great Britain presents the annual Kate Greenaway Medal to an illustrator living and publishing in Britain who has produced the most distinguished children`s book illustrations for that year. The Greenaway quadrangle occupies an 8,400,000 km2 equatorial swath of lowlands and highlands. The map area is bounded by the crustal plateau, Thetis Regio, to the south and Gegute Tessera to the west. The rest of the quadrangle consists of part of Llorona Planitia, which is part of the vast lowlands that cover about 80 percent of Venus` surface. The southern map area marks the north edge of Aphrodite Terra, including Thetis Regio, that includes the highest topography in the quadrangle with elevations reaching >1 km above the Mean Planetary Radius (MPR; 6,051.84 km). Northern Aphrodite Terra abruptly slopes north to Llorona Planitia. A broad northeast-trending topographic arch pocked with coronae separates two northeast-trending elongate basins, Llorona Planitia on the east, that form depositional centers for shield and coronae-sourced materials; both basins drop to elevations of <-1 km. In addition to these major features, the map area hosts thousands of small volcanic constructs (shields); seven coronae; ribbon-tessera terrain; suites of faults, fractures, and wrinkle ridges; 23 impact craters; and one craterless splotch. Our goal for mapping the geology of the Greenaway quadrangle was to determine the geologic history for this region, which in turn provides insights into volcanic and tectonic processes that shaped the Venusian surface. Map relations illustrate that aerially expansive shield terrain (unit st) played a primary role and coronae played a secondary role in volcanic resurfacing across the map area.

Preliminary interpretation of industry two-dimensional seismic data from Susitna Basin, south-central Alaska

USGS Publications Warehouse

Lewis, Kristen A.; Potter, Christopher J.; Shah, Anjana K.; Stanley, Richard G.; Haeussler, Peter J.; Saltus, Richard W.

2015-07-30

The eastern seismic lines show evidence of numerous short-wavelength antiforms that appear to correspond to a series of northeast-trending lineations observed in aeromagnetic data, which have been interpreted as being due to folding of Paleogene volcanic strata. The eastern side of the basin is also cut by a number of reverse faults and thrust faults, the majority of which strike north-south. The western side of the Susitna Basin is cut by a series of regional reverse faults and is characterized by synformal structures in two fault blocks between the Kahiltna River and Skwentna faults. These synforms are progressively deeper to the west in the footwalls of the east-vergent Skwentna and northeast-vergent Beluga Mountain reverse faults. Although the seismic data are limited to the south, we interpret a potential regional south-southeast-directed reverse fault striking east-northeast on the east side of the basin that may cross the entire southern portion of the basin.

Geological mapping of the Kuiper quadrangle (H06) of Mercury

NASA Astrophysics Data System (ADS)

Giacomini, Lorenza; Massironi, Matteo; Galluzzi, Valentina

2017-04-01

Kuiper quadrangle (H06) is located at the equatorial zone of Mercury and encompasses the area between longitudes 288°E - 360°E and latitudes 22.5°N - 22.5°S. The quadrangle was previously mapped for its most part by De Hon et al. (1981) that, using Mariner10 data, produced a final 1:5M scale map of the area. In this work we present the preliminary results of a more detailed geological map (1:3M scale) of the Kuiper quadrangle that we compiled using the higher resolution of MESSENGER data. The main basemap used for the mapping is the MDIS (Mercury Dual Imaging System) 166 m/pixel BDR (map-projected Basemap reduced Data Record) mosaic. Additional datasets were also taken into account, such as DLR stereo-DEM of the region (Preusker et al., 2016), global mosaics with high-incidence illumination from the east and west (Chabot et al., 2016) and MDIS global color mosaic (Denevi et al., 2016). The preliminary geological map shows that the western part of the quadrangle is characterized by a prevalence of crater materials (i.e. crater floor, crater ejecta) which were distinguished into three classes on the basis of their degradation degree (Galluzzi et al., 2016). Different plain units were also identified and classified as: (i) intercrater plains, represented by densely cratered terrains, (ii) intermediate plains, which are terrains with a moderate density of superposed craters, and (iii) smooth plains, which are poorly cratered volcanic deposits emplaced mainly on the larger crater floors. Finally, several structures were mapped all over the quadrangle. Most of these features are represented by thrusts, some of which appear to form systematic alignments. In particular, two main thrust systems have been identified: i) the "Thakur" system, a 1500 km-long system including several scarps with a NNE-SSW orientation, located at the edge between the Kuiper and Beethoven (H07) quadrangles; ii) the "Santa Maria" system, located at the centre of the quadrangle. It is a 1700 km-long system encompassing faults with a prevalent NNW-SSE orientation. Once the mapping activity is accomplished, the geological map of Kuiper quadrangle will be integrated into the global 1:3M geological map of Mercury (Galluzzi et al., 2017). References Chabot et al., 2016, LPS XLVII, #1256. De Hon et al., 1981, IMAP #1233. Denevi et al., 2016 LPS XLVII, #1264. Galluzzi et al., 2016, Geology, J. Maps, 12, 226-238. Galluzzi et al., 2017, EGU General Assembly 2017, #13822. Preusker et al., 2016, Earth and Planet. Astrophys., arXiv:1608.08487.

Geochemistry of stream-sediment samples from the Santa Renia Fields and Beaver Peak quadrangles, northern Carlin Trend, Nevada

USGS Publications Warehouse

Theodore, Ted G.; Kotlyar, Boris B.; Berger, Vladimir I.; Moring, Barry C.; Singer, Donald A.; Edstrom, Sven A.

1999-01-01

A broad west-to-east increase of many metal concentrations has been found in stream sediments during a reconnaissance investigation conducted in conjunction with geologic studies in the Santa Renia Fields and Beaver Peak 7–1/2 minute quadrangles near the northern end of the Carlin trend of gold deposits in the Tuscarora Mountains. This regional increase in metal concentrations coincides with a dramatic change in landform wherein high concentrations of metals in stream sediments appear to correlate directly with areas of high elevations and steep slopes in the Beaver Peak quadrangle. Robust erosion combined with high flow rates in streams from these higher elevations are envisaged to have contributed significantly to increased metal concentrations in the stream sediments by an enhanced presence of minerals with high specific gravities and a correspondingly diminished presence of minerals with low specific gravities. Minerals with low specific gravities probably have been preferentially flushed down stream because of high transporting capacities for sediment by streams in the Beaver Peak quadrangle. In addition, the Carlin trend, a generally northwest-alignment of gold deposits in the Santa Renia Fields quadrangle, is well outlined by arsenic concentrations that include a maximum of approximately 54 parts per million. Further, a weakly developed distal-to-proximal metal zonation towards these gold deposits appears to be defined respectively in plots showing distributions of thallium, arsenic, antimony, and zinc. A broad area of high metal concentrations—including sharply elevated abundances of Ag, As, Au, Cd, Co, Cu, Mn, Ni, P, Sb, Sc, Te, V, and especially Zn—near the southeast corner of the Beaver Peak quadrangle primarily could be the result of stratiform mineralized rocks in the Ordovician Vinini Formation or Devonian Slaven Chert, or the result of a subsequent Mesozoic or Tertiary epigenetic overprint.

Geologic map of the Ennis 30' x 60' quadrangle, Madison and Gallatin Counties, Montana

USGS Publications Warehouse

Kellogg, Karl S.; Williams, Van S.

