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Sample records for north basin icnologia

  1. VIEW TO EAST OF THE NORTH END OF BASIN NO. ...

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

    VIEW TO EAST OF THE NORTH END OF BASIN NO. 1 (THE WESTERN-MOST BASIN) SHOWING THE CRANEWAY AND GALLERY BETWEEN BASINS NO. 1 AND 2. BASSWOOD BUOY TENDER AND THREE SMALL VESSELS ARE BERTHED IN BASIN NO. 1. LARGER VESSELS ARE BERTHED IN BASINS TO THE EAST, SEEN IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  2. 9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. ...

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

    9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. NOTE THE LEVEE TO THE RIGHT. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  3. AERIAL VIEW, LOOKING NORTH NORTHWEST, OF ARRASTRA BASIN, SILVER LAKE, ...

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

    AERIAL VIEW, LOOKING NORTH NORTHWEST, OF ARRASTRA BASIN, SILVER LAKE, AND THE SHENANDOAH-DIVES (MAYFLOWER) MILL IN DISTANT ANIMAS VALLEY. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  4. Subsidence history of Williston basin in North Dakota

    SciTech Connect

    Lefever, R.D.

    1988-07-01

    The tectonic subsidence history of the Williston basin in North Dakota has been estimated through the examination of wireline logs from 30 wells that penetrated to Precambrian basement. The initial subsidence of the basin in North Dakota began at a time not later than during deposition of the middle portion of the Deadwood Formation (earliest Ordovician; about 495-490 Ma), significantly earlier than had been estimated by most workers. The initial subsidence was centered in a north-south-trending elongate area in western North Dakota; the maximum calculated tectonic subsidence rate for this event is about 15 m/m.y. Since the Early Ordovician, exclusive of the basin initiation event, the basin has undergone at least five distinct episodes of tectonic subsidence: (1) from about 450-420 Ma, (2) from 420-355 Ma, (3) from 355-315 Ma, (4) from 270-245 Ma, and (5) beginning in the interval between about 90 and 70 Ma. Each of the subsidence episodes was characterized by a rapid initial subsidence, followed by a decline to very low subsidence rates. The maximum calculated initial subsidence rates for these episodes are 26, 32, 16, 9, and 15 m/m.y, respectively. The time between episodes 4 and 5 seems to have been one of relative quiescence; the few rocks preserved from that time interval were deposited during highstands of sea level. The subsidence history curves for episodes 1-4 are consistent with a thermal expansion model; however, with the exception of episode 3 and possibly episode 4, none of the first four subsidence events appears to be temporally coincident with major tectonic events elsewhere in North America.

  5. Paleozoic tectonic history of the Arctic basin north of Alaska

    USGS Publications Warehouse

    Churkin, M.

    1969-01-01

    The geology of the margin of the Canada Basin, together with geophysical data, leads me to reject the continental subsidence theory for the origin of the deep Canada Basin. Instead, the Canada Basin is, I believe, a true and probably very ancient ocean basin floored by oceanic crust and rimmed by an early Paleozoic geosynclinal belt. In the Upper Devonian, uplifts in this circumarctic geosyncline, accompanied by granitic intrusion, produced a wedge of coarse clastic sediments (exogeosyncline) that spread southward onto adjoining areas of Alaska, Canada, and Siberia. In both northern Alaska and the Canadian Arctic Islands, thick sequences of upper Paleozoic and younger strata were deposited unconformably on the rocks of the early Paleozoic geosyncline, showing a similarity in tectonic history between the areas. The Paleozoic history of the southern rim of the Canada Basin resembles that of other mobile belts bordering North America. The movement of the floor of the Arctic Ocean against the continental crust of North America (sea-floor spreading) would provide a mechanism to account for the long history of orogenic activity along the basin margin. The sharp bend in the structural elements of southern Alaska (the Alaska orocline) has been cited as evidence of clockwise rotation of the Arctic Islands of Canada from Alaska and the Soviet Arctic to their present position during the Mesozoic. However, the geologic and geophysical evidence available indicates that the Arctic basin has a longer history, extending into the Paleozoic, and that this bend in Alaskan structures may have been largely caused by spreading of the Pacific sea floor against the continental margin in the Gulf of Alaska.

  6. Accretion and hydrothermalism in North Fiji basin, Southwest Pacific

    SciTech Connect

    Auzende, J.M.; Eissen, J.P.

    1986-07-01

    The North Fiji basin is a marginal basin surrounded by: (1) the New Hebrides island arc in the west, which ends at the Matthew-Hunter Ridge in the south; (2) the Hunter fracture zone in the southeast; (3) the Fiji Islands in the east; and (4) the complex Vitiaz Trench system in the north. The investigations in this area suggest a complex opening has been active for approximately the past 10 m.y. The detailed bathymetry and the structure of the central part of this basin are still poorly known. The major element consists of an axial ridge. The trend of this ridge is imprecise, but it is probably oriented north-south near 173.5/sup 0/E, at least between 21/sup 0/ and 15/sup 0/S. The other remarkable feature consists of a complex system of ridges and faulted blocks running along the western edge of the Fiji Archipelago. This system has been interpreted by some authors as an accretion ridge. The purposes of the third leg of SEAPSO cruise onboard the R/V Jean-Charcot (December 2-24, 1985) are as follows: (1) to explore the typical structures of the North Fiji basin between 21/sup 0/ and 17/sup 0/S (axial ridge, seamounts, fracture zones, and the complex border west of Fiji), using multibeam echo-sounder (Seabeam), seismic reflection, magnetic, and gravimetric surveys; and (2) to complete Seabeam coverage and samplings (such as dredging, coring, water sampling, and bottom photographs) of two to three small box-shaped areas on the axial ridge, in order to localize and eventually characterize hydrothermal vents. The various morphotectonic, petrologic, chemical, and geodynamic results of this survey will be discussed.

  7. Corals of Madison Group (Mississippian), Williston Basin, North Dakota

    SciTech Connect

    Waters, D.L.; Holland, F.D. Jr.

    1983-08-01

    Coral faunas studied from subsurface cores of the Mississippian Madison Group in the Williston Basin of North Dakota indicate that Sando's coral zones for outcrops in western North America can be extended into the subsurface of North Dakota. Coral zones II and III are recognized as corresponding roughly to lower and upper Mission Canyon strata, respectively. These data were obtained from 12 wells along the northern border of North Dakota in Divide, Burke, Renville, and Bottineau Counties, and two wells near the center of Williston basin in Dunn and McKenzie Counties. Corals found in dark argillaceous crinoid-skeletal wackestones representing deeper waters are robust, and this may infer a hospitable environment for their growth. However, evidence from the coral and lithologic associations refute the pervading dogma that the occurrence of corals is strictly facies controlled. Abundant smaller corals have been found from buff-colored skeletal wackestones and algal mudstones which alternate with subaqueous anhydrites representing a marginal marine environment. In addition, corals have been found in buff-colored skeletal and peloidal grainstones of adjacent shoals and in brown pisolitic-oolitic packstones-wackestones of possible tidal ponds. These latter deposits may represent allochthonous accumulations, but the amount of time involved in transport of corals would not invalidate their usefulness as biostratigraphic tools.

  8. Sediment quality in the north coastal basin of Massachusetts, 2003

    USGS Publications Warehouse

    Breault, Robert F.; Ashman, Mary S.; Heath, Douglas

    2004-01-01

    The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, completed a reconnaissance-level study of bottom-sediment quality in selected lakes, rivers, and estuaries in the North Coastal Basin of Massachusetts. Bottom-sediment grab samples were collected from 20 sites in the North River, Lake Quannapowitt, Saugus River, Mill River, Shute Brook, Sea Plane Basin, Pines River, and Bear Creek. The samples were tested for various types of potentially harmful contaminants? including 33 elements, 17 polyaromatic hydrocarbons (PAHs), 22 organochlorine pesticides, and 7 polychlorinated biphenyl (PCB) mixtures (Aroclors)?to benthic organisms (bottom-dwelling) and humans. The results were compared among sampling sites, to background concentrations, and to concen-trations measured in other urban rivers, and sediment-quality guidelines were used to predict toxicity at the sampling sites to benthic organisms and humans. Because there are no standards for human toxicity for aquatic sediment, standards for contaminated upland soil were used. Contaminant concentrations measured in sediment collected from the North Coastal Basin generally were equal to or greater than concentrations in sediment from uncontaminated rivers throughout New England. Contaminants in North Coastal Basin sediment with elevated concentrations (above back-ground levels) included arsenic, chromium, copper, lead, nickel, and zinc, some of the PAHs, dichlorodiphenyltrichloro-ethane (DDT) and its metabolites, and dieldrin. No PCBs were measured above the detection limits. Measured concentrations of arsenic, chromium, and lead were also generally greater than those measured in other urban rivers throughout the conter-minous United States. With one exception (arsenic), local con-centrations measured in sediment samples collected from the North Coastal Basin were lower than concentrations measured in sediment collected from two of three urban rivers draining to Boston

  9. The North Pyrenean Aquitaine Basin, France: Evolution and hydrocarbons

    SciTech Connect

    Bourrouilh, R.; Richert, J.P.; Zolnaie, G.

    1995-06-01

    The Mesozoic-Tertiary Aquitaine basin overlaps the Aquitaine block and the northern edge of the Iberian margin. Both units are situated in the southwesternmost part of the European Continent. The Aquitaine shelf is a stable platform overlying a relatively thin crustal segment; it underwent extensional block faulting and many of its folded structures are related to salt tectonism. The Iberian block is a thicker lithospheric unit that acted as a buttress. At the junction of these two structural domains the South Aquitaine or North Pyrenean area developed, where crustal stretching, rifting, wrenching, and orogenic compression were maximal from the Mesozoic to the Tertiary. The history of the basin has been a suite of rifting attempts, in the context of the progressive opening of the Bay of Biscay, which never completely succeeded. The relative plate motions and the later convergence led, nevertheless, to the formation of the Aquitaine basin and to the emergence of the Pyrenean fold belt. The Mesozoic-Tertiary sedimentary infill of the basin is mostly marine, with thick evaporates, stable platform carbonates, subsiding platform shaly-calcareous deposits, and a characteristic, diachronous turbiditic (flysch) and molasse complex. Events during the basin-forming, extensional, and translational periods contributed more to the generation of the hydrocarbon accumulations than did the effects of the subsequent compressive structural regime. The latter, however, may have enhanced thermal flow and, thus, maturation of hydrocarbon source rocks.

  10. The Mesozoic rift basins of eastern North America: Potential reservoir or Explorationist's folly

    SciTech Connect

    Pyron, A.

    1991-08-01

    Mesozoic rift basins are found on the East Coast of North America from Georgia to Nova Scotia. The basins formed as a result of extensional activity associated with the breakup of Pangaea. The internal geometry of the basins includes a depositional sequence ranging from coarse fanglomerates to fine-grained siltstones and argillites. Since these Mesozoic rift basins were first studied, they have not been considered to be likely spots for hydrocarbon accumulations. Recently, geologists have reconsidered these Mesozoic basins and have developed a more synergistic approach that suggests that many of these rift basins might be suitable targets for exploration. By analogy, these Mesozoic basins are correlative to similar basins in northwestern Africa, where significant reserved of oil and natural gas have been developed. The similarity between the productive basins in northwestern Africa and the Mesozoic basins of North America and their proximity to major markets provides sufficient rationale to further investigate these basins.

  11. Lithosphere structure beneath the Phanerozoic intracratonic basins of North America

    NASA Astrophysics Data System (ADS)

    Kaminski, Edouard; Jaupart, Claude

    2000-05-01

    Four intracratonic basins of North America, the Hudson Bay, Michigan, Illinois and Williston basins, have similar ages and are close to one another. Yet, they exhibit different subsidence histories characterised by different time-scales and sediment thicknesses. They can be explained by local lithosphere thinning and by the cooling of the induced thermal anomaly. Within the framework of 1D thermal models for vertical heat transport, each basin requires a different lithosphere thickness or a different boundary condition at the base of the lithosphere. Heat flow and seismic studies show that, beneath the North American craton, the lithosphere is too thick for the assumption of purely vertical heat transfer to be valid. Thermal models are developed to account for finite thermal anomaly width and for two types of basal boundary conditions, fixed temperature or fixed heat flux. Different subsidence histories are explained by deep lithospheric anomalies of different sizes. The stability of thick continental roots requires the mantle part of the lithosphere to be compositionally buoyant with respect to 'normal' convecting mantle. Localised lithospheric thinning, due for example to plume penetration, results in the emplacement of compositionally denser mantle into the lithosphere. This represents a load which drives permanent flexure. The cooling time and the characteristics of flexure allow constraints on the dimensions of these deep lithospheric anomalies. There are no solutions for lithosphere thicknesses less than 170 km. The Williston and Illinois basins are associated with wide (˜200 km) and thin anomalies (˜100 km), whereas the Michigan and Hudson Bay are located on top of narrow (˜100 km) and tall (˜200 km) anomalies.

  12. Landslide inventory for the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

    This geodatabase is an inventory of existing landslides in the Little North Santiam River Basin, Oregon (2009). Each landslide feature shown has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  13. Madison Group (Mississippian) reservoir facies of Williston Basin, North Dakota

    SciTech Connect

    Lindsay, R.F.

    1985-02-01

    Twenty-seven oil fields producing from the Mission Canyon Limestone and Charles Formation (Madison Group) were studied: 1) along the eastern basin margin (Bluell, Sherwood, Mohall, Glenburn, Haas, and Chola fields), 2) northeast of Nesson anticline (Foothills, North Black Slough, South Black Slough, Rival, Lignite, and Flaxton), 3) along Nesson anticline (North Tioga, Tioga, Beaver Lodge, Capa, Hoffland, Charlson, Hawkeye, Blue Buttes, Antelope, and Clear Creek), and 4) south of the basin center (Lone Butte, Little Knife, Big Stick, Fryburg, and Medora). Mission Canyon reservoirs along the eastern margin are in several shoaling-upward carbonate to anhydrite cycles of pisolitic packstone or grainstone buildups. South of the basin center, only a single shoaling-upward sequence is present, with dolomitized, mostly restructed-marine skeletal wackstone to pelletal wackstone or packstone reservoir facies. Nesson anticline, between these 2 areas, contains a single shoaling-upward sequence without an anhydrite cap. In northern Nesson anticline, Mission Canyon reservoir facies are oolitic-pisolitic, intraclastic wackestone or grainstone buildups or open-marine skeletal packstone or grainstone. Both limestones and dolostones are productive in southern Nesson anticline. Limestone reservoir facies are transitional, open to restricted-marine slightly intraclastic, skeletal wackestone or packstone facies. Dolostone reservoir facies are restricted-marine mudstone to skeletal mudstone and pelletal wackestone or packstone. Northeast of the Nesson anticline, production is from oolitic to pisolitic packstone or grainstone buildups in the Rival subinterval and from restricted-marine, dolomitized spiculitic mudstone in the Midale subinterval (base of Charles Formation). In the northern Nesson anticline, Rival reservoir facies are offshore open to restricted-marine, skeletal, intraclastic, pelletal wackestone and/or packstones.

  14. Surface waters of North Boggy Creek basin in the Muddy Boggy Creek basin in Oklahoma

    USGS Publications Warehouse

    Laine, L.L.

    1958-01-01

    Analysis of short-term streamflow data in North Boggy Creek basin indicates that the average runoff in this region is substantial. The streamflow is highly variable from year to year and from month to month. The estimated total yield from the North Boggy Creek watershed of 231 square miles averages 155,000 acre-feet annually, equivalent to an average runoff depth of 12 1/2 inches. Almost a fourth of the annual volume is contributed by Chickasaw Creek basin, where about 35,000 acre-feet runs off from 46 square miles. Two years of records show a variation in runoff for the calendar year 1957 in comparison to 1956 in a ratio of 13 to 1 for the station on North Boggy Creek and a ratio of 18 to 1 for the station on Chickasaw Creek. In a longer-term record downstream on Muddy Boggy Creek near Farris, the corresponding range was 17 to 1, while the calendar years 1945 and 1956 show a 20-fold variation in runoff. Within a year the higher runoff tends to occur in the spring months, April to June, a 3-month period that, on the average, accounts for at least half of the annual flow. High runoff may occur during any month in the year, but in general, the streamflow is relatively small in the summer. Records for the gaging stations noted indicate that there is little or no base flow in the summer, and thus there will be periods of no flow at times in most years. The variation in runoff during a year is suggested by a frequency analysis of low flows at the reference station on Muddy Boggy Creek near Farris. Although the mean flow at that site is 955 cfs (cubic feet per second), the median daily flow is only 59 cfs and the lowest 30-day flow in a year will average less than 1 cfs in 4 out of 10 years on the average. The estimated mean flow on North Boggy Creek near Stringtown is 124 cfs, but the estimated median daily flow is only 3 1/2 cfs. Because of the high variability in streamflow, development of storage by impoundment will be necessary to attain maximum utilization of the

  15. Sedimentation and subsidence patterns in the central and north basins of Lake Baikal from seismic stratigraphy

    USGS Publications Warehouse

    Moore, T.C.; Klitgord, Kim D.; Golmshtok, A.J.; Weber, E.

    1997-01-01

    Comparison of sedimentation patterns, basement subsidence, and faulting histories in the north and central basins of Lake Baikal aids in developing an interbasinal seismic stratigraphy that reveals the early synrift evolution of the central portion of the Baikal rift, a major continental rift system. Although there is evidence that the central and northern rift basins evolved at approximately the same time, their sedimentation histories are markedly different. Primary sediment sources for the initial rift phase were from the east flank of the rift; two major deltas developed adjacent to the central basin: the Selenga delta at the south end and the Barguzin delta at the north end. The Barguzin River system, located at the accommodation zone between the central and north basins, also fed into the southern part of the north basin and facilitated the stratigraphic linkage of the two basins. A shift in the regional tectonic environment in the mid Pliocene(?) created a second rift phase distinguished by more rapid subsidence and sediment accumulation in the north basin and by increased subsidence and extensive faulting in the central basin. The Barguzin delta ceased formation and parts of the old delta system were isolated within the north basin and on Academic Ridge. These isolated deltaic deposits provide a model for the development of hydrocarbon plays within ancient rift systems. In this second tectonic phase, the dominant sediment fill in the deeper and more rapidly subsiding north basin shifted from the flexural (eastern) margin to axial transport from the Upper Angara River at the north end of the basin.

  16. Impact origin of the Newporte structure, Williston basin, North Dakota

    SciTech Connect

    Forsman, N.F.; Gerlach, T.R.; Anderson, N.L.

    1996-05-01

    The Newporte field is located just south of the United States-Canada border in Renville County, North Dakota, in the north-central portion of the Williston basin. Integration of seismic, well-log, and core data supports the interpretation of an impact origin for the Newporte structure. The structure involves both Precambrian basement and lower Paleozoic sedimentary units. Oil and gas production began in 1977 from brecciated basement rocks along the rim of the 3.2-km-diameter circular structure. Both well logs and seismic data were used to determine thickness changes of sedimentary units overlying the structure. Resulting isopach maps reveal a circular, bowl-shaped feature with a recognizable rim. Microscopic shock metamorphic features in quartz and feldspar are visible in basement clasts that form a mixed breccia with Cambrian Deadwood sandstone within the western rim of the structure. A Late Cambrian-Early Ordovician age is suggested for the structure because of the presence of flatlying Deadwood sandstone overlying mixed basement/sandstone breccia along portions of the rim. Identification of the Newporte structure as an impact crater adds to the growing base of evidence revealing the relevance of impact craters to petroleum exploration.

  17. Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin

    NASA Astrophysics Data System (ADS)

    Galloway, W.; Ganey-Curry, P. E.

    2010-12-01

    The Cenozoic fill of the Gulf of Mexico basin contains a continuous record of sediment supply from the North American continental interior for the past 65 million years. Regional mapping of unit thickness and paleogeography for 18 depositional episodes defines patterns of shifting entry points of continental fluvial systems and quantifies the total volume of sediment supplied during each episode. Eight fluvio-deltaic depocenters, named for geographic similarities to entry points and drainage basins of modern rivers, are present. From southwest to northeast, they are the Rio Bravo, Rio Grande, Guadalupe, Colorado, Houston-Brazos, Red, Mississippi, and Tennessee axes. Sediment volume was calculated from hand-contoured unit thickness maps compiled from basin-wide well and seismic control. Using a GIS algorithm to sum volumes within polygons bounding interpreted North American river contribution, the total extant volume was then calculated. General compaction factors were used to convert modern volume to quantitative approximations of total grain volume. Grain volume rate of supply for each depositional episode was then calculated. Values vary by more than an order of magnitude. Supply rate has commonly varied by two-fold or more between successive depositional episodes. Sediment supply is a significant, independent variable in development of stratigraphic sequences within the Gulf basin. Paleogeographic maps of the continental interior for eleven Cenozoic time intervals display the evolving and complex interplay of intracontinental tectonism, climate change, and drainage basin evolution. Five tectono-climatic eras are differentiated: Paleocene late Laramide era; early to middle Eocene terminal Laramide era; middle Cenozoic (Late Eocene—Early Miocene) dry, volcanogenic era; middle Neogene (Middle—Late Miocene) arid, extensional era; and late Neogene (Plio—Pleistocene) monsoonal, epeirogenic uplift era. Sediment supply to the GOM reflects the interplay of (1

  18. Modeled sulfate concentrations in North Dakota streams, 1993-2008, based on spatial basin characteristics

    USGS Publications Warehouse

    Galloway, Joel M.; Vecchia, Aldo V.

    2014-01-01

    Modeled sulfate concentrations generally were highest (greater than 750 milligrams per liter) in basins in western North Dakota and lowest (less than 250 milligrams per liter) in basins in the upper Sheyenne River and upper James River. Area-weighted means for the basin characteristics also were computed for 10-digit and 8-digit hydrologic units for streams in North Dakota and modeled sulfate concentrations were computed from the characteristics. The resulting distribution of modeled sulfate concentrations was similar to the distribution of estimates for the 12-digit hydrologic units, but less variable because the basin characteristics were averaged over larger areas.

  19. Flash heat simulation events in the north Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Mazon, Jordi; Pino, David

    2013-04-01

    According to the definition of flash heat event proposed by Mazon et al. in the European Meteorology Meeting (2011 and 2012) from the studied case produced in the Northeast of the Iberian peninsula on 27th August 20120, some other flash heat events have been detected by automatic weather stations around the in the Mediterranean basin (South Italy, Crete island, South Greece and the northeast of the Iberian peninsula). Flash heat event covers those events in which a large increase of temperature last a spatial and temporal scale between heat wave (defined by the WMO as a phenomenon in which the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5°C, with respect to the 1961-1990 period) and heat burst (defined by the AMS as a rare atmospheric event characterized by gusty winds and a rapid increase in temperature and decrease in humidity that can last some minutes). Thus flash heat event may be considered as a rapid modification of the temperature that last several hours, lower than 48 hours, but usually less than 24 hours. Two different flash heat events have been simulated with the WRF mesoscale model in the Mediterranean basin. The results show that two different mechanisms are the main causes of these flash heat events. The first one occurred on 23rd March 2008 in Crete Island due to a strong Foehn effect caused by a strong south and southeast wind, in which the maximum temperature increased during some hours on the night at 32°C. The second one occurred on 1st August 2012 in the northeast of the Iberian Peninsula, caused by a rapid displacement of warm a ridge from North Africa that lasted around 24 hours.

  20. Depositional sequences in a foreland basin (north-western domain of the continental Duero basin, Spain)

    NASA Astrophysics Data System (ADS)

    Herrero, Antonio; Alonso-Gavilán, Gaspar; Colmenero, Juan Ramón

    2010-01-01

    The Cenozoic record of the north-western domain of the Duero basin is articulated at the surface through a set of continental depositional sequences called, from base to top, the Vegaquemada sequence, the Candanedo sequence, and the Barrillos sequence. These depositional sequences were deposited in continental sedimentary environments. The deposition of the first sequence occurred through a fluvial system with floodplains cut by low-sinuosity channels. The Vegaquemada sequence was developed between the Middle Eocene and the Early Agenian. The second sequence was formed by a set of highly efficient transport alluvial fans that evolved laterally towards fluvial systems with low-sinuosity fluvial channels and an extensive floodplain, where several types of palaeosols were formed. This sequence developed between the Early Agenian and the Late Vallesian. The third unit-the Barrillos sequence (between the Late Vallesian and the Turolian/Ruscinian transition), was generated by a set of highly efficient transport alluvial fans dominated by low-sinuosity fluvial channels. In subsurface geology, seismic and well data are used to rebuild the stratigraphic architecture. The two basal depositional sequences can be identified with two seismic units: the Palaeogene Seismic Unit (PgSU) and the Neogene Seismic Unit (NgSU), respectively. In the present work, we obtained the isovelocity, isochron, and isobath maps for the top and base of the two Cenozoic units. The Palaeozoic (PzSU) and Mesozoic (MzSU) seismic units are found under these two units. Through study of the logs of the various boreholes, it was only possible to analyse the upper 700 m of the Candanedo Sequence (NgSU), without encompassing the total thickness of the unit. Several middle-order sequences were differentiated, in general showing a sequential fining-upwards evolutionary character. Additionally, for the boreholes analysed two main types of electrofacies were identified, both representing fluvial channels and

  1. Avalonian crustal controls on basin evolution: implications for the Mesozoic basins of the southern North Sea

    NASA Astrophysics Data System (ADS)

    Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

    2015-04-01

    Little is known of the Southern North Sea Basin's (SNSB) Pre-Permian basement due to a lack of outcrop and cores. The nature and structure of the East Avalonian crust and lithosphere remain even less constrained in the absence of deep seismic (refraction) lines. However, various studies have hinted at the importance of the Reactivation of the Early Carboniferous fault network during each consecutive Mesozoic and Cenozoic tectonic phase, demonstrating the key role of weak zones from the Early Carboniferous structural grain in partitioning of structural deformation and vertical basin motions at various scales. Although the older basin history and the basement attract increasing attention, the Pre-Permian tectonics of the SNSB remains little studied with most attention focused on the Permian and younger history. The strong dispersal of existing constraints requires a comprehensive study from Denmark to the UK, i.e. the East Avalonian microplate, bordered by the Variscan Rheïc suture, the Atlantic and Baltica. Based on an extensive literature study and the reinterpretation of publicly available data, linking constraints from the crust and mantle to stratigraphic-sedimentological information, we complement the map of Early Carboniferous rifting of East Avalonia and propose a new tectonic scenario. From the reinterpretation of the boundary between Avalonia and Baltica we propose a new outline for the Avalonian microplate with implications for the tectonics of the North German Basin. Furthermore, we highlight the nature and extent of the major crustal/lithospheric domains with contrasting structural behaviour and the major boundaries that separate them. Results shed light on the effects of long lived differences in crustal fabric that are responsible for spatial heterogeneity in stress and strain magnitudes and zonations of fracturing, burial history and temperature history. The geomechanical control of large crustal-scale fault structures will provide the constraints

  2. Gulf of California analogue for origin of Late Paleozoic ocean basins adjacent to western North America

    SciTech Connect

    Murchey, B.L. )

    1993-04-01

    Ocean crust accreted to the western margin of North America following the Late Devonian to earliest Missippian Antler orogeny is not older than Devonian. Therefore, ocean crust all along the margin of western North America may have been very young following the Antler event. This situation can be compared to the present-day margin of North America which lies adjacent to young ocean crust as a result of the subduction of the Farallon plate and arrival of the East Pacific spreading ridge. Syn- and post-Antler rifting that occurred along the North American margin may well be analogous to the formation of the Gulf of California by the propagation of the East Pacific spreading ridge. Black-arc rifting associated with the subduction of very old ocean crust seems a less likely mechanism for the early stages of ocean basin formation along the late Paleozoic margin of western North America because of the apparent absence of old ocean crust to the west of the arc terranes. The eastern Pacific basins were as long-lived as any truly oceanic basins and may have constituted, by the earliest Permian, a single wedge-shaped basin separated from the western Pacific by rifted fragments of North American arc-terranes. In the Permian, the rifted arcs were once again sites of active magmatism and the eastern Pacific basins began to close, from south (Golconda terrane) to north. Final closure of the northernmost eastern Pacific basin (Angayucham in Alaska) did not occur until the Jurassic.

  3. Estimating the Length of the North Atlantic Basin Hurricane Season

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2012-01-01

    For the interval 1945-2011, the length of the hurricane season in the North Atlantic basin averages about 130 +/- 42 days (the +/-1 standard deviation interval), having a range of 47 to 235 days. Runs-testing reveals that the annual length of season varies nonrandomly at the 5% level of significance. In particular, its trend, as described using 10-yr moving averages, generally has been upward since about 1979, increasing from about 113 to 157 days (in 2003). Based on annual values, one finds a highly statistically important inverse correlation at the 0.1% level of significance between the length of season and the occurrence of the first storm day of the season. For the 2012 hurricane season, based on the reported first storm day of May 19, 2012 (i.e., DOY = 140), the inferred preferential regression predicts that the length of the current season likely will be about 173 +/- 23 days, suggesting that it will end about November 8 +/- 23 days, with only about a 5% chance that it will end either before about September 23, 2012 or after about December 24, 2012.

  4. RELATION OF ENVIRONMENTAL CHARACTERISTICS TO FISH ASSEMBLAGES IN THE UPPER FRENCH BROAD RIVER BASIN, NORTH CAROLINA

    EPA Science Inventory

    Fish assemblages at 16 sites in the upper French Broad River basin, North Carolina were related to environmental variables using detrended correspondence analysis (DCA) and linear regression. This study was conducted at the landscape scale because regional variables are controlle...

  5. Hydrologic data for North Creek Trinity River Basin, Texas, 1975

    USGS Publications Warehouse

    Kidwell, C.C.

    1977-01-01

    This report contains the rainfall, runoff, and storage data collected during the 1975 water year for the 21.6-square-mile area above the stream-gaging station North Creek near Jacksboro, Texas. The weighted-mean rainfall in the study area during the water year was 39.01 inches, which is greater than the 18-year average of 30.21 inches for the period 1958-75. Monthly rainfall totals ranged from 1.04 inches in November to 7.94 inches in May. The mean discharge for 1975 at the stream-gaging station was 5.98 cfs, compared with the 14-year (1957-70) average of 5.75 cfs. The annual runoff from the basin above the stream-gaging station was 4,330 acre-feet or 3.76 inches. Three storms were selected for detailed computations for the 1975 water year. The storms occurred on Oct. 30-31, 1974, May 2, 1975 , and Aug. 26, 1975. Rainfall and discharge were computed on the basis of a refined time breakdown. Patterns of the storms are illustrated by hydrographs and mass curves. A summary of rainfall-runoff data is tabulated. There are five floodwater-retarding structures in the study area. These structures have a total capacity of 4,425 acre-feet below flood-spillway crests and regulate streamflow from 16.3 square miles, or 75 percent of the study area. A summary of the physical data at each of the floodwater-retarding structures is included. (Woodard-USGS)

  6. Regional Stratigraphy and Petroleum Systems of the Michigan Basin, North America

    USGS Publications Warehouse

    Swezey, Christopher S.

    2008-01-01

    Although more than 100 years of research have gone into deciphering the stratigraphy of the Michigan basin of North America, it remains a challenge to visualize the basin stratigraphy on a regional scale and to describe stratigraphic relations within the basin. Similar difficulties exist for visualizing and describing the regional distribution of petroleum source rocks and reservoir rocks. This publication addresses these difficulties by combining data on Paleozoic and Mesozoic stratigraphy and petroleum geology of the Michigan basin. The areal extent of this structural basin is presented along with data in eight schematic chronostratigraphic sections arranged from north to south, with time denoted in equal increments along the sections. The stratigraphic data are modified from American Association of Petroleum Geologists (AAPG) (1984), Johnson and others (1992), Sanford (1993), and Cross (1998), and the time scale is taken from Harland and others (1990). Informal North American chronostratigraphic terms from AAPG (1984) are shown in parentheses. Stratigraphic sequences as defined by Sloss (1963, 1988) and Wheeler (1963) also are included, as well as the locations of major petroleum source rocks and major petroleum plays. The stratigraphic units are colored according to predominant lithology, in order to emphasize general lithologic patterns and to provide a broad overview of the Michigan basin. For purposes of comparison, schematic depictions of stratigraphy and interpreted events in the Michigan basin and adjacent Appalachian basin are shown. The paper version of this map is available for purchase from the USGS Store.