1998-01-01

The Ennis 1:100,000 quadrangle lies within both the Laramide (Late Cretaceous to early Tertiary) foreland province of southwestern Montana and the northeastern margin of the middle to late Tertiary Basin and Range province. The oldest rocks in the quadrangle are Archean high-grade gneiss, and granitic to ultramafic intrusive rocks that are as old as about 3.0 Ga. The gneiss includes a supracrustal assemblage of quartz-feldspar gneiss, amphibolite, quartzite, and biotite schist and gneiss. The basement rocks are overlain by a platform sequence of sedimentary rocks as old as Cambrian Flathead Quartzite and as young as Upper Cretaceous Livingston Group sandstones, shales, and volcanic rocks. The Archean crystalline rocks crop out in the cores of large basement uplifts, most notably the 'Madison-Gravelly arch' that includes parts of the present Tobacco Root Mountains and the Gravelly, Madison, and Gallatin Ranges. These basement uplifts or blocks were thrust westward during the Laramide orogeny over rocks as young as Upper Cretaceous. The thrusts are now exposed in the quadrangle along the western flanks of the Gravelly and Madison Ranges (the Greenhorn thrust and the Hilgard fault system, respectively). Simultaneous with the west-directed thrusting, northwest-striking, northeast-side-up reverse faults formed a parallel set across southwestern Montana; the largest of these is the Spanish Peaks fault, which cuts prominently across the Ennis quadrangle. Beginning in late Eocene time, extensive volcanism of the Absorka Volcanic Supergroup covered large parts of the area; large remnants of the volcanic field remain in the eastern part of the quadrangle. The volcanism was concurrent with, and followed by, middle Tertiary extension. During this time, the axial zone of the 'Madison-Gravelly arch,' a large Laramide uplift, collapsed, forming the Madison Valley, structurally a complex down-to-the-east half graben. Basin deposits as thick as 4,500 m filled the graben. Pleistocene glaciers sculpted the high peaks of the mountain ranges and formed the present rugged topography.

Geologic map of the Ennis 30' x 60' quadrangle, Madison and Gallatin Counties, Montana, and Park County, Wyoming

USGS Publications Warehouse

Kellogg, Karl S.; Williams, Van S.

2000-01-01

The Ennis 1:100,000 quadrangle lies within both the Laramide (Late Cretaceous to early Tertiary) foreland province of southwestern Montana and the northeastern margin of the middle to late Tertiary Basin and Range province. The oldest rocks in the quadrangle are Archean high-grade gneiss, and granitic to ultramafic intrusive rocks that are as old as about 3.0 Ga. The gneiss includes a supracrustal assemblage of quartz-feldspar gneiss, amphibolite, quartzite, and biotite schist and gneiss. The basement rocks are overlain by a platform sequence of sedimentary rocks as old as Cambrian Flathead Quartzite and as young as Upper Cretaceous Livingston Group sandstones, shales, and volcanic rocks. The Archean crystalline rocks crop out in the cores of large basement uplifts, most notably the 'Madison-Gravelly arch' that includes parts of the present Tobacco Root Mountains and the Gravelly, Madison, and Gallatin Ranges. These basement uplifts or blocks were thrust westward during the Laramide orogeny over rocks as young as Upper Cretaceous. The thrusts are now exposed in the quadrangle along the western flanks of the Gravelly and Madison Ranges (the Greenhorn thrust and the Hilgard fault system, respectively). Simultaneous with the west-directed thrusting, northwest-striking, northeast-side-up reverse faults formed a parallel set across southwestern Montana; the largest of these is the Spanish Peaks fault, which cuts prominently across the Ennis quadrangle. Beginning in late Eocene time, extensive volcanism of the Absorka Volcanic Supergroup covered large parts of the area; large remnants of the volcanic field remain in the eastern part of the quadrangle. The volcanism was concurrent with, and followed by, middle Tertiary extension. During this time, the axial zone of the 'Madison-Gravelly arch,' a large Laramide uplift, collapsed, forming the Madison Valley, structurally a complex down-to-the-east half graben. Basin deposits as thick as 4,500 m filled the graben. Pleistocene glaciers sculpted the high peaks of the mountain ranges and formed the present rugged topography.

Geological Evolution of the Ganiki Planitia Quadrangle (V14) on Venus

NASA Technical Reports Server (NTRS)

Grosfils, E. B.; Drury, D. E.; Hurwitz, D. M.; Kastl, B.; Long, s. M.; Richards, J. W.; Venechuk, E. M.

2005-01-01

The Ganiki Planitia quadrangle (25-50degN, 180-210degE) is located north of Atla Regio, south of Vinmara Planitia, and southeast of Atalanta Planitia. The region contains a diverse array of volcanic-, tectonic- and impact-derived features, and the objectives for the ongoing mapping effort are fivefold: 1) explore the formation and evolution of radiating dike swarms within the region, 2) use the diverse array of volcanic deposits to further test the neutral buoyancy hypothesis proposed to explain the origin of reservoir-derived features, 3&4) unravel the volcanic and tectonic evolution in this area, and 5) explore the implications of 1-4 for resurfacing mechanisms. Here we summarize our onging analysis of the material unit stratigraphy in the quadrangle, data central to meeting the aforementioned objectives successfully.

Large Scale Geomorphic Mapping of Cryoplanation Terraces in Central and Eastern Alaska

NASA Astrophysics Data System (ADS)

Queen, C.; Nyland, K. E.; Nelson, F. E.

2017-12-01

Cryoplanation terraces (CTs) are large periglacial landforms characterized by alternating treads and risers, giving the appearance of giant staircases ascending ridgecrests and hillsides. The risers (scarps) are typically covered with coarse clastic material, while the surfaces of the nearly planar treads are a mosaic of vegetation, rock debris, and surficial periglacial landforms. CTs are best developed in areas of moderate relief across Beringia, the largely unglaciated region between the Lena and Mackenzie rivers, including Bering Sea islands that were formerly highlands on the Bering Land Bridge. CTs are generally thought to develop through locally intensified weathering at the base of scarps by processes associated with late lying bodies of snow. This hypothesis has been the subject of much speculative literature, but until recently there have been few process-oriented field studies performed on them. The work reported here builds on foundational work by R. D. Reger, who inventoried and investigated a large number of CTs in central and western Alaska. The resultant large-scale (1:2000) maps of cryoplanation terraces at Eagle Summit and Mount Fairplay in east-central Alaska were created using traditional and GPS-based mapping methodologies. Pits were excavated at representative locations across treads to obtain information about subsurface characteristics. The resulting maps show the location and morphology of surficial geomorphic features on CT scarps, treads, and sideslopes, superimposed on high-resolution topographic maps and perspective diagrams. GIS-based analysis of the assembled map layers promotes three-dimensional understanding of the spatial relationships between CT morphology, material properties, and erosional processes, and provides key insights into intra- and inter- terrace relationships. In concert with relative and absolute dating of material on the landforms, this research is generally supportive of the "nivation hypothesis of CT development."

Lidar-revised geologic map of the Uncas 7.5' quadrangle, Clallam and Jefferson Counties, Washington

USGS Publications Warehouse

Tabor, Rowland W.; Haeussler, Peter J.; Haugerud, Ralph A.; Wells, Ray E.