  7. Geologic Assessment of Undiscovered Oil and Gas Resources of the North Cuba Basin, Cuba

    USGS Publications Warehouse

    Schenk, Christopher J.

    2010-01-01

    Petroleum generation in the North Cuba Basin is primarily the result of thrust loading of Jurassic and Cretaceous source rocks during formation of the North Cuba fold and thrust belt in the Late Cretaceous to Paleogene. The fold and thrust belt formed as Cuban arc-forearc rocks along the leading edge of the Caribbean plate translated northward during the opening of the Yucatan Basin and collided with the passive margin of southern North America in the Paleogene. Petroleum fluids generated during thrust loading migrated vertically into complex structures in the fold and thrust belt, into structures in the foreland basin, and possibly into carbonate reservoirs along the margins of the Yucatan and Bahama carbonate platforms. The U.S. Geological Survey (USGS) defined a Jurassic-Cretaceous Composite Total Petroleum System (TPS) and three assessment units (AU)-North Cuba Fold and Thrust Belt AU, North Cuba Foreland Basin AU, and the North Cuba Platform Margin Carbonate AU-within this TPS based mainly on structure and reservoir type (fig. 1). There is considerable geologic uncertainty as to the extent of petroleum migration that might have occurred within this TPS to form potential petroleum accumulations. Taking this geologic uncertainty into account, especially in the offshore area, the mean volumes of undiscovered resources in the composite TPS of the North Cuba Basin are estimated at (1) 4.6 billion barrels of oil (BBO), with means ranging from an F95 probability of 1 BBO to an F5 probability of 9 BBO; and (2) 8.6 trillion cubic feet of of gas (TCFG), of which 8.6 TCFG is associated with oil fields, and about 1.2 TCFG is in nonassociated gas fields in the North Cuba Foreland Basin AU.

  8. Different sedimentological and thermal evolution of three north-pyrenean basins during their set-up

    NASA Astrophysics Data System (ADS)

    Chelalou, Roman; Nalpas, Thierry; Bousquet, Romain; Lahfid, Abdeltif

    2015-04-01

    The Pyrenean belt is resulting in the inversion of several lower Cretaceous basins, separating the Iberia micro-plate from the Eurasia plate. The eat-west oriented basins are well known for their high-temperature metamorphism synchronous of the last deposits during Aptian-Albian times. For the first time, we present a combined sedimentological and thermal study of three north pyrenean basins (Boucheville, St Paul-de-Fenouillet and Bas-Agly). With the help of detailed stratigraphic logs of each basin, we propose restored cross-sections for the whole area. North-south sections across Boucheville and St Paul-de-Fenouillet basins show that theses basins have large asymmetrical structure. The Boucheville basin is a large anticline bordered by two isoclinal syncline highly skewed, while the St Paul-de-Fenouillet one is a unique syncline. Detailed sedimentalogical observations show common features for these basins: deposits of white limestones and breccias during the Jurassic time following by black sandstones with a calcareous matrix of lower Cretaceous age. On one hand, Jurassic limestones were deposited on a shelf environment and their thickness is homogeneous all over each basin. On the other hand, sandstones deposits seem to occur at greater depths during the Albian time and are displaying asymmetrical north-south variation of their thickness. The quantification of the temperature overprint occurred in the basin was done using the graphitisation of the carbonaceous material, and was measured by RAMAN spectroscopy (Lahfid et al. 2010). Despite their similar deposits, the mapping of the temperature-peak inside the three basins show contrasted thermal evolution. Then we document a lower temperature overprint around 150-200˚C in the northern basin {St Paul-de-Fenouillet) while the highest overprint up to 600˚C has been reached in the southern basin (Boucheville) in which diopside - scapolite and also probably olivine are occurring. These three north-pyrenean basin turn

  9. New insights into the North Taranaki Basin from New Zealand's first broadband 3D survey

    NASA Astrophysics Data System (ADS)

    Uzcategui, Marjosbet; Francis, Malcolm; Kong, Wai Tin Vincent; Patenall, Richard; Fell, Dominic; Paxton, Andrea; Allen, Tristan

    2016-06-01

    The Taranaki Basin is the only hydrocarbon producing basin in New Zealand. The North Taranaki Basin has widespread two-dimensional (2D) seismic coverage and numerous wells that have not encountered commercial accumulations. This is attributed to the structural complexity in the central graben and the absence of necessary information to help understand the basin's evolution. An active petroleum system has been confirmed by hydrocarbon shows and non-commercial oil and gas discoveries (Karewa-1 and Kora-1). A broadband long offset three-dimensional (3D) seismic survey was acquired and processed by Schlumberger in 2013 to evaluate the hydrocarbon potential of the North Taranaki Basin. Innovative acquisition techniques were combined with advanced processing and imaging methods. Raypath distortions and depth uncertainty were significantly reduced by processing through tilted transverse isotropy (TTI) anisotropic Kirchhoff prestack depth migration with a geologically constrained velocity model. The survey provided the necessary information to understand the petroleum system and provide evidence for material hydrocarbon accumulations. In this investigation, we assessed the hydrocarbon potential of the North Taranaki Basin using the newly acquired data. 3D seismic interpretation and amplitude-versus-offset (AVO) analysis support the renewed potential of the basin and demonstrate effectiveness of these technologies that together can achieve encouraging results for hydrocarbon exploration.

  10. Holocene aeolian activity in the Gonghe Basin, north-eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Stauch, Georg; Lai, Zhongping; Lehmkuhl, Frank; Schulte, Philipp

    2016-04-01

    The Gonghe Basin is located on the north-eastern edge of Tibetan Plateau and has a mean altitude of 3000 m asl. With a size of 20.000 km² it is the largest intramontane Basin on the north-eastern Plateau. The well-studied Qinghai Basin is situated north of the Basin, while the drier central Plateau is further south-west. Previous research indicated an early onset of the aeolian accumulation in the Qinghai Basin at around 18 ka while in the areas further to the south-west aeolian archives date back only to the beginning of the Holocene. First new OSL ages from aeolian sand and loess indicate a intermediate timing of the aeolian accumulation in the Gonghe Basin at the transition from the late glacial to the Holocene. Late glacial and early Holocene ages of aeolian sediments were hitherto associated with wetter climate conditions caused by the strengthening of the Asian summer monsoon. Higher moisture availability resulted in an increased vegetation cover, leading to the permanent stabilization of the aeolian sediments. Under glacial climate conditions a constant remobilization of the sediments can be assumed. The new OSL ages from the Gonghe Basin indicate a progressive shift of the monsoonal strength in westward directions during the late glacial until the early Holocene.

  11. Statistical summaries of water-quality data for selected streamflow-gaging stations in the Red River of the North basin, North Dakota, Minnesota, and South Dakota

    USGS Publications Warehouse

    Macek-Rowland, Kathleen M.; Dressler, Valerie M.

    2002-01-01

    The quantity and quality of current and future water resources in the Red River of the North Basin in North Dakota, Minnesota, and South Dakota are concerns of people who reside within the basin. Additional water resources are needed because of recent growth in population, industry, and agriculture. How the management of current and future water-resources will impact water quality within the basin is a critical issue. Water-quality data, particularly for surface-water sources, will help water-resources managers make decisions about current and future water resources in the Red River of the North Basin. Statistical summaries of water-quality data for 43 streamflow-gaging stations in the Red River of the North Basin in North Dakota, Minnesota, and South Dakota are presented in this report. Statistical summaries include sample size, maximum, minimum, mean, and values for the 95th, 75th, 50th, 25th, and 5th percentiles.

  12. Proceedings of the North Aleutian Basin information status and research planning meeting.

    SciTech Connect

    LaGory, K. E.; Krummel, J. R.; Hayse, J. W.; Hlohowskyj, I.; Stull, E. A.; Gorenflo, L.; Environmental Science Division

    2007-10-26

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant ecological and natural resources. The Basin includes most of the southeastern part of the Bering Sea continental shelf including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals including federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012 and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory (Argonne) were contracted to assist the MMS Alaska Outer Continental Shelf (OCS) Region in identifying and prioritizing information needs related to the North Aleutian Basin and potential future oil and gas leasing and development activities. The overall approach focused on three related but separate tasks: (1) identification and

  13. Anatomy of a rift system: Triassic-Jurassic basins of eastern North America

    SciTech Connect

    Schlische, R.W. ); Olsen, P.E. )

    1991-03-01

    Basins containing the early Mesozoic Newark Supergroup formed during the incipient rifting of Pangaea. The basins are characterized by the following: (1) The border fault systems (BFS) represent reactivated older faults. (2) A regionally persistent northwest-southeast to west-northeast-east-southeast extension direction reactivated northeast- to north-striking structures as predominantly normal dip-slip faults. (3) The half-grabens are lozenge-shaped basins in which subsidence-fault slip was greatest at or near the center of the BFS and decreased to zero toward either end. (4) Transverse folds in the hanging walls immediately adjacent to the BFS formed as a result of higher-frequency variations in subsidence. (5) Subsidence also decreased in a direction perpendicular to the BFS. (6) Intrabasinal faults are overwhelmingly synthetic and predominantly post-depositional. (7) Younger strata progressively onlap prerift rocks of the hanging wall block; this indicates that the basins grew both in width and length as they filled. (8) In all basins initial sedimentation was fluvial, reflecting an oversupply of sediment with respect to basin capacity. (9) Sediments were derived largely from the hanging wall block, which sloped toward the basin, and from streams that entered the basin axially; a direct footwall source was minor, owing to footwall uplift. (10) In strike-slip-dominated basins, subsidence was considerably less than in dip-slip basins, and mosaics of strike- and dip-slip faults are common.

  14. A history of early geologic research in the Deep River Triassic Basin, North Carolina

    USGS Publications Warehouse

    Clark, T.W.

    1998-01-01

    The Deep River Triassic basin has one of the longest recorded histories of geologic research in North Carolina. A quick perusal of nineteenth century geologic literature in North Carolina reveals the Deep River basin has received a tremendous amount of attention, second only, perhaps, to the gold deposits of the Carolina slate belt. While these early researchers' primary interests were coal deposits, many other important discoveries, observations, and hypotheses resulted from their investigations. This article highlights many of the important advances made by these early geo-explorers by trying to include information from every major geologic investigation made in the Deep River basin from 1820 to 1955. This article also provides as thorough a consolidated history as is possible to preserve the exploration history of the Deep River basin for future investigators.

  15. Comparative stratigraphy and subsidence history of Mesozoic rift basins of north Atlantic

    SciTech Connect

    Hiscott, R.N. ); Wilson, R.C.L. ); Gradstein, F.M. ); Pujalte, V.; Garcia-Mondejar, J. ); Boudreau, R.R.; Wishart, H.A. )

    1990-01-01

    The North Atlantic Mesozoic basins share many features because they had a common origin controlled by intracontinental rifting and subsequent separation of Europe and North America. Pulses of extension generally are reflected in the stratigraphy of all of the basins. Superimposed on this record are the effects of eustatic sea level variations. The main difference between the Canadian Jeanne d'Arc basin and Iberian basins is the significantly greater Early and Middle Jurassic basement subsidence rate in the form (about 40 m/m.y. vs. 0-10 m/m.y.). This difference may result from prolonged extension on the Canadian side, perhaps due to northward transfer of shear stress from left-lateral transform motion between the Grand Banks and northwestern Africa. 6 figs., 3 tabs.

  16. Statistical Aspects of the North Atlantic Basin Tropical Cyclones: Trends, Natural Variability, and Global Warming

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2007-01-01

    Statistical aspects of the North Atlantic basin tropical cyclones for the interval 1945- 2005 are examined, including the variation of the yearly frequency of occurrence for various subgroups of storms (all tropical cyclones, hurricanes, major hurricanes, U.S. landfalling hurricanes, and category 4/5 hurricanes); the yearly variation of the mean latitude and longitude (genesis location) of all tropical cyclones and hurricanes; and the yearly variation of the mean peak wind speeds, lowest pressures, and durations for all tropical cyclones, hurricanes, and major hurricanes. Also examined is the relationship between inferred trends found in the North Atlantic basin tropical cyclonic activity and natural variability and global warming, the latter described using surface air temperatures from the Armagh Observatory Armagh, Northern Ireland. Lastly, a simple statistical technique is employed to ascertain the expected level of North Atlantic basin tropical cyclonic activity for the upcoming 2007 season.

  17. Modes of sedimentary basin formation in the north-eastern Black Sea

    NASA Astrophysics Data System (ADS)

    Stephenson, Randell; Starostenko, Vitaly; Sydorenko, Grygoriy; Yegorova, Tamara

    2016-04-01

    The Greater Caucasus and Black Sea sedimentary basins developed in a Mesozoic back-arc setting, the former older than the latter (Jurassic v. Cretaceous). Compressional shortening of the former and accompanying ongoing development of marginal basin depocentres in the north-eastern Black Sea - which is closely tied to the formation of the Crimea-Greater Caucasus orogen - is a Cenozoic phenomenon, starting in the Eocene and proceeding until the present day. Recently, the sedimentary basin/crust/lithosphere geometry of the study area has been characterised across a range of scales using regional seismic reflection profiling, long-offset refraction/wide-angle reflection profiling and local earthquake tomography. These provide a new integrated image of the present-day crustal structure and sedimentary basin architecture of the northern margin of the eastern Black Sea, north across the Azov Sea and provide evidence of the deeper expression of sedimentary basins and the processes controlling the geometry of their inversion during the Cenozoic. It is inferred that the Greater Caucasus paleo-Basin, lying stratigraphically below the Black Sea and younger sedimentary successions, extends further to the west than previously known. This basin has significant thickness in the area between the Azov and Black seas and probably forms the deeper core of the Crimea-Caucasus inversion zone. The Crimea-Greater Caucasus orogenic belt is the expression of "basin inversion" of the Jurassic Greater Caucasus paleo-Basin, the degree of inversion of which varies along strike. The Greater Caucasus foredeep basins - Indolo-Kuban and Sorokin-Tuapse troughs -represent syn-inversional marginal troughs to the main inversion zone. The Shatsky Ridge - the northern flank of the main East Black Sea Basin - may also be mainly a syn-inversional structure, underlain by a blind thrust zone expressed as a northward dipping zone of seismicity on the northern margin of the eastern Black Sea.

  18. Large-scale diabase intrusion in the Durham Triassic Basin of North Carolina: geophysics and geochemistry

    SciTech Connect

    Bolich, R.E.; Bevis, M.G.; Won, I.J.; Fodor, R.V.

    1985-01-01

    Gravity and magnetic data obtained from the Durham Triassic Basin of North Carolina reveal pronounced positive gravity and magnetic anomalies of 10 milligals and 300 gammas, respectively, along the western border of the basin. In the vicinity of these anomalies, diabase outcrops, some with chilled margins and others with flow features, occur sporadically, but have a combined area of about 100 sq. km. Two-dimensional modeling of the gravity data indicates that the diabase body accounts for the gravity anomaly as a semi-continuous subsurface intrusion. The intrusive body is greater than 250 m thick near the western border of the basin, but thins to about 100 m near the center of the basin. Geochemical data for samples recovered from 4 air-drill sites at one diabase outcrop in Butner, North Carolina yield high MgO concentrations, and low FeO, K2O, and TiO2. The geophysical and geochemical data are consistent with an uncontaminated basaltic magma ascending along a major fissure or fissures and into the basin. In the basin, the diabase encountered unlithified sediments, resulting in both intrusive and extrusive forms. Although similar chemical compositions for Mesozoic North American dikes have been reported, this is the first indication of an intrusive body of such a large extent and primitive chemical composition.

  19. Geology of petroleum and coal deposits in the North China Basin, eastern China

    SciTech Connect

    Lee, K.Y.

    1989-01-01

    The North China Basin evolved from a rifted intercratonic graben system on the east-central Sino-Korean Platform during the Jurassic through Paleogene tectonic movement, and contains significant petroleum and coal resources. Petroleum production in the North China Basin ranks second after the Songliao Basin in China. The ultimate recoverable oil and gas reserves are 11,251 million barrels of oil and 8,425 billion ft{sup 3} of gas. Of the six petroleum-producing depressions within the basin, The Jiyang Depression ranks first, and is followed by the Jizhong Depression, where the rich Tertiary lacustrine source beds and deltaic sandstone reservoirs are extensive in areal distribution. Late Carboniferous to Permian coal reserves in the basin are estimated to be about 30 percent of total reserves (411.3 billion tons in the North China region). Because of deep burial of the coal beds (1,800 m) coal-mining activities are confined to the basin border.

  20. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2009-01-01

    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  1. Cascadia Basin Sediments as a Source for the North Pacific Silica Plume

    NASA Astrophysics Data System (ADS)

    Johnson, H. P.; Hautala, S. L.; Hammond, D. E.; Bjorklund, T. A.; Evans, R.; Esther, T.; Engstrom, P.; Worsnopp, M.; Lagerloef, M.; Kevin, J.; Penton, R.; Paukert, A.; Chung, E.; Schwartz, R.; Morello, A.

    2006-12-01

    The North Pacific silica plume extends from the North American margin almost to Siberia at an approximate mid-water depth of 2300 meters, and may be the largest single chemical anomaly in the global ocean. The plume contains 164 Teramols of silica and is sustained by a flux equivalent to one third of the total riverine silica input (1.5 Tmol/year) into the oceans. Cascadia Basin source estimates are 15-35 percent of the total flux that sustains the plume. A cruise in August 2006 examined potential source regions for dissolved silica within the small Cascadia/Gorda Basins adjacent to the Oregon/Washington/BC margins. During this cruise, 43 CTD and Niskin bottle casts, 11 sediment multi-core stations and 17 heat flow probe measurements were made. Water column samples for Rn-222 and Ra-228 were also taken to estimate vertical mixing rates and residence times. Sampling strategy focused on profiles within topographic 'gateways' that control entrance/egress of near-bottom water to/from the topographically restricted Cascadia/Gorda Basins. Sediment multi-core and heat flow stations were located to provide broad geographic coverage of the two Basins. Benthic fluxes of Si were estimated from core incubations and pore water profiles. Bottom water from the deep North Pacific enters into the Gorda/Cascadia Basins via the southern Mendocino/Gorda gateway with silica concentrations near 185 micromol/L, enriched by 20 micromol/L from the passage over the 4000 m deep western flank of the Juan de Fuca Ridge. Spatial distribution of dissolved silica within Cascadia Basin is non-uniform, with two large areas showing concentrations in excess of 200 micromol/L. These two areas include the western mid-Basin region and a N-S elongated area near, but not directly adjacent to, the OR/WA/BC continental margin. The two high concentration regions are divided by a tongue of cold and relatively low silica water that enters the Basin from the south through Cascadia Channel. The new data suggests

  2. Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota

    USGS Publications Warehouse

    Ludden, A.P.; Frink, D.L.; Johnson, D.H.

    1983-01-01

    Photogrammetric mapping techniques were used to derive the water storage capacities of natural wetland depressions other than lakes in the Devils Lake Basin of North Dakota. Results from sample quarter-section areas were expanded to the entire basin. Depressions in the Devils Lake Basin have a maximum storage capacity of nearly 811,000 cubic dekameters (657,000 acre-feet). The depressions store about 72 percent of the total runoff volume from a 2-year-frequency runoff and about 41 percent of the total runoff volume from a 100-year-frequency runoff.

  3. Asymmetric basin subsidence and horizontal-axis block rotations in the Miocene North Whipple Basin, SE California and W Arizona

    SciTech Connect

    Dorsey, R.J.; Roberts, P. . Dept. of Geology)

    1992-01-01

    A thick, faulted sequence of post-18.5-Ma Miocene sedimentary and volcanic rocks is well exposed in the Aubrey Hills, W Arizona, and the northeastern Whipple Mountains, SE California. These strata were deposited in alluvial fans and playa lakes of a syntectonic sedimentary basin (North Whipple Basin), which evolved in the upper plate of the Whipple detachment fault on the north flank of the growing proto-Whipple Mountains. Sedimentary deposits reveal substantial lateral changes in thickness and depositional facies (lacustrine to proximal-fan) that provide a record of asymmetric basin subsidence and upper-plate block rotations during strong regional extension. Final uplift, exhumation and unroofing of lower-plate rocks occurred during this time, as evidenced by sandstone-petrographic and conglomerate clast-count studies. Two horizontal orthogonally oriented axes of synbasinal crustal rotation are recognized: extension-perpendicular (NW-SE), and extension-parallel (NE-SW). Rotation about extension-perpendicular axes occurred by displacements on NW-striking normal faults that formed classic half-graben basins in the extending upper plate. Evidence for rotation about an extension-parallel axis is seen in pronounced lateral thickening and coarsening of sedimentary lithofacies toward the SE in the Aubrey Hills. This was likely controlled by synbasinal growth of an extension-parallel syncline, which formed on the NW flank of the Whipple Mountain extension-parallel antiform.

  4. Hydrogeological restrictions to saline ground-water discharge in the Red River of the North drainage basin, North Dakota

    SciTech Connect

    Strobel, M.L. Univ. of North Dakota, Grand Forks, ND )

    1992-01-01

    Discharge of saline water from bedrock aquifers along the eastern margin of the Williston basin is restricted by surficial glacial till and lacustrine deposits in the Red River of the North drainage basin. Water from these aquifers reaches the surface by (1) diffusion; (2) slow, upward seepage along zones of relatively larger hydraulic conductivity in the till and lacustrine deposits; or (3) flow from artesian wells. Ground-water quality varies near the surface because of mixing of water being discharged from bedrock aquifers with shallower ground water in the surficial deposits. Ground-water quality, hydraulic-gradient, and hydraulic-conductivity data obtained from pumped-well and slug tests indicate that flow in the surficial deposits is eastward, but at slow rates because of small hydraulic conductivities. Base-flow and specific-conductance measurements of water in tributaries to the Red River of the North indicate that focused points of ground-water discharge result in substantial increases in salinity in surface water in the northern part of the basin in North Dakota. Core analyses and drillers' logs were used to generalize hydrogeologic characteristics of the deposits in the basin, and a two-dimensional ground-water-flow model was used to simulate the basin's geohydrologic processes. Model results indicate that the ground-water flow paths in the bedrock aquifers and surficial deposits converge, and that water from the bedrock aquifers contributes to the overall increase in ground-water discharge toward the east. Model results are supported by water-quality data collected along an east-west hydrogeologic section.

  5. Petroleum geology and resources of the North Ustyurt Basin, Kazakhstan and Uzbekistan

    USGS Publications Warehouse

    Ulmishek, Gregory F.

    2001-01-01

    The triangular-shaped North Ustyurt basin is located between the Caspian Sea and the Aral Lake in Kazakhstan and Uzbekistan and extends offshore both on the west and east. Along all its sides, the basin is bounded by the late Paleozoic and Triassic foldbelts that are partially overlain by Jurassic and younger rocks. The basin formed on a cratonic microcontinental block that was accreted northward to the Russian craton in Visean or Early Permian time. Continental collision and deformation along the southern and eastern basin margins occurred in Early Permian time. In Late Triassic time, the basin was subjected to strong compression that resulted in intrabasinal thrusting and faulting. Jurassic-Tertiary, mostly clastic rocks several hundred meters to 5 km thick overlie an older sequence of Devonian?Middle Carboniferous carbonates, Upper Precambrian massifs and deformed Caledonian foldbelts. The Carboniferous?Lower Permian clastics, carbonates, and volca-basement is at depths from 5.5 km on the highest uplifts to 11 nics, and Upper Permian?Triassic continental clastic rocks, pri-km in the deepest depressions. marily red beds. Paleogeographic conditions of sedimentation, Three total petroleum systems are identified in the basin. the distribution of rock types, and the thicknesses of pre-Triassic Combined volumes of discovered hydrocarbons in these sysstratigraphic units are poorly known because the rocks have been tems are nearly 2.4 billion barrels of oil and 2.4 trillion cubic penetrated by only a few wells in the western and eastern basin feet of gas. Almost all of the oil reserves are in the Buzachi Arch areas. The basement probably is heterogeneous; it includes and Surrounding Areas Composite Total Petroleum System in 2 Petroleum Geology, Resources?North Ustyurt Basin, Kazakhstan and Uzbekistan the western part of the basin. Oil pools are in shallow Jurassic and Neocomian sandstone reservoirs, in structural traps. Source rocks are absent in the total petroleum

  6. Literature and information related to the natural resources of the North Aleutian Basin of Alaska.

    SciTech Connect

    Stull, E.A.; Hlohowskyj, I.; LaGory, K. E.; Environmental Science Division

    2008-01-31

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant natural resources. The Basin includes most of the southeastern part of the Bering Sea Outer Continental Shelf, including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals, including several federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, 'Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012' and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory were contracted to assist MMS with identifying and prioritizing information needs related to potential future oil and gas leasing and development activities in the North Aleutian Basin. Argonne focused on three related tasks: (1) identify and gather relevant literature published since 1996, (2) synthesize and summarize the

  7. Basin Management under the Global Climate Change (Take North-East Asia Heilongjiang -Amur Basin and Taihu Basin For Example)

    NASA Astrophysics Data System (ADS)

    Liu, S.; Zhou, Z.; Zhong, G.; Zhang, X.

    2015-12-01

    The impact of global climate change on environment and society causes increasingly concern in different countries around the world. The main climate characteristic values, such as precipitation and temperature, have been changed, which leads to the variation of water resources, especially in large basins. Heilongjiang-Amur Basin and Taihu Basin are two large and important basins in China with large area and population. As global climate change and human activities have siganificant impacts on hydrology and water resources in two basins, the analysis of climate change are of great value. In this study, in Heilongjiang-Amur Basin, precipitation and temperature are investigated and their variation are predicted. And in Taihu Basin, precipitation including plum rain and typhoon, are studied and the variation trend of precipitation is predicted. Hence, the impacts of global climate change are assessed. From the result, it shows that the average temperature will continue to increase, and the precipitation will reduce first and then turn to increase in these two basins. It demonstrates that the water resources have been affected a lot by climate change as well as human activities. And these conclusions are provided as reference for policy makers and basin authorities in water resources management and natural hazards mitigation. Meanwhile, according to basins' particualr characters, the suggestions to future water resources management in two basins are given, and more scientific, comprehensive and sustained managements are required. Especially, in Heilongjiang-Amur River, which is a boundary river between China and Russia, it is very essential to enhance the cooperation between two countries.

  8. Timber harvest change in the Little North Santiam River Basin, Oregon, 1995 to 2009

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2009-01-01

    Using available aerial photos from approximately a 15-year period, changes in timber harvest were mapped in the Little North Santiam River Basin, Oregon. Timber harvest plots as seen on digital orthophotos from 1995, 2000, 2005, and 2009 were digitized and attributed based on harvest type or purpose: clearcut, thinning, or development.

  9. Assessment of undiscovered oil and gas resources of the North Sakhalin Basin Province, Russia, 2011

    USGS Publications Warehouse

    Klett, T.R.; Schenk, Christopher J.; Wandrey, Craig J.; Charpentier, Ronald R.; Brownfield, Michael E.; Pitman, Janet K.; Pollastro, Richard M.; Cook, Troy A.; Tennyson, Marilyn E.

    2011-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated volumes of undiscovered, technically recoverable, conventional petroleum resources for the North Sakhalin Basin Province of Russia. The mean volumes were estimated at 5.3 billion barrels of crude oil, 43.8 trillion cubic feet of natural gas, and 0.8 billion barrels of natural gas liquids.

  10. A model for the three-dimensional evolution of continental rift basins, north-east Africa

    NASA Astrophysics Data System (ADS)

    Bosworth, William

    1994-12-01

    Large areas of north-east Africa were dominated by regional extension in the Late Phanerozoic. Widespread rifting occurred in the Late Jurassic, with regional extension culminating in the Cretaceous and resulting in the greatest areal extent and degree of interconnection of the west, central and north African rift systems. Basin reactivation continued in the Paleocene and Eocene and new rifts probably formed in the Red Sea and western Kenya. In the Oligocene and Early Miocene, rifts in Kenya, Ethiopia and the Red Sea linked and expanded to form the new east African rift system. This complex history of rifting resulted in failed rift basins with low to high strain geometries, a range of associated volcanism and varying degrees of interaction with older structures. One system, the Red Sea rift, has partially attained active seafloor spreading. From a comparison of these basins, a general model of three-dimensional rift evolution is proposed. Asymmetrical crustal geometries dominated the early phases of these basins, accompanied by low angle normal faulting that has been observed at least locally in outcrop. As rifting progressed, the original fault and basin forms were modified to produce larger, more through-going structures. Some basins were abandoned, others experienced reversals in regional dip and, in general, extension and subsidence became focused along narrower zones near the rift axes. The final transition to oceanic spreading was accomplished in the Red Sea by a change to high angle, planar normal faulting and diffuse dike injection, followed by the organization of an axial magma chamber.

  11. Late Pennsylvanian to Wuchiapingian palynostratigraphy of the Baode section in the Ordos Basin, North China

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Zhu, Huaicheng; Ouyang, Shu

    2015-11-01

    Well-preserved miospores are recorded and illustrated from the Penchi to the lower part of the Sunjiagou formations in the Baode section of the Ordos Basin, North China. Eight palynological biozones are proposed for the Late Pennsylvanian to Wuchiapingian interval. Among them, five biozones are refined from pre-existing biozones. The biozones are comparable throughout the North China Craton. In contrast, long distance palynological correlation between North China and Euramerica only extends to the end of the Bolsovian (early Moscovian). By reference of associated marine fossils and magnetostratigraphic data, approximate stratigraphic correlation with the international stages is possible in Ordos Basin. Quantitative abundances of spores and pollen from the Late Pennsylvanian to Wuchiapingian reflect a wet-hot palaeoclimate in the Ordos Basin but with an increasing tendency of palaeoclimatic drying from the Early Kungurian. This drying tendency can be recognized throughout the North China Craton and seems to be related to the suturing process between North China Craton with the combined northeastern China blocks. Reduviasporonites which occurs often in relatively high frequencies in many Permian-Triassic boundary sections was recorded for the first time from the early Kungurian Shansiensis Biozone.

  12. Tectonic fabric of northern North Fiji and Lau basins from GLORIA sidescan

    SciTech Connect

    Tiffin, D.L. ); Clarke, J.E.H.; Johnson, D. ); Jarvis, P. ); Hill, P. ); Huggett, Q.; Pearson, L. ); Price, R. )

    1990-06-01

    GLORIA mosaics, Seabeam, and seismic data over parts of the backarc New Hebrides arc, northwest and central North Fiji basin, Fiji Fracture Zone north of Fiji, Peggy Ridge, northeast Lau basin, northern Tonga arc, northwestern Tonga Trench, and Western Samoa reveal a complex tectonic framework for the region. Two triple junctions and several rifts are clearly delineated by outcrops and ridges of neovolcanic rocks. Backarc troughs in the New Hebrides Arc are commonly floored by volcanic rocks with little sediment cover. The locus of major faults are well defined in places by volcanic ridges and scarps. On the Fiji Fracture Zone north of Fiji, scarps indicate the trace, but west of Fiji it disappears for about 100 km, becoming well pronounced again near the central North Fiji basin triple junction. At Peggy Ridge a very extensive area of sheet-like volcanics indicates activity extends northeast from Peggy Ridge toward the western extension of the Tonga Trench passing west of Niuafo'ou Island, possibly marking a fault-to-trench transition. East of Niuafo'ou Island, backarc spreading close to the Tofua Arc is seen at a nascent triple junction, its northern arm approaching close to the western Tonga Trench. Long linear fault scarps in the trench result from bending of the crust. Only a few areas, including the seafloor north of Samoa, are mainly sediment covered. Two known hydrothermal deposits near the two triple junctions have been imaged, but other mapped areas of extensive neo-volcanics in the vicinity of propagators and pull-apart basins suggest sites for further investigation. The prevalence of ridge propagators and extensional basins suggests their significant role in the development of the region.

  13. Suspended-Sediment Budget for the North Santiam River Basin, Oregon, Water Years 2005-08

    USGS Publications Warehouse

    Bragg, Heather M.; Uhrich, Mark A.

    2010-01-01

    Significant Findings An analysis of sediment transport in the North Santiam River basin during water years 2005-08 indicated that: Two-thirds of sediment input to Detroit Lake originated in the upper North Santiam River subbasin. Two-thirds of the sediment transported past Geren Island originated in the Little North Santiam River subbasin. The highest annual suspended-sediment load at any of the monitoring stations was the result of a debris flow on November 6, 2006, on Mount Jefferson. About 86 percent of the total sediment input to Detroit Lake was trapped in the lake, whereas 14 percent was transported farther downstream. More than 80 percent of the sediment transport in the basin was in November, December, and January. The variance in the annual suspended-sediment loads was better explained by the magnitude of the annual peak streamflow than by the annual mean streamflow.

  14. Aquatic communities and contaminants in fish from streams of the Red River of the North basin, Minnesota and North Dakota

    USGS Publications Warehouse

    Goldstein, R.M.

    1995-01-01

    Available data on the ecology of aquatic organisms in the Red River of the North Basin, a study unit of the U.S. Geological Survey's National Water-Quality Assessment program, were collated from numerous sources. Lack of information for invertebrates and algae precluded a general summary of distribution and ecology throughout the basin. Data on fish species distributions in the major streams of the Red River of the North Basin were analyzed based on the drainage area of the stream and the number of ecoregions the stream flowed through. Species richness increased with both drainage area (log drainage area in square kilometers, R2=0.41, p=0.0055) and the number of ecoregions a river flowed through. However, theses two factors are autocorrelated because the larger the drainage, the more likely that the river will flow through more than one ecoregion. A cluster analysis identified five river groups based on similarity of species within the fish community. Analysis of trophic and taxonomic composition provided justification for the cluster groups. There were significant differences (p=0.05) in the trophic composition of the river cluster groups with respect to the number of predator species, omnivore species, benthic insectivore species, and general insectivore species. Although there were no significant differences in the number of species in the bass and sunfish family or the sucker family, the number of species in the minnow family and the darter subfamily were different (p=0.05) among the groups identified by cluster analysis. Data on contaminant concentrations in fish from the Red River of the North indicated that most trace elements and organochlorine compounds present in tissues were not at levels toxic to fish or humans. Minnesota and North Dakota have issued a fish consumption advisory based on levels of mercury and (or) PCBs found in some species.

  15. Watershed scale response to climate change--Starkweather Coulee Basin, North Dakota

    USGS Publications Warehouse

    Vining, Kevin C.; Hay, Lauren E.; Markstrom, Steven L.

    2012-01-01

    Fourteen basins for which the Precipitation Runoff Modeling System has been calibrated and evaluated were selected as study sites. Precipitation Runoff Modeling System is a deterministic, distributed parameter watershed model developed to evaluate the effects of various combinations of precipitation, temperature, and land use on streamflow and general basin hydrology. Output from five General Circulation Model simulations and four emission scenarios were used to develop an ensemble of climate-change scenarios for each basin. These ensembles were simulated with the corresponding Precipitation Runoff Modeling System model. This fact sheet summarizes the hydrologic effect and sensitivity of the Precipitation Runoff Modeling System simulations to climate change for the Starkweather Coulee Basin near Webster, North Dakota.

  16. Use of natural basin wetlands by breeding waterfowl in North Dakota

    USGS Publications Warehouse

    Kantrud, H.A.; Stewart, R.E.

    1977-01-01

    Use of basin wetlands by breeding populations of 12 species of waterfowl was investigated in 1965 and during 1967-69 throughout the prairie pothole region of North Dakota. Data were obtained primarily by random sampling techniques. Of the total population occupying natural basin wetlands 55 percent occupied seasonal and 36 percent occupied semipermanent wetlands. Seasonal wetlands contained 60 percent of the population of dabbling ducks, while semipermanent wetlands supported 75 percent of the population of diving ducks. On basins with ponded water, highest concentrations of breeding pairs occurred on temporary, seasonal, and semipermanent wetlands; moderate concentrations were recorded on ephemeral, fen, and undifferentiated tillage wetlands, and low concentrations occurred on permanent and alkali wetlands. The proportion of basins that retained ponded water had a direct bearing on the value of each type of wetland to breeding waterfowl. Relative values of the more intermittent types of wetlands are greatly increased during years of ample precipitation.

  17. Sequence stratigraphy, sedimentology, and hydrocarbon potential in the North-Eastern part of the Pannonian Basin

    SciTech Connect

    Lazar, O.R.; Corbeanu, R.; Vasiliu, G.

    1995-08-01

    The Pannonian basin lies within the Alpine mountain belts of east-central Europe. Deformation of the Pannonian region occurred during the final stage of thrusting and folding in the outer part of the Carpathians. The result was a system of several smaller individual basins separated by relatively shallow basement blocks. The {open_quotes}North-eastern part of the Pannonian basin{close_quotes} represents one of these individual basins. Over the basement, the Neogene sedimentation started with continental or marine transgressive beds followed by shallow-marine shales and marls with sandy intercalations. Several stratigraphic sequences were separated within the succession of sedimentary deposits using the seismic, paleontologic, and well-log data. These sequences with their hydrocarbon significance are largely described in the paper.

  18. Relation of environmental characteristics to fish assemblages in the upper French Broad River basin, North Carolina.

    PubMed

    Rashleigh, Brenda

    2004-01-01

    Fish assemblages at 16 sites in the upper French Broad River basin, North Carolina were related to environmental characteristics using detrended correspondence analysis, principal components analysis, and linear regression. The primary gradient affecting sites in this basin was related to agricultural influence, characterized by high levels of agricultural land cover, nitrate plus nitrite, sulfate, specific conductance, and sediment. Agricultural influence on the fish assemblage was represented as a trophic shift from specialized insectivores to generalized insectivores and an herbivore. A secondary influence on variation among sites was related to urban land cover, population density, increased concentrations of metals, and soil erodibility. This primarily urban gradient was characterized by an increase in the number of native and introduced fish species, particularly sunfish and omnivores species, and a decline in the percent of piscivores. These results support the identification of indicators for different environmental influences, which can improve the ability of resource managers to diagnose impairment in this basin and in similar basins.

  19. Diachronous fault array growth within continental rift basins: Quantitative analyses from the East Shetland Basin, northern North Sea

    NASA Astrophysics Data System (ADS)

    Claringbould, Johan; Bell, Rebecca; Jackson, Christopher; Gawthorpe, Robert; Odinsen, Tore

    2016-04-01

    The evolution of rift basins has been the subject of many studies, however, these studies have been mainly restricted to investigating the geometry of rift-related fault arrays. The relative timing of development of individual faults that make up the fault array is not yet well constrained. First-order tectono-stratigraphic models for rifts predict that normal faults develop broadly synchronously throughout the basin during a temporally distinct 'syn-rift' episode. However, largely due to the mechanical interaction between adjacent structures, distinctly diachronous activity is known to occur on the scale of individual fault segments and systems. Our limited understanding of how individual segments and systems contribute to array-scale strain largely reflects the limited dimension and resolution of the data available and methods applied. Here we utilize a regional extensive subsurface dataset comprising multiple 3D seismic MegaSurveys (10,000 km2), long (>75km) 2D seismic profiles, and exploration wells, to investigate the evolution of the fault array in the East Shetland Basin, North Viking Graben, northern North Sea. Previous studies propose this basin formed in response to multiphase rifting during two temporally distinct extensional phases in the Permian-Triassic and Middle-to-Late Jurassic, separated by a period of tectonic quiescence and thermal subsidence in the Early Jurassic. We document the timing of growth of individual structures within the rift-related fault array across the East Shetland Basin, constraining the progressive migration of strain from pre-Triassic-to-Late Jurassic. The methods used include (i) qualitative isochron map analysis, (ii) quantitative syn-kinematic deposit thickness difference across fault & expansion index calculations, and (iii) along fault throw-depth & backstripped displacement-length analyses. In contrast to established models, we demonstrate that the initiation, growth, and cessation of individual fault segments and

  20. Hydrologic data for North Creek, Trinity River basin, Texas, 1979

    USGS Publications Warehouse

    Kidwell, C.C.

    1981-01-01

    This report contains rainfall and runoff data collected during the 1979 water year for the 21.6-square mile area above the stream-gaging station North Creek near Jacksboro, Texas. A continuous water-stage recording gage was installed at one representative floodwater-retarding structure (site 28-A) on Oct. 5, 1972. The data are collected to compute the contents, surface area, inflow, and outflow at this site. The stream-gaging station on North Creek near Jacksboro continuously records the water level which, with measurements of streamflow, is used to compute the runoff from the study area. Streamflow records at this gage began on Aug. 8, 1956. Detailed rainfall-runoff computations are included for one storm during the 1979 water year at the stream-gaging station. (USGS)

  1. Hydrologic data for North Creek Trinity River Basin, Texas, 1976

    USGS Publications Warehouse

    Kidwell, C.C.

    1978-01-01

    This report contains rainfall and runoff data collected during the 1976 water year for a 21.6-square mile area above the stream-gaging station on North Creek near Jacksboro, Texas. A continuous water-stage recording gage was installed at one representative floodwater-retarding structure (site 28-A) on Oct. 5, 1972. The data are used to compute the contents, surface area, inflow, and outflow at this site. The stream-gaging station on North Creek near Jacksboro continuously records the water level which, with measurements of streamflow, is used to compute the runoff from the study area. Streamflow records at this gage began on Aug. 8, 1956. Detailed rainfall-runoff computations, including hydrographs and mass curves, are included for two storm periods during the 1976 water year at the stream-gaging station. (Woodard-USGS)

  2. Oblique opening of Skyros Basin in the North Aegean Sea, based on Morphotectonic Analysis

    NASA Astrophysics Data System (ADS)

    Papanikolaou, Dimitris; Nomikou, Paraskevi; Livanos, Isidoros; Papantoniou, George; Rousakis, Grigoris; Lampridou, Danai

    2015-04-01

    Detailed analysis of swath bathymetry and seismic reflection profiling has revealed the morphotectonic structure of the Skyros Basin in North Aegean Sea (Greece). The overall geometry of the basin is shaped by a major slope discontinuity, separating the continental platform from the continental slope at depths between 200-400m. The basin forms an equilateral triangle. Its base is 50km long NW-SE trending at the southwest, parallel to the Skyros Island, whereas its pic is located at the northeast, north of Lesvos Island. The basin comprises 9 sub-basins at depths varying from 1200m at the southwest to 600m to the northeast and is structurally divided into three parts: i) the eastern part forms a longitudinal semi-graben with one sub-basin trending ENE-WSW of 45km length, but only 5-8 Km width at depths varing between 600-700m. This sub-basin is bounded to the south by a marginal fault of >1.5km throw but with unknown horizontal displacement. ii) the central part that forms the predominant part of the triangle with 45 Km long NW-SE trending base and 70km long axis at the NE-SW direction. The central part corresponds to an assymetric graben with a 70km long major marginal fault with >1500m throw along its southern slopes and a 70 km long antithetic fault with >400m throw along its northern slopes. It comprises 5 sub-basins with depths ranging between 950-700m, bounded by important E-W trending strike slip fault zones, characterized by flower structures, with minor vertical components ranging from a few meters up to 200m. iii) the western part of the basin trends NW-SE, is 55 Km long and 25 Km wide, revealing a NW-SE tectonic graben. It comprises two sub-basins, oriented NW-SE separated by an intermediate transverse fault zone. The throw of the western marginal faults offshore Skyros Island exceeds 1200m, whereas the throw of the parallel faults creating the NW-SE tectonic graben is limited to a few hundreds meters. It should be emphasized that the Alpine basement was

  3. Development and hydrocarbon potential of Mesozoic sedimentary basins around margins of North Atlantic

    SciTech Connect

    Masson, D.G.; Miles, P.R.

    1986-06-01

    The Late Triassic-Early Jurassic rift basins of Iberia, offshore eastern Canada, and the continental shelf of western Europe are fragments of a formerly coherent northeast-trending rift system that probably formed as a result of tensional stress between Europe, Africa, and North America. The separation of Europe, North America, and Iberia was preceded by a Late Jurassic-Early Cretaceous rifting phase that is clearly distinct from the earlier Mesozoic rifting episode and was little influenced by it. The two periods of rifting are separated by a Middle Jurassic relatively tectonically quiet period. The distribution of hydrocarbon finds within the rift basin suggests that the best prospects are in areas where the two rifting episodes are superimposed. Lack of mature source rocks in the later Mesozoic rift basins and an unfavorable temporal relationship between hydrocarbon generation and tectonic activity in the early Mesozoic basins are proposed as explanations for the apparently poor hydrocarbon prospectivity of large areas of the Mesozoic basins.

  4. Diachronous Growth of Normal Fault Systems in Multiphase Rift Basins: Structural Evolution of the East Shetland Basin, Northern North Sea

    NASA Astrophysics Data System (ADS)

    Claringbould, Johan S.; Bell, Rebecca E.; A-L. Jackson, Christopher; Gawthorpe, Robert L.; Odinsen, Tore

    2015-04-01

    Our ability to determine the structural evolution and interaction of fault systems (kinematically linked group of faults that are in the km to 10s of km scale) within a rift basin is typically limited by the spatial extent and temporal resolution of the available data and methods used. Physical and numerical models provide predictions on how fault systems nucleate, grow and interact, but these models need to be tested with natural examples. Although field studies and individual 3D seismic surveys can provide a detailed structural evolution of individual fault systems, they are often spatially limited and cannot be used examine the interaction of fault systems throughout the entire basin. In contrast, regional subsurface studies, commonly conducted on widely spaced 2D seismic surveys, are able to capture the general structural evolution of a rift basin, but lack the spatial and temporal detail. Moreover, these studies typically describe the structural evolution of rifts as comprising multiple discrete tectonic stages (i.e. pre-, syn- and post-rift). This simplified approach does not, however, consider that the timing of activity can be strongly diachronous along and between faults that form part of a kinematically linked system within a rift basin. This study focuses on the East Shetland Basin (ESB), a multiphase rift basin located on the western margin of the North Viking Graben, northern North Sea. Most previous studies suggest the basin evolved in response to two discrete phases of extension in the Permian-Triassic and Middle-Late Jurassic, with the overall geometry of the latter rift to be the result of selective reactivation of faults associated with the former rift. Gradually eastwards thickening intra-rift strata (deposited between two rift phases) that form wedges between and within fault blocks have led to two strongly contrasting tectonic interpretations: (i) Early-Middle Jurassic differential thermal subsidence after Permian-Triassic rifting; or (ii

  5. Tectono-stratigraphic evolution and crustal architecture of the Orphan Basin during North Atlantic rifting

    NASA Astrophysics Data System (ADS)

    Gouiza, Mohamed; Hall, Jeremy; Welford, J. Kim

    2016-06-01

    The Orphan Basin is located in the deep offshore of the Newfoundland margin, and it is bounded by the continental shelf to the west, the Grand Banks to the south, and the continental blocks of Orphan Knoll and Flemish Cap to the east. The Orphan Basin formed in Mesozoic time during the opening of the North Atlantic Ocean between eastern Canada and western Iberia-Europe. This work, based on well data and regional seismic reflection profiles across the basin, indicates that the continental crust was affected by several extensional episodes between the Jurassic and the Early Cretaceous, separated by events of uplift and erosion. The preserved tectono-stratigraphic sequences in the basin reveal that deformation initiated in the eastern part of the Orphan Basin in the Jurassic and spread towards the west in the Early Cretaceous, resulting in numerous rift structures filled with a Jurassic-Lower Cretaceous syn-rift succession and overlain by thick Upper Cretaceous to Cenozoic post-rift sediments. The seismic data show an extremely thinned crust (4-16 km thick) underneath the eastern and western parts of the Orphan Basin, forming two sub-basins separated by a wide structural high with a relatively thick crust (17 km thick). Quantifying the crustal architecture in the basin highlights the large discrepancy between brittle extension localized in the upper crust and the overall crustal thinning. This suggests that continental deformation in the Orphan Basin involved, in addition to the documented Jurassic and Early Cretaceous rifting, an earlier brittle rift phase which is unidentifiable in seismic data and a depth-dependent thinning of the crust driven by localized lower crust ductile flow.

  6. Water quality in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1992-95

    USGS Publications Warehouse

    Stoner, Jeffrey D.; Lorenz, D.L.; Goldstein, R.M.; Brigham, M.E.; Cowdery, T.K.

    1998-01-01

    This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the River River of the North basin study unit and to relate these findings to water-quality issues of regional and national concern. The information in primarily intended for those who are involved in water-resource management. Yet the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

  7. Petroleum geology and resources of the North Caspian Basin, Kazakhstan and Russia

    USGS Publications Warehouse

    Ulmishek, Gregory F.

    2001-01-01

    The North Caspian basin is a petroleum-rich but lightly explored basin located in Kazakhstan and Russia. It occupies the shallow northern portion of the Caspian Sea and a large plain to the north of the sea between the Volga and Ural Rivers and farther east to the Mugodzhary Highland, which is the southern continuation of the Ural foldbelt. The basin is bounded by the Paleozoic carbonate platform of the Volga-Ural province to the north and west and by the Ural, South Emba, and Karpinsky Hercynian foldbelts to the east and south. The basin was originated by pre-Late Devonian rifting and subsequent spreading that opened the oceanic crust, but the precise time of these tectonic events is not known. The sedimentary succession of the basin is more than 20 km thick in the central areas. The drilled Upper Devonian to Tertiary part of this succession includes a prominent thick Kungurian (uppermost Lower Permian) salt formation that separates strata into the subsalt and suprasalt sequences and played an important role in the formation of oil and gas fields. Shallow-shelf carbonate formations that contain various reefs and alternate with clastic wedges compose the subsalt sequence on the 1 basin margins. Basinward, these rocks grade into deep-water anoxic black shales and turbidites. The Kungurian salt formation is strongly deformed into domes and intervening depressions. The most active halokinesis occurred during Late Permian?Triassic time, but growth of salt domes continued later and some of them are exposed on the present-day surface. The suprasalt sequence is mostly composed of clastic rocks that are several kilometers thick in depressions between salt domes. A single total petroleum system is defined in the North Caspian basin. Discovered reserves are about 19.7 billion barrels of oil and natural gas liquids and 157 trillion cubic feet of gas. Much of the reserves are concentrated in the supergiant Tengiz, Karachaganak, and Astrakhan fields. A recent new oil discovery

  8. Thermal maturity map of Devonian shale in the Illinois, Michigan, and Appalachian basins of North America

    USGS Publications Warehouse

    East, Joseph A.; Swezey, Christopher S.; Repetski, John E.; Hayba, Daniel O.

    2012-01-01

    Much of the oil and gas in the Illinois, Michigan, and Appalachian basins of eastern North America is thought to be derived from Devonian shale that is within these basins (for example, Milici and others, 2003; Swezey, 2002, 2008, 2009; Swezey and others, 2005, 2007). As the Devonian strata were buried by younger sediments, the Devonian shale was subjected to great temperature and pressure, and in some areas the shale crossed a thermal maturity threshold and began to generate oil. With increasing burial (increasing temperature and pressure), some of this oil-generating shale crossed another thermal maturity threshold and began to generate natural gas. Knowledge of the thermal maturity of the Devonian shale is therefore useful for predicting the occurrence and the spatial distribution of oil and gas within these three basins. This publication presents a thermal maturity map of Devonian shale in the Illinois, Michigan, and Appalachian basins. The map shows outlines of the three basins (dashed black lines) and an outline of Devonian shale (solid black lines). The basin outlines are compiled from Thomas and others (1989) and Swezey (2008, 2009). The outline of Devonian shale is a compilation from Freeman (1978), Thomas and others (1989), de Witt and others (1993), Dart (1995), Nicholson and others (2004), Dicken and others (2005a,b), and Stoeser and others (2005).

  9. Paleoproterozoic basin development and sedimentation in the Lake Superior region, North America

    USGS Publications Warehouse

    Ojakangas, R.W.; Morey, G.B.; Southwick, D.L.

    2001-01-01

    The peneplaned Archean craton in the Lake Superior region was the platform upon which a continental margin assemblage was deposited. Extension resulted in localized rifts that received thicker accumulations of sediments and volcanic rocks than did adjacent parts of the platform. Seas transgressed onto the continent several times and an ocean basin opened south of the present-day Lake Superior. Island arcs that formed during subduction collided with the craton margin as the ocean basin closed; oceanic crust is poorly preserved as a dismembered ophiolite sequence. The arc volcanics are preserved as the Wisconsin magmatic terranes. The collision resulted in a fold-and-thrust belt known as the Penokean orogen. To the north of the fold-and-thrust belt, a northward-migrating foreland basin - the Animikie basin - developed. Thick turbidite successions were deposited along the basin axis, and terrigenous clastics and Lake Superior-type iron-formation were deposited on the shelf along the northern margin of the basin. The primary paleoclimatic indicators are: (1) glaciogenic rocks at the base of the Paleoproterozoic succession in Michigan indicating ice-house conditions; 2) remnants of a paleosol on the glaciogenic rocks indicative of deep weathering, probably under subtropical conditions and therefore of greenhouse conditions; and (3) carbonate minerals after gypsum, halite, and anhydrite in stromatolitic dolomite, indicative of aridity. Three second-order depositional sequences are bounded by major unconformities, and can be correlated throughout the Lake Superior region. ?? 2001 Elsevier Science B.V. All rights reserved.

  10. The Norwegian Danish Basin: A key to understanding the Cenozoic in the eastern North Sea

    NASA Astrophysics Data System (ADS)

    Rasmussen, Thomas L.; Clausen, Ole R.; Andresen, Katrine J.; Goledowski, Bartosz

    2015-04-01

    The Danish part of Norwegian-Danish Basin, which constitutes the eastern part of the North Sea Basin, has been the key area for sequence stratigraphic subdivision and analysis of the Cenozoic succession since the mid 1990's. Widespread 3D seismic data, in the central parts of the North Sea Basin, as well as more scattered 3D seismic data in the Danish part of the Norwegian-Danish Basin, have given a more detailed understanding of the sequences and indicate that climate is tenable for the origin of Cenozoic sequence boundaries. The previous sequence stratigraphic interpretations have been an integrated part of an ongoing debate concerning vertical movements of the Fennoscandian shield versus the impact of climate and erosion. A newly accessed coherent regional 2D and reprocessed 3D seismic data set, in the Norwegian part of the Norwegian-Danish Basin, constitute the database for a new sequence stratigraphic analysis of the entire area. The objective of the new study is to test previous subdivisions and introduce a coherent 3D sequence stratigraphic analysis and depositional model for the entire Norwegian-Danish Basin. This analysis is necessary to get out of the stalemate with the uplift discussion. The study shows that the original subdivision by Michelsen et al. (1995, 1998) stands. However, revision of few a sequence boundaries may have to be adjusted due to new biostratigraphic information published. Furthermore, high-angle clinoforms and geomorphological transport complexes observed in the Danish North Sea Basin can be traced into the Norwegian sector. This together with the recognition of several other high-angle clinoform complexes, and their associated seismic facies distribution maps and thickness-maps, enhances the level of detail and constrains the previous published paleogeographic reconstructions of the Cenozoic. The geometry of the Cenozoic infill, in the Norwegian part of the Norwegian-Danish Basin, is here interpreted to be controlled by relative sea

  11. Location of photographs showing landslide features in the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

    Data points represent locations of photographs taken of landslides in the Little North Santiam River Basin, Oregon. Photos were taken in spring of 2010 during field verification of landslide locations (deposits previously mapped using LiDAR-derived imagery). The photographs depict various landslide features, such as scarps, pistol-butt trees, or colluvium deposits. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  12. Head scarp boundary for the landslides in the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

    Polygons represent head scarps and flank scarps associated with landslide deposits in the Little North Santiam River Basin, Oregon. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  13. Physical characteristics of stream subbasins in the Blue Earth River Basin, south-central Minnesota and north-central Iowa

    USGS Publications Warehouse

    Lorenz, D.L.; Payne, G.A.

    1992-01-01

    This report presents data describing the physical characteristics of stream basins upstream from selected points on streams in the Blue Earth River basin, located in south-central Minnesota and north-central Iowa. The physical characteristics are the drainage area of the basin, the percentage area of the basin covered only by lakes, the percentage area of the basin covered by both lakes and wetlands, the main-channel length, and the mainchannel slope. The points on the stream include outlets of subbasins of at least five square miles, outfalls of sewage treatment plants, and locations of U.S. Geological Survey gaging stations.

  14. Assessment of undiscovered oil and gas resources of the Chad Basin Province, North-Central Africa

    USGS Publications Warehouse

    Brownfield, Michael E.; Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Cook, Troy A.; Pollastro, Richard M.; Tennyson, Marilyn E.

    2010-01-01

    The Chad Basin Province located in north-central Africa recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 2.32 billion barrels of oil, 14.65 trillion cubic feet of natural gas, and 391 million barrels of natural gas liquids.

  15. Appraisal report, water resources appraisal for hydroelectric licensing: Pigeon River Basin, North Carolina, Tennessee

    SciTech Connect

    Not Available

    1981-09-01

    The water resources of the Pigeon River Basin which covers approximately 666 square mile in eastern Tennessee and western North Carolina are evaluated. Data are presented on existing and potential water resource development, on water uses, e.g., for irrigation, municipal water supplies, or flood control and on the status of hydro plant licensing. Past and current planning studies are summarized. The information presented is current as of September 1981. (LCL)

  16. Hydrologic and chemical-quality data from four rural basins in Guilford County, North Carolina, 1985-88

    USGS Publications Warehouse

    Hill, C.L.

    1989-01-01

    An investigation was begun in 1984 in Guilford County, North Carolina, to monitor water quality and soil erosion in basins with various land-management practices. Hydrologic and chemical-quality data were collected from four rural drainage basins, including two agricultural basins (7.4 and 4.8 acres) cultivated in tobacco and small grains, a mixed rural land-use basin (665 acres) currently under standard land-management practices, and a forested control basin (44 acres) characterizing background conditions. Mean concentrations of total nitrite plus nitrate were 1.0 milligrams per liter from the agricultural basin under standard land-management practices. This was nearly 10 times greater than concentrations from the forested basin. Records of streamflow discharge, chemical quality, ground-water levels, precipitation, and farming activities collected from October 1984 through September 1988 at one or more of the basins are also presented in this report.

  17. Sensitivity of the North Atlantic Basin to cyclic climatic forcing during the early Cretaceous

    USGS Publications Warehouse

    Dean, W.E.; Arthur, M.A.

    1999-01-01

    Striking cyclic interbeds of laminated dark-olive to black marlstone and bioturbated white to light-gray limestone of Neocomian (Early Cretaceous) age have been recovered at Deep Sea Drilling Project (DSDP) and Ocean Drilling Project (ODP) sites in the North Atlantic. These Neocomian sequences are equivalent to the Maiolica Formation that outcrops in the Tethyan regions of the Mediterranean and to thick limestone sequences of the Vocontian Trough of France. This lithologic unit marks the widespread deposition of biogenic carbonate over much of the North Atlantic and Tethyan seafloor during a time of overall low sealevel and a deep carbonate compensation depth. The dark clay-rich interbeds typically are rich in organic carbon (OC) with up to 5.5% OC in sequences in the eastern North Atlantic. These eastern North Atlantic sequences off northwest Africa, contain more abundant and better preserved hydrogen-rich, algal organic matter (type II kerogen) relative to the western North Atlantic, probably in response to coastal upwelling induced by an eastern boundary current in the young North Atlantic Ocean. The more abundant algal organic matter in sequences in the eastern North Atlantic is also expressed in the isotopic composition of the carbon in that organic matter. In contrast, organic matter in Neocomian sequences in the western North Atlantic along the continental margin of North America has geochemical and optical characteristics of herbaceous, woody, hydrogen-poor, humic, type III kerogen. The inorganic geochemical characteristics of the dark clay-rich (80% CaCO3) interbeds in both the eastern and western basins of the North Atlantic suggest that they contain minor amounts of relatively unweathered eolian dust derived from northwest Africa during dry intervals.

  18. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

    NASA Astrophysics Data System (ADS)

    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  19. Reexamination of the geological structure of the North German Basin in Lower Saxony

    NASA Astrophysics Data System (ADS)

    Rienäcker, Julia; Sattler, Sabine

    2016-04-01

    The North German Basin (NGB), as part of the Southern Permian Basin in Europe, extends from the North Sea, across Denmark, the Netherlands through Northern Germany, to Poland. It contains sediments from the Lower Permian to the Quaternary, and experienced a minimum subsidence of 2000 m from the Permian to the Mesozoic. This was followed by uplift during Late Cretaceous-Early Cenozoic inversion. The hundreds of meters thick and mobile Zechstein salt of Late Permian was remobilized in several phases to form complex salt structures. The salt moved laterally and vertically thus creating salt pillows and tall asymmetrical salt diapirs, some of which broke through the overburden until they were exposed at the paleo-surface. Salt structures influenced both the sedimentation and structural style throughout the NGB. Within the joint project TUNB (Deeper Underground North German Basin), 2-D/3-D seismic datasets, borehole data, structural maps and the existing 3-D geological model of Lower Saxony, will be used to create a new, detailed, geological 3-D model of the Lower Saxony part of the NGB. This allows new insights into the interplay between salt tectonics, sedimentation and tectonic movement, and in particular may help to resolve issues regarding the influence of the Zechstein salt on the sediment distribution. We show the different structural styles of important reservoir formations for, e.g., hydrocarbons, geothermal energy and gas storage, such as the Middle Buntsandstein, Rhaetkeuper, Middle Jurassic, and Lower Cretaceous, especially related to salt structures.

  20. Reservoir heterogeneity in Carter Sandstone, North Blowhorn Creek oil unit and vicinity, Black Warrior Basin, Alabama

    SciTech Connect

    Kugler, R.L.; Pashin, J.C.

    1992-05-01

    This report presents accomplishments made in completing Task 3 of this project which involves development of criteria for recognizing reservoir heterogeneity in the Black Warrior basin. The report focuses on characterization of the Upper Mississippian Carter sandstone reservoir in North Blowhorn Creek and adjacent oil units in Lamar County, Alabama. This oil unit has produced more than 60 percent of total oil extracted from the Black Warrior basin of Alabama. The Carter sandstone in North Blowhorn Creek oil unit is typical of the most productive Carter oil reservoirs in the Black Warrior basin of Alabama. The first part of the report synthesizes data derived from geophysical well logs and cores from North Blowhorn Creek oil unit to develop a depositional model for the Carter sandstone reservoir. The second part of the report describes the detrital and diagenetic character of Carter sandstone utilizing data from petrographic and scanning electron microscopes and the electron microprobe. The third part synthesizes porosity and pore-throat-size-distribution data determined by high-pressure mercury porosimetry and commercial core analyses with results of the sedimentologic and petrographic studies. The final section of the report discusses reservoir heterogeneity within the context of the five-fold classification of Moore and Kugler (1990).

  1. Tectonic structure, seismic stratigraphy and hydrocarbon potential of the North Kara Basin (Russian Arctic)

    NASA Astrophysics Data System (ADS)

    Verzhbitsky, V.; Kosenkova, N.; Murzin, R.; Vasilyev, V.; Malysheva, S.; Komissarov, D.; Ananyev, V.; Roslov, Yu.; Khudoley, A.