2011-01-01

In 2000 and 2001, the Puget Sound Lidar Consortium obtained 1 pulse/m2 lidar data for about 65 percent of the Uncas 7.5' quadrangle. For a brief description of LIDAR (LIght Detection And Ranging) and this data acquisition program, see Haugerud and others (2003). This map combines geologic interpretation (mostly by Haugerud and Tabor) of the 6-ft (2-m) lidar-derived digital elevation model (DEM) with the geology depicted on the Preliminary Geologic Map of the Uncas 7.5' Quadrangle, Clallam and Jefferson Counties, Washington, by Peter J. Haeussler and others (1999). The Uncas quadrangle in the northeastern Olympic Peninsula covers the transition from the accreted terranes of the Olympic Mountains on the west to the Tertiary and Quaternary basin fills of the Puget Lowland to the east. Elevations in the map area range from sea level at Port Discovery to 4,116 ft (1,255 m) on the flank of the Olympic Mountains to the southwest. Previous geologic mapping within and marginal to the Uncas quadrangle includes reports by Cady and others (1972), Brown and others (1960), Tabor and Cady (1978a), Yount and Gower (1991), and Yount and others (1993). Paleontologic and stratigraphic investigations by University of Washington graduate students (Allison, 1959; Thoms, 1959; Sherman, 1960; Hamlin, 1962; Spencer, 1984) also encompass parts of the Uncas quadrangle. Haeussler and Wells mapped in February 1998, following preliminary mapping by Yount and Gower in 1976 and 1979. The description of surficial map units follows Yount and others (1993) and Booth and Waldron (2004). Bedrock map units are modified from Yount and Gower (1991) and Spencer (1984). We used the geologic time scale of Gradstein and others (2005). The Uncas quadrangle lies in the forearc of the Cascadia subduction zone, about 6.25 mi (10 km) east of the Cascadia accretionary complex exposed in the core of the Olympic Mountains (Tabor and Cady, 1978b). Underthrusting of the accretionary complex beneath the forearc uplifted and tilted eastward the Coast Range basalt basement and overlying marginal basin strata, which comprise most of the rocks of the Uncas quadrangle. The Eocene submarine and subaerial tholeiitic basalt of the Crescent Formation on the Olympic Peninsula is thought to be the exposed mafic basement of the Coast Range, which was considered by Snavely and others (1968) to be an oceanic terrane accreted to the margin in Eocene time. In this interpretation, the Coast Range basalt terrane may have originated as an oceanic plateau or by oblique marginal rifting, but its subsequent emplacement history was complex (Wells and others, 1984). Babcock and others (1992) and Haeussler and others (2003) favor the interpretation that the basalts were the product of an oceanic spreading center interacting with the continental margin. Regardless of their origin, onlapping strata in southern Oregon indicate that the Coast Range basalts were attached to North America by 50 Ma; but on southern Vancouver Island, where the terrane-bounding Leech River Fault is exposed, Brandon and Vance (1992) concluded that suturing to North America occurred in the broad interval between 42 and 24 Ma. After emplacement of the Coast Range basalt terrane, the Cascadia accretionary wedge developed by frontal accretion and underplating (Tabor and Cady, 1978b; Clowes and others, 1987). Domal uplift of the part of the accretionary complex beneath the Olympic Mountains occurred after ~18 Ma (Brandon and others, 1998). Continental and alpine glaciation during Quaternary time reshaped the uplifted rocks of the Olympic Mountains.

South-central Alaska forests: inventory highlights.

Treesearch

Sally Campbell; Willem W.S. van Hees; Bert. Mead

2005-01-01

This publication presents highlights of a recent south-central Alaska inventory conducted by the Pacific Northwest Research Station Forest Inventory and Analysis Program (USDA Forest Service). South-central Alaska has about 18.5 million acres, of which one-fifth (4 million acres) is forested. Species diversity is greatest in closed and open Sitka spruce forests, spruce...

Geology of the Windsor quadrangle, Massachusetts

USGS Publications Warehouse

Norton, Stephen A.

1967-01-01

The Windsor quadrangle lies on the boundary between the eugeosynclinal and miogeosynclinal rocks of the Appalachian geosyncline on the western flank of the metamorphic high in western New England. Precambrian rocks crop out in a north-trending belt in the central part of the quadrangle. They have been classified into 2 formations. The Stamford Granite Gneiss crops out in the eastern half of the Precambrian terrane. It is a microcline-quartz-biotite augen gneiss. Stratified Precambrian rocks (the Hinsdale Gneiss) crop out entirely the west of the Stamford Granite Gneiss. They are predominantly highly metamorphosed felsic gneisses and .quartzites with minor calc-silicate rock, amphibolite, and graphitic gneiss. Eugeosynclinal rocks (the Hoosac Formation and the Rowe Schist), .ranging in age from Lower Cambrian to Lower Ordovician, crop out in a north-trending belt east of the Precambrian terrane. They are composed predominantly of albite schist and muscovite-chlorite schist with minor garnet schist, quartz-muscovite-calcite schist, felsic granulite and gneiss, quartzite, greenschist, and carbonaceous phyllite and schist. West of the Precambrian rocks, the Hoosac Formation is overlain by a miogeosynclinal sequence (the Dalton Formation, Cheshire Quartzite, Kitchen Brook Dolomite, Clarendon Springs Dolomite, Shelburne Marble, and the Bascom Formation) ranging in age from Lower Cambrian to Lower Ordovician. These rocks are unconformably overlain by the Berkshire Schist of Middle Ordovician age that is composed of carbonaceous schist, phyllite, and quartzite. The relationships in the zone of transition between the miogeosynclinal and eugeosynclinal rocks are unknown because the rocks of this zone are no longer present. The contact between the eugeosynclinal Hoosac Formation and the Dalton Format ion is conformable and deposition. The dominant structure is a large recumbent, northwest-facing anticline (the Hoosac nappe) with a Precambrian co re. The miogeosynclinal rocks are inverted in the northwestern part of the quadrangle and upright in the southwestern part of the quadrangle. A later generation of open, post-metamorphic folds has folded the recumbent folds in the miogeosynclinal rocks. The eugeosynclinal rocks show 3 phases of folding. The earliest folds are isoclinal, have steep plunges, were synmetamorphic, and have a strong axial plane schistosity. Two post-metamorphic generations of folds are more open and have axial plane cleavage. The development of the Hoosac nappe and the isoclinal folds was accompanied by regional metamorphism of the garnet zone. The pressure exceeded the pressure for the triple point of the Al2SiO 5 polymorphs. The composition of the paragonite coexisting with muscovite suggests a period of retrograde metamorphism for the Paleozoic rocks as well as the Cambrian rocks that were originally of higher grade (sillimanite? ). Later events include high-angle faulting (Triassic?), erosion, and Pleistocene glaciation.

Aqueous geochemical data from the analysis of stream water samples collected in August 2004--Taylor Mountains 1:250,000 scale Quadrangle, Alaska

USGS Publications Warehouse

Wang, Bronwen; Mueller, Seth; Bailey, Elizabeth; Lee, Greg

2006-01-01

We report on the chemical analysis of water samples collected from the Taylor Mountains 1:250,000 quadrangle. Samples were collected as part of the multi-year U.S. Geological Survey's project -- Geologic and Mineral Deposit Data for Alaskan Economic Development. Data presented here are from water samples collected primarily in the northeastern part of the Taylor Mountains quadrangle. The data include samples taken from the Taylor Mountains C1, C2, D1, D2, and D4 1:63,360 scale quadrangles. The data are being released at this time with minimal interpretation. Site selection was based on a regional sampling strategy that focused on first and second order drainages. Water sampling site selection was based on landscape parameters that included physiography, wetland extent, lithological changes, and the cursory field review of the mineralogy from the pan concentrates. Stream water in the Taylor Mountians quadrangle is dominated by bicarbonate (HCO3-), though in a few samples more than 50% of the anionic charge can be attibuted to sulfate ( SO42-). The major-cation chemistry range from Ca/Mg dominated to a mix of Ca/Mg/Na+K. Good agreement was found between the major cation and anions in the duplicate samples. Many trace elements were at or near the method detection limit in these samples but good agreement was found between duplicate samples for elements with detectable concentrations. Major ion concentrations were below detection in all field blanks and the trace elements concentrations generally were below detection. However, Ta (range 0.9 -.1 ug/L) and Zn (1 to 3.5 ug/L) were detected in all blanks and Ba ( 0.24 ug/L) and Th (0.2 ug/L) were detected in one blank. There was good agreement between dupilicate total- and methyl- mercury and DOC samples; however, total mercury, methyl-mercury and dissolve organic carbon (DOC) were detected in the blank at 2.35 ng/L, 0.07 ng/L and 0.57 mg/L, respectively.

Geologic map of the Providence Mountains in parts of the Fountain Peak and adjacent 7.5' quadrangles, San Bernardino County, California

USGS Publications Warehouse

Stone, Paul; Miller, David M.; Stevens, Calvin H.; Rosario, Jose J.; Vazquez, Jorge A.; Wan, Elmira; Priest, Susan S.; Valin, Zenon C.