    2012-04-01

    North Kara shelf represents one of the remote and still poorly studied sedimentary megabasins of Russian West Arctic. North Kara area lacks any offshore wells so the understanding of its structure is based on the geology of adjacent East Barents Basin, as well as surrounding land areas (Taimyr, Severnaya and Novaya Zemlya fold belts) and stratigraphic columns of the scattered Arctic Islands. It is widely believed that North Kara shelf is mostly composed of Riphean-Paleozoic sedimentary units, underlain by Precambrian basement (North Kara massif), and represents one of the most promising areas of the Russian Arctic for hydrocarbon (mostly oil) discoveries. Our study is based on the reinterpretation of several regional seismic lines acquired by Sevmorgeo. We used the main Paleozoic and Mesozoic tectonic events known for Severnaya Zemlya Archipelago and Taimyr Peninsula for interpretation of the age of main seismic complexes/boundaries within the North Kara sedimentary cover (first of all within the Priseverozemelsky Trough). We correlated the sharp angular unconformity in the lower part of sedimentary succession with Cambrian/Ordovician unconformity described earlier on the nearby Severnaya Zemlya onshore domain. It is likely that the pre-Ordovician tectonic event corresponds to the Late Baikalian (Timanian) orogeny, which took place on Timan-Pechora and Novaya Zemlya areas. Above the unconformity we proposed the occurrence of Ordovician-Silurian shelfal sedimentary sequence of ~ 2 km thickness. This strata are overlain by thick (~3-4 km) progradational unit. It is likely that this sequence should correspond to molassic deposits of old red sandstones, related to the regional Caledonian orogeny. We believe that general structural pattern of the North Kara region was formed in Late Carboniferous-Early Permian time as a result of Kara massif/Siberian Craton collision-related Hercynian orogeny of Taimyr-Severnaya Zemlya domain. This event led to gentle folding of the

  2. River Gain and Loss Studies for the Red River of the North Basin, North Dakota and Minnesota

    USGS Publications Warehouse

    Williams-Sether, Tara

    2004-01-01

    The Dakota Water Resources Act passed by the U.S. Congress in 2000 authorized the Secretary of the Interior to conduct a comprehensive study of future water-quantity and -quality needs of the Red River of the North (Red River) Basin in North Dakota and of possible options to meet those water needs. To obtain the river gain and loss information needed to properly account for available streamflow within the basin, available river gain and loss studies for the Sheyenne, Turtle, Forest, and Park Rivers in North Dakota and the Wild Rice, Sand Hill, Clearwater, South Branch Buffalo, and Otter Tail Rivers in Minnesota were reviewed. Ground-water discharges for the Sheyenne River in a reach between Lisbon and Kindred, N. Dak., were about 28.8 cubic feet per second in 1963 and about 45.0 cubic feet per second in 1986. Estimated monthly net evaporation losses for additional flows to the Sheyenne River from the Missouri River ranged from 1.4 cubic feet per second in 1963 to 51.0 cubic feet per second in 1976. Maximum water losses for a reach between Harvey and West Fargo, N. Dak., for 1956-96 ranged from about 161 cubic feet per second for 1976 to about 248 cubic feet per second for 1977. Streamflow gains of 1 to 1.5 cubic feet per second per mile were estimated for the Wild Rice, Sand Hill, and Clearwater Rivers in Minnesota. The average ground-water discharge for a 5.2-mile reach of the Otter Tail River in Minnesota was about 14.1 cubic feet per second in August 1994. The same reach lost about 14.1 cubic feet per second between February 1994 and June 1994 and about 21.2 cubic feet per second between August 1994 and August 1995.

  3. Magnetic anomalies and tectonic fabric of marginal basins North of New Zealand

    SciTech Connect

    Malahoff, A.; Feden, R.H.; Fleming, H.S.

    1982-05-10

    Detailed airborne magnetic studies conducted over the region of the S. W. Pacific marginal basins extending from the Solomon Islands to New Zealand suggest that three major phases of basin formation and island arc development have occurred in this region. Development of the Tasman Sea took place during the Late Cretaceous-Paleocene. Development of the basins to the east of the Tasman Sea occurred predominantly during the Oligocene as well as during the Upper Miocene to Recent. The South Fuji Basin, consisting of the Kupe and Minerva Abyssal Plains, is marked by the presence of possibly two RRR triple junction spreading centers that were active between the times of anomalies 13 to 7 (36--25.5 m.y.). The Kupe Abyssal Plain shows the presence of residual magnetic anomalies 7 to 13 of the eastern limb of the proposed spreading center. The western limb appears to have been subducted beneath the present site of the Three Kings Rise. This seafloor spreading phase (calculated half-spreading rate of 35 mm/yr) was coincident with the overthrusting phase of the New Caledonia ultramafic rocks. During that period, active volcanism along the then continuous Solomons-New Hebrides-Fiji-Lau Island arc was taking place. Magnetic anomalies from 1 to 4 (0--8 m.y. B. P.) are seen to extend along a clearly defined lineation pattern over the North Fuji Basin.

  4. South China connected to north India in Gondwana: sedimentary basin and detrital provenance analyses

    NASA Astrophysics Data System (ADS)

    Yao, W.; Li, Z. X.; Li, W. X.; Li, X. H.; Yang, J. H.

    2015-12-01

    The paleoposition of South China during the Ediacaran-Silurian is important for understanding the assembly of Gondwana. We report here the tectonostratigraphic evolution of the Ediacaran-Silurian Nanhua foreland basin in South China, and discuss South China's connection with Gondwana and potential tectonic triggers for both the Wuyi-Yunkai orogeny in South China and the Bhimphedian orogeny in north India. The Nanhua basin was involved in a three-stage evolution, which are: Stage 1 (the Ediacaran-Cambrian) recording the start of tectonic subsidence with turbiditic marine clastic deposition, fed by exotic orogens outboard South China; Stage 2 (the Ordovician to earliest-Silurian) featured by migrating depocentres with dominant shallow marine to deltaic clastic deposition, fed by the local Wuyi-Yunkai orogen; and Stage 3 (the Silurian) showing the arrival of depocentre in the Yangtze Block during the waning stage of the Wuyi-Yunkai orogeny with deltaic deposition in the remanent foreland basin. Detrital zircon analyses of the Ediacaran-Silurian sandstones across the Nanhua basin reveal a prominent age population of 1100-900 Ma (with a peak age at ~980 Ma) and moderate populations of Archean-Paleozoic ages, grossly matching that of crystalline and sedimentary rocks in northern India. Zircon isotopes of the Stage 1 samples suggest three Precambrian episodes of juvenile crustal growth at 3.0 Ga, 2.5 Ga and 1.0 Ga, and a major crustal reworking at 580-500 Ma for the source areas, which are constraint to be northwestern India and its surrounding orogens. Together with other evidence, we propose that South China likely collided with northwestern India during the Gondwana assembly, generated the Bhimphedian orogeny in north India and formed two foreland basins on both the north India and South China sides. Far-field stress of the collision triggered the Ordovician-Silurian Wuyi-Yunkai orogeny in South China. The Stage 2-3 samples in the Nanhua basin of South China were shed

  5. Estimating the magnitude and frequency of floods in rural basins of North Carolina

    USGS Publications Warehouse

    Pope, Benjamin F.; Tasker, Gary D.; Robbins, Jeanne C.

    2001-01-01

    A statewide study was conducted to develop two methods for estimating the magnitude and frequency of floods in rural ungaged basins in North Carolina. Flood-frequency estimates for gaged sites in North Carolina were computed by fitting the annual peak flows for each site to a log-Pearson Type III distribution. As part of the computation of flood-frequency estimates for gaged sites, new values for generalized skew coefficients were developed. Basin characteristics for these gaged sites were computed by using a geographic information system and automated computer algorithms. Flood-frequency estimates and basin characteristics for 317 gaged sites were combined to form the data base that was used for this analysis. Regional regression analysis, using generalized least-squares regression, was used to develop a set of predictive equations that can be used to estimate the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval discharges for rural ungaged basins in the Blue Ridge-Piedmont, Coastal Plain, and Sand Hills hydrologic areas. The predictive equations are all functions of drainage area. Average errors of prediction for these regression equations range from 36 to 65 percent. A region-of-influence method also was developed that interactively estimates recurrence interval discharges for rural ungaged basins in the Blue Ridge-Piedmont and Coastal Plain hydrologic areas of North Carolina. Regression techniques are used to develop a unique relation between flood discharge and basin characteristics for a subset of gaged sites with similar basin characteristics. This, then, can be used to estimate flood discharges at ungaged sites. Because the computations required for this method are somewhat complex, a computer application was developed that performs the computations and compares the predictive errors for this method. The computer application also includes the option of using the regression equations to compute estimated flood discharges and errors of

  6. Mesozoic tectonic setting of rift basins in eastern North China and implications for destruction of the North China Craton

    NASA Astrophysics Data System (ADS)

    Qi, Guo-wei; Zhang, Jin-Jiang; Wang, Meng

    2015-11-01

    Destruction of the North China Craton (NCC) in the Mesozoic due to subduction of the Paleo-Pacific Plate has attracted a lot of recent interest, with numerous studies focusing on regional tectonics and associated magmatism. Although the peak ages for this event have been established, the timing of its initiation remains poorly understood. In this paper, two rift basins in the northern Hebei Province of China, the Diaoe Basin (DB) and Houcheng Basin (HB), are studied in order to constrain the timing of destruction of the northern margin of the NCC. Both NNE-striking basins developed on Proterozoic basement. The DB is a graben controlled by normal faults on its two margins, and the HB is a half-graben bounded by normal faults on its eastern side. Basin fills include detrital sediments and volcanic rocks, which are (from bottom to top) the Houcheng Formation (Fh), the Zhangjiakou Formation (Fzh), the Shijiayao Formation (Fs), and the Huajiying Formation (Fhj). The Fh is composed mainly of detrital sediments interlayered with andesite in its lower section, and interlayered with felsic volcanics (rhyolite) in its upper section. There exists a transitional change from the Fh to the thick felsic volcanic strata of the Fzh. Geochemically, the andesite layers in the lower Fh were most likely derived from mixing of crust and mantle melts, whereas the felsic rocks were derived from melting of the lower crust. U-Pb dating of zircons by LA-ICP-MS yielded ages for the lower Fh andesites of ca. 165.7 Ma in the HB and ca. 157.4 Ma in the DB. The felsic rocks at the base of the Fzh yielded ages of ca. 155.1 Ma in the HB and ca. 149.2-143.4 Ma in the DB. The Fs and Fhj in the DB both yielded similar ages of ca. 136 Ma. The development of rift basins, together with the occurrence of massive felsic volcanic rocks, indicates a period of significant extension and thinning of the NCC. The ca. 165.7-155.1 Ma age for andesites not only represents the initial timing of crustal extension

  7. Temperature and zooplankton size structure: climate control and basin-scale comparison in the North Pacific

    PubMed Central

    Chiba, Sanae; Batten, Sonia D; Yoshiki, Tomoko; Sasaki, Yuka; Sasaoka, Kosei; Sugisaki, Hiroya; Ichikawa, Tadafumi

    2015-01-01

    The global distribution of zooplankton community structure is known to follow latitudinal temperature gradients: larger species in cooler, higher latitudinal regions. However, interspecific relationships between temperature and size in zooplankton communities have not been fully examined in terms of temporal variation. To re-examine the relationship on a temporal scale and the effects of climate control thereon, we investigated the variation in copepod size structure in the eastern and western subarctic North Pacific in 2000–2011. This report presents the first basin-scale comparison of zooplankton community changes in the North Pacific based on a fully standardized data set obtained from the Continuous Plankton Recorder (CPR) survey. We found an increase in copepod community size (CCS) after 2006–2007 in the both regions because of the increased dominance of large cold-water species. Sea surface temperature varied in an east–west dipole manner, showing the typical Pacific Decadal Oscillation pattern: cooling in the east and warming in the west after 2006–2007. The observed positive correlation between CCS and sea surface temperature in the western North Pacific was inconsistent with the conventional interspecific temperature–size relationship. We explained this discrepancy by the geographical shift of the upper boundary of the thermal niche, the 9°C isotherm, of large cold-water species. In the eastern North Pacific, the boundary stretched northeast, to cover a large part of the sampling area after 2006–2007. In contrast, in the western North Pacific, the isotherm location hardly changed and the sampling area remained within its thermal niche throughout the study period, despite the warming that occurred. Our study suggests that while a climate-induced basin-scale cool–warm cycle can alter copepod community size and might subsequently impact the functions of the marine ecosystem in the North Pacific, the interspecific temperature–size relationship

  8. Temperature and zooplankton size structure: climate control and basin-scale comparison in the North Pacific.

    PubMed

    Chiba, Sanae; Batten, Sonia D; Yoshiki, Tomoko; Sasaki, Yuka; Sasaoka, Kosei; Sugisaki, Hiroya; Ichikawa, Tadafumi

    2015-02-01

    The global distribution of zooplankton community structure is known to follow latitudinal temperature gradients: larger species in cooler, higher latitudinal regions. However, interspecific relationships between temperature and size in zooplankton communities have not been fully examined in terms of temporal variation. To re-examine the relationship on a temporal scale and the effects of climate control thereon, we investigated the variation in copepod size structure in the eastern and western subarctic North Pacific in 2000-2011. This report presents the first basin-scale comparison of zooplankton community changes in the North Pacific based on a fully standardized data set obtained from the Continuous Plankton Recorder (CPR) survey. We found an increase in copepod community size (CCS) after 2006-2007 in the both regions because of the increased dominance of large cold-water species. Sea surface temperature varied in an east-west dipole manner, showing the typical Pacific Decadal Oscillation pattern: cooling in the east and warming in the west after 2006-2007. The observed positive correlation between CCS and sea surface temperature in the western North Pacific was inconsistent with the conventional interspecific temperature-size relationship. We explained this discrepancy by the geographical shift of the upper boundary of the thermal niche, the 9°C isotherm, of large cold-water species. In the eastern North Pacific, the boundary stretched northeast, to cover a large part of the sampling area after 2006-2007. In contrast, in the western North Pacific, the isotherm location hardly changed and the sampling area remained within its thermal niche throughout the study period, despite the warming that occurred. Our study suggests that while a climate-induced basin-scale cool-warm cycle can alter copepod community size and might subsequently impact the functions of the marine ecosystem in the North Pacific, the interspecific temperature-size relationship is not

  9. Temperature and zooplankton size structure: climate control and basin-scale comparison in the North Pacific.

    PubMed

    Chiba, Sanae; Batten, Sonia D; Yoshiki, Tomoko; Sasaki, Yuka; Sasaoka, Kosei; Sugisaki, Hiroya; Ichikawa, Tadafumi

    2015-02-01

    The global distribution of zooplankton community structure is known to follow latitudinal temperature gradients: larger species in cooler, higher latitudinal regions. However, interspecific relationships between temperature and size in zooplankton communities have not been fully examined in terms of temporal variation. To re-examine the relationship on a temporal scale and the effects of climate control thereon, we investigated the variation in copepod size structure in the eastern and western subarctic North Pacific in 2000-2011. This report presents the first basin-scale comparison of zooplankton community changes in the North Pacific based on a fully standardized data set obtained from the Continuous Plankton Recorder (CPR) survey. We found an increase in copepod community size (CCS) after 2006-2007 in the both regions because of the increased dominance of large cold-water species. Sea surface temperature varied in an east-west dipole manner, showing the typical Pacific Decadal Oscillation pattern: cooling in the east and warming in the west after 2006-2007. The observed positive correlation between CCS and sea surface temperature in the western North Pacific was inconsistent with the conventional interspecific temperature-size relationship. We explained this discrepancy by the geographical shift of the upper boundary of the thermal niche, the 9°C isotherm, of large cold-water species. In the eastern North Pacific, the boundary stretched northeast, to cover a large part of the sampling area after 2006-2007. In contrast, in the western North Pacific, the isotherm location hardly changed and the sampling area remained within its thermal niche throughout the study period, despite the warming that occurred. Our study suggests that while a climate-induced basin-scale cool-warm cycle can alter copepod community size and might subsequently impact the functions of the marine ecosystem in the North Pacific, the interspecific temperature-size relationship is not

  10. Sedimentary facies and depositional environments of early Mesozoic Newark Supergroup basins, eastern North America

    USGS Publications Warehouse

    Smoot, J.P.

    1991-01-01

    The early Mesozoic Newark Supergroup consists of continental sedimentary rocks and basalt flows that occupy a NE-trending belt of elongate basins exposed in eastern North America. The basins were filled over a period of 30-40 m.y. spanning the Late Triassic to Early Jurassic, prior to the opening of the north Atlantic Ocean. The sedimentary rocks are here divided into four principal lithofacies. The alluvial-fan facies includes deposits dominated by: (1) debris flows; (2) shallow braided streams; (3) deeper braided streams (with trough crossbeds); or (4) intense bioturbation or hyperconcentrated flows (tabular, unstratified muddy sandstone). The fluvial facies include deposits of: (1) shallow, ephemeral braided streams; (2) deeper, flashflooding, braided streams (with poor sorting and crossbeds); (3) perennial braided rivers; (4) meandering rivers; (5) meandering streams (with high suspended loads); (6) overbank areas or local flood-plain lakes; or (7) local streams and/or colluvium. The lacustrine facies includes deposits of: (1) deep perennial lakes; (2) shallow perennial lakes; (3) shallow ephemeral lakes; (4) playa dry mudflats; (5) salt-encrusted saline mudflats; or (6) vegetated mudflats. The lake margin clastic facies includes deposits of: (1) birdfoot deltas; (2) stacked Gilbert-type deltas; (3) sheet deltas; (4) wave-reworked alluvial fans; or (5) wave-sorted sand sheets. Coal deposits are present in the lake margin clastic and the lacustrine facies of Carnian age (Late Triassic) only in basins of south-central Virginia and North and South Carolina. Eolian deposits are known only from the basins in Nova Scotia and Connecticut. Evaporites (and their pseudomorphs) occur mainly in the northern basins as deposits of saline soils and less commonly of saline lakes, and some evaporite and alkaline minerals present in the Mesozoic rocks may be a result of later diagenesis. These relationships suggest climatic variations across paleolatitudes, more humid to the

  11. Pleistocene deformations in the contexte of the Rharb foredeep basin (north western Atlantic Moroccan margin)

    NASA Astrophysics Data System (ADS)

    Maad, N.; Le Roy, P.; Sahabi, M.; Gutscher, M. A.; Dakki, M.; Hssain, M.; van Vliet-Lanoë, B.; Brahim, L. Ait; M'hammdi, N.; Trenteseaux, A.

    2009-04-01

    This study relates to the Cenozoic post rift deformations of Rharb foredeep basin in response to the Europe-Africa convergence. Here we are going to retail the tectonic structures of the Rharb basin, in particular the active front of the Prerifaine nappe in the area of Lalla Zahra. The method is based on the interpretations of the high resolution seismic reflection data acquired during the Protit2 (2003) and the Nomads cruises (2007). The surveys were conducted by the University of Brest in France and the Faculté des Sciences d'El Jadida in Morocco. They allowed to record more than 2000 km of seismic lines through the Rharb continental shelf. The integration of new data with industrial seismic lines provided by ONHYM and field observations collected along the coastline allows us to identify the formation and the recent evolution of the western termination of the Southern Rif Corridor. This coastal basin corresponds to the foredeep basin linked to the Rif Cordillera and extends southwards through the northern Moroccan Meseta that defines the foreland region of the Western Rif (Flinch,93). The integrated study clarifies the post-nappe evolution of the offshore Rharb basin during Neogene and quaternary times. A succession of deformations affect the Rharb basin with separating episodes of relaxation and quiescence. Their ages are based on chronostratigraphical attribution of mean unconformities. A Lower Pliocene episode is characterized by reactivation of faults affecting the Nappe. The uplift of the basin and the individualization of the Lallah Zarah ridge increases and controls the terrigenous fluxes. A Middle Pleistocene still active episode and corresponds to a new uplift of the two margins of the basin. Faulting remains more active in the North along the Lallah Zarah ridge and offshore Larache where large active listric faults are observed. The progressive segmentation of the basin determinates the sedimentary filling with cyclic sequences extending progressively

  12. Mesozoic tectonically driven climatic partitioning of the south Junggar and north Tarim basins, northwest China

    SciTech Connect

    Hendrix, M.S.; Graham, S.A.; Brassell, S.C. )

    1991-03-01

    Detailed basin analysis of Mesozoic strata exposed in the south Junggar and north Tarim foreland basin Mesozoic depocenters, northwest China, has documented periodic structural reactivation of the intervening Tian Shan during that era. Coarse alluvial pulses, contained in an otherwise relatively fine-grained section of fluvial lacustrine sediments, were shed off both the north and south flanks of the Tian Shan during the Late Triassic, Latest Jurassic, and late Cretaceous. The lofty modern Tian Shan and associated rain shadow cast over the Tarim basin to the south reflect deformation associated with the early Cenozoic Himalayan collision; so too were the two basins climatically partitioned during the Mesozoic in response to relief produced by orogenesis. During prolonged episodes of relative tectonic quiescence, it appears that Tian Shan relief was too low to confine moisture to the windward side of the range. Most notable is the Middle Jurassic section that is dominated in both basins by a relatively fine-grained series of organic-rich, meandering fluvial, and lacustrine sediments. Pyrolytic analyses of organic-rich mudstones associated with these sediments document high H.I. kerogens, suggesting algal-dominated organic matter typical of anoxic lacustrine settings. However, detailed GC-MS biomarker analysis of the alipaphatic fraction also suggests substantial input from higher land plants in addition to algal sources. Not only are n-alkane distributions typically dominated by high molecular weight compounds with an odd-over-even preference typical of higher land plants, but the abundance of specific diterpenoid biomarker compounds strongly suggests the development of widespread coniferous forests on either side of the range during the Middle Jurassic.

  13. Low-flow characteristics and profiles for selected streams in the Roanoke River basin, North Carolina

    USGS Publications Warehouse

    Weaver, J.C.

    1996-01-01

    An understanding of the magnitude and frequency of low-flow discharges is an important part of protecting surface-water resources and planning for municipal and industrial economic expansion. Low-flow characteristics are summarized for 22 continuous-record gaging stations in North Carolina (19 sites) and Virginia (3 sites) and 60 partial-record gaging stations in the North Carolina Roanoke River Basin. Records of discharge collected through the 1994 water year are used. Flow characteristics included in the summary are (1) average annual unit flow, (2) 7Q10 low-flow discharge, the minimum average discharge for a 7-consecutive-day period occurring, on average, once in 10 years; (3) 30Q2 low-flow discharge; (4) W7Q10 low-flow discharge, similar to 7Q10 discharge except that flow during November through March only is considered; and (5) 7Q2 low-flow discharge. The potential for sustaining base flows is moderate to high in the western part of the basin as well as in the eastern and western fringes of the Piedmont and Coastal Plain physiographic provinces, respectively. Areas of low potential for sustaining base flow exist in the central part of the basin (between eastern Caswell County and western Warren County), where soils have low infiltration rates, and in lower regions of the Coastal Plain, where small streams tend to have zero flow during prolonged drought. Drainage area and low-flow discharge profiles are presented for 10 streams in the Roanoke River Basin in North Carolina and reflect a wide range in basin size, characteristics, and streamflow conditions. The selected streams are Town Fork Creek, Hogans Creek, Mayo River, Buffalo Creek, Smith River, Country Line Creek, Dan River, Marlow Creek, Hyco River, and Roanoke River. The drainage-area profiles show the increases in drainage areas as streams travel their course in the basin. At the mouths of streams profiles, the drainage areas range from 22 miles to about 9,700 miles. Low-flow discharges for each stream

  14. Water use and availability in the Woonasquatucket and Moshassuck River basins, north-central Rhode Island

    USGS Publications Warehouse

    Nimiroski, Mark T.; Wild, Emily C.

    2005-01-01

    The Woonasquatucket River Basin includes 51.0 square miles, and the Moshassuck River Basin includes 23.8 square miles in north-central Rhode Island. The study area comprises these two basins. The two basins border each other with the Moshassuck River Basin to the northeast of the Woonasquatucket River Basin. Seven towns are in the Woonasquatucket River Basin, and six towns are in the Moshassuck River Basin. To determine the water use and availability in the study area, water supply and discharge data were collected for these river basins for the 1995–99 period, and compared to estimated long-term water available. The study area is unique in the State of Rhode Island, because no withdrawals from major public suppliers were made during the study period. Withdrawals were, therefore, limited to self-supplied domestic use, two minor suppliers, and one self-supplied industrial user. Because no metered data were available, the summer water withdrawals were assumed to be the same as the estimates for the rest of the year. Seven major water suppliers distribute an average of 17.564 million gallons per day for use in the study area from sources outside of the study area. The withdrawals from minor water suppliers were 0.017 million gallons per day in the study area, all in the town of Smithfield in the Woonasquatucket River Basin. The remaining withdrawals in the study area were estimated to be 0.731 million gallons per day by self-supplied domestic, commercial, industrial, and agricultural users. Return flows in the study area included self-disposed water and disposal from permitted dischargers, including the Smithfield Sewage Treatment Plant. Return flows accounted for 4.116 million gallons per day in the study area. Most public-disposed water (15.195 million gallons per day) is collected by the Narragansett Bay Commission and is disposed outside of the basin in Narragansett Bay. The PART program, a computerized hydrograph-separation application, was used at one index

  15. The Sulfur content and origin of the North Thrace Basin coals, Turkey

    NASA Astrophysics Data System (ADS)

    Erarslan, Cemile; Örgün, Yüksel; Çelik Balcı, Nurgül

    2016-04-01

    Sulfur (S) is one of the major and hazardous components of the coal, and it may be originated from different sources depending on coal formation. The defined main sulfur types in the coal are pyritic sulfur, organic sulfur and sulfate sulfur. Thrace basin which have approximately 2 billion tons coal reserves is one of the most important coal basins of Turkey and Edirkoy (Saray-Tekirdaǧ) is the largest coal production site in north of Thrace basin. The obtained results show that the total S contents in the Edirköy coal samples vary from 3.21 to 14.1%. According to this result, the coal in Edirköy field is in the form of high -sulfur coal and the sulfur types analysis indicate that the ratio of pyritic sulfur vary from 0.78 to 5.25%, the organic sulfur vary from 1.1 to 7.47 % and the sulfate sulfur vary from 0.54 to 1.38% in the field. It was revealed that the ratio of organic sulfur in the coal increase towards the north of the field. In this study, the sulfur content and origin of the coal in Edirköy field will be discussed with sulfur isotope data.

  16. Salt distribution in the Norwegian-Danish Basin, Central North Sea

    NASA Astrophysics Data System (ADS)

    Sassier, Caroline; Jarsve, Erlend; Heeremans, Michel; Mansour Abdelmalak, Mohamed; Faleide, Jan Inge; Helge Gabrielsen, Roy

    2014-05-01

    Salt tectonics have extensively been studied in most parts of the Central North Sea. However, few studies have been done in the Norwegian side of the Norwegian-Danish Basin. In this contribution, we report a new regional analysis of the salt patterns across the offshore Norwegian-Danish Basin. We have mapped the regional distribution of salt structures in the Norwegian-Danish Basin using both old and recent 2D seismic reflection profiles tied to wells. The salt-thickness map shows three distinct salt structures patterns: (1) NW-SE trending salt walls in the northern part of the basin; the spacing between the walls vary between 7 to 12 km; (2) a dense and irregular distribution of salt diapirs in the southern part of the studied area; (3) an irregular pattern of sparse but big salt diapirs in the eastern part of the basin. This domain is characterized by numerous turtle structures associated with salt diapirs. Reflection seismic cross-sections show that most salt structures only pierce the Triassic sedimentary strata whereas only few salt structures reach the seabed. Rotated fault blocks indicate a gliding vergence towards the South in the eastern part of the basin and towards the SE in the western side of the Norwegian-Danish Basin. No mature or compressive salt structures, except some squeezed salt diapirs, are observed in the topographic lows of the basin. The initiation of salt tectonics started during the early Middle Triassic in the entire basin; salt tectonics reactivations were recorded during the Middle Jurassic, Paleogene, and prior to the Quaternary but are not homogeneous across the basin. Salt movements inferred from our study are in good agreement with previous studies. The trend of salt walls (domain 1) indicates a NE-SW extension which is not compatible with N-S trending pre-salt faults. Instead, the strong Triassic subsidence towards the SW has most likely controlled the formation of the salt walls. The salt was initially thicker in domain 2 that

  17. U-series disequilibria in volcanic rocks from the Futuna spreading centre (North Fiji Basin)

    NASA Astrophysics Data System (ADS)

    Le Faouder, A.; Hemond, C.; Benoit, M.; Lagabrielle, Y.; Guivel, C.; Pelletier, B.; Bollinger, C.

    2005-05-01

    The North Fiji basin is the largest active back arc basin of the SW Pacific. It is 12 m.y. old and characterised by a regional upper mantle thermal anomaly (Garel, 2001). The 200Km long Futuna spreading centre (Pelletier et al., 2001) is located west of Futuna and Alofi islands at the border between Lau and North Fijian Basins. This ridge is composed of an axial valley spotted with numerous seamounts. It starts from the north of the Fiji platform (15° 40'S) and ends in the north Fiji transform zone, northwest of the Futuna and Alofi islands (13° 35'S). New U series measurements were performed by TIMS on fresh dredged glassy samples. As the topography of this spreading centre exhibits a peculiar structure, the geochemical signature is also unusual. U and Th concentrations range between 0,0930%, six have a 230Th excess within 25 ± 5% and three have 230Th excess of about 15%. These 230Th excesses are typical of MORB or OIB source melting and not a back arc volcanic processes. It is also symptomatic of a melting in presence of garnet. In the equiline diagram, samples fall on a linear correlation indicating a mixing between two end-members with different Th/Usources ratios. The trend observed in this diagram requires the involvement of an enriched component, likely an EMII component, as defined by the trace elements and Sr-Nd-Pb isotope compositions (Benoit et al., in prep). This trend falls within the OIB field and plots close to Samoan samples analysed by Newman et al. (1984). This trend demonstrates the influence of a melt may be even more enriched than the samples of Savai'i volcano. This EMII melt mixes, within the upper mantle, with the Indian ocean like component as it was already established that

  18. Red River of the North Basin, Minnesota, North Dakota, and South Dakota

    USGS Publications Warehouse

    Stoner, Jeffrey D.; Lorenz, David L.; Wiche, Gregg J.; Goldstein, Robert M.

    1993-01-01

    This report describes the physical, chemical, and aquatic-biological characteristics that could affect regional water quality in the Red River of the North study unit. These characteristics define the overall environmental setting of the study unit. This report provides base line and historical information for future reports that will address specific water-quality issues and processes controlling and affecting water quality in the study unit, and for reports for the national-synthesis component of the NAWQA program that will integrate the results of the study-unit investigations.

  19. 3D structural model of the North Alpine Foreland Basin, Bavarian Part

    NASA Astrophysics Data System (ADS)

    Przybycin, Anna M.; Scheck-Wenderoth, Magdalena; Schneider, Michael

    2013-04-01

    The continental collision of Europe and Africa leads to the rise of the European Alps, which gave way to the formation of the North Alpine Foreland Basin, also referred to as the Molasse Basin, since the Tertiary. This typically wedge formed "foredeep" basin is filled with predominantly clastic sediments originating from erosional processes of the Alps which overly a southward dipping Mesozoic and Paleozoic succession. With our project we want to contribute to the understanding of the structure and subsequently of the thermal configuration of the Molasse Basin and its underlying deposits on a basin wide scale. We constructed a 3D structural model of the basin down to the crust-mantle-boundary, beginning with the Bavarian part. Therefore we used an approach of already existing local to midscale 2D and 3D structural models (e.g. Lüschen et al. 2006) as well as surface maps, seismic, well and gravity data. This 3D structural model resolves 5 sedimentary layers of the Mesozoic, including the geothermally utilized carbonate Malm aquifer (e.g. Birner et al. 2011), as well as the combined Paleozoic basement. Assuming isostatic equilibrium of the system a lithosphere-asthenosphere-boundary (LAB) has been calculated and compared to other published LABs of the region. Subsequently the model has been further constrained by 3D gravity modeling. The outcomes show that Cretaceous sediments are restricted to a small region in the central to eastern model area and are mostly overlain by the Tertiary Molasse sediments. The Triassic sediments occur in the northern and western part of the model area and do not continue far under the Molasse basin proper, while the Jurassic can be tracked as far south as beneath the Alps. The evaluation of the gravity indicates that the crystalline crust consists of a lighter upper crust and a denser lower crust. Our final LAB is shallowest under the Triassic subbasin, descending below the Bohemian Massif and the Molasse Basin proper and rising again

  20. Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

    NASA Astrophysics Data System (ADS)

    Neff, K.; Meixner, T.; De La Cruz, L.

    2014-12-01

    Groundwater recharge is the primary source of aquifer replenishment, an important source of freshwater for human consumption and riparian area sustainability in semi-arid regions. It is critical to understand the current groundwater recharge regimes in groundwater basins throughout the Western U.S. and how those regimes might shift in the face of climate change, land use change and management manipulations that impact the availability and composition of groundwater resources. Watersheds in the Basin and Range Province are characterized by a variable precipitation regime of wet winters, and variable summer precipitation. The horst-graben structure of these basins lends itself to orographic and continental precipitation effects that make mountain block and mountain front recharge critical components of annual recharge. The current assumption is that the relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation dominating in the northern parts of the region, and summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon extends its influence. To test this hypothesis, stable water isotope data of groundwater and precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to characterize and compare groundwater recharge regimes throughout the region. Preliminary stable water isotope results from the southernmost Rio San Miguel Basin in Sonora, Mexico indicate that groundwater is composed of 64%±14% summer monsoon precipitation, in contrast to more northern basins where winter precipitation is the source of 79-90% of basin groundwater.

  1. Petrographically deduced triassic climate for the Deep River Basin, eastern piedmont of North Carolina

    SciTech Connect

    McCarn, S.T.; Mansfield, C.F.

    1985-01-01

    A petrographic comparison of Triassic, fluvial sandstones from the Deep River Basin in the eastern piedmont of North Carolina with nearby Holocene stream sands (1) indicates that he Triassic climate was more arid than today's and (2) distinguishes an eastern, more plutonic terrane from a western, more metamorphic source terrane. The paleoclimatic interpretation is based on differences in framework composition between modern and ancient sands of the same grain size, derived from the same rock type, transported similar distances and deposited in similar settings. The Triassic sandstones contain more lithic-fragments but less quartz than otherwise equivalent, modern sand in the Deep River Basin. Feldspar content is more complex, controlled by both source-rock composition and climate. Sand from the more plutonic terrane contains more feldspar and plutonic lithic-fragments than sand from the more metamorphic terrane, which contains more quartz and metamorphic lithic-fragments. This petrographic interpretation of the Triassic sandstones along with the presence of coal, limestone, chert and caliche in the middle of the section suggests that the Triassic climate was cyclic, changing from arid to humid and back to arid. Plate-tectonic reconstructions place the Deep River Basin between the Triassic equator and Tropic of cancer, where the easterly trade winds would predominate. Therefore, the arid portions of the cycle could have been due to a periodic, orographic, rain shadow formed as the result of intermittent movement along the Jonesboro Fault, creating a highland area east of the Deep River Basin.

  2. Structuring and evolution of Neogene transcurrent basins in the Tellian foreland domain, north-eastern Tunisia

    NASA Astrophysics Data System (ADS)

    Melki, Fetheddine; Zouaghi, Taher; Harrab, Salah; Sainz, Antonio Casas; Bédir, Mourad; Zargouni, Fouad

    2011-07-01

    The Neogene sedimentary basins (Serravallian to Quaternary) of the Tellian tectonic foreland in north-eastern Tunisia formed within the overall NE-SW sinistral strike-slip tectonic framework of the Ras El Korane-Thibar and El Alia-Teboursouk fault systems. From stratigraphic logs, structural cross sections and interpretation of 2D seismic lines and boreholes, the pre-Neogene basement can be interpreted to be structured according to Eocene (NW-SE) compressional and Oligocene extensional phases. This basement comprises structural highs (anticlines and horsts) and subsiding areas (synclines, half-grabens and grabens) formed during the Neogene. The subsiding areas are delineated by faults striking N030E, N-S and N140E, defining (i) narrow, strongly subsiding synclines, (ii) lozenge-shaped basins and (iii) trapezoidal basins. The architecture of their fill results from the sedimentary balance between tectonics and eustatism. Halokinesis and clay diapirism (driven by Triassic and Neogene evaporites and clays) also played an important role in basin evolution, contributing to the formation of domes and diapirs along active faults.

  3. Acidic and alkaline precipitation in the Cilician Basin, north-eastern Mediterranean Sea.

    PubMed

    Ozsoy, T; Saydam, A C

    2000-05-15

    Samples from precipitation events collected at Erdemli during February 1996-June 1997 were analyzed to determine their particulate aluminium content, in addition to pH and conductivity measurements. Backward air mass trajectories corresponding to the rainy days were analyzed to determine potential source regions of acidic and alkaline constituents transported to the Cilician Basin. Approximately 28% of the rain samples were found to be acidic and the trajectories associated with half of the acid precipitation events were from the Mediterranean Basin and the Balkan Peninsula, while the other half were from the Anatolian mainland and local sources. Rain samples were found to be alkaline (58%), with their trajectories originating from North Africa and the Middle East. As a result of its CaCO3 content, mineral dust from these arid regions significantly increased the pH of rainwater.

  4. [Ecological function evaluation and related management strategies of river ecosystem in Taizi River basin, North China].

    PubMed

    Liu, Hong-Yan; Zhang, Yuan; Ma, Shu-Qin; Meng, Wei

    2013-10-01

    By the method of index evaluation at reach scale, this paper evaluated the ecological functions of aquatic biodiversity maintenance, habitat maintenance, water quality sustainment, and hydrological support of the river system in Taizi River basin of North China. The dominant ecological functions and the total ecological function were determined after sorting and summing. All the reaches in the basin were divided into four hierarchies of ecological functions. Overall, the total ecological function showed a spatially degrading trend from the mountainous region to the plain. Based on the evaluation results of the total function and dominant functions, six ecosystem management strategies were proposed. For the reaches with the functions of aquatic biodiversity- and habitat maintenance, the primary ecological management strategies included ecological conservation, ecological maintenance, and ecological restoration; for the reaches with the functions of water quality sustainment and hydrological support, the primary strategies of ecological management included limited development, development optimization, and exploitation.

  5. Shelf sheet-sand reservoir of the lower Cretaceous Greensand, North Celtic Sea Basin, offshore Ireland

    SciTech Connect

    Winn, R.D. Jr.

    1994-11-01

    Core and log data show that the marine, early to middle Albian {open_quotes}A{close_quotes} Sand of the Aptian to lower Cenomanian Greensand-Gault interval, North Celtic Sea Basin, offshore Ireland, was deposited as an approximately tabular sand body in shelf water depths. The {open_quotes}A{close_quotes} Sand is the major reservoir interval at Kinsale Head and Ballycotton gas fields. The reservoir sandstone is bioturbated, variably glauconitic, shell rich, and least muddy toward its provenance in a local area of the Irish massif and finer grained southeastward into the basin. Thickness and coarseness of the {open_quotes}A{close_quotes} Sand are related, in part, to distance from a narrow area of the paleoshore. Bathymetric control of sand thickness was superimposed on proximal-distal trends. Specifically, thick intervals are inferred to have been deposited in shelf lows, and thin zones were deposited over bathymetric highs. The {open_quotes}A{close_quotes} Sand was not deposited as a ridge sand, and positive relief on the depositional sand body appears to have been minor. Deposition of the Greensand occurred during thermal subsidence of the North Celtic Sea Basin following Early Cretaceous rifting. Overall late Early Cretaceous to Late Cretaceous transgression was interrupted by progradation of the {open_quotes}A{close_quotes} Sand, probably caused by a relative drop in sea level (forced regression). The {open_quotes}A{close_quotes} Sand sheet consists of several units within the central depositional basin. Three slightly coarsening-upward units up to 15 m thick probably are the consequence of high-frequency fluctuations in sea level during progradation. The top of the {open_quotes}A{close_quotes} Sand consists of a several-meter-thick, very glauconitic, muddy sandstone to sandy mudstone. The upper unit accumulated in deepening water following the maximum lowstand.

  6. Structure and dynamics in the north Jizhong Depression, Bohai Bay Basin, Eastern China

    NASA Astrophysics Data System (ADS)

    Miao, Q.; Qi, J.; Zhang, J.

    2015-12-01

    Study of structural geology in the north Jizhong Depression, Bohai Bay has achieved great breakthroughs in recent years. However the studies of structure and dynamics still remain much controversy. Based on the 3D and partial 2D seismic data, combined with regional geology and well data, the characteristics of structures in the north Jizhong Deprssion are analyzed, the dynamics is discussed. Our analyses show that the Cenozoic structures in the north Jizhong Depression can be subdivided into extensional system and strike-slip system. Extensional system concludes series of normal faults and transfer faults. Normal faults are mainly trend NNE and NE. They control the Paleogene sediments in sub-depressions of hanging-wall, and bottom out into a sub-horizontal detachment zone in deep level shaped like listric. Transfer faults mainly adjust displacement of normal faults, yet some like Tongbozhen and Niutuozhen are transfer faults in Paleocene and Eocene but change to normal faults in Oligocene. Strike-slip system is predominantly consisted by sub-vertical right-lateral strike-slip faults such as Xin`anzhen and Maxi. From seismic profiles, Xin`anzhen and Maxi cut into basement but only influence the sediments of Ed of Paleogene and Lower Neogene. Based on the relation of sedimentary sequence and faults, the extensional system mainly develops from Paleocene to Late Oligocene, but strike-slip system predominantly develops from Late Oligocene to Miocene. From the superposed section of crustal structure and basin structure in Jizhong Depression, the Cenozoic sub-basin is just located on the thinner zones of crustal, corresponding with the location of mantle uplift. It indicates that the Paleogene development of Jizhong Depression is related to the horizontal tension caused by uplift of magma in mantle. The results illustrate that extensional deformation in Jizhong depression is caused by the uplift of magma. The right-lateral strike-slip deformation, same with Tancheng

  7. Statistical Aspects of Tropical Cyclone Activity in the North Atlantic Basin, 1945-2010

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2012-01-01

    Examined are statistical aspects of the 715 tropical cyclones that formed in the North Atlantic basin during the interval 1945-2010. These 715 tropical cyclones include 306 storms that attained only tropical storm strength, 409 hurricanes, 179 major or intense hurricanes, and 108 storms that struck the US coastline as hurricanes. Comparisons made using 10-year moving average (10-yma) values between tropical cyclone parametric values and surface air and ENSO-related parametric values indicate strong correlations to exist, in particular, against the Armagh Observatory (Northern Ireland) surface air temperature, the Atlantic Multi-decadal Oscillation (AMO) index, the Atlantic Meridional Mode (AMM) index, and the North Atlantic Oscillation (NAO) index, in addition to the Oceanic Ni o index (ONI) and Quasi-Biennial Oscillation (QBO) indices. Also examined are the decadal variations of the tropical cyclone parametric values and a look ahead towards the 2012 hurricane season and beyond.

  8. A Geochemical Transect Across the Lau and North Fiji Basins: New Evidence for the Distribution of Multiple Mantle Plume Components

    NASA Astrophysics Data System (ADS)

    Price, A. A.; Jackson, M. G.; Blichert-Toft, J.; Arculus, R. J.; Conatser, C. S.; Konter, J. G.; Koppers, A. A. P.; Blusztajn, J.

    2014-12-01

    The Lau and North Fiji backarc basins are located in a tectonically complex region of the South Pacific, where the upper mantle may have been modified by up to five hotspots (Samoa, Rurutu, Rarotonga, Macdonald, and Louisville), each with distinct geochemical fingerprints. We present new Hf, Nd, Sr, and Pb isotopic data for basaltic samples dredged from seven areas along an east-west transect spanning the Lau and North Fiji basins to determine the possible influence and distribution of these various hotspot sources. We find that the isotope ratios of nearly all samples can be explained by mixing a depleted mantle component, which is ubiquitous in the Lau Basin, with a component similar to that found in Samoan shield (EMII) and/or rejuvenated (EMI) lavas. Lavas as far southwest as the Fiji Triple Junction (North Fiji Basin) show enriched geochemical signatures (87Sr/86Sr and 206Pb/204Pb up to 0.7037 and 18.635 respectively, and 143Nd/144Nd and 176Hf/177Hf down to 0.51285 and 0.283023, respectively) trending toward Samoa. This observation extends the range of Samoan influence into the North Fiji Basin 400 km south of its previous observed extent at South Pandora Ridge. The few samples that cannot be explained solely by incorporation of Samoan material are from the northeastern Lau Basin (Falloon et al., 2007) and host a dilute HIMU component that may relate to the incorporation of material from the Rurutu hotspot. This component is not observed further to the west in the Lau and North Fiji basins. A ubiquitous EMI signature in the region may be linked to the Rarotonga hotspot. New dredges from the northeast Lau Basin may give clearer signals that will reveal the identity of the enriched plume component.

  9. Brittle deformation within the eastern North American volcanic margin: Paleostress inversion of faults in the Hartford basin

    NASA Astrophysics Data System (ADS)

    Farrell, J.; Crespi, J. M.; Ostebo, D.; Weingart, M.

    2014-12-01

    The Hartford basin is an early Mesozoic, fault-bounded half-graben that formed during the breakup of Pangea. Along with other eastern North American rift basins, it has incurred significant post-rift deformation. Previous authors have identified three phases of deformation in the Hartford basin: WNW-ESE extension (rifting), NNE-SSW shortening (basin-parallel inversion), and E-W shortening (consistent with the current state of stress on the eastern North American margin). More recent work from other rift basins suggests a fourth phase of deformation possibly associated with massive volcanic activity shortly after cessation of rifting. Paleostress directions inferred from CAMP dike orientations and large-scale compressive structures in the southern rift basins reflect a NW-SE shortening phase that is seemingly absent from the Hartford, Newark, and Fundy basins of the central segment. If this compressional phase is consistent along volcanic passive margins, it should be recorded in the synrift deposits of the central basins. Our preliminary dataset shows a significant number of faults that are inconsistent with the previous three-phase model of WNW-ESE rifting, NNE-SSW compression, and E-W compression. A paleostress inversion of these incompatible faults reveals a distinct conjugate pattern of strike-slip faults that are indicative of NW-SE compression. This phase is consistent with the basin inversion seen in the southern rift basins. The presence of a NW-SE compressional stage is also consistent with the hypothesis that depicts massive volcanic upwelling that acts to shorten the upper crust after rifting. If this model is consistent along the eastern North American margin, it is likely applicable to volcanic margins around the world.

  10. Tidal exchange between the North Sea and Dutch Wadden Sea and mixing time scales of the tidal basins

    NASA Astrophysics Data System (ADS)

    Ridderinkhof, H.; Zimmerman, J. T. F.; Philippart, M. E.

    Particle trajectories in a numerical model of the western Dutch Wadden Sea and the adjacent North Sea are used to study the tidal exchange between the North Sea and the tidal basins. Tidal exchange of water masses appears to depend strongly on the tidal phase at which the computation is started. In general the volume displaced by the large-scale through-flow between connected tidal basins is much smaller than the exchanged volume. For all inlets North Sea water mainly enters the Wadden Sea from the southern side of the inlet whereas basin water leaves the Wadden Sea mainly along the northern coast. Differences in exchanged volume between the inlets are caused by differences in bathymetry at the seaward side of the different inlets. Schematizing each tidal basin as a single well-mixed box, in which an exchange coefficient parameterizes the exchange with the North Sea, allows a rough estimate of the turnover time of a tidal basin. A salt balance for a simple two-box schematization of the Marsdiep and Vlie basins gives an independent estimate of the exchange coefficient between the Marsdiep basin and the North Sea. Its value appears to be larger than the tidally exchanged volume. The revised salt balance, in which the effect of the through-flow between the Marsdiep and Vlie basins is incorporated, is used to calculate the flushing time of fresh water in the western Dutch Wadden Sea which appears to be larger than previous estimates. The tidally exchanged volume through the inlets, as calculated with the numerical model combined with the relation between the exchange coefficient and the tidally exchanged volume for the Marsdiep basin, is used to give a rough estimate of the turnover time of all Dutch Wadden Sea basins. For the Eierlandse Gat and the Borndiep the exchanged volume is calculated by means of our hydrodynamical model. For the other basins it is assumed that its value is a fixed percentage of the tidal prism entering a basin.

  11. An Estimate of the North Atlantic Basin Tropical Cyclone Activity for the 2011 Hurricane Season

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2011-01-01

    Estimates are presented for the expected level of tropical cyclone activity for the 2011 North Atlantic Basin hurricane season. It is anticipated that the frequency of tropical cyclones for the North Atlantic Basin during the 2011 hurricane season will be near to above the post-1995 means. Based on the Poisson distribution of tropical cyclone frequencies for the current more active interval 1995-2010, one computes P(r) = 63.7% for the expected frequency of the number of tropical cyclones during the 2011 hurricane season to be 14 plus or minus 3; P(r) = 62.4% for the expected frequency of the number of hurricanes to be 8 plus or minus 2; P(r) = 79.3% for the expected frequency of the number of major hurricanes to be 3 plus or minus 2; and P(r) = 72.5% for the expected frequency of the number of strikes by a hurricane along the coastline of the United States to be 1 plus or minus 1. Because El Nino is not expected to recur during the 2011 hurricane season, clearly, the possibility exists that these seasonal frequencies could easily be exceeded. Also examined are the effects of the El Nino-Southern Oscillation phase and climatic change (global warming) on tropical cyclone seasonal frequencies, the variation of the seasonal centroid (latitude and longitude) location of tropical cyclone onsets, and the variation of the seasonal peak wind speed and lowest pressure for tropical cyclones.

  12. Landslide deposit boundaries for the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

    This layer is an inventory of existing landslides deposits in the Little North Santiam River Basin, Oregon (2009). Each landslide deposit shown on this map has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey.Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  13. Influences of North Atlantic climate variability on low-flows in the Connecticut River Basin

    NASA Astrophysics Data System (ADS)

    Steinschneider, Scott; Brown, Casey

    2011-10-01

    SummaryConnections between summertime, ecologically relevant low-flow indicators and both winter and spring climate phenomena are explored for the Connecticut River Basin, with an emphasis on assessing forecast potential. Low-flow streamflow statistics deemed important for ecological health, including minimum 1-day mean flows, minimum 7-day mean flows, and monthly streamflow averages from June to September, are derived from 61 years of continuous, daily streamflow data at 15 United States Geological Survey streamflow gauging stations across the basin. Relationships between the ecological flow indicators with leading sea-surface temperature and sea-level pressure are investigated using correlation and composite analysis. Results suggest lagged relationships of up to 5 months between summer streamflow and the wintertime North Atlantic Oscillation, springtime east coast pressure trough, and springtime North Atlantic Tripole. These climate states have been linked to shifts between zonal and meridonal airflow as well as sea-surface temperature anomalies off the coast of the eastern US, both of which have implications for the movement of moisture systems over the study region. This study suggests that residual influences on airflow and sea-surface temperature persist into the summer following these earlier climate states, influencing low-flow hydrology in the region. As eco-hydrologic flow targets often conflict with other stakeholder objectives within a watershed, reservoir operators may utilize such lagged teleconnection patterns to predict annual low-flow characteristics in the region and help negotiate tradeoffs between traditional water management objectives and those emphasizing ecological conservation.

  14. Progress report: chemical character of surface waters in the Devils Lake Basin, North Dakota

    USGS Publications Warehouse

    Swenson, Herbert A.

    1950-01-01

    Devils Lake in northeastern North Dakota was at one time the most popular summer resort in the state. With decline in lake level the lake has become a shallow body pf vary saline water, which scenic value and recreational appeal completely destroyed. Under the Missouri River development program, it is proposed to restore the lake level to an altitude of 1,425 feet by diversion of Missouri River water. The chemical character of the water in Devils Lake and in other surface bodies in Devils Lake Basin is determined from the analyses of 95 samples. The physical and chemical properties of lake bed deposits are also shown. Lake water in the basin vary considerable in both concentration and composition, ranging from fresh bicarbonate waters of 300 parts per million dissolved solids to sulfate waters of over 100,000 parts per million of soluble salts. Twenty-four samples indicates the chemical character of water in the Red River of the North and its tributaries. The probable concentration of dissolved solids in water of Devils Lake at altitude 1,425 feet has been estimated as ranging from 3,000 to 7,600 parts per million. Final concentration will largely depend upon the percentage of deposited salts reentering solution and the quality of the inflow water. The possible effects of lake effluents on downstream developments, with particular reference to sanitation and pollution problems, are also discussed in this report.

  15. Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

    NASA Astrophysics Data System (ADS)

    Yin, A.; Yu, X.; Shen, Z.

    2014-12-01

    Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

  16. Chemostratigraphy of Upper Cretaceous chalk sequences in Norwegian-Danish basin and North Sea Central Trough

    SciTech Connect

    Joergensen, N.O.

    1987-05-01

    Geochemical studies of subsurface sections and outcrops in the Upper Cretaceous chalk sequences from the Norwegian-Danish basin and the North Sea Central Trough have resulted in a detailed chemostratigraphy for these strata. The most applicable chemostratigraphic markers are based on the distribution of strontium, magnesium, manganese, the /sup 13/C//sup 12/C ratio, and the variations in the carbonate contents. It is demonstrated that the chemostratigraphic approach is valid at two levels: (1) a superior chemostratigraphy in which deep-sea cores from the Atlantic Ocean and sections from western Europe are correlated on the basis of significant geochemical anomalies and long-term variations most likely induced by oceanic geochemical cycles and sea level fluctuations; (2) a subordinate but detailed intrabasinal chemostratigraphic correlation which primarily reflects the physicochemical conditions in the depositional environment. The Upper Cretaceous chemostratigraphy established in the Danish area allows a detailed correlation between relatively continuous chalk sequences in the Norwegian-Danish basin and the rather condensed and hiati-influenced sections in the oil fields of the North Sea. The results emphasize the applicability of chemostratigraphy in the subsurface exploration for hydrocarbon reservoirs in chalk.

  17. Circumpolar oil-and-gas-bearing basins of the arctic part of the North American continent

    NASA Astrophysics Data System (ADS)

    Zabanbark, A.; Lobkovsky, L. I.

    2015-09-01

    Major geotectonic elements of the reviewed territory of the Arctic part of the North American continent are the Hyperborean Precambrian Platform, the Franklin folding belt, the northern part of the Precambrian Canadian platform, and the Mesozoic folding belt of Canada and Alaska. The rise of the Arctic slope of Alaska, the Beaufort Sea, and the Sverdrup basin are located in the southern margins of the Hyperborean Platform. The structure and peculiarities of development of these structural elements are genetically related to the evolution of this platform, as well as the current state of petroleum potential of the most promising exploration region of Arctic in the 21st century. The forced exploration of the Arctic regions of the United States and Canada has become an important milestone in the current development of the world energetics. Up to 100 oil, gas, and gas condensate fields have been discovered as a result of violent studies, and the potential oil and gas reserves in the Arctic part of the North American continent have been estimated to 30 billiion t and 50 trillion cubic meters, respectively. Many prospects are related to the continental slopes of all three above-mentioned basins; the total potential reserves of slopes are estimated as 10-12 billion t of oil and 20-25 trillion cubic meters of gas.

  18. An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2009-01-01

    An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

  19. An Estimate of North Atlantic Basin Tropical Cyclone Activity for 2008

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2008-01-01

    The statistics of North Atlantic basin tropical cyclones for the interval 1945-2007 are examined and estimates are given for the frequencies of occurrence of the number of tropical cyclones, number of hurricanes, number of major hurricanes, number of category 4/5 hurricanes, and number of U.S. land-falling hurricanes for the 2008 hurricane season. Also examined are the variations of peak wind speed, average peak wind speed per storm, lowest pressure, average lowest pressure per storm, recurrence rate and duration of extreme events (El Nino and La Nina), the variation of 10-yr moving averages of parametric first differences, and the association of decadal averages of frequencies of occurrence of North Atlantic basin tropical cyclones against decadal averages of Armagh Observatory, Northern Ireland, annual mean temperature (found to be extremely important for number of tropical cyclones and number of hurricanes). Because the 2008 hurricane season seems destined to be one that is non-El Nino-related and is a post-1995 season, estimates of the frequencies of occurrence for the various subsets of storms should be above long-term averages.

  20. Hydrocarbon Source Rocks in the Deep River and Dan River Triassic Basins, North Carolina

    USGS Publications Warehouse

    Reid, Jeffrey C.; Milici, Robert C.

    2008-01-01

    This report presents an interpretation of the hydrocarbon source rock potential of the Triassic sedimentary rocks of the Deep River and Dan River basins, North Carolina, based on previously unpublished organic geochemistry data. The organic geochemical data, 87 samples from 28 drill holes, are from the Sanford sub-basin (Cumnock Formation) of the Deep River basin, and from the Dan River basin (Cow Branch Formation). The available organic geochemical data are biased, however, because many of the samples collected for analyses by industry were from drill holes that contained intrusive diabase dikes, sills, and sheets of early Mesozoic age. These intrusive rocks heated and metamorphosed the surrounding sediments and organic matter in the black shale and coal bed source rocks and, thus, masked the source rock potential that they would have had in an unaltered state. In places, heat from the intrusives generated over-mature vitrinite reflectance (%Ro) profiles and metamorphosed the coals to semi-anthracite, anthracite, and coke. The maximum burial depth of these coal beds is unknown, and depth of burial may also have contributed to elevated thermal maturation profiles. The organic geochemistry data show that potential source rocks exist in the Sanford sub-basin and Dan River basin and that the sediments are gas prone rather than oil prone, although both types of hydrocarbons were generated. Total organic carbon (TOC) data for 56 of the samples are greater than the conservative 1.4% TOC threshold necessary for hydrocarbon expulsion. Both the Cow Branch Formation (Dan River basin) and the Cumnock Formation (Deep River basin, Sanford sub-basin) contain potential source rocks for oil, but they are more likely to have yielded natural gas. The organic material in these formations was derived primarily from terrestrial Type III woody (coaly) material and secondarily from lacustrine Type I (algal) material. Both the thermal alteration index (TAI) and vitrinite reflectance data

  1. Heterogeneities of mechanical properties in potential geothermal reservoir rocks of the North German Basin

    NASA Astrophysics Data System (ADS)

    Reyer, D.; Philipp, S. L.

    2012-04-01

    Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical phenomena in sedimentary basins such as the North German Basin. To be able to model reservoir stimulation in layered stratifications and to better adapt the drilling strategy to the rock mechanical conditions it is important to have knowledge about the effects of heterogeneous rock properties on fracture propagation and fault zone infrastructure for typical sedimentary reservoir rocks in the North German Basin. Therefore we aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses. The field studies in Rotliegend sandstones (Lower Permian), the sandstones of the Middle Bunter (Lower Triassic) and the sandstones of the Upper Keuper (Upper Triassic) focus on 1) host rock fracture systems and 2) fault zone infrastructure. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems separately for host rocks and fault damage zones. The results show that in rocks with distinctive layering (sandstones and shales) natural fractures are often restricted to individual layers, that is, they are stratabound. The probability of fracture arrest seems to depend on the stiffness contrast between the two layers and on the thickness of the softer layer. The field studies are complemented by systematic sampling to obtain mechanical property variations caused by the layering. For the samples we measure the parameters Young's modulus, compressive and tensile strengths, elastic strain energy, density and porosity. The results show that the mechanical properties vary considerably and many samples are clearly anisotropic. That is, samples taken perpendicular to layering commonly have higher strengths but lower stiffnesses than those taken parallel to layering. We combine the results of laboratory analyses and field measurements to specify the mechanical

  2. Response of North American Great Basin Lakes to Dansgaard-Oeschger oscillations

    USGS Publications Warehouse

    Benson, L.; Lund, S.; Negrini, R.; Linsley, B.; Zic, M.

    2003-01-01

    We correlate oscillations in the hydrologic and/or cryologic balances of four Great Basin surface-water systems with Dansgaard-Oeschger (D-O) events 2-12. This correlation is relatively strong at the location of the magnetic signature used to link the lake records, but becomes less well constrained with distance/time from the signature. Comparison of proxy glacial and hydrologic records from Owens and Pyramid lakes indicates that Sierran glacial advances occurred during times of relative dryness. If our hypothesized correlation between the lake-based records and the GISP2 ??18O record is correct, it suggests that North Atlantic D-O stades were associated with relatively cold and dry conditions and that interstades were associated with relatively warm and wet conditions throughout the Great Basin between 50,500 and 27,000 GISP2yr B.P. The Great Basin lacustrine climate records reinforce the hypothesis that D-O events affected the climate throughout much of the Northern Hemisphere during marine isotope stages 2 and 3. However, the absolute phasing between lake-size and ice-core ??18O records remains difficult to determine.

  3. Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

    NASA Astrophysics Data System (ADS)

    Neff, K. L.; Meixner, T.; Ajami, H.; De La Cruz, L.

    2015-12-01

    For water-scarce communities in the western U.S., it is critical to understand groundwater recharge regimes and how those regimes might shift in the face of climate change and impact groundwater resources. Watersheds in the Basin and Range Geological Province are characterized by a variable precipitation regime of wet winters and variable summer precipitation. The relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation recharge dominant in the northern parts of the region, and recharge from summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon (NAM) extends its influence. Stable water isotope data of groundwater and seasonal precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to estimate and compare groundwater recharge seasonality throughout the region. Contributions of winter precipitation to annual recharge vary from 69% ± 41% in the southernmost Río San Miguel Basin in Sonora, Mexico, to 100% ± 36% in the westernmost Mojave Desert of California. The Normalized Seasonal Wetness Index (NSWI), a simple water budget method for estimating recharge seasonality from climatic data, was shown to approximate recharge seasonality well in several winter precipitation-dominated systems, but less well in basins with significant summer precipitation.

  4. The Lithic Assemblages of Xiaochangliang, Nihewan Basin: Implications for Early Pleistocene Hominin Behaviour in North China.

    PubMed

    Yang, Shi-Xia; Hou, Ya-Mei; Yue, Jian-Ping; Petraglia, Michael D; Deng, Cheng-Long; Zhu, Ri-Xiang

    2016-01-01

    Xiaochangliang (XCL), located in the Nihewan Basin of North China, is a key archaeological locality for understanding the behavioural evolution of early humans. XCL dates to ca. 1.36 Ma, making it one of the earliest sites in Northeast Asia. Although XCL represents the first excavation of an Early Pleistocene site in the Nihewan Basin, identified and excavated in the 1970's, the lithic assemblages have never been published in full detail. Here we describe the lithic assemblages from XCL, providing information on stone tool reduction techniques and the influence of raw materials on artefact manufacture. The XCL hominins used both bipolar and freehand reduction techniques to manufacture small flakes, some of which show retouch. Bipolar reduction methods at XCL were used more frequently than previously recognized. Comparison of XCL with other Early Pleistocene sites in the Nihewan Basin indicates the variable use of bipolar and freehand reduction methods, thereby indicating a flexible approach in the utilization of raw materials. The stone tools from XCL and the Nihewan sites are classifiable as Mode I lithic assemblages, readily distinguished from bifacial industries manufactured by hominins in Eastern Asia by ca. 800 ka. PMID:27205881

  5. The Lithic Assemblages of Xiaochangliang, Nihewan Basin: Implications for Early Pleistocene Hominin Behaviour in North China

    PubMed Central

    Yang, Shi-Xia; Hou, Ya-Mei; Yue, Jian-Ping; Petraglia, Michael D.; Deng, Cheng-Long; Zhu, Ri-Xiang

    2016-01-01

    Xiaochangliang (XCL), located in the Nihewan Basin of North China, is a key archaeological locality for understanding the behavioural evolution of early humans. XCL dates to ca. 1.36 Ma, making it one of the earliest sites in Northeast Asia. Although XCL represents the first excavation of an Early Pleistocene site in the Nihewan Basin, identified and excavated in the 1970’s, the lithic assemblages have never been published in full detail. Here we describe the lithic assemblages from XCL, providing information on stone tool reduction techniques and the influence of raw materials on artefact manufacture. The XCL hominins used both bipolar and freehand reduction techniques to manufacture small flakes, some of which show retouch. Bipolar reduction methods at XCL were used more frequently than previously recognized. Comparison of XCL with other Early Pleistocene sites in the Nihewan Basin indicates the variable use of bipolar and freehand reduction methods, thereby indicating a flexible approach in the utilization of raw materials. The stone tools from XCL and the Nihewan sites are classifiable as Mode I lithic assemblages, readily distinguished from bifacial industries manufactured by hominins in Eastern Asia by ca. 800 ka. PMID:27205881

  6. Trace elements and organic contaminants in stream sediments from the Red River of the North Basin

    USGS Publications Warehouse

    Brigham, M.E.; Tornes, L.H.