2017-03-22

IntroductionThe Providence Mountains are in the eastern Mojave Desert about 60 km southeast of Baker, San Bernardino County, California. This range, which is noted for its prominent cliffs of Paleozoic limestone, is part of a northeast-trending belt of mountainous terrain more than 100 km long that also includes the Granite Mountains, Mid Hills, and New York Mountains. Providence Mountains State Recreation Area encompasses part of the range, the remainder of which is within Mojave National Preserve, a large parcel of land administered by the National Park Service. Access to the Providence Mountains is by secondary roads leading south and north from Interstate Highways 15 and 40, respectively, which bound the main part of Mojave National Preserve.The geologic map presented here includes most of Providence Mountains State Recreation Area and land that surrounds it on the north, west, and south. This area covers most of the Fountain Peak 7.5′ quadrangle and small adjacent parts of the Hayden quadrangle to the north, the Columbia Mountain quadrangle to the northeast, and the Colton Well quadrangle to the east. The map area includes representative outcrops of most of the major geologic elements of the Providence Mountains, including gneissic Paleoproterozoic basement rocks, a thick overlying sequence of Neoproterozoic to Triassic sedimentary rocks, Jurassic rhyolite that intrudes and overlies the sedimentary rocks, Jurassic plutons and associated dikes, Miocene volcanic rocks, and a variety of Quaternary surficial deposits derived from local bedrock units. The purpose of the project was to map the area in detail, with primary emphasis on the pre-Quaternary units, to provide an improved stratigraphic, structural, and geochronologic framework for use in land management applications and scientific research.

Geology of the Lachesis Tessera Quadrangle (V-18), Venus

NASA Technical Reports Server (NTRS)

McGill, George E.

2008-01-01

The Lachesis Tessera Quadrangle (V-18) lies between 25deg and 50deg north, 300deg and 330deg east. Most of the quadrangle consists of "regional plains" (1) of Sedna and Guinevere Planitiae. A first draft of the geology has been completed, and the tentative number of mapped units by terrain type is: Tesserae - 2; plains - 4; ridge belts - 1; fracture belts - 1 (plus embayed fragments of possible additional belts); coronae - 3; central volcanoes - 1; shield flows - 2; paterae - 1; impact craters - 1; undifferentiated flows - 1; bright materials - 1. By far the areally most extensive materials are regional plains. These are mapped as two units, based on radar backscatter ("radar brightness"). The brighter unit appears to be younger than the darker unit. This inference is based on the common presence within the lighter unit of circular or nearly circular inliers of material with radar backscatter characteristic of the darker unit. The circular inliers are most likely low shield volcanoes, which are commonly present on the darker unit, that were only partially covered by the brighter unit. Clear cut examples of wrinkle ridges and fractures superposed on the darker unit but truncated by the brighter unit have not been found to date. These relationships indicate that the brighter unit is superposed on the darker unit, but that the difference in age between them is very small. Because they are so widespread, the regional plains are a convenient relative age time "marker." The number of impact craters superposed on these plains is too small to measure age differences (2), and thus we cannot estimate how much time elapsed between the emplacement of the darker and brighter regional plains units. More local plains units are defined by significantly lower radar backscatter or by a texture that is mottled at scores to hundreds of kilometers scale. A plains-like unit with a homogenous, bright diffuse backscatter is present as scattered exposures in the eastern part of the quadrangle. These exposures have been mapped as "bright material," but it is not clear at present if this is a valid unit or if it is part of the brighter regional plains unit. Tessera terrain is primarily found along the western border of the quadrangle, where Lachesis Tessera refers to the southern exposures, and Zirka Tessera refers to northern exposures. A second tessera unit has been mapped with the symbol "t?." This unit appears to be deformed by the requisite 2 sets of closely spaced structures, but it is so extensively flooded by regional plains materials that the structural fabric is partially obscured. Tessera terrain is present in the adjacent V-17 quadrangle, where both Lachesis Tessera and Zirka Tessera are areally more extensive than in V-18. Ridge and fracture belts are both present, but not as extensive as is the case in, for example, the Pandrosos Dorsa (3) and Lavinia Planitia (4) quadrangles. As is commonly the case, it is difficult to determine if the materials of these belts are older or younger than regional plains. A recent study using radar properties (5) demonstrated that at least most ridge belts appear to be older than regional plains. The materials of fracture belts probably are also older than regional plains, but the fractures themselves can be both older and younger than regional plains (e.g., 3).

Geological Mapping of the Ac-H-3 Dantu Quadrangle of Ceres from NASA's Dawn Mission.

NASA Astrophysics Data System (ADS)

Kneissl, Thomas; Schmedemann, Nico; Neesemann, Adrian; Williams, David A.; Crown, David A.; Mest, Scott C.; Buczkowski, Debra L.; Scully, Jennifer E. C.; Frigeri, Allessandro; Ruesch, Ottaviano; Hiesinger, Harald; Walter, Sebastian H. G.; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Kersten, Elke; Naß, Andrea; Nathues, Andreas; Platz, Thomas; Russell, Chistopher T.

2016-04-01

The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for Vesta [1,2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the geologic evolution of the Ac-H-3 Dantu Quadrangle. The current map is based on a Framing Camera (FC) clear-filter image mosaic from HAMO data (~140 m/px) as well as a digital terrain model (DTM) derived from imagery of the Survey phase [3]. Albedo variations were identified and mapped using a mosaic of photometrically corrected HAMO images provided by DLR. FC color images provided further context for map unit identification. LAMO images (35m/pixel), which have just become available at the time of writing, will be used to update the map to be presented as a poster. The quadrangle is located between 21-66°N and 90-180°E in a large-scale depression north of the impact basin Kerwan. The northern and southeastern parts of the quadrangle are characterized by cratered terrain while the south and southwest are dominated by the partially smooth ejecta blankets of craters Dantu and Gaue. East-west oriented pit/crater chains in the southern half of the quadrangle might be related to tectonic processes [4,5]. Dantu crater (d=~126 km) is a complex impact crater showing slump terraces and a partially smooth crater floor with concentric and radial fractures. Furthermore, Dantu shows a central pit structure with pitted terrain on its floor as well as several bright spots in the interior and exterior of the crater. High-resolution measurements of crater size-frequency distributions (CSFDs) superposed on Dantu indicate a formation/modification age of ~200 - 700 Ma. Most of the ejecta appear to be relatively bright and correspond to parts of the #2 high albedo region observed with the Hubble Space Telescope [6]. However, the southwestern portion of the ejecta blanket is characterized by relatively dark ejecta material. The albedo variations and differences in color data indicate materials of different compositions in the subsurface. Interestingly, Dantu is located in a longitude range where the Herschel space telescope might have observed the release of water vapor [7]. In the course of the mission, analyses of LAMO imagery as well as VIR spectral data will help to identify potential water sources, constrain the compositional variations, and the overall geologic history of the Dantu crater region. Further CSFD measurements we will help to determine the formation ages of other impact structures in the quadrangle. Acknowledgements: We acknowledge the support of M. Hoffmann, M. Schaefer, M.C. De Sanctis, C.A. Raymond, and the Dawn Instrument, Operations, and Science Teams. This work is partly supported by the German Space Agency (DLR), grant 50 OW 1101. References: [1] Williams D.A. et al. (2014) Icarus, 244, 1-12. [2] Yingst R.A. et al. (2014) PSS, 103, 2-23. [3] Preusker, F. et al. (2016), LPSC abstract. [4] Scully, J.E.C. et al. (2016), this meeting. [5] Buczkowski D. L. et al. (2015), AGU abstract #P44B-05. [6] Li, J-Y. et al. (2006), Icarus, 182, 143-160. [7] Küppers, M., et al. (2014), Nature, v. 505, 525-527.