    1996-01-01

    To assess the presence and distribution of a variety of hydro-phobic chemicals in streams in the Red River of the North Basin, bottom sediments were analyzed for trace elements, organochlorines, and polycyclic aromatic hydrocarbons (PAHs). Glaciolacustrine clays and carbonate minerals are common in fine sediments of the region, and can help explain the distribution of many elements. Aluminum (Al), an indicator of glaciolacustrine clay minerals, correlates strongly (r>0.75, p<0.05) with Cr, Co, Fe, La, Li, K, Sc, and Ti; and moderately (0.55Basin, Eu, Nb, Ce, La, Nd, and Ni also have strong correlations with Al. Al correlates negatively with major elements associated with carbonate minerals (Ca, Mg, and inorganic carbon). No significant correlations with Al, Ca, or Mg were observed for As, Pb, Mn, Hg, Se, or Ag, which implies that these elements have different environmental sources or behaviors than glaciolacustrine clays or carbonate minerals. Reduction-oxidation processes may influence Mn distribution. Lead (Pb) and mercury (Hg) are known to be anthropogenically enriched in the environment--their distribution may indicate environmental enrichment in Red River of the North Basin streams. Organochlorines detected are limited to traces of DDT and its metabolites (mostlyp,p'-DDE). Fourteen PAHs, which are constituents of fossil fuels and of combustion byproducts, were detected in at least halfthe sediment samples; pyrene and fluoranthene were detected in about 90 percent of samples. The contaminants detected in this study were present at low levels, likely indicative of diffuse or remote sources; they occur widely in the environment. 

  7. Water-use data for the Red River of the North Basin, North Dakota, Minnesota, and South Dakota, 1979-2001

    USGS Publications Warehouse

    Macek-Rowland, Kathleen M.; Arntson, Allan D.; Ryberg, Karen R.; Dahl, Ann L.; Lieb, Amy

    2004-01-01

    The Red River of the North, located in the north-central plains of the United States, plays an important role in population growth and economic development of the region. Because of recent and projected growth in population, industry, and agriculture in the Red River of the North Basin, alternatives to additional water resources will be needed to supplement future water needs. Past and current water-use data are needed to help select the most viable water-resource alternatives. Withdrawal and return flow data were collected from various sources throughout the Red River of the North Basin from 1979 through 2001. The withdrawal data were aggregated by subbasin, monthly totals, and water-use categories. The return flow data were aggregated by subbasin and monthly totals. The Red River of the North Basin was divided into subbasins based on locations of U.S. Geological Survey streamflow-gaging stations and by specifically-identified reaches. Results of the water-use compilation are provided in this report.

  8. New sedimentological, structural and paleo-thermicity data in the Boucheville Basin (eastern North Pyrenean Zone, France)

    NASA Astrophysics Data System (ADS)

    Chelalou, Roman; Nalpas, Thierry; Bousquet, Romain; Prevost, Maxime; Lahfid, Abdeltif; Poujol, Marc; Ringenbach, Jean-Claude; Ballard, Jean-François

    2016-03-01

    The Boucheville Basin is one of the easternmost Mesozoic basins of the North Pyrenean Zone (NPZ) that was opened during the Albian extension between the Iberian and European plates. During the extension, a HT/LP metamorphism event affected the Albian basins near the North Pyrenean Fault (NPF). Our aim is to better understand the evolution of the Boucheville Basin during the Albian-Cenomanian lithospheric thinning, which occurred under high thermal conditions. Sedimentological and structural data were collected in the basin and are used to produce synthetic stratigraphic columns of different portions of the basin and to restore selected cross-sections. North-south cross-sections show that the Boucheville Basin is a large and asymmetrical deformed syncline with inverted borders. Synthetic stratigraphic columns show that the sedimentation of the Boucheville Basin starts with carbonate platforms deposited under low bathymetric conditions showing slope deposits and evolves to deep bathymetric conditions of marls deposited without evidence of slopes. Raman spectroscopy on carbonaceous material (RSCM) was made on samples used to construct the sedimentological stratigraphic columns in order to obtain a temperature map of the Albian metamorphism. They reveal homogeneity in the temperatures between 500 and 600 °C. In situ LA-ICP-MS U-Pb dating of titanite grains found in a syn-deformation located in the Albian calcschists provided an age of ca. 97 Ma that gives a time constraint for both the deformation and metamorphism. These data are used collectively to propose a model for the tectono-sedimentary and metamorphic evolution of the Boucheville Basin during the Albian extension.

  9. Neogene transpressional foreland basin development on the north side of the central alaska range, usibelli group and nenana gravel, tanana basin

    USGS Publications Warehouse

    Ridgway, K.D.; Thoms, E.E.; Layer, P.W.; Lesh, M.E.; White, J.M.; Smith, S.V.

    2007-01-01

    Neogene strata of the Tanana basin provide a long-term record of a northwardpropagating, transpressional foreland-basin system related to regional shortening of the central Alaska Range and strike-slip displacement on the Denali fault system. These strata are ???2 km thick and have been deformed and exhumed in thrust faults that form the foothills on the north side of the Alaska Range. The lower part of the sedimentary package, the Usibelli Group, consists of 800 m of mainly Miocene strata that were deposited in fluvial, lacustrine, and peat bog environments of the foredeep depozone of the foreland-basin system. Compositional data from conglomerate and sandstone, as well as recycled Upper Cretaceous palynomorphs, indicate that the Miocene foreland-basin system was supplied increasing amounts of sediment from lithologies currently exposed in thrust sheets located south of the basin. The upper part of the sedimentary package, the Nenana Gravel, consists of 1200 m of mainly Pliocene strata that were deposited in alluvial-fan and braidplain environments in the wedge-top depozone of the foreland-basin system. Compositional data from conglomerate and sandstone, as well as 40Ar/39Ar dating of detrital feldspars in sandstone and from granitic clasts in conglomerate, indicate that lithologies exposed in the central Alaska Range provided most of the detritus to the Pliocene foreland-basin system. 40Ar/39Ar dates from detrital feldspar grains also show that two main suites of plutons contributed sediment to the Nenana Gravel. Detrital feldspars with an average age of 56 Ma are interpreted to have been derived from the McKinley sequence of plutons located south of the Denali fault. Detrital feldspars with an average age of 34 Ma are interpreted to have been derived from plutons located north of the Denali fault. Plutons located south of the Denali fault provided detritus for the lower part of the Nenana Gravel, whereas plutons located north of the Denali fault began to

  10. Palaeohydrology of the Fazzan Basin, Libyan Sahara: Evidence for multiple phases of North African humidity.

    NASA Astrophysics Data System (ADS)

    Armitage, S. J.; White, K.; Drake, N.

    2008-12-01

    The Fazzan is a large closed basin with an area of 450,000 km2, located in south-western Libya. The present-day climate is hyper-arid. Modern human occupation is restricted to oases, notably at the foot of the Messak Sattafat, a Nubian Sandstone escarpment which divides the Fazzan into two sub-basins. However widespread lithic scatters with varying inferred ages, and numerous Holocene hearth fields, indicate that the Fazzan has a long history of human occupation. In addition, regionally extensive lake deposits attest to the presence of a large palaeolake, here termed Lake Mega-Fazzan, at various periods in the past. Although the Sahara contains evidence for several other large palaeolakes, Lake Mega-Fazzan is the only one fed exclusively by rivers draining the Sahara proper. Thus, the Lake Mega-Fazzan sediments and archaeological remains provide an important resource for advancing our understanding of climate change in this part of the Sahara. Optically stimulated luminescence (OSL) dating techniques have been applied to a range of lacustrine deposits, and more experimentally to the Holocene hearth fields, to provide an internally consistent chronology for the Fazzan record. Results indicate that sediments within the Fazzan Basin record a very long history of palaeohydrological change. The oldest lacustrine sediments are beyond the range of conventional OSL dating techniques, but younger humid periods during oxygen isotope stages 11, 5 and 1 are recognised. Initial results from one hearth field also indicate that OSL has the potential to reveal human responses to changes in hydrology during the Holocene. These results, when compared with similar studies of adjacent closed basins, indicate that the Sahara may not always have provided as formidable a barrier to faunal migration as it does at present. The implications of this finding for our understanding of North African palaeoclimate and biogeography will be discussed.

  11. Ordovician platform, slope, and basin facies in subsurface of southern North America

    SciTech Connect

    Alberstadt, L.P.; Colvin, G.; Sauve, J.

    1986-05-01

    Ordovician carbonates of the Nashville dome and Ozark dome regions have long been considered typical shelf deposits. In the subsurface to the south, in the Black Warrior basin, Mississippi Embayment, and Arkoma basin, these shelf carbonate units changed facies. The most significant change is the occurrence of a thick limestone unit characterized by a faunal and floral assemblage of Nuia, Girvanella (isolated long strands), Sphaerocodium, a delicate stacked-chambered organism (.algal), and sponge spicules and sponge mudstone clumps. In ascending order, the complete Ordovician sequence consists of: a lower dolostone, the Nuia-sponge limestone, a dolostone, and a limestone. The upper part of this four-fold sequence changes character westward into the Arkoma basin. The lower two units maintain their character for long distances along depositional strike and occur in parts of the Appalachians as far north as Newfoundland, and on the opposite side of the continent in Nevada. The Nuia-sponge assemblage is a distinctive petrographic marker and seems to be a persistent Ordovician rock and fossil assemblage of widespread occurrence. In Nevada, it occurs on the surface where it is associated with slump and slide features that suggest that it is an outer shelf or upper slope deposit. Coeval carbonates in the Ouachita Mountains are different and show indications of being deep water (basinal). Biostratigraphic evidence indicates that the succession in the subsurface is continuous; the regional Lower Ordovician-Middle Ordovician unconformity is absent. The Lower Ordovician-Middle Ordovician boundary falls near the top of the Nuia-sponge mudstone unit and not at the top of the underlying thick dolostone unit.

  12. Sequence Stratigraphy of the Lower Cretaceous in Aer Sag, Erlian Basin, North China

    NASA Astrophysics Data System (ADS)

    Yao, Wei; De Batist, Marc; Wu, Chonglong

    2014-05-01

    The concepts of sequence stratigraphy, initially developed for the study of marine depositional systems, are increasingly also being applied to sequences deposited in lacustrine basins, particularly in the context of petroleum exploration. However, lacustrine basins differ from marine basins. They are typically smaller, exhibit a strong diversification in sedimentary facies, generally contain thinner sequences and are characterized by multiple sedimentary source regions. These characteristics should be taken into account when analyzing sequence stratigraphy in lacustrine basins. Aer Sag is a balanced-fill sag in Erlian basin, North China. During the Early Cretaceous tectonic subsidence is the main controlling factor for sequence development. Based on the unconformities observed at the top of different inversion-induced depositional cycles, the 2nd-order sequence of the Lower Cretaceous can be sub-divided into six 3rd-order sequences of which the lower four, which bear most of the hydrocarbon reservoirs, are the focus of this study. Generally, a complete 3rd-order sequence can be partitioned into four systems tracts: i.e. lowstand systems tract (LST), transgressive systems tract (TST), highstand systems tract (HST) and forced regression systems tract (FRST). In LSTs, tectonic activity is weak and there is a slow subsidence rate. Thus, the rate of creation of accommodation space is so slow that coarsening-upward prograding sedimentary units develop. In TSTs, tectonic activity becomes stronger and the rate of creation of accommodation space outpaces the rate of sediment supply. TSTs are characterized by fining-upward retrograding sedimentary units and by onlaps on seismic profiles that are caused by the expansion of the lake. In HSTs, tectonic activity slows down again and the rate of creation of accommodation space becomes lower than the rate of sediment supply, which causes the lake to shrink and the development of coarsening-upward prograding sedimentary units. In

  13. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    NASA Astrophysics Data System (ADS)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  14. U-Pb Detrital Zircon Geochronology and Implications: the Mesozoic southern Ordos Basin, North Central China

    NASA Astrophysics Data System (ADS)

    Xie, X.; Heller, P. L.; Chamberlain, K. R.

    2007-12-01

    Two deformation belts -- the Qinling orogenic belt (QOB) to the south and the Western Liupanshan thrust belt (WLTB) to the west, including the Qilian-Qaidam terrane (QQT) -- control the evolution of the southern Ordos Basin during early Mesozoic time. U-Pb detrital zircon geochronology is used to identify provenance, reconstruct paleogeography, and document the relative timing of basin margin deformation. Two correlated strata same age samples of the Middle to Late Triassic Yanchang Fm. were collected from the southern and southwestern basin margin respectively. In total 258 zircon grains were analyzed using LA-ICP-MS. Three major age populations -- 240-490 Ma, 1.8-2.0 Ga, and 2.2-2.8 Ga -- characterize the detrital zircon grains of the Yanchang Fm. Regional geochronology studies show that the two oldest age groups match ages of basement rocks found in the underlying North China block. The younger age group can be subdivided into three distinctive groups: 240-300 Ma, 300-400, and 400-490 Ma. The youngest age group matches ages exposed to the west in the QQT, whereas the other two match grains from southern QOB source. In all samples detrital zircon from the WLTB source area overwhelms the QOB source, regardless of its proximity to either basin margin. This result suggests that either the source rock with the youngest zircon grains (e.g. 240- 490 Ma) from the QOB to the south have been eroded away and no longer existed, or simply the QOB, even during deformation, was never the dominant source of detrital zircon to the southern Ordos Basin. Probably some drainage systems far from the west combine with some local tributary systems from the south control the sedimentation in the south Ordos Basin during the middle to Late Triassic time. This is surprising in that most studies suggest that the QOB was a longer lived and more dominant tectonic feature in this part of China during early Mesozoic time. Furthermore, it also indicates that: 1) deformation in the QOB and WLTB

  15. Major Turbidity Events in the North Santiam River Basin, Oregon, Water Years 1999-2004

    USGS Publications Warehouse

    Sobieszczyk, Steven; Uhrich, Mark A.; Bragg, Heather M.

    2007-01-01

    Multiple high-turbidity events with values greater than 250 Formazin Nephelometric Units occurred in streams of the North Santiam River basin during water years 1999-2004. By using a combination of field reconnaissance, aerial photography, and geographic information systems, eight of these high-turbidity events were investigated and linked to at least one likely source area and became known as 'major turbidity events.' Sediment source type and location, the amount of material transported, and the results of any follow-up investigation of the source area were recorded for each event. Significant findings from this study include: * Although heavy precipitation caused basinwide erosion that increased turbidity in streams, a major turbidity event often required at least one landslide or similar type of contributing source to introduce enough sediment to raise the turbidity value to greater than 250 Formazin Nephelometric Units. * Different processes drove sediment loading at different times. In general, precipitation eroded sediment from source areas or induced landslides. However, in two cases, warm temperatures caused rapid snowmelt, which supplied the water necessary to erode unconsolidated glacial soils or other sediment material and increase turbidity. * Some source areas, such as existing earthflows, repeatedly supplied a large volume of sediment to streams, whereas other sources, such as landslides or debris flows, were unpredictable and sporadically supplied large volumes of sediment to streams. * Major turbidity events were well distributed throughout the North Santiam River basin; discrete events were observed in each of the five subbasins along unregulated streams. * Suspended-sediment loads and clay-water (persistently turbid water) volume estimates were event-specific and varied greatly between major turbidity events, even though, in some cases, the source area was the same; however, high yields generally were observed for events in the Blowout Creek

  16. Patterns of genetic diversity in Hepatozoon spp. infecting snakes from North Africa and the Mediterranean Basin.

    PubMed

    Tomé, Beatriz; Maia, João P; Salvi, Daniele; Brito, José C; Carretero, Miguel A; Perera, Ana; Meimberg, Harald; Harris, David James

    2014-03-01

    Species of Hepatozoon Miller, 1908 are blood parasites most commonly found in snakes but some have been described from all tetrapod groups and a wide variety of hematophagous invertebrates. Previous studies have suggested possible associations between Hepatozoon spp. found in predators and prey. Particularly, some saurophagous snakes from North Africa and the Mediterranean region have been found to be infected with Hepatozoon spp. similar to those of various sympatric lizard hosts. In this study, we have screened tissue samples of 111 North African and Mediterranean snakes, using specific primers for the 18S rRNA gene. In the phylogenetic analysis, the newly-generated Hepatozoon spp. sequences grouped separately into five main clusters. Three of these clusters were composed by Hepatozoon spp. also found in snakes and other reptiles from the Mediterranean Basin and North Africa. In the other two clusters, the new sequences were not closely related to geographically proximate known sequences. The phylogeny of Hepatozoon spp. inferred here was not associated with intermediate host taxonomy or geographical distribution. From the other factors that could explain these evolutionary patterns, the most likely seems series of intermediate hosts providing similar ribotypes of Hepatozoon and a high prevalence of host shifts for Hepatozoon spp. This is indicated by ribotypes of high similarity found in different reptile families, as well as by divergent ribotypes found in the same host species. This potentially low host specificity has profound implications for the systematics of Hepatozoon spp.

  17. Patterns of genetic diversity in Hepatozoon spp. infecting snakes from North Africa and the Mediterranean Basin.

    PubMed

    Tomé, Beatriz; Maia, João P; Salvi, Daniele; Brito, José C; Carretero, Miguel A; Perera, Ana; Meimberg, Harald; Harris, David James

    2014-03-01

    Species of Hepatozoon Miller, 1908 are blood parasites most commonly found in snakes but some have been described from all tetrapod groups and a wide variety of hematophagous invertebrates. Previous studies have suggested possible associations between Hepatozoon spp. found in predators and prey. Particularly, some saurophagous snakes from North Africa and the Mediterranean region have been found to be infected with Hepatozoon spp. similar to those of various sympatric lizard hosts. In this study, we have screened tissue samples of 111 North African and Mediterranean snakes, using specific primers for the 18S rRNA gene. In the phylogenetic analysis, the newly-generated Hepatozoon spp. sequences grouped separately into five main clusters. Three of these clusters were composed by Hepatozoon spp. also found in snakes and other reptiles from the Mediterranean Basin and North Africa. In the other two clusters, the new sequences were not closely related to geographically proximate known sequences. The phylogeny of Hepatozoon spp. inferred here was not associated with intermediate host taxonomy or geographical distribution. From the other factors that could explain these evolutionary patterns, the most likely seems series of intermediate hosts providing similar ribotypes of Hepatozoon and a high prevalence of host shifts for Hepatozoon spp. This is indicated by ribotypes of high similarity found in different reptile families, as well as by divergent ribotypes found in the same host species. This potentially low host specificity has profound implications for the systematics of Hepatozoon spp. PMID:24563141

  18. Climatology, hydrology, and simulation of an emergency outlet, Devils Lake basin, North Dakota

    USGS Publications Warehouse

    Wiche, Gregg J.; Vecchia, A.V.; Osborne, Leon; Wood, Carrie M.; Fay, James T.

    2000-01-01

    Devils Lake is a natural lake in northeastern North Dakota that is the terminus of a nearly 4,000-square-mile subbasin in the Red River of the North Basin. The lake has not reached its natural spill elevation to the Sheyenne River (a tributary of the Red River of the North) in recorded history. However, geologic evidence indicates a spill occurred sometime within the last 1,800 years. From 1993 to 1999, Devils Lake rose 24.5 feet and, at the present (August 2000), is about 13 feet below the natural spill elevation. The recent lake-level rise has caused flood damages exceeding $300 million and triggered development of future flood-control options to prevent further infrastructure damage and reduce the risk of a potentially catastrophic uncontrolled spill. Construction of an emergency outlet from the west end of Devils Lake to the Sheyenne River is one flood-control option being considered. This report describes the climatologic and hydrologic causes of the recent lake level rise, provides information on the potential for continued lake-level rises during the next 15 years, and describes the potential effectiveness of an emergency outlet in reducing future lake levels and in reducing the risk of an uncontrolled spill. The potential effects of an outlet on downstream water quantity and quality in the upper Sheyenne River also are described.

  19. Estimation of evapotranspiration in the Rainbow Springs and Silver Springs basins in North-Central Florida

    USGS Publications Warehouse

    Knowles, Leel

    1996-01-01

    Estimates of evapotranspiration (ET) for the Rainbow and Silver Springs ground-water basins in north-central Florida were determined using a regional water-~budget approach and compared to estimates computed using a modified Priestley-Taylor (PT) model calibrated with eddy-correlation data. Eddy-correlation measurements of latent 0~E) and sensible (H) heat flux were made monthly for a few days at a time, and the PT model was used to estimate 3,E between times of measurement during the 1994 water year. A water-budget analysis for the two-basin area indicated that over a 30-year period (196594) annual rainfall was 51.7 inches. Of the annual rainfall, ET accounted for about 37.9 inches; springflow accounted for 13.1 inches; and the remaining 0.7 inch was accounted for by stream-flow, by ground-water withdrawals from the Floridan aquifer system, and by net change in storage. For the same 30-year period, the annual estimate of ET for the Silver Springs basin was 37.6 inches and was 38.5 inches for the Rainbow Springs basin. Wet- and dry-season estimates of ET for each basin averaged between nearly 19 inches and 20 inches, indicating that like rainfall, ET rates during the 4-month wet season were about twice the ET rates during the 8-month dry season. Wet-season estimates of ET for the Rainbow Springs and Silver Springs basins decreased 2.7 inches, and 3.4 inches, respectively, over the 30-year period; whereas, dry-season estimates for the basins decreased about 0.4 inch and1.0 inch, respectively, over the 30-year period. This decrease probably is related to the general decrease in annual rainfall and reduction in net radiation over the basins during the 30-year period. ET rates computed using the modified PT model were compared to rates computed from the water budget for the 1994 water year. Annual ET, computed using the PT model, was 32.0 inches, nearly equal to the ET water-budget estimate of 31.7 inches computed for the Rainbow Springs and Silver Springs basins

  20. Helium Isotope Variations in the Northern Lau and North Fiji Basins

    NASA Astrophysics Data System (ADS)

    Lupton, J. E.; Arculus, R. J.; Jenner, F. E.; Evans, L.; Greene, R.

    2012-12-01

    Recent measurements of submarine basalts from the Northern Lau Basin exhibit a fascinating pattern in the helium isotopes. In particular, basalts along the NW Lau Spreading Center and the Rochambeau Rifts (NWLSC-RR) all have elevated 3He/4He ratios ranging from 11 to 28 Ra, much higher than the MORB-like values of 7 - 9 Ra that might be expected for a typical back-arc spreading center (Lupton et al, GRL 2009) (R = 3He/4He and Ra = Rair = 1.39E-6). This has been interpreted as indicating the presence of a mantle plume component, possibly from the Samoan hotspot, which has somehow intruded into the northern Lau Basin. Furthermore, neon isotopes analyzed in this same suite of basalts exhibit enrichments in 21Ne/22Ne and 20Ne/22Ne distinct from MORB neon and similar to neon isotopes measured in Samoan lavas (Lupton et al., GRL, 2012), further evidence for intrusion of a Samoan plume component. Surprisingly, this hotspot component is only evident along the NWLSC-RR, while samples from seafloor basalts and submarine hydrothermal fluids in the NE Lau Basin have MORB-like values or lower, varying from 6.5 to 8.5 Ra. However, very few samples have been collected to the west of the NWLSC-RR, and the question thus remains as to the origin and extent of this 3He-rich component in the northern Lau Basin. Recently, expedition SS2012 of the R/V Southern Surveyor collected submarine rock samples from the volcanic zones in the northwestern Lau Basin and North Fiji Basin. These samples have 3He/4He ratios ranging from 9.0 up to 14.6 Ra, above the range for normal MORBs. Of particular interest is the zone immediately to the west of the Rochambeau Rifts. Samples from the SE Futuna Volcanic Zone and from the Futuna Spreading Center have 3He/4He varying from 9.2 to 10.6 Ra. Farther west, samples from the West Cikobia Volcanic Zone due north of the Fiji Islands have helium with 9.3 up to 12.2 Ra. Still farther west in the Fiji Basin at 17S, 174E, samples dredged from the NE Fiji Triple

  1. Tropical Cyclone Activity in the North Atlantic Basin During the Weather Satellite Era, 1960-2014

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2016-01-01

    This Technical Publication (TP) represents an extension of previous work concerning the tropical cyclone activity in the North Atlantic basin during the weather satellite era, 1960-2014, in particular, that of an article published in The Journal of the Alabama Academy of Science. With the launch of the TIROS-1 polar-orbiting satellite in April 1960, a new era of global weather observation and monitoring began. Prior to this, the conditions of the North Atlantic basin were determined only from ship reports, island reports, and long-range aircraft reconnaissance. Consequently, storms that formed far from land, away from shipping lanes, and beyond the reach of aircraft possibly could be missed altogether, thereby leading to an underestimate of the true number of tropical cyclones forming in the basin. Additionally, new analysis techniques have come into use which sometimes has led to the inclusion of one or more storms at the end of a nominal hurricane season that otherwise would not have been included. In this TP, examined are the yearly (or seasonal) and 10-year moving average (10-year moving average) values of the (1) first storm day (FSD), last storm day (LSD), and length of season (LOS); (2) frequencies of tropical cyclones (by class); (3) average peak 1-minute sustained wind speed () and average lowest pressure (); (4) average genesis location in terms of north latitudinal () and west longitudinal () positions; (5) sum and average power dissipation index (); (6) sum and average accumulated cyclone energy (); (7) sum and average number of storm days (); (8) sum of the number of hurricane days (NHD) and number of major hurricane days (NMHD); (9) net tropical cyclone activity index (NTCA); (10) largest individual storm (LIS) PWS, LP, PDI, ACE, NSD, NHD, NMHD; and (11) number of category 4 and 5 hurricanes (N4/5). Also examined are the December-May (D-M) and June-November (J-N) averages and 10-year moving average values of

  2. Chemical analyses of surface water in Illinois, 1958-74; Volume II, Illinois River basin and Mississippi River tributaries north of Illinois River basin

    USGS Publications Warehouse

    Healy, R.W.; Toler, L.G.

    1978-01-01

    Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency and its predecessor, the Stream Pollution Control Bureau of the Illinois Department of Public Health. The results for the period 1958 to 1974 are presented in tabular form and the history of sampling and analytical methods are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. The report is contained in three volumes. This volume (Volume II) includes Illinois River basin and Mississippi River tributaries north of Illinois River basin. (See also W78-10034 and W78-10036) (Woodard-USGS)

  3. Chemical analyses of surface water in Illinois, 1975-77; Volume 2, Illinois River basin and Mississippi River tributaries north of Illinois River basin

    USGS Publications Warehouse

    Grason, David; Healy, R.W.

    1979-01-01

    Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency. The results from water years 1975 to 1977 are presented in three volumes. The history of sampling and analytical methods used during that period are summarized. Stream discharge data from records of the U.S. Geological Survey are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. Volume II includes the Illinois River basin and Mississippi River tributaries north of Illinois River basin. (Woodard-USGS)

  4. Disentangling Middle Paleozoic sea level and tectonic events in cratonic margins and cratonic basins of North America

    NASA Astrophysics Data System (ADS)

    Bond, Gerard C.; Kominz, Michelle A.

    1991-04-01

    The cratonic margins and basins of North America contain evidence of distinct changes in relative sea level, one of the most intriguing of which occurred in middle Paleozoic time. The change in relative sea level began in Frasnian time (Late Devonian) and continued through Visean time (Middle Mississippian) in the Cordilleran miogeocline, in the Southern Oklahoma Aulacogen, in the Appalachian miogeocline and in the Michigan, Illinois, and Williston basins. The synchroneity and wide geographic distribution of this event are striking and would seem to argue for an eustatic mechanism. An estimate of the middle Paleozoic sea level rise relative to the stable craton in Iowa suggests that while a large sea level rise occurred, it is smaller than the magnitude of subsidence in the cratonic basins and margins. Flexural foreland basin models do not appear to account for the all of the events in the cratonic margins, and thermal subsidence mechanisms do not seem appropriate for the subsidence in the cratonic basins. The middle Paleozoic stratigraphic record from the North American craton and its margins, therefore, poses a basic problem of identifying a mechanism for producing a large-amplitude rise in sea level relative to the stable craton at the same time as a synchronous onset of tectonic subsidence in widespread basinal and marginal settings of diverse tectonic origin. One plausible mechanism for the tectonic subsidence in the basins and margins is a pulse of intraplate compressive stress. The origin of the large sea level rise relative to the stable craton could reflect an unusually large eustatic sea level change, but we cannot eliminate the possibility of a small component of subsidence or change in dynamic topography of the North American craton. The synchroneity of the sea level rise relative to the craton with the subsidence of basins and margins may be fortuitous, but it is also predicted by recent mantle convection models for the early stages of accretion of

  5. Estimation of hydrothermal deposits location from magnetization distribution and magnetic properties in the North Fiji Basin

    NASA Astrophysics Data System (ADS)

    Choi, S.; Kim, C.; Park, C.; Kim, H.

    2013-12-01

    The North Fiji Basin is belong to one of the youngest basins of back-arc basins in the southwest Pacific (from 12 Ma ago). We performed the marine magnetic and the bathymetry survey in the North Fiji Basin for finding the submarine hydrothermal deposits in April 2012. We acquired magnetic and bathymetry datasets by using Multi-Beam Echo Sounder EM120 (Kongsberg Co.) and Overhouser Proton Magnetometer SeaSPY (Marine Magnetics Co.). We conducted the data processing to obtain detailed seabed topography, magnetic anomaly, reduce to the pole(RTP), analytic signal and magnetization. The study areas composed of the two areas(KF-1(longitude : 173.5 ~ 173.7 and latitude : -16.2 ~ -16.5) and KF-3(longitude : 173.4 ~ 173.6 and latitude : -18.7 ~ -19.1)) in Central Spreading Ridge(CSR) and one area(KF-2(longitude : 173.7 ~ 174 and latitude : -16.8 ~ -17.2)) in Triple Junction(TJ). The seabed topography of KF-1 existed thin horst in two grabens that trends NW-SE direction. The magnetic properties of KF-1 showed high magnetic anomalies in center part and magnetic lineament structure of trending E-W direction. In the magnetization distribution of KF-1, the low magnetization zone matches well with a strong analytic signal in the northeastern part. KF-2 area has TJ. The seabed topography formed like Y-shape and showed a high feature in the center of TJ. The magnetic properties of KF-2 displayed high magnetic anomalies in N-S spreading ridge center and northwestern part. In the magnetization distribution of KF-2, the low magnetization zone matches well with a strong analytic signal in the northeastern part. The seabed topography of KF-3 presented a flat and high topography like dome structure at center axis and some seamounts scattered around the axis. The magnetic properties of KF-3 showed high magnetic anomalies in N-S spreading ridge center part. In the magnetization of KF-2, the low magnetization zone mismatches to strong analytic signal in this area. The difference of KF-3

  6. Study of the geothermal production potential in the Williston Basin, North Dakota

    SciTech Connect

    Chu, Min H.

    1991-09-10

    Preliminary studies of geothermal production potential for the North Dakota portion of the Williston Basin have been carried out. Reservoir data such as formation depth, subsurface temperatures, and water quality were reviewed for geothermal brine production predictions. This study, in addition, provides important information about net pay thickness, porosity, volume of geothermal water available, and productivity index for future geothermal direct-use development. Preliminary results show that the Inyan Kara Formation of the Dakota Group is the most favorable geothermal resource in terms of water quality and productivity. The Madison, Duperow, and Red River Formations are deeper formations but because of their low permeability and great depth, the potential flow rates from these three formations are considerably less than those of the Inyan Kara Formation. Also, poor water quality and low porosity will make those formations less favorable for geothermal direct-use development.

  7. Late Cenozoic crustal deformation of the north-central Basin and Range

    SciTech Connect

    Eyal, Y. . Dept. of Geology); Ron, H. )

    1993-04-01

    Late Cenozoic deformation of Basin and Range in north-central Nevada is examined by small fault analysis. Consistency between fault types, fault trends and sense of displacement was found for this area in which normal faults strike N-S, and right-lateral and left-lateral faults strike NNW and NNE respectively. The existence of strike-slip faulting, mainly right-lateral, is consistent with horizontal counter clockwise rotation suggested by paleomagnetic declination data. The results of this analysis indicate that crustal deformation of this area did not occur by only simple E-W uniaxial extension but also by N-S compression and shortening, and that the contribution of strike slip faulting to the extension of this area is substantial almost similar to that of normal faulting.

  8. Assessment of Undiscovered Oil and Gas Resources of the Williston Basin Province of North Dakota, Montana, and South Dakota, 2008

    USGS Publications Warehouse

    Anna, Lawrence O.; Pollastro, Richard M.; Gaswirth, Stephanie B.; Lewan, Michael D.; Lillis, Paul G.; Roberts, Laura N.R.; Schenk, Christopher J.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.

    2008-01-01

    Using a geology-based assessment method, the U.S. Geological Survey estimated mean undiscovered volumes of 3.8 billion barrels of undiscovered oil, 3.7 trillion cubic feet of associated/dissolved natural gas, and 0.2 billion barrels of undiscovered natural gas liquids in the Williston Basin Province, North Dakota, Montana, and South Dakota.

  9. Assessment of Undiscovered Oil Resources in the Devonian-Mississippian Bakken Formation, Williston Basin Province, Montana and North Dakota, 2008

    USGS Publications Warehouse

    Pollastro, Richard M.; Cook, Troy A.; Roberts, Laura N.R.; Schenk, Christopher J.; Lewan, Michael D.; Anna, Lawrence O.; Gaswirth, Stephanie B.; Lillis, Paul G.; Klett, Timothy R.; Charpentier, Ronal R.

    2008-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 3.65 billion barrels of oil, 1.85 trillion cubic feet of associated/dissolved natural gas, and 148 million barrels of natural gas liquids in the Bakken Formation of the Williston Basin Province, Montana and North Dakota.

  10. RELATION OF LANDSCAPE-SCALE ENVIRONMENTAL CHARACTERISTICS TO FISH ASSEMBLAGES IN THE UPPER FRENCH BROAD RIVER BASIN, NORTH CAROLINA

    EPA Science Inventory

    Fish assemblages at 16 sites in the upper French Broad river basin in North Carolina were related to environmental characteristics at the landscape scale, the scale at which management activities and decisions are most likely to occur. Indirect gradient analysis and subsequent re...

  11. MODELING THE DISTRIBUTION OF NONPOINT NITROGEN SOURCES AND SINKS IN THE NEUSE RIVER BASIN OF NORTH CAROLINA, USA

    EPA Science Inventory

    This study quantified nonpoint nitrogen (N) sources and sinks across the 14,582 km2 Neuse River Basin (NRB) located in North Carolina, to provide a tabular database to initialize in-stream N decay models and graphic overlay products for the development of management approaches to...

  12. A new age model for the early-middle Miocene in the North Alpine Foreland Basin

    NASA Astrophysics Data System (ADS)

    Reichenbacher, Bettina; Krijgsman, Wout; Pippèrr, Martina; Sant, Karin; Kirscher, Uwe

    2016-04-01

    The establishment of high-resolution age models for sedimentary successions is crucial for numerous research questions in the geosciences and related disciplines. Such models provide an absolute chronology that permits precise dating of depositional episodes and related processes such as mountain uplift or climate change. Recently, our work in the Miocene sediments of the North Alpine Foreland Basin (NAFB) has revealed a significantly younger age (16.6 Myr) for sediments that were thought to have been deposited 18 Myr ago. This implies that a fundamentally revised new age model is needed for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB (20 to 15-Myr). Our new data also indicate that previously published reconstructions of early-middle Miocene palaeogeography, sedimentation dynamics, mountain uplift and climate change in the NAFB all require a critical review and revision. Further, the time-span addressed is of special interest, since it encompasses the onset of a global warming phase. However, it appears that a fundamentally revised new age model for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB can only be achieved based on a 500 m deep drilling in the NAFB for which we currently seek collaboration partners to develop a grant application to the International Continental Deep Drilling Program (ICDP). Reference: Reichenbacher, B., W. Krijgsman, Y. Lataster, M. Pippèrr, C. G. C. Van Baak, L. Chang, D. Kälin, J. Jost, G. Doppler, D. Jung, J. Prieto, H. Abdul Aziz, M. Böhme, J. Garnish, U. Kirscher, and V. Bachtadse. 2013. A new magnetostratigraphic framework for the Lower Miocene (Burdigalian/Ottnangian, Karpatian) in the North Alpine Foreland Basin. Swiss Journal of Geosciences 106:309-334.

  13. Revision of the biostratigraphy of the Chatham Group (Upper Triassic), Deep River basin, North Carolina, USA

    USGS Publications Warehouse

    Litwin, R.J.; Ash, S.R.

    1993-01-01

    Paleontological evidence from the Upper Triassic Chatham Group in the three subbasins of the Deep River basin (North Carolina, USA) supports a significant revision of the ages assigned to most of this non-marine continental sedimentary sequence. This study confirms an early(?) or mid-Carnian age in the Sanford subbasin for the base of the Pekin Formation, the lowest unit of the Chatham Group. However, diagnostic late Carnian palynomorphs have been recovered from coals in the lower part of the Cumnock Formation in the Sanford subbasin, and from a sample of the Cumnock Formation equivalent in the Wadesboro subbasin. Plant megafossils and fossil verebrates from rocks in the Sanford subbasin also support a late Carnian age for the Cumnock Formation and its equivalents. The overlying Sanford Formation, which has not yet been dated paleontologically, probably includes beds of Norian age, as over 1000 m of strata may be present between the Cumnock Formation coals (dated here as late Carnian) and the top of the Sanford Formation. This chronostratigraphic interval appears similar to, but slightly longer than, that preserved in the Dan River-Danville and Davie County basins 100 km to the northwest. Our evidence, therefore, indicates that the Chatham Group was deposited over a much longer time interval [early(?) to mid-Carnian through early Norian] than previously was believed. ?? 1993.

  14. Use of Remote Sensed Imagery to Evaluate Land Cover Change: North Platte River Basin

    NASA Astrophysics Data System (ADS)

    Kerr, G.; Piburn, J.; Rudolph, J.; Tootle, G.; Marks, J. A.

    2012-12-01

    High resolution remote sensed data for land cover classification, such as LiDAR, is often times not readily available in rural areas. For basin-wide and other small-scale projects, proprietary LiDAR collection may not be cost effective and an alternative is found with the use of the National Agricultural Imagery Program (NAIP). NAIP imagery provides 1-meter resolution aerial imagery for the entire United States, temporally updated on a state by state basis at no charge to the user. NAIP imagery was used to classify forest cover change due to beetle infestation in the roughly 4,000 square-mile North Platte River Basin (NPRB). Using an interactive classification method with an underlying maximum likelihood classification algorithm, it was found that forest cover in the NPRB decreased by approximately 25% from 2005-2006 to 2009. Using focal histograms to refine the classifications to large-scale USGS 7.5 minute quadrangles, the land cover results will be used as parameters in the Variable Infiltration Capacity (VIC) Macroscale Hydrologic Model to estimate how this physical change in land cover affects the riparian system of the NPRB, specifically streamflow response.

  15. Traveltime and reaeration of selected streams in the North Platte and Yampa River basins, Colorado

    USGS Publications Warehouse

    Ruddy, B.C.; Britton, L.J.

    1989-01-01

    Traveltime characteristics were measured using rhodamine WT dye as a tracer in the Canadian and Michigan Rivers in the North Platte river basin and in the Yampa, Elk, and Williams Fork Rivers, and Trout and Fish Creeks in the Yampa River basin of Colorado. Reaeration coefficients were determined by use of the modified-tracer techniques using ethylene and propane gas for selected stream reaches during low-flow conditions. Stream reach velocities determined during traveltime and reaeration measurements ranged from 0.09 mi/hour at 5.1 cu ft/sec on the Canadian River to 4.04 mi/hour at 746 cu ft/sec on the Williams Fork. A modified longitudinal dispersion model or results from cumulative traveltime curves were used to estimate traveltimes in the measured streams for streamflow conditions other than those measured. Traveltime-discharge curves were developed by using the estimated and measured traveltimes. Reaeration coefficients were determined for 20 different subreaches in the study area. Rearation coefficients were determined for 20 different subreaches in the study area. Reaeration coefficients ranged from 1.6/day in a pooled subreach of the Yampa River Craig, Colorado, to 98/day in a turbulent subreach of Trout Creek near Oak Creek, Colorado. (USGS)

  16. Prospect ranking in the North Sea: New frontiers in 3D basin modeling

    SciTech Connect

    Bracaccia, V.; Bozzoni, P.; Cavecchi, C.

    1995-08-01

    The application of Agip`s 3D basin modeling code (SEBE3) in a block of the Norwegian Sector of the South Viking Graben has demonstrated the capability of this methodology, which integrates in a three-dimensional time-dependent simulation the geological, hydrodynamic and maturation models of a basin, to represent an effective tool in ranking different structures. The deceiving results of the first exploration phase during which two dry wells were drilled, have suggested that, although hydrocarbons could reach the block from the Fisher Bank area and from the Sleipner Complex through spillover mechanisms, hydrodynamic constraints and morphological divides have probably played a major role in regulating the migration of hydrocarbons in the area. The effect of these constraints was confirmed and better understood through a regional application of the code on the South Viking Graben, whose results entered in the block scale simulation as boundary conditions. The block scale simulation has indicated that hydrodynamic constraints (Tornquist Lineaments) to the north and the morphology of the carrier in the northwestern edge of the block, seem to have highly constrained fluid flow up to the complete compartmentalization of the system (Pliocene to Recent), preventing large amounts of hydrocarbons from spilling into the structure that extends over most of the retained acreage of the Block. Nonetheless, the simulation has singled out a possible migration route in the northeastern corner of the block where a different and alternative prospect is located.

  17. Pesticides in streams in the Tar-Pamlico drainage basin, North Carolina, 1992-94

    USGS Publications Warehouse

    Woodside, Michael D.; Ruhl, Kelly E.

    2001-01-01

    From 1992 to 1994, 147 water samples were collected at 5 sites in the Tar-Pamlico drainage basin in North Carolina and analyzed for 46 herbicides, insecticides, and pesticide metabolites as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Based on a common adjusted detection limit of 0.01 microgram per liter, the most frequently detected herbicides were metolachlor (84 percent), atrazine (78 percent), alachlor (72 percent), and prometon (57 percent). The insecticides detected most frequently were carbaryl (12 percent), carbofuran (7 percent), and diazinon (4 percent). Although the pesticides with the highest estimated uses generally were the compounds detected most frequently, there was not a strong correlation between estimated use and detection frequency. The development of statistical correlations between pesticide use and detection frequency was limited by the lack of information on pesticides commonly applied in urban and agricultural areas, such as prometon, chlorpyrifos, and diazinon, and the small number of basins included in this study. For example, prometon had the fourth highest detection frequency, but use information was not available. Nevertheless, the high detection frequency of prometon indicates that nonagricultural uses also contribute to pesticide levels in streams in the Tar-Pamlico drainage basin. Concentrations of the herbicides atrazine, alachlor, and trifluralin varied seasonally, with elevated concentrations generally occurring in the spring, during and immediately following application periods, and in the summer. Seasonal concentration patterns were less evident for prometon, diazinon, and chlorpyrifos. Alachlor is the only pesticide detected in concentrations that exceeded current (2000) drinking-water standards.

  18. Effects of coal mining on the water quality and sedimentation of Lake Tuscaloosa and selected tributaries, North River basin, Alabama

    USGS Publications Warehouse

    Cole, E.F.

    1985-01-01

    Lake Tuscaloosa, a reservoir on North River, is the primary source of water supply for the city of Tuscaloosa, Alabama, and surrounding areas. Between October 1982 and September 1983, 14 sites in the North River basin were sampled to determine if surface coal mining has impacted the quality of water in the lake and selected tributaries. Water draining mined basins showed increases in specific conductance, sulfate concentrations , and dissolved and total recoverable iron and manganese concentrations after mining started in 1975. Although water in the reservoir has become more mineralized with only an estimated 5 percent of the basin mined, total dissolved solids concentrations are still very low, ranging from 28 to 35 milligrams per liter at the dam. The quality of water at most sites was, except for pH, iron, and manganese, within secondary drinking water standards. The pH of water from streams draining either mined or unmined basins was generally less than 6.5. Sedimentation has occurred at most measured lake cross sections since impoundment. However, natural factors such as steep overland and channel slopes, may cause more sedimentation in the lake from unmined basins than from coal mining in a different basin. (USGS)

  19. Beyond Colorado's Front Range - A new look at Laramide basin subsidence, sedimentation, and deformation in north-central Colorado

    USGS Publications Warehouse

    Cole, James C.; Trexler, James H.; Cashman, Patricia H.; Miller, Ian M.; Shroba, Ralph R.; Cosca, Michael A.; Workman, Jeremiah B.

    2010-01-01

    This field trip highlights recent research into the Laramide uplift, erosion, and sedimentation on the western side of the northern Colorado Front Range. The Laramide history of the North Park?Middle Park basin (designated the Colorado Headwaters Basin in this paper) is distinctly different from that of the Denver basin on the eastern flank of the range. The Denver basin stratigraphy records the transition from Late Cretaceous marine shale to recessional shoreline sandstones to continental, fluvial, marsh, and coal mires environments, followed by orogenic sediments that span the K-T boundary. Upper Cretaceous and Paleogene strata in the Denver basin consist of two mega-fan complexes that are separated by a 9 million-year interval of erosion/non-deposition between about 63 and 54 Ma. In contrast, the marine shale unit on the western flank of the Front Range was deeply eroded over most of the area of the Colorado Headwaters Basin (approximately one km removed) prior to any orogenic sediment accumulation. New 40Ar-39Ar ages indicate the oldest sediments on the western flank of the Front Range were as young as about 61 Ma. They comprise the Windy Gap Volcanic Member of the Middle Park Formation, which consists of coarse, immature volcanic conglomerates derived from nearby alkalic-mafic volcanic edifices that were forming at about 65?61 Ma. Clasts of Proterozoic granite, pegmatite, and gneiss (eroded from the uplifted core of the Front Range) seem to arrive in the Colorado Headwaters Basin at different times in different places, but they become dominant in arkosic sandstones and conglomerates about one km above the base of the Colorado Headwaters Basin section. Paleocurrent trends suggest the southern end of the Colorado Headwaters Basin was structurally closed because all fluvial deposits show a northward component of transport. Lacustrine depositional environments are indicated by various sedimentological features in several sections within the >3 km of sediment

  20. Macrofossils of Bakken Formation (Devonian and Mississippian), Williston Basin, North Dakota

    SciTech Connect

    Thrasher, L.; Holland, F.D. Jr.

    1983-08-01

    Results of this study of the macrofossils of the Bakken Formation in North Dakota have reinforced the suggestion, based on previous paleontological work in Saskatchewan, that the Bakken is of both Devonian and Mississippian age, rather than being entirely of Lower Mississippian age as originally considered. Increased drilling and coring activity in the North Dakota part of the Williston Basin has provided the opportunity for acquiring a larger fauna that was previously available. Based on lithologic character, the Bakken has been divided into three informal members. These consist of a calcareous siltstone unit between two lithologically similar units of carbonaceous shale. These black shales contain similar faunas distinct from that of the middle member. The black shales contain inarticulate brachiopods, conchostracans, and rare cephalopods and fish remains as well as more abundant conodonts, ostracods, and palynomorphs. The middle siltstone unit contains a more abundant and diverse fauna consisting of inarticulate and articulate brachiopods together with corals, gastropods, cephalopods, ostracods, echinoderm remains, and trace fossils. This is the first report of cephalopods, conchostracans, ostracods, corals, trace fossils, and some of the brachiopods in the Bakken, although all, except the gastropods, have been reported from stratigraphic equivalents (Exshaw Formation of south-central Montana, the Leatham Formation of northeastern Utah, and the middle member of the Pilot Shale in western Utah and eastern Nevada).

  1. Megascopic lithologic studies of coals in the Powder River basin in Wyoming and in adjacent basins in Wyoming and North Dakota

    USGS Publications Warehouse

    Trippi, Michael H.; Stricker, Gary D.; Flores, Romeo M.; Stanton, Ronald W.; Chiehowsky, Lora A.; Moore, Timothy A.

    2010-01-01

    Between 1999 and 2007, the U.S. Geological Survey (USGS) investigated coalbed methane (CBM) resources in the Wyoming portion of the Powder River Basin. The study also included the CBM resources in the North Dakota portion of the Williston Basin of North Dakota and the Wyoming portion of the Green River Basin of Wyoming. This project involved the cooperation of the State Office, Reservoir Management Group (RMG) of the Bureau of Land Management (BLM) in Casper, Wyo., and 16 independent gas operators in the Powder River, Williston, and Green River Basins. The USGS and BLM entered into agreements with these CBM operators to supply samples for the USGS to analyze and provide the RMG with rapid, timely results of total gas desorbed, coal quality, and high-pressure methane adsorption isotherm data. This program resulted in the collection of 963 cored coal samples from 37 core holes. This report presents megascopic lithologic descriptive data collected from canister samples extracted from the 37 wells cored for this project.

  2. Cretaceous stratigraphic sequences of north-central California suggest a discontinuity in the Late Cretaceous forearc basin

    SciTech Connect

    Haggart, J.W.

    1986-10-01

    The Cretaceous sedimentary succession preserved east of Redding, at the northern end of California's Great Valley, indicates that marine deposition was widespread in the region for only two periods during the Late Cretaceous. If it is assumed that there was minimal Cenozoic offset between the northern Sierra Nevada and eastern Klamath Mountains terranes, Cretaceous sedimentation in this region was most likely restricted to a narrow trough and was not a continuation of the wide, Cretaceous forearc basin of central California. The dissimilar depositional histories of the Redding basin and the Hornbrook basin of north-central California suggest that the basins were not linked continuously during the Late Cretaceous. A thick section of Cretaceous strata beneath the southwestern Modoc Plateau is considered unlikely.

  3. Resistivity structures across the Humboldt River basin, north-central Nevada

    USGS Publications Warehouse

    Rodriguez, Brian D.; Williams, Jackie M.

    2002-01-01

    Magnetotelluric data collected along five profiles show deep resistivity structures beneath the Battle Mountain-Eureka and Carlin gold trends in north-central Nevada, which appear consistent with tectonic breaks in the crust that possibly served as channels for hydrothermal fluids. It seems likely that gold deposits along these linear trends were, therefore, controlled by deep regional crustal fault systems. Two-dimensional resistivity modeling of the magnetotelluric data generally show resistive (30 to 1,000 ohm-m) crustal blocks broken by sub-vertical, two-dimensional, conductive (1 to 10 ohmm) zones that are indicative of large-scale crustal fault zones. These inferred fault zones are regional in scale, trend northeast-southwest, north-south, and northwest-southeast, and extend to mid-crustal (20 km) depths. The conductors are about 2- to 15-km wide, extend from about 1 to 4 km below the surface to about 20 km depth, and show two-dimensional electrical structure. By connecting the locations of similar trending conductors together, individual regional crustal fault zones within the upper crust can be inferred that range from about 4- to 10-km wide and about 30- to 150-km long. One of these crustal fault zones coincides with the Battle Mountain-Eureka mineral trend. The interpreted electrical property sections also show regional changes in the resistive crust from south to north. Most of the subsurface in the upper 20 km beneath Reese River Valley and southern Boulder Valley are underlain by rock that is generally more conductive than the subsurface beneath Kelly Creek Basin and northern Boulder Valley. This suggests that either elevated-temperature or high-salinity fluids, alteration, or carbonaceous rocks are more pervasive in the more conductive area (Battle Mountain Heat-Flow High), which implies that the crust beneath these valleys is either more fractured or has more carbonaceous rocks than in the area surveyed along the 41st parallel.

  4. National Water-Quality Assessment Program: Data collection in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1992-95

    USGS Publications Warehouse

    Stoner, J.D.; Lorenz, D.L.

    1995-01-01

    A water-quality assessment began in 1991 for the Red River of the North (Red River) Basin as part of a national study. Data collection for the reconnainssance and intensive phases of the study briefly is described for each of the major components (streams, aquatic biology, and ground water) used to assess regional water quality. The data will be analyzed to address national and local water-quality concerns.

  5. Nutrients, suspended sediment, and pesticides in waters of the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1970-90

    USGS Publications Warehouse

    Tornes, L.H.; Brigham, M.E.

    1994-01-01

    A relatively large fraction of stream samples had detectable quantities of 2,4-D, a- and y-HCH, and atrazine. These samples covered time spans of as much as 15 years and were from sites downstream from large drainage basins; however, concentrations were well below US EPA MCLs. One county-level study showed higher 2,4-D concentrations at upstream sites than at the outlet from a small basin. This indicates that downstream sites may fail to show impaired water-quality and the fate of pesticides used in the basin. Following the 1972 ban on DDT, concentrations of DDT in fish samples from the Red River of the North quickly decreased. Fish concentrations of DDE and DDD decreased more slowly. Low levels of DDE and DDD were detected in fish 14 years after the DDT ban.

  6. Track-pattern-based seasonal prediction model for intense tropical cyclone activities over the North Atlantic and the western North Pacific basins

    NASA Astrophysics Data System (ADS)

    Choi, W.; Ho, C. H.

    2015-12-01

    Intense tropical cyclones (TCs) accompanying heavy rainfall and destructive wind gusts sometimes cause incredible socio-economic damages in the regions near their landfall. This study aims to analyze intense TC activities in the North Atlantic (NA) and the western North Pacific (WNP) basins and develop their track propensity seasonal prediction model. Considering that the number of TCs in the NA basin is much smaller than that in the WNP basin, different intensity criteria are used; category 1 and above for NA and category 3 and above for WNP based on Saffir-Simpson hurricane wind scale. By using a fuzzy clustering method, intense TC tracks in the NA and the WNP basins are classified into two and three representative patterns, respectively. Each pattern shows empirical relationships with climate variabilities such as sea surface temperature distribution associated with El Niño/La Niña or Atlantic Meridional Mode, Pacific decadal oscillation, upper and low level zonal wind, and strength of subtropical high. The hybrid statistical-dynamical method has been used to develop the seasonal prediction model for each pattern based on statistical relationships between the intense TC activity and seasonal averaged key predictors. The model performance is statistically assessed by cross validation for the training period (1982-2013) and has been applied for the 2014 and 2015 prediction. This study suggests applicability of this model to real prediction work and provide bridgehead of attempt for intense TC prediction.

  7. Late Cretaceous-Paleogene deepwater basin of North Afghanistan and the Central Pamirs: Issue of Hindu Kush earthquakes

    NASA Astrophysics Data System (ADS)

    Kaz'min, V. G.; Lobkovsky, L. I.; Tikhonova, N. F.

    2010-03-01

    The within-Iranian backarc basins, including the largest Sebzawar Basin, opened in the Mid-Cretaceous. Spreading in this basin was completed by the end of the Cretaceous. The basin closed in the Eocene with the formation of subduction zones and volcanic-plutonic belts. Data on North Afghanistan and the Central Pamirs have allowed us to reconstruct the eastern continuation of the Sebzawar Basin up to the west of the Central Pamirs. No fragments of oceanic crust are retained in Afghanistan and the Pamirs, but by analogy with the Sebzawar Basin, thick Paleogene flysch sequences and volcanic-plutonic complexes indicate setting of the active margin and subduction. It is suggested that the belt of mantle seismicity that extends for 550 km to the south of the Central Pamirs is related to the plunging and deformation of the lithosphere once underlying the Cretaceous-Paleogene basin. The extremely vigorous seismicity of the Hindu Kush megasource at the western termination of the seismic belt is caused by a number of specific tectonic features that predetermined the early onset of plunging of the subducted sheet (slab). In the megasource, the slab sank to a depth of 300 km and became vertical; its active deformation has proceeded up to the present. In the eastern part of the seismic belt, the slab started to plunge much later and therefore has retained a gentle slope, so that the depth of the hypocenters is shallower (down to 200 km), and earthquakes are less strong.

  8. Magnetostratigraphy of the Neogene Chaka basin and its implications for mountain building processes in the north-eastern Tibetan Plateau

    USGS Publications Warehouse

    Zhang, H.-P.; Craddock, W.H.; Lease, R.O.; Wang, W.-T.; Yuan, D.-Y.; Zhang, P.-Z.; Molnar, P.; Zheng, D.-W.; Zheng, W.-J.

    2012-01-01

    Magnetostratigraphy of sedimentary rock deposited in the Chaka basin (north-eastern Tibetan Plateau) indicates a late Miocene onset of basin formation and subsequent development of the adjacent Qinghai Nan Shan. Sedimentation in the basin initiated at ~11Ma. In the lower part of the basin fill, a coarsening-upward sequence starting at ~9Ma, as well as rapid sedimentation rates, and northward paleocurrents, are consistent with continued growth of the Ela Shan to the south. In the upper section, several lines of evidence suggest that thrust faulting and topographic development of the Qinghai Nan Shan began at ~6.1Ma. Paleocurrent indicators, preserved in the basin in the proximal footwall of the Qinghai Nan Shan, show a change from northward to southward flow between 6.5 and 3.8Ma. At the same location, sediment derived from the Qinghai Nan Shan appears at 6.1Ma. Finally, the initiation of progressively shallowing dips observed in deformed basin strata and a change to pebbly, fluvial deposits at 6.1Ma provide a minimum age for the onset of slip on the thrust fault that dips north-east beneath the Qinghai Nan Shan. We interpret a decrease in sediment accumulation rates since ~6Ma to indicate a reduction in Chaka basin accommodation space due to active faulting and folding along the Qinghai Nan Shan and incorporation of the basin into the wedge-top depozone. Declination anomalies indicate the beginning of counter-clockwise rotation since 6.1Ma, which we associate with local deformation, not regional block rotation. The emergence of the Qinghai Nan Shan near the end of the Miocene Epoch partitioned the once contiguous Chaka-Gonghe and Qinghai basin complex. In a regional framework, our study adds to a growing body of evidence that points to widespread initiation and/or reactivation of fault networks during the late Miocene across the north-eastern Tibetan Plateau. ?? 2011 The Authors. Basin Research ?? 2011 Blackwell Publishing Ltd, European Association of Geoscientists

  9. Late Pliocene and Early Pleistocene Temperature Reconstructions from Paleolakes of the West Turkana and North Awash Basins, East Africa

    NASA Astrophysics Data System (ADS)

    Castañeda, I. S.; Thompson-Munson, M.; Lupien, R.; Russell, J. M.

    2015-12-01

    The Hominin Sites and Paleolakes Drilling Project (HSPDP) aims to reconstruct past environments of the East African Rift Valley from locations in close proximity to some of the world's most important fossil hominin and artifact sites. In this study, we investigate sediments from the West Turkana and North Awash Basins, which were recently drilled as part of the HSPDP. The North Awash Basin contains abundant early hominin fossils and the lakebeds of the Hadar Formation (~3.6 to ~2.9 Ma) will provide a record of climate variability during the Pliocene, prior to the intensification of Northern Hemisphere glaciation at ~2.7 Ma. The lakebeds of the Turkana Basin are Early Pleistocene in age (~1.9 to ~1.45 Ma) and span the interval that includes some the earliest fossils of Homo rudolfensis and H. ergaster/erectus. Here we examine the organic geochemistry of West Turkana and North Awash Basin sediments and investigate the use of proxies based on isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs) to reconstruct temperature, including TEX86 and the methylation and cyclization (MBT and CBT) ratios and relative abundances of branched GDGTs. We also examine variability in the abundances and ratios of plant leaf waxes (n-alkanes) to provide insight into past vegetation changes on the East African landscape.

  10. Three-Dimensional Compartmentalization of Subsurface Ground Water Flow in Eastern North American Mesozoic Basins

    NASA Astrophysics Data System (ADS)

    Ryan, M. P.; Sutphin, D. M.; Daniels, D. L.; Pierce, H. A.; Smoot, J. P.

    2002-05-01

    An extensive network of diabase intrusions occurs in several of the largest Mesozoic basins of Eastern North America, including the Culpeper, Gettysburg, Newark, and Hartford basins. Within each, great dikes, inclined sheets, and lopoliths cut through the surrounding sandstones, siltstones, and conglomerates in ways that subdivide the regional subsurface flow field, and thus compartmentalize the basin. In the Culpeper basin, for example, the scale- and direction-dependent permeability of diabase spans the range 10-17 to 10-21 m2, whereas the permeability of the heavily fractured sediments is in the range 10-12 to 10-14 m2. Thus there is at least three, and upwards of nine, orders of magnitude difference in permeability between the diabase and the surrounding sediments. This great permeability contrast is at the heart of basin compartmentalization and the related subsurface hydrologic phenomena. In the Culpeper basin, our understanding of compartmentalization is guided by the following geological, geophysical, and hydrologic measurements and observations: (1) Short wavelength aeromagnetic anomalies constrain the geometry of the up-turned margins of diabase lopoliths. These lopoliths bound compartments horizontally and vertically; (2) Deep compartment structure has been resolved to 800 meters by in-situ AudioMagnetotelluric experiments; (3) Alignments of hornfels-hosted springs parallel to the diabase-hornfels contact along a compartment wall. We posit that eastward-migrating ground water is forced up and out to the surface when it comes into contact with the low permeability diabase at depth; (4) Direct observations of high fluid flow from bedding plane fractures within hornfels in the diabase-hornfels contact ``no-flow boundary condition'' region of a compartment's walls; (5) Direct drilling into and through a compartment's margins. Pumping yields within diabase are ~2 gal./min., whereas penetration of the compartment margins (drilling from diabase into the

  11. Status and understanding of groundwater quality in the North San Francisco Bay groundwater basins, 2004

    USGS Publications Warehouse

    Kulongoski, Justin T.; Belitz, Kenneth; Landon, Matthew K.; Farrar, Christopher

    2010-01-01

    Groundwater quality in the approximately 1,000-square-mile (2,590-square-kilometer) North San Francisco Bay study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in northern California in Marin, Napa, and Sonoma Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA North San Francisco Bay study was designed to provide a spatially unbiased assessment of untreated groundwater quality in the primary aquifer systems. The assessment is based on water-quality and ancillary data collected by the USGS from 89 wells in 2004 and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter referred to as primary aquifers) were defined by the depth interval of the wells listed in the CDPH database for the North San Francisco Bay study unit. The quality of groundwater in shallower or deeper water-bearing zones may differ from that in the primary aquifers; shallower groundwater may be more vulnerable to surficial contamination. The first component of this study, the status of the current quality of the groundwater resource, was assessed by using data from samples analyzed for volatile organic compounds (VOC), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. This status assessment is intended to characterize the quality of groundwater resources within the primary aquifers of the North San Francisco Bay study unit, not the treated drinking water delivered to consumers by water purveyors. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used for evaluating groundwater quality for those constituents that have Federal and (or

  12. Gas desorption and adsorption isotherm studies of coals in the Powder River basin, Wyoming and adjacent basins in Wyoming and North Dakota

    USGS Publications Warehouse

    Stricker, Gary D.; Flores, Romeo M.; McGarry, Dwain E.; Stillwell, Dean P.; Hoppe, Daniel J.; Stillwell, Cathy R.; Ochs, Alan M.; Ellis, Margaret S.; Osvald, Karl S.; Taylor, Sharon L.; Thorvaldson, Marjorie C.; Trippi, Michael H.; Grose, Sherry D.; Crockett, Fred J.; Shariff, Asghar J.