27 CFR 9.119 - Middle Rio Grande Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... “Middle Rio Grande Valley” viticultural area are 24 U.S.G.S. Quadrangle (7.5 Minute Series) maps and 1 (15 Minute Series) U.S.G.S. map. They are titled: (1) Abeytas, N. Mex. (1952), revised 1979. (2) Alameda, N... the Santa Ana Pueblo, N. Mex. U.S.G.S. map; (2) The boundary follows the power transmission line east...

High-Resolution Digital Terrain Models of the Sacramento/San Joaquin Delta Region, California

USGS Publications Warehouse

Coons, Tom; Soulard, Christopher E.; Knowles, Noah

2008-01-01

The U.S. Geological Survey (USGS) Western Region Geographic Science Center, in conjunction with the USGS Water Resources Western Branch of Regional Research, has developed a high-resolution elevation dataset covering the Sacramento/San Joaquin Delta region of California. The elevation data were compiled photogrammically from aerial photography (May 2002) with a scale of 1:15,000. The resulting dataset has a 10-meter horizontal resolution grid of elevation values. The vertical accuracy was determined to be 1 meter. Two versions of the elevation data are available: the first dataset has all water coded as zero, whereas the second dataset has bathymetry data merged with the elevation data. The projection of both datasets is set to UTM Zone 10, NAD 1983. The elevation data are clipped into files that spatially approximate 7.5-minute USGS quadrangles, with about 100 meters of overlap to facilitate combining the files into larger regions without data gaps. The files are named after the 7.5-minute USGS quadrangles that cover the same general spatial extent. File names that include a suffix (_b) indicate that the bathymetry data are included (for example, sac_east versus sac_east_b). These files are provided in ESRI Grid format.

Spatial digital database for the geologic map of the east part of the Pullman 1° x 2° quadrangle, Idaho

USGS Publications Warehouse

Rember, William C.; Bennett, Earl H.

2001-01-01

he paper geologic map of the east part of the Pullman 1·x 2· degree quadrangle, Idaho (Rember and Bennett, 1979) was scanned and initially attributed by Optronics Specialty Co., Inc. (Northridge, CA) and remitted to the U.S. Geological Survey for further attribution and publication of the geospatial digital files. The resulting digital geologic map GIS can be queried in many ways to produce a variety of geologic maps. This digital geospatial database is one of many being created by the U.S. Geological Survey as an ongoing effort to provide geologic information in a geographic information system (GIS) for use in spatial analysis. Digital base map data files (topography, roads, towns, rivers and lakes, and others.) are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:250,000 (for example, 1:100,000 or 1:24,000). The digital geologic map graphics and plot files (pull250k.gra/.hp /.eps) that are provided in the digital package are representations of the digital database.

Publications - GMC 361 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 361 Publication Details Title: X-ray Diffraction Analysis of: Drew Point #1, East Simpson Test , 2009, X-ray Diffraction Analysis of: Drew Point #1, East Simpson Test Well #1, East Simpson #2

Reconnaissance surficial geologic map of the Taylor Mountains quadrangle, southwestern Alaska

USGS Publications Warehouse

Wilson, Frederic H.

2015-09-28

I used the Platt and Muller 1950s-era aerial photographic interpretation map as the starting point for the surficial geology; their unpublished data were produced using a reconnaissance quality topographic base map. In addition to transferring their data to a modern base to use as a guide, all of the photographs were re-examined. As result, in a number of areas, the features have been reinterpreted and the linework revised. A major difference between the maps is the recognition of much more extensive glacially dammed lake deposits and reassignment of some glacial deposits to different glacial events.

Stromatolite- and coated-grain-bearing carbonate rocks of the western Brooks Range: A section in Geologic studies in Alaska by the U.S. Geological Survey during 1987

USGS Publications Warehouse

Dumoulin, Julie A.

1988-01-01

Carbonate rocks characterized by locally abundant stromatolites and coated grains have been found at several localities in the Baird Mountains and Ambler River quadrangles (fig. 1). These rocks are part of a belt of metasedimentary and metaigneous rocks that constitutes the southwestern flank of the Brooks Range; all are included in the parautochthon (Schwatka sequence) of Mayfield and others (1983). The rocks have been deformed and metamorphosed to blueschist and greenschist facies, but primary textures and sedimentary structures are locally well preserved.

A geological and geochemical reconnaissance of the Tathlith one-degree quadrangle, sheet 19/43, Kingdom of Saudi Arabia

USGS Publications Warehouse

Overstreet, William C.

1978-01-01

The Tathlith one-degree quadrangle occupies an area of 11,620 sq km in the northeastern Asir region of the Kingdom of Saudi Arabia, in the southeastern part of the Precambrian shield. In the eastern part of the quadrangle the Precambrian rocks are covered by exposures of easterly-dipping sandstone of Cambrian or Ordovician age. A well-developed and highly integrated drainage system trending northward is worn into the Precambrian rocks, but for most of the year the wadis are dry. The Precambrian rocks of the quadrangle consist of an old, non-metamorphosed to variably metamorphosed sequence of volcanic and sedimentary rocks intruded by three main successions of plutonic and hypabyssal igneous rocks. The interlayered volcanic and sedimentary rocks occupy arcuate, north-trending fold belts in which old, rather tight north-trending folds have been refolded at least once by open folds with nearly east-trending axes. Old, north-trending left-lateral faults are associated with the fold belts and are themselves intersected by younger, northwest-trending faults. Motion on both sets of faults has been reactivated several times. The interlayered volcanic and sedimentary rocks are an eugeosynclinal sequence of graywacke and andesite with sparse marble, quartzite, and rhyolite. Andesite is the dominant component of the sequence. Plutonic or hypabyssal equivalents of the andesite intrude the volcanic-sedimentary sequence. In many places these rocks are essentially non-metamorphosed, but elsewhere they are faintly to strongly metamorphosed, or even polymetamorphosed. Dynamothermal metamorphism associated with the northerly folding, and contact metamorphism are the principal kinds of metamorphism. The metamorphic grade is mostly greenschist facies or albite-epidote amphibolite facies. The largest intrusive in the area is a batholith of regional dimension, the east side of which intrudes and divides the fold belts. Granite gneiss and granodiorite gneiss are the main components of the batholith. Biotite granite of calc-alkaline composition, and somewhat younger than the granite gneiss and granodiorite gneiss, forms northerly elongate to subcircular plutons in the gneisses and the rocks of the volcanic-sedimentary sequence.

Surficial geologic map of the Elizabethtown 30' x 60' quadrangle, North Carolina

USGS Publications Warehouse

Weems, Robert E.; Lewis, William C.; Crider, E. Allen

2011-01-01

The Elizabethtown 30' x 60' quadrangle is located in southeastern North Carolina between Fayetteville and Wilmington. Most of the area is flat to gently rolling, although steep slopes occur locally along some of the larger streams. Total relief in the area is slightly over 210 feet (ft), with elevations ranging from slightly less than 10 ft above sea level along the Black River (east of Rowan in the southeastern corner of the map) to slightly over 220 ft in the northwestern corner northeast of Hope Mills. The principal streams in the area are the Cape Fear, Black, South, and Lumber Rivers, which on average flow from northwest to southeast across the map area. The principal north-south roads are Interstate Route 95, Interstate Route 40, U.S. Route 117, U.S. Route 301, U.S. Route 421, and U.S. Route 701, and the principal east-west roads are N.C. State Route 241 and N.C. State Route 41. This part of North Carolina is primarily rural and agricultural. The largest communities in and adjacent to the area are Elizabethtown, Hope Mills, Clinton, Warsaw, and Lumberton. The map lies entirely within the Atlantic Coastal Plain physiographic province. Outstanding features of this area are the large number of sand-rimmed Carolina bays, five of which contain enough water to constitute natural lakes: Bay Tree Lake, Salter Lake, Little Singletary Lake, Singletary Lake, and White Lake. These are associated with widespread windblown sand deposits on which are grown abundant crops of blueberries. The extent and distribution of these deposits have been estimated based on a combination of augerhole, outcrop, and light-detection and ranging (LIDAR) data. The geology of the Elizabethtown 30' x 60' quadrangle was originally mapped on 32 7.5-minute quadrangles at 1:24,000 scale and then compiled on this 1:100,000-scale base. The base-map topographic contours on this compilation are shown in meters; the cross sections, structure contours, and well and corehole basement elevations have been carried over unconverted from the 1:24,000-scale maps and are shown in feet.

Aerial gamma ray and magnetic survey: Powder River II Project, Newcastle Quadrangle, Wyoming. Final report

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

Not Available

1979-04-01

Thick Phanerozoic sediments (greater than 17,000 ft) fill the northwest trending Powder River Basin which is the dominant tectonic structure in the Newcastle quadrangle. Lower Tertiary sediments comprise more than 85% of exposed units at the surface of the Basin. A small portion of the Black Hills Uplift occupies the eastern edge of the quadrangle. Residual magnetics clearly reflect the great depth to crystalline Precambrian basement in the Basin. The Basin/Uplift boundary is not readily observed in the magnetic data. Economic uranium deposits of roll-type configuration are present in the southwest within the Monument Hill-Box Creek District in fluvial sandstonesmore » of the Paleocene Fort Union Formation. Numerous small claims and prospects are found in the Pumpkin Buttes-Turnercrest District in the northwest. Interpretation of the radiometric data resulted in 86 statistical uranium anomalies listed for this quadrangle. Most anomalies are in the eastern-central portion of the map within Tertiary Fort Union and Wasatch Formations. However, several lie in the known uranium districts in the southwest and northwest.« less

Surficial Geologic Map of the Ashby-Lowell-Sterling-Billerica 11-Quadrangle Area in Northeast-Central Massachusetts

USGS Publications Warehouse

Stone, Byron D.; Stone, Janet R.

2007-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of eleven 7.5-minute quadrangles (total 505 mi2) in northeast-central Massachusetts. 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 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. 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 report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (PDF files), GIS data layers (ArcGIS shapefiles), metadata for the GIS layers, scanned topographic base maps (TIF), and a readme.txt file.

Geologic Map of the Wilderness and Handy Quadrangles, Oregon, Carter, and Ripley Counties, Missouri

USGS Publications Warehouse

Harrison, Richard W.; McDowell, Robert C.

2003-01-01

The bedrock exposed in the Wilderness and Handy Quadrangles, Missouri, comprises Early Ordovician aged dolomite, sandstone, and chert. The sedimentary rocks are nearly flat-lying except where they are adjacent to faults. The carbonate rocks are karstified and the area contains numerous sinkholes, springs, caves, and losing-streams. This map is one of several being produced under the U.S. Geological Survey National Cooperative Geologic Mapping Program to provide geologic data applicable to land-use problems in the Ozarks of south-central Missouri. Ongoing and potential industrial and agricultural development in the Ozarks region has presented issues of ground-water quality in karst areas. These quadrangles contain significant areas of the Mark Twain National Forest, including part of the Eleven Point National Scenic Riverway and the Irish Wilderness Roadless Area. A National Park in this region (Ozark National Scenic Riverways, Missouri ) is concerned about the effects of activities in areas outside of their stewardship on the water resources that define the heart of this Park. This task applies geologic mapping and karst investigations to address issues surrounding competing land use in south-central Missouri. For more information see: http://geology.er.usgs.gov/eespteam/Karst/index.html

Frequency dependent Lg attenuation in south-central Alaska

USGS Publications Warehouse

McNamara, D.E.

2000-01-01

The characteristics of seismic energy attenuation are determined using high frequency Lg waves from 27 crustal earthquakes, in south-central Alaska. Lg time-domain amplitudes are measured in five pass-bands and inverted to determine a frequency-dependent quality factor, Q(f), model for south-central Alaska. The inversion in this study yields the frequency-dependent quality factor, in the form of a power law: Q(f) = Q0fη = 220(±30) f0.66(±0.09) (0.75≤f≤12Hz). The results from this study are remarkably consistent with frequency dependent quality factor estimates, using local S-wave coda, in south-central Alaska. The consistency between S-coda Q(f) and Lg Q(f) enables constraints to be placed on the mechanism of crustal attenuation in south-central Alaska. For the range of frequencies considered in this study both scattering and intrinsic attenuation mechanisms likely play an equal role.

Reconnaissance geologic map of the Hyampom 15' quadrangle, Trinity County, California

USGS Publications Warehouse

Irwin, William P.

2010-01-01

The Hyampom 15' quadrangle lies west of the Hayfork 15' quadrangle in the southern part of the Klamath Mountains geologic province of northern California. It spans parts of four generally northwest-trending tectono- stratigraphic terranes of the Klamath Mountains, the Eastern Hayfork, Western Hayfork, Rattlesnake Creek, and Western Jurassic terranes, as well as, in the southwest corner of the quadrangle, a small part of the Pickett Peak terrane of the Coast Range province. Remnants of the Cretaceous Great Valley overlap sequence that once covered much of the pre-Cretaceous bedrock of the quadrangle are now found only as a few small patches in the northeast corner of the quadrangle. Fluvial and lacustrine deposits of the mid-Tertiary Weaverville Formation crop out in the vicinity of the village of Hyampom. The Eastern Hayfork terrane is a broken formation and m-lange of volcanic and sedimentary rocks that include blocks of chert and limestone. The chert has not been sampled; however, chert from the same terrane in the Hayfork quadrangle contains radiolarians of Permian and Triassic ages, but none clearly of Jurassic age. Limestone at two localities contains late Paleozoic foraminifers. Some of the limestone from the Eastern Klamath terrane in the Hayfork quadrangle contains faunas of Tethyan affinity. The Western Hayfork terrane is part of an andesitic volcanic arc that was accreted to the western edge of the Eastern Hayfork terrane. It consists mainly of metavolcaniclastic andesitic agglomerate and tuff, as well as argillite and chert, and it includes the dioritic Ironside Mountain batholith that intruded during Middle Jurassic time (about 170 Ma). This intrusive body provides the principal constraint on the age of the terrane. The Rattlesnake Creek terrane is a melange consisting mostly of highly dismembered ophiolite. It includes slabs of serpentinized ultramafic rock, basaltic volcanic rocks, radiolarian chert of Triassic and Jurassic ages, limestone containing Late Triassic conodonts and Permian or Triassic foraminifers, and small exotic(?) plutons. The plutons probably are similar to ones to the southeast beyond the quadrangle boundary that yielded isotopic ages ranging from 193 Ma to 207 Ma. The Rattlesnake Creek terrane contains several areas of well- bedded sedimentary rocks (rcs) that somewhat resemble the Galice(?) Formation and may be inliers of the Western Jurassic terrane. The Western Jurassic terrane in the Hyampom quadrangle appears to consist only of a narrow tectonic sliver of slaty to semischistose detrital sedimentary rocks of the Late Jurassic Galice(?) Formation. The isotopic age of metamorphism of the rocks is about 150 Ma, which probably indicates when the terrane was accreted to the Rattlesnake Creek terrane. The Pickett Peak terrane, which is the most westerly of the succession of terranes in the Hyampom quadrangle, is the accreted eastern margin of the Coast Ranges province. It mainly consists of semischistose and schistose metagraywacke of the South Fork Mountain Schist and locally contains the blueschist-facies mineral lawsonite. Isotopic analysis indicates a metamorphic age of 120 to 115 Ma. During the Cretaceous period, much of the southern fringe of the Klamath Mountains was onlapped by sedimentary strata of the Great Valley sequence. However, much of the onlapping Cretaceous strata has since been eroded away, and in the Hyampom quadrangle only a few small remnants are found in the northeast corner near Big Bar. Near the west edge of the quadrangle, in the vicinity of the village of Hyampom, weakly consolidated fluvial and lacustrine rocks and coaly deposits of Oligocene and (or) Miocene age are present. These rocks are similar to the Weaverville Formation that occurs in separate sedimentary basins to the east in the Weaverville and Hayfork 15? quadrangles. This map of the Hyampom 15' quadrangle is a digital version of U.S. Geological Survey Miscellaneous Field Stu

77 FR 19564 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher Vessels Using Trawl...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-02

... Catcher Vessels Using Trawl Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National... (CVs) using trawl gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... apportioned to CVs using trawl gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs...