    2006-01-01

    The U.S. Geological Survey (USGS), in cooperation with the State Office, Reservoir Management Group (RMG), of the Bureau of Land Management (BLM) in Casper (Wyoming), investigated the coalbed methane resources (CBM) in the Powder River Basin, Wyoming and Montana, from 1999 to the present. Beginning in late 1999, the study also included the Williston Basin in Montana and North and South Dakota and Green River Basin and Big Horn Basin in Wyoming. The rapid development of CBM (referred to as coalbed natural gas by the BLM) during the early 1990s, and the lack of sufficient data for the BLM to fully assess and manage the resource in the Powder River Basin, in particular, gave impetus to the cooperative program. An integral part of the joint USGS-BLM project was the participation of 25 gas operators that entered individually into confidential agreements with the USGS, and whose cooperation was essential to the study. The arrangements were for the gas operators to drill and core coal-bed reservoirs at their cost, and for the USGS and BLM personnel to then desorb, analyze, and interpret the coal data with joint funding by the two agencies. Upon completion of analyses by the USGS, the data were to be shared with both the BLM and the gas operator that supplied the core, and then to be released or published 1 yr after the report was submitted to the operator.

  13. Water Quality and Algal Data for the North Umpqua River Basin, Oregon, 2005

    USGS Publications Warehouse

    Tanner, Dwight Q.; Arnsberg, Andrew J.; Anderson, Chauncey W.; Carpenter, Kurt D.

    2006-01-01

    The upper North Umpqua River Basin has experienced a variety of water-quality problems since at least the early 1990's. Several reaches of the North Umpqua River are listed as water-quality limited under section 303(d) of the Clean Water Act. Diamond Lake, a eutrophic lake that is an important source of water and nutrients to the upper North Umpqua River, is also listed as a water-quality limited waterbody (pH, nuisance algae). A draft Total Maximum Daily Load (TMDL) was proposed for various parameters and is expected to be adopted in full in 2006. Diamond Lake has supported potentially toxic blue-green algae blooms since 2001 that have resulted in closures to recreational water contact and impacts to the local economy. Increased populations of the invasive tui chub fish are reportedly responsible, because they feed on zooplankton that would otherwise control the algal blooms. The Final Environmental Impact Statement (FEIS) for the Diamond Lake Restoration Project advocates reduced fish biomass in Diamond Lake in 2006 as the preferred alternative. A restoration project scheduled to reduce fish biomass for the lake includes a significant water-level drawdown that began in January 2006. After the drawdown of Diamond Lake, the fish toxicant rotenone was applied to eradicate the tui chub. The lake will be refilled and restocked with game fish in 2007. Winter exports of nutrients from Diamond Lake during the restoration project could affect the summer trophic status of the North Umpqua River if retention and recycling in Lemolo Lake are significant. The FEIS includes comprehensive monitoring to assess the water quality of the restored Diamond Lake and the effects of that restoration downstream. One component of the monitoring is the collection of baseline data, in order to observe changes in the river's water quality and algal conditions resulting from the restoration of Diamond Lake. During July 2005, the USGS, in cooperation with Douglas County, performed a synoptic

  14. Development of basins in the Inner Moray Firth and the North Sea by crustal extension and dextral displacement of the Great Glen Fault

    NASA Astrophysics Data System (ADS)

    McQuillin, R.; Donato, J. A.; Tulstrup, J.

    1982-08-01

    Reflection seismic data provide evidence that Mesozoic dextral movements along the Great Glen Fault line have had an important influence on the development of the Inner Moray Firth Basin. Geophysical evidence further indicates that deep structure beneath the inner basin is dissimilar to that beneath the outer part and Viking and Central Grabens in the North Sea. Tectonic development of the inner basin can nevertheless be fitted into a pattern of North Sea extensional movements which led to the formation of the graben system with which the major North Sea hydrocarbon resources are associated.

  15. Water-Quality Trends in the Neuse River Basin, North Carolina, 1974-2003

    NASA Astrophysics Data System (ADS)

    Harned, D. A.

    2003-12-01

    Data from two U.S. Geological Survey (USGS) sites in the Neuse River basin were reviewed for trends in major ions, sediment, nutrients, and pesticides during the period 1974-2003. In 1997, the North Carolina Division of Water Quality implemented management rules to reduce nitrogen loading to the Neuse River by 30 percent by 2003. Therefore, the 1997-2003 period was reviewed for trends associated with the management changes. The Neuse River at Kinston basin (2,695 square miles) includes much of Raleigh, N.C., with 8-percent urban and 30-percent agricultural land use (1992 data). The Contentnea Creek basin (734 square miles), a Neuse River tributary, is 42-percent agricultural and 3-percent urban. Agricultural land uses in the Contentnea Creek basin have changed over the last decade from predominantly corn, soybean, and tobacco row crops to corn, soybeans, and cotton, with reduced tobacco acreages, and development of the hog industry. Data for this analysis were collected by the USGS for the National Stream Quality Accounting Network and National Water-Quality Assessment Program. Data were examined for trends using the Seasonal Kendall trend test or Tobit regression. The Seasonal Kendall test, which accounts for seasonal variability and adjusts for effects of streamflow on concentration with residuals from LOWESS (LOcally Weighted Sum of Squares) curves, was used to analyze trends in major ions, nutrients, and sediment. The Tobit test, appropriate for examining values with reporting limits, was used for the pesticide analysis. Monotonic trends are considered significant at the alpha < 0.05 probability level. Long-term (1974-2003) decreasing trends in the Neuse River at Kinston were detected for dissolved oxygen, silica, and sediment concentrations; increasing trends were detected for potassium, alkalinity, and chloride. Decreasing trends in Contentnea Creek were detected for silica, sulfate, and sediment concentrations during 1979-2003; increasing trends were

  16. Vesta's north pole quadrangle Av-1 (Albana): Geologic map and the nature of the south polar basin antipodes

    NASA Astrophysics Data System (ADS)

    Blewett, David T.; Buczkowski, Debra L.; Ruesch, Ottaviano; Scully, Jennifer E.; O'Brien, David P.; Gaskell, Robert; Roatsch, Thomas; Bowling, Timothy J.; Ermakov, Anton; Hiesinger, Harald; Williams, David A.; Raymond, Carol A.; Russell, Christopher T.

    2014-12-01

    As part of systematic global mapping of Vesta using data returned by the Dawn spacecraft, we have produced a geologic map of the north pole quadrangle, Av-1 Albana. Extensive seasonal shadows were present in the north polar region at the time of the Dawn observations, limiting the ability to map morphological features and employ color or spectral data for determination of composition. The major recognizable units present include ancient cratered highlands and younger crater-related units (undivided ejecta, and mass-wasting material on crater floors). The antipode of Vesta's large southern impact basins, Rheasilvia and Veneneia, lie within or near the Av-1 quadrangle. Therefore it is of particular interest to search for evidence of features of the kind that are found at basin antipodes on other planetary bodies. Albedo markings known as lunar swirls are correlated with basin antipodes and the presence of crustal magnetic anomalies on the Moon, but lighting conditions preclude recognition of such albedo features in images of the antipode of Vesta's Rheasilvia basin. “Hilly and lineated terrain,” found at the antipodes of large basins on the Moon and Mercury, is not present at the Rheasilvia or Veneneia antipodes. We have identified small-scale linear depressions that may be related to increased fracturing in the Rheasilvia and Veneneia antipodal areas, consistent with impact-induced stresses (Buczkowski, D. et al. [2012b]. Analysis of the large scale troughs on Vesta and correlation to a model of giant impact into a differentiated asteroid. Geol. Soc. of America Annual Meeting. Abstract 152-4; Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre.20123). The general high elevation of much of the north polar region could, in part, be a result of uplift caused by the Rheasilvia basin-forming impact, as predicted by numerical modeling (Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre

  17. Mid-Cretaceous unconformity in the Methow basin, north-central Washington

    SciTech Connect

    Haugerud, R.A.; Hurlow, H.A. ); Tabor, R.W. ); Snee, L.W. )

    1993-04-01

    New mapping in the Methow basin demonstrates a significant unconformity beneath mid-Cretaceous strata of the Pasayten Group and may explain stratigraphic contrasts puzzling to earlier workers. The Pasayten Group, defined along regional strike to the north in Manning Park, includes Virginia Ridge Fm. (shallow-marine argillite and chert-clast-rich sandstone and conglomerate), Winthrop Sandstone (fluvial arkose), and Midnight Peak Fm. (redbeds and andesitic volcanic rocks) in ascending stratigraphic order. Local unconformities and lateral gradations amongst Pasayten Group units result in no one unit lying above the unconformity. Hornblende from Midnight Peak andesite on Isabella Ridge yields an [sup 40]Ar-[sup 39]Ar age of 87.0 [+-] 0.4 (1[sigma]) Ma, though Pasayten Group strata elsewhere are intruded by 88--90 Ma plutons and thus much of the unit is older. From west to east the Pasayten Group lies on progressively older strata. In upper Three Fools Creek, west of the Cascade crest, it lies on unnamed marine strata, more than 1 km thick, which conformably overlie 3 km of sand-rich turbidites of the Albian Harts Pass Fm. In the Osceola Peak-Harts Pass area it lies on upper Harts Pass turbidites. Southwest of Monument 85 and west of Hidden Lakes it lies on probable Early Cretaceous (pre-Harts Pass-age) lithic marine sandstone and siltstone. On Isabella Ridge it lies on [approximately]150 Ma tonalite and older volcanic rocks. This unconformity predates most of the conspicuous thrusts and related folds that characterize the Methow basin. Adjacent to the Pasayten fault, pre- and intra-Pasayten Group unconformities have reduced the stratigraphic section to scraps of Winthrop Sandstone and probable lower Cretaceous conglomerate locally preserved between Midnight Peak andesite and older volcanic rocks, suggesting continued early and mid-Cretaceous movement along the Pasayten fault.

  18. Re-Evaluating Geothermal Potential with GIS Methods and New Data: Williston Basin, North Dakota

    NASA Astrophysics Data System (ADS)

    Crowell, A. M.; Gosnold, W. D.; UND Geothermal Laboratory

    2011-12-01

    The University of North Dakota Geothermal Laboratory is working on the National Geothermal Data Aggregation project in conjunction with Southern Methodist University (SMU) and other partners, and funded by the Department of Energy to collect data for exploration and utilization of resources for geothermal power production. We have examined 10,951 wells in the Williston Basin to determine accurate methods for estimating power extraction potential in a sedimentary basin. The calculations we used involved defining the area of wells within designated ranges and calculating the geothermal fluid reservoir volume using porosity data from the North Dakota Geological Survey Wilson M. Laird Core Library. We defined the parameters for our calculations as: bottom-hole temperature (BHT), formation thickness data, surface area of the polygon around wells within the temperature range, and porosity data. The wells in each formation with a BHT over 90°C were imported into ArcGIS, buffered to 1.6 kilometers from centroid, and outlined with a polygon feature to define the surface area. We then included average formation thickness to determine an approximate volume for ten water and rock reservoirs. In calculating this available energy the following three assumptions were made; that 1/1000 of the water volume is available to use per year, that the temperature is lowered to 50°C during electrical power production, and that the efficiency of the binary power plant utilized is 14%. The estimated recoverable energy in the volume of rock containing geothermal fluids by temperature range is as follows: 1.32 x 108 MW for 90°-100° C, 1.92 x 108 MW for 100°-110° C, 2.15 x 108 MW for 110°-120° C, 2.4 x 108 MW for 120°-130° C, 1.4 x 108 MW for 130°-140° C, 4.95 x 107 MW for 140°-150° C, and 3.67 x 107 MW for 150° C and up.

  19. Fluid and gas migration in the North German Basin: fluid inclusion and stable isotope constraints

    NASA Astrophysics Data System (ADS)

    Lüders, Volker; Reutel, Christian; Hoth, Peer; Banks, David A.; Mingram, Birgit; Pettke, Thomas

    2005-12-01

    Fluid inclusions have been studied in minerals infilling fissures (quartz, calcite, fluorite, anhydrite) hosted by Carboniferous and Permian strata from wells in the central and eastern part of the North German Basin in order to decipher the fluid and gas migration related to basin tectonics. The microthermometric data and the results of laser Raman spectroscopy reveal compelling evidence for multiple events of fluid migration. The fluid systems evolved from a H2O-NaCl±KCl type during early stage of basin subsidence to a H2O-NaCl-CaCl2 type during further burial. Locally, fluid inclusions are enriched in K, Cs, Li, B, Rb and other cations indicating intensive fluid-rock interaction of the saline brines with Lower Permian volcanic rocks or sediments. Fluid migration through Carboniferous sediments was often accompanied by the migration of gases. Aqueous fluid inclusions in quartz from fissures in Carboniferous sedimentary rocks are commonly associated with co-genetically trapped CH4-CO2 inclusions. P-T conditions estimated, via isochore construction, yield pressure conditions between 620 and 1,650 bar and temperatures between 170 and 300°C during fluid entrapment. The migration of CH4-rich gases within the Carboniferous rocks can be related to the main stage of basin subsidence and stages of basin uplift. A different situation is recorded in fluid inclusions in fissure minerals hosted by Permian sandstones and carbonates: aqueous fluid inclusions in calcite, quartz, fluorite and anhydrite are always H2O-NaCl-CaCl2-rich and show homogenization temperatures between 120 and 180°C. Co-genetically trapped gas inclusions are generally less frequent. When present, they show variable N2-CH4 compositions but contain no CO2. P-T reconstructions indicate low-pressure conditions during fluid entrapment, always below 500 bar. The entrapment of N2-CH4 inclusions seems to be related to phases of tectonic uplift during the Upper Cretaceous. A potential source for nitrogen in the

  20. Chemical quality of surface waters in Devils Lake basin, North Dakota

    USGS Publications Warehouse

    Swenson, Herbert; Colby, Bruce R.

    1955-01-01

    Devils Lake basin, a closed basin in northeastern North Dakota, covers about 3,900 square miles of land, the topography of which is morainal and of glacial origin. In this basin lies a chain of waterways, which begins with the Sweetwater group and extends successively through Mauvais Coulee, Devils Lake, East Bay Devils Lake, and East Devils Lake, to Stump Lake. In former years when lake levels were high, Mauvais Coulee drained the Sweetwater group and discharged considerable water into Devils Lake. Converging coulees also transported excess water to Stump Lake. For at least 70 years prior to 1941, Mauvais Coulee flowed only intermittently, and the levels of major lakes in this region gradually declined. Devils Lake, for example, covered an area of about 90,000 acres in 1867 but had shrunk to approximately 6,500 acres by 1941. Plans to restore the recreational appeal of Devils Lake propose the dilution and eventual displacement of the brackish lake water by fresh water that would be diverted from the Missouri River. Freshening of the lake water would permit restocking Devils Lake with fish. Devils and Stump Lake have irregular outlines and numerous windings and have been described as lying in the valley of a preglacial river, the main stem and tributaries of which are partly filled with drift. Prominent morainal hills along the south shore of Devils Lake contrast sharply with level farmland to the north. The mean annual temperature of Devils Lake basin ranges between 36 ? and 42 ? F. Summer temperatures above 100 ? F and winter temperatures below -30 ? Fare not uncommon. The annual precipitation for 77 years at the city of Devils Lake averaged 17.5 inches. Usually, from 75 to 80 percent of the precipitation in the basin falls during the growing season, April to September. From 1867 to 1941 the net fall of the water surface of Devils Lake was about 38 feet. By 1951 the surface had risen fully 14 feet from its lowest altitude, 1,400.9 feet. Since 1951, the level has

  1. Modeling the Nd isotopic composition in the North Atlantic basin using an eddy-permitting model

    NASA Astrophysics Data System (ADS)

    Arsouze, T.; Treguier, A. M.; Peronne, S.; Dutay, J.-C.; Lacan, F.; Jeandel, C.

    2010-09-01

    Boundary Exchange (BE - exchange of elements between continental margins and the open ocean) has been emphasized as a key process in the oceanic cycle of neodymium (Nd) (Lacan and Jeandel, 2005a). Here, we use a regional eddy-permitting resolution Ocean General Circulation Model (1/4°) of the North Atlantic basin to simulate the distribution of the Nd isotopic composition, considering BE as the only source. Results show good agreement with the data, confirming previous results obtained using the same parameterization of the source in a coarse resolution global model (Arsouze et al., 2007), and therefore the major control played by the BE processes in the Nd cycle on the regional scale. We quantified the exchange rate of the BE, and found that the time needed for the continental margins to significantly imprint the chemical composition of the surrounding seawater (further referred as characteristic exchange time) is of the order of 0.2 years. However, the timescale of the BE may be subject to large variations as a very short exchange time (a few days) is needed to reproduce the highly negative values of surface waters in the Labrador Sea, whereas a longer one (up to 0.5 years) is required to simulate the radiogenic influence of basaltic margins and distinguish the negative isotopic signatures of North Atlantic Deep Water from the more radiogenic southern origin water masses. This likely represents geographical variations in erosion fluxes and the subsequent particle load onto the continental margins. Although the parameterization of the BE is the same in both configurations of the model, the characteristic exchange time in the eddy-permitting configuration is significantly lower than the previous evaluations using a low resolution configuration (6 months to 10 years), but however in agreement with the available seawater Nd isotope data. This results highlights the importance of the model dynamics in simulating the BE process.

  2. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard

    2005-04-15

    The principal research effort for the first six months of Year 2 of the project has been petroleum system characterization. Understanding the burial and thermal maturation histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in petroleum system characterization. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and thermal maturation and hydrocarbon expulsion modeling indicate that an effective regional petroleum source rock in the onshore interior salt basins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was the Upper Jurassic Smackover lime mudstone. The Upper Cretaceous Tuscaloosa shale was an effective local petroleum source rock in the Mississippi Interior Salt Basin and a possible local source bed in the North Louisiana Salt Basin. Hydrocarbon generation and expulsion was initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin. Hydrocarbon generation and expulsion was initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Reservoir rocks include Jurassic, Cretaceous and Tertiary siliciclastic and carbonate strata. Seal rocks include Jurassic, Cretaceous and Tertiary anhydrite and shale beds. Petroleum traps include structural and combination traps.

  3. Surface-water quality assessment of the North Fork Red River basin upstream from Lake Altus, Oklahoma, 2002

    USGS Publications Warehouse

    Smith, S. Jerrod; Schneider, M.L.; Masoner, J.R.; Blazs, R.L.

    2003-01-01

    Elevated salinity in the North Fork Red River is a major concern of the Bureau of Reclamation W. C. Austin Project at Lake Altus. Understanding the relation between surface-water runoff, ground-water discharge, and surface-water quality is important for maintaining the beneficial use of water in the North Fork Red River basin. Agricultural practices, petroleum production, and natural dissolution of salt-bearing bedrock have the potential to influence the quality of nearby surface water. The U.S. Geological Survey, in cooperation with the Bureau of Reclamation, sampled stream discharge and water chemistry at 19 stations on the North Fork Red River and tributaries. To characterize surface-water resources of the basin in a systematic manner, samples were collected synoptically during receding streamflow conditions during July 8-11, 2002. Together, sulfate and chloride usually constitute greater than half of the dissolved solids. Concentrations of sulfate ranged from 87.1 to 3,450 milligrams per liter. The minimum value was measured at McClellan Creek near Back (07301220), and the maximum value was measured at Bronco Creek near Twitty (07301303). Concentrations of chloride ranged from 33.2 to 786 milligrams per liter. The minimum value was measured at a North Fork Red River tributary (unnamed) near Twitty (07301310), and the maximum value was measured at the North Fork Red River near Back (07301190), the most upstream sample station.

  4. Thin and layered subcontinental crust of the great Basin western north America inherited from Paleozoic marginal ocean basins?

    USGS Publications Warehouse

    Churkin, M.; McKee, E.H.

    1974-01-01

    The seismic profile of the crust of the northern part of the Basin and Range province by its thinness and layering is intermediate between typical continental and oceanic crust and resembles that of marginal ocean basins, especially those with thick sedimentary fill. The geologic history of the Great Basin indicates that it was the site of a succession of marginal ocean basins opening and closing behind volcanic arcs during much of Paleozoic time. A long process of sedimentation and deformation followed throughout the Mesozoic modifying, but possibly not completely transforming the originally oceanic crust to continental crust. In the Cenozoic, after at least 40 m.y. of quiescence and stable conditions, substantial crustal and upper-mantle changes are recorded by elevation of the entire region in isostatic equilibrium, crustal extension resulting in Basin and Range faulting, extensive volcanism, high heat flow and a low-velocity mantle. These phenomena, apparently the result of plate tectonics, are superimposed on the inherited subcontinental crust that developed from an oceanic origin in Paleozoic time and possibly retained some of its thin and layered characteristics. The present anomalous crust in the Great Basin represents an accretion of oceanic geosynclinal material to a Precambrian continental nucleus apparently as an intermediate step in the process of conversion of oceanic crust into a stable continental landmass or craton. ?? 1974.

  5. Top of head scarp and internal scarps for landslide deposits in the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

    Data points represent head scarps, flank scarps, and minor internal scarps (linear) associated with landslide deposits in the Little North Santiam River Basin, Oregon. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  6. Assessment of undiscovered oil and gas resources of the Williston Basin Province of North Dakota, Montana, and South Dakota, 2010

    USGS Publications Warehouse

    ,

    2011-01-01

    Using a geology-based assessment method, the U.S. Geological Survey estimated mean undiscovered volumes of 3.8 billion barrels of undiscovered oil, 3.7 trillion cubic feet of associated/dissolved natural gas, and 0.2 billion barrels of undiscovered natural gas liquids in the Williston Basin Province, North Dakota, Montana, and South Dakota. The U.S. Geological Survey (USGS) recently completed a comprehensive oil and gas assessment of the Williston Basin, which encompasses more than 90 million acres in parts of North Dakota, eastern Montana, and northern South Dakota. The assessment is based on the geologic elements of each total petroleum system (TPS) defined in the province, including hydrocarbon source rocks (source-rock maturation, hydrocarbon generation, and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined 11 TPS and 19 Assessment Units (AU).

  7. Insights into mantle heterogeneities: mid-ocean ridge basalt tapping an ocean island magma source in the North Fiji Basin

    NASA Astrophysics Data System (ADS)

    Brens, R., Jr.; Jenner, F. E.; Bullock, E. S.; Hauri, E. H.; Turner, S.; Rushmer, T. A.

    2015-12-01

    The North Fiji Basin (NFB), and connected Lau Basin, is located in a complex area of volcanism. The NFB is a back-arc basin (BAB) that is a result of an extinct subduction zone, incorporating the complicated geodynamics of two rotating landmasses: Fiji and the Vanuatu island arc. Collectively this makes the spreading centers of the NFB the highest producing spreading centers recorded. Here we present volatile concentrations, major, and trace element data for a previously undiscovered triple junction spreading center in the NFB. We show our enrichment samples contain some of the highest water contents yet reported from (MORB). The samples from the NFB exhibit a combination of MORB-like major chemical signatures along with high water content similar to ocean island basalts (OIB). This peculiarity in geochemistry is unlike other studied MORB or back-arc basin (to our knowledge) that is not attributed to subduction related signatures. Our results employ the use of volatiles (carbon dioxide and water) and their constraints (Nb and Ce) combined with trace element ratios to indicate a potential source for the enrichment in the North Fiji Basin. The North Fiji Basin lavas are tholeiitic with similar major element composition as averaged primitive normal MORB; with the exception of averaged K2O and P2O5, which are still within range for observed normal MORB. For a mid-ocean ridge basalt, the lavas in the NFB exhibit a large range in volatiles: H2O (0.16-0.9 wt%) and CO2 (80-359 ppm). The NFB lavas have volatile levels that exceed the range of MORB and trend toward a more enriched source. In addition, when compared to MORB, the NFB lavas are all enriched in H2O/Ce. La/Sm values in the NFB lavas range from 0.9 to 3.8 while, Gd/Yb values range from 1.2 to 2.5. The NFB lavas overlap the MORB range for both La/Sm (~1.1) and Gd/Yb (~1.3). However, they span a larger range outside of the MORB array. High La/Sm and Gd/Yb ratios (>1) are indications of deeper melting within the

  8. Gravity modeling constraints on the Gatun-Chagres Basin and tectonic evolution of north-central Panama

    NASA Astrophysics Data System (ADS)

    Mynhier, Kelci

    The Oligocene-Miocene collision between Panama and South America significantly influenced ocean currents, global climate, and species diversification. Intraplate deformation of the Panama Block also played an important role in the evolution of this tectonic system, but is not well understood. A high-resolution gravity survey, coupled with geologic observations, was conducted in north-central Panama to better constrain the processes responsible for the Isthmus' modern configuration. Approximately 110 gravity stations were collected from Colon to Nombre de Dios, Panama and merged with existing data. Subsequently, four 2.5-D gravity models were produced to constrain the geometry of the Gatun-Chagres Basin using different sedimentary densities (1.8, 2.0, and 2.2 g/cm 3) to produce a realistic range of basin thicknesses. Overall, models with an average basin density of 2.0 g/cm3 are most consistent with offshore seismic profiles and field evidence, suggesting basin thickness is ~3.0--3.5 km. Previous seismic reflection data and geochemical analyses of Miocene arc volcanic rocks delineate a zone of extension in the Panama Canal Region, and gravity analysis from this study supports this hypothesis. Field evidence of multiple NW-facing normal faults suggests that they separate the basin from uplifted arc basement rocks east of the Canal, resulting in a 60 mGal gravity gradient. Beneath the basin, gravity models indicate ~5--10 km of crustal thinning. 3-D reconstruction of the 2.5-D models show a northward thickening basin and two depocenters that correspond to the Rio Indio and Toro facies of the Chagres Formation. This analysis suggests two directional extension of the Gatun-Chagres Basin; an east-west direction corresponding to the initial formation of the basin, and a modern northwest-southeast direction. To the northeast, gravity modeling indicates that there is a ~150 m-thick, Cretaceous-Holocene sedimentary basin present from Portobelo to Nombre de Dios. Sedimentary

  9. Genetic sequence relationships of Winnipegosis platform carbonates, southern Elk Point basin, North Dakota

    SciTech Connect

    Shanley, K.W.; Cross, T.A.

    1988-01-01

    Examination of cores and well log data from the Winnipegosis Formation (Givetian) within a study area of approximately 11,500 mi/sup 2/ (30,000 km/sup 2/) in northern North Dakota allows recognition of seven time-stratigraphic progradational units within the Winnipegosis Formation. Together with the underlying Ashern Formation, these units are arranged in landward-stepping, vertical stacking, and seaward-stepping geometric patterns, which reflect changes in relative sea level. Abrupt juxtaposition of shallow over deeper water lithologies, evidence for subaerial exposure, and onlap geometries further suggest that these progradational units form two larger, Vail-type sequences separated by regionally persistent unconformities or their correlative conformities. Sea level rise during the early Eifelian caused southeastward onlap of the Ashern Formation onto Middle Silurian carbonates of the Interlake Formation. Maximum flooding, expressed by deepest marine facies and a hardground surface, suggests the existence of a condensed section at the top of the Ashern Formation. This was developed during the maximum rate of sea level rise. A decrease in the rate of sea level rise resulted in aggradation of lower Winnipegosis units on a gently dipping ramp. These are represented by nodular and burrowed open marine limestones with scattered stromatoporoid patch reefs and grainstone shoals. During the subsequent sea level fall, represented by Temple units, a shelf margin with pronounced depositional topography and adjacent starved basin were developed. Temple strata include coral-brachiopod-stromatoporoid reefs and productive fore-reef talus deposits along the shelf margin rim.

  10. Numerical modeling of fracking fluid migration through fault zones and fractures in the North German Basin

    NASA Astrophysics Data System (ADS)

    Pfunt, Helena; Houben, Georg; Himmelsbach, Thomas

    2016-09-01

    Gas production from shale formations by hydraulic fracturing has raised concerns about the effects on the quality of fresh groundwater. The migration of injected fracking fluids towards the surface was investigated in the North German Basin, based on the known standard lithology. This included cases with natural preferential pathways such as permeable fault zones and fracture networks. Conservative assumptions were applied in the simulation of flow and mass transport triggered by a high pressure boundary of up to 50 MPa excess pressure. The results show no significant fluid migration for a case with undisturbed cap rocks and a maximum of 41 m vertical transport within a permeable fault zone during the pressurization. Open fractures, if present, strongly control the flow field and migration; here vertical transport of fracking fluids reaches up to 200 m during hydraulic fracturing simulation. Long-term transport of the injected water was simulated for 300 years. The fracking fluid rises vertically within the fault zone up to 485 m due to buoyancy. Progressively, it is transported horizontally into sandstone layers, following the natural groundwater flow direction. In the long-term, the injected fluids are diluted to minor concentrations. Despite the presence of permeable pathways, the injected fracking fluids in the reported model did not reach near-surface aquifers, either during the hydraulic fracturing or in the long term. Therefore, the probability of impacts on shallow groundwater by the rise of fracking fluids from a deep shale-gas formation through the geological underground to the surface is small.

  11. Regional significance of an early Holocene moraine in Enchantment Lakes basin, North Cascade Range, Washington

    USGS Publications Warehouse

    Waitt, R.B., Jr.; Yount, J.C.; Davis, P.T.

    1982-01-01

    The upper Enchantment Lakes basin in the North Cascade Range of Washington displays two moraine belts, each recording an episode of glacier advance after the end of the last glaciation. The inner belt, the Brynhild, 0.1 to 0.5 km beyond existing glaciers, postdates Mount St. Helens Wn tephra (???450 yr old), which lies only beyond the moraines. The morainal surface is only slightly weathered, is almost barren of lichens, and is devoid of soil, evidence suggesting that the Brynhild moraines are no more than a century old. The outer moraine, the Brisingamen, 0.3 to 0.7 km beyond existing glaciers, is weathered and is covered with large lichens. On and behind the Brisingamen moraine the Mazama ash (6900 yr old) is present beneath the Mount St. Helens Yn and Wn tephras. Despite more than 7 millennia of weathering, the rock surface behind the Brisingamen moraine is measurably less weathered than the surface beyond, which was last glaciated during the Rat Creek advance about 13,000 yr ago. The age of the Brisingamen moraine therefore is probably early Holocene. The Brisingamen moraine evidently correlates with moraines near Glacier Peak, near Mount Rainier, in northeastern and central Oregon, in the southern Canadian Rockies, and in the northern U.S. Rocky Mountains. These regional effects suggest that a climatic episode of cooling or increased snowfall affected the entire region some time during the early Holocene. ?? 1982.

  12. An Estimate of the North Atlantic Basin Tropical Cyclone Activity for the 2010 Hurricane Season

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2010-01-01

    Estimates are presented for the tropical cyclone activity expected for the 2010 North Atlantic basin hurricane season. It is anticipated that the 2010 season will be more active than the 2009 season, reflecting increased frequencies more akin to that of the current more active phase that has been in vogue since 1995. Averages (+/- 1 sd) during the current more active phase are 14.5+/-4.7, 7.8+/-3.2, 3.7+/-1.8, and 2+/- 2, respectively, for the number of tropical cyclones (NTC), the number of hurricanes (NH), the number of major hurricanes (NMH), and the number of United States (U.S.) land-falling hurricanes (NUSLFH). Based on the "usual" behavior of the 10-yma parametric first differences, one expects NTC = 19+/-2, NH = 14+/-2, NMH = 7+/-2, and NUSLFH = 4+/-2 for the 2010 hurricane season; however, based on the "best guess" 10-yma values of surface-air temperature at the Armagh Observatory (Northern Ireland) and the Oceanic Nino Index, one expects NTC > or equals 16, NH > or equals 14, NMH > or equals 7, and NUSLFH > or equals 6.

  13. Diagenetic Evolution and Reservoir Quality of Sandstones in the North Alpine Foreland Basin: A Microscale Approach.

    PubMed

    Gross, Doris; Grundtner, Marie-Louise; Misch, David; Riedl, Martin; Sachsenhofer, Reinhard F; Scheucher, Lorenz

    2015-10-01

    Siliciclastic reservoir rocks of the North Alpine Foreland Basin were studied focusing on investigations of pore fillings. Conventional oil and gas production requires certain thresholds of porosity and permeability. These parameters are controlled by the size and shape of grains and diagenetic processes like compaction, dissolution, and precipitation of mineral phases. In an attempt to estimate the impact