78 FR 18528 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher Vessels Using Trawl...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

... Catcher Vessels Using Trawl Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National... (CVs) using trawl gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... apportioned to CVs using trawl gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs...

78 FR 73454 - Fisheries of the Exclusive Economic Zone Off Alaska; Reallocation of Pacific Cod in the Central...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

... in the Gulf of Alaska exclusive economic zone according to the Fishery Management Plan for Groundfish.... 120918468-3111-02] RIN 0648-XC976 Fisheries of the Exclusive Economic Zone Off Alaska; Reallocation of Pacific Cod in the Central Regulatory Area of the Gulf of Alaska Management Area AGENCY: National Marine...

2005 Volcanic Activity in Alaska, Kamchatka, and the Kurile Islands: Summary of Events and Response of the Alaska Volcano Observatory

USGS Publications Warehouse

McGimsey, R.G.; Neal, C.A.; Dixon, J.P.; Ushakov, Sergey

2008-01-01

The Alaska Volcano Observatory (AVO) responded to eruptive activity or suspected volcanic activity at or near 16 volcanoes in Alaska during 2005, including the high profile precursory activity associated with the 2005?06 eruption of Augustine Volcano. AVO continues to participate in distributing information about eruptive activity on the Kamchatka Peninsula, Russia, and in the Kurile Islands of the Russian Far East, in conjunction with the Kamchatkan Volcanic Eruption Response Team (KVERT) and the Sakhalin Volcanic Eruption Response Team (SVERT), respectively. In 2005, AVO helped broadcast alerts about activity at 8 Russian volcanoes. The most serious hazard posed from volcanic eruptions in Alaska, Kamchatka, or the Kurile Islands is the placement of ash into the atmosphere at altitudes traversed by jet aircraft along the North Pacific and Russian Trans East air routes. AVO, KVERT, and SVERT work collaboratively with the National Weather Service, Federal Aviation Administration, and the Volcanic Ash Advisory Centers to provide timely warnings of volcanic eruptions and the production and movement of ash clouds.

Reconnaissance geochemical survey of Al Jurdhawiyah and Wadi al Jarir quadrangles, sheets 25/42 D and 25/42 C, Kingdom of Saudia Arabia

USGS Publications Warehouse

Samater, Rashid M.

1983-01-01

A reconnaissance wadi-sediment geochemical survey was conducted in the Al Jurdhawiyah (sheet 28/42 D) and Wadi al Jarir (sheet 2G/42 C) quadrangles in order to identify anomalies potentially related to mineralized rock. Sieved bulk-sediment fractions and pan concentrates were created from the original samples collected from wadis in the two quadrangles. A semiquantitative 30-element spectrographic analysis was completed on both the sieved bulk-sediment fraction and the pan concentrate of each sample. The results were statistically analyzed in an attempt to identify anomalous regions. Anomaly threshold values were calculated for most elements; the threshold value of an element in a data set is defined as the geometric mean value plus two standard deviations. The Bald al Jimalah West tin-tungsten deposit (MODS 02661) in the southern part of the Al Jurdhawiyah quadrangle was identified by one pan-concentrate sample containing anomalous concentrations of tin and tungsten. Samples near the Bald al Jimalah East ancient lead-zinc-silver mines (MODS 00960) contain strongly anomalous concentrations of tin and lead and to a lesser extent of tungsten and copper. Both of these regions and other regions containing anomalous concentrations of certain elements are recommended for additional studies. A comparison of results obtained from sieved bulk-sediment fractions and pan concentrates indicates that the latter is the better medium for these geochemical investigations.

Geochemistry, petrography, and zircon U-Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon-Tanana terrane

USGS Publications Warehouse

Dusel-Bacon, Cynthia; Day, Warren C.; Aleinikoff, John N.

2013-01-01

We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and Fortymile River assemblages. Whole-rock trace-element data from the tonalitic gneiss, whose igneous protolith was dated by SHRIMP U–Pb zircon geochronology at 332.6 ± 5.6 Ma, indicate derivation from tholeiitic arc basalt. Whole-rock analyses of the mafic rocks suggest that greenschist-facies rocks from the Chicken metamorphic complex, a mafic metavolcanic rock from the Nasina assemblage, and an amphibolite from the Fortymile River assemblage formed as island-arc tholeiite in a back-arc setting; another Nasina assemblage greenschist has MORB geochemical characteristics, and another mafic metaigneous rock from the Fortymile River assemblage has geochemical characteristics of calc-alkaline basalt. Our geochemical results imply derivation in an arc and back-arc spreading region within the allochthonous YTT crustal fragment, as previously proposed for correlative units in other parts of the terrane. We also describe the petrography and geochemistry of a newly discovered tectonic lens of Alpine-type metaharzburgite. The metaharzburgite is interpreted to be a sliver of lithospheric mantle from beneath the Seventymile ocean basin or from sub-continental mantle lithosphere of the allochthonous YTT or the western margin of Laurentia that was tectonically emplaced within crustal rocks during closure of the Seventymile ocean basin and subsequently displaced and fragmented by faults.

Surficial Geologic Map of the Salem Depot-Newburyport East-Wilmington-Rockport 16-Quadrangle Area in Northeast Massachusetts

USGS Publications Warehouse

Stone, Byron D.; Stone, Janet Radway; DiGiacomo-Cohen, Mary L.

2006-01-01

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of 16 7.5-minute quadrangles (total 658 mi2) in northeast Massachusetts. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (grain size, sedimentary structures, mineral and rock-particle composition), constructional geomorphic features, stratigraphic relationships, and age. 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. 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 report includes explanatory text (PDF), a regional map at 1:50,000 scale (PDF), quadrangle maps at 1:24,000 scale (PDF files), GIS data layers (ArcGIS shapefiles), metadata for the GIS layers, scanned topographic base maps (TIF), and a readme.txt file.

[Systematics and genegeography of Juniperus communis inferred from isoenzyme data].

PubMed

Khantemirova, E V; Berkutenko, A N; Semerikov, V L

2012-09-01

Using isoenzyme analysis, 35 populations of Juniperus communis L. from various parts of the Russian species range and by one population from Sweden and Alaska were studied. The total sample size was 1200 plants. As a result, the existence ofJ. communis var. oblonga in North Caucasus and J. communis var. depressa in North America was confirmed, but genetic differences between J. communis var. communis and J. communis var. saxatilis were not detected in the main part of the Russian species range (European part of Russia, Ural, Siberia). These populations proved to be genetically uniform with the same predominant allelic frequencies, which may evidence recent settling of this species from one of Central or East European refugium. J. communis var. saxatilis from northeastern Russia inhabiting the region behind Verkhoyansk mountain and Russian Far East showed considerable differentiation in frequencies of alleles at three loci and geographical subdivision. These populations also exhibit high intrapopulation variation. This can be connected with the refugium in this territory. The origin of this group is probably connected with migrations from Central Asia (Tibet) in the direction to northeastern Russia along mountains connecting Central and North Asia. It is also assumed that migrations of this species previously proceeded across the Beringian land bridge.

Geologic Map of the Albuquerque 30' x 60' Quadrangle, North-Central New Mexico

USGS Publications Warehouse

Williams, Paul L.; Cole, James C.

2007-01-01

The Albuquerque 30' x 60' quadrangle spans the Rio Grande rift between the Colorado Plateau and Great Plains geologic provinces, and includes parts of the Basin and Range and Southern Rocky Mountain physiographic provinces. Geologic units exposed in the quadrangle range in age from Early Proterozoic schist and granite to modern river alluvium. The principal geologic features of the area, however, chiefly reflect contractional folding and thrusting of the Late Cretaceous Laramide orogeny and the Neogene extension of the Rio Grande rift. Significant parts of the history of the rift in this region are displayed and documented by the geology exposed in the Albuquerque quadrangle. Post-Laramide erosion, beginning at about 60 Ma, is recorded by the Diamond Tail and Galisteo Formations (upper Paleocene and Eocene) that are preserved in the Hagan Basin and around the uplifted margins of the younger Rio Grande rift. Intermediate volcaniclastic deposits of the Espinaso Formation (upper Eocene and Oligocene) were shed in and around the contemporaneous volcanic-intrusive complexes of the Ortiz porphyry belt in the northeastern part of the quadrangle. The earliest fluvial sediments attributed to extension in the Rio Grande rift in this area are the Tanos and Blackshare Formations (upper Oligocene and Miocene) in the Hagan Basin, which indicate extension was underway by 25 Ma. Farther west, the oldest rift-filling sediments are eolian sand and interdune silty deposits of the Zia Formation (lower to middle Miocene). Major extension occurred during the Miocene, but subsidence and sedimentation were highly irregular from place to place. Parts of three rift sub-basins are known within the Albuquerque quadrangle, each basin locally as deep as about 14,000 ft, separated by less-extended zones (structural horsts) where the rift fill is much thinner. The geometry of these early, deep rift sub-basins suggests the primary extension direction was oriented northeast-southwest. Significant local folding and uplift within the complex rift seems to have occurred in the late Miocene, accompanied by erosion and recycling of earlier rift-fill sediments. This deformation may reflect clockwise reorientation of the primary extension direction to its Pliocene and current east-west alignment. Late Miocene and early Pliocene uplift and erosion were widespread in the region, as indicated by channeled and local angular unconformities at the bases of all Pliocene units, especially prominent along basin margins. These Pliocene fluvial and alluvial deposits (Ceja and Ancha Formations and Tuerto Gravel) and the upper part of the Cochiti Formation are all conspicuously coarser grained than the Miocene beds they cover, particularly near source areas along the margins of the rift. These observations together indicate that the regional streams flowed at much greater discharge than the Miocene streams and that the Pliocene onset of cooler, wetter climate worldwide was the most likely cause. Despite these higher discharge conditions, it appears there was no Pliocene trunk stream through the rift valley because the youngest Pliocene beds in the basin center are largely fine grained sand, pebbly sand, and sandy silt. No Pliocene cobble-gravel deposits, or thick crossbed sets indicative of major stream discharge, have been documented in the basin center. Considerable evidence indicates significant erosion began in late Pliocene time, coincident with and following eruption of abundant basalt from several local centers at about 2.7-2.6 Ma. The onset of central valley erosion marks the initiation of the first through-flowing, high-energy trunk stream (the 'ancestral' Rio Grande), which most likely was caused by integration of drainage southward through the Socorro region. No upper Pliocene fluvial deposits have been identified in the valley center; rather, a significant unconformity separates beds with medial (or earliest late) Blancan fauna (older than about 2.2 Ma) from

Major- and trace-element concentrations in rock samples collected in 2004 from the Taylor Mountains 1:250,000-scale quadrangle, Alaska

USGS Publications Warehouse

Klimasauskas, Edward P.; Miller, Marti L.; Bradley, Dwight C.; Karl, Sue M.; Baichtal, James F.; Blodgett, Robert B.

2006-01-01

The Kuskokwim mineral belt of Bundtzen and Miller (1997) forms an important metallogenic region in southwestern Alaska that has yielded more than 3.22 million ounces of gold and 400,000 ounces of silver. Precious-metal and related deposits in this region associated with Late Cretaceous to early Tertiary igneous complexes extend into the Taylor Mountains 1:250,000-scale quadrangle. The U.S. Geological Survey is conducting geologic mapping and a mineral resource assessment of this area that will provide a better understanding of the geologic framework, regional geochemistry, and may provide targets for mineral exploration and development. During the 2004 field season 137 rock samples were collected for a variety of purposes. The 4 digital files accompanying this report reflect the type of analysis performed and its intended purpose and are available for download as an Excel workbook, comma delimited format (*.csv), dBase 4 files (*.dbf) or as point coverages in ArcInfo interchange format (*.e00). Data values are provided in percent, pct (1gram per 100grams), or parts per million, ppm (1gram per 1,000,000grams) per the column heading in the table. All samples were analyzed for a suite of 42 trace-elements (icp42.*) to provide data for use in geochemical exploration as well as some baseline data. Selected samples were analyzed by additional methods; 104 targeted geochemical exploration samples were analyzed for gold, arsenic, and mercury (auashg.*); 21 of these samples were also analyzed to obtain concentrations of 10 loosely bound metals (icp10.*); 33 rock samples were analyzed for major element oxides to support the regional mapping program (reg.*), of which 28 sedimentary rock samples were also analyzed for total carbon, and carbonate carbon.

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance bedrock geologic map for the northern Alaska peninsula area, southwest Alaska

USGS Publications Warehouse

,

2006-01-01

he growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Uranium hydrogeochemical and stream sediment reconnaissance data from the area of the Shishmaref, Kotzebue, Selawik and Shungnak Quadrangles, northern Seward Peninsula and vicinity, Alaska

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

Warren, R.G.; Hill, D.E.; Sharp, R.R. Jr.

1978-05-01

During the summer of 1976, 1336 water and 1251 sediment samples were collected for Los Alamos Scientific Laboratory (LASL) from 1356 streams and small lakes or ponds within Shishmaref, Kotzebue, Selawik, and western portion of Shungnak NTMS quadrangles in western Alaska. Both a water and sediment sample were generally obtained from each location at a nominal location density of 1/23 km/sup 2/. Total uranium was measured in waters by fluorometry and in sediments and a few waters by delayed neutron counting at LASL. Uranium concentrations in waters have a mean of 0.31 ppB and a maximum of 9.23 ppB, andmore » sediments exhibit a mean of 3.44 ppM and a maximum of 37.7 ppM. A large number of high-uranium concentrations occur in both water and sediment samples collected in the Selawik Hills. At least two locations within the Selawik Hills appear favorable for further investigation of possible uranium mineralization. A cluster of high-uranium sediments, seen in the Waring Mountains, are probably derived from a lower Cretaceous conglomerate unit which is assocated with known airborne radiometric anomalies. Apparently less favorable areas for further investigation of possible uranium mineralization are also located in the Waring Mountains and Kiana Hills. Additional samples were collected within the Shungnak quadrange to increase the sampling density used elsewhere in the area to about one location per 11 km/sup 2/ (double-density). Contoured plots of uranium concentrations for both waters and sediments were prepared for all double-density sample locations, and then for the even-numbered and odd-numbered locations separately. These plots indicate that the HSSR sampling density of 1/23 km/sup 2/ used in lowland areas of Alaska provide essentially the same definition of relative areal uranium distributions in waters and sediments as seen when the density is doubled. These plots indicate that regional distribution patterns for uranium are well defined without selective sampling of geologic units.« less

75 FR 73981 - Fisheries of the Exclusive Economic Zone Off Alaska; Big Skate in the Central Regulatory Area of...

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2010-11-30

.... 0910131362-0087-02] RIN 0648-XA066 Fisheries of the Exclusive Economic Zone Off Alaska; Big Skate in the... prohibiting retention of big skate in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2010 total allowable catch (TAC) of big skate in the Central Regulatory Area of the...

77 FR 62464 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

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2012-10-15

... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2012 Pacific cod total allowable catch apportioned to vessels using pot gear in the Central...

78 FR 23683 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher/Processors Using...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

... Catcher/Processors Using Trawl Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National... (C/Ps) using trawl gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... apportioned to C/Ps using trawl gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hours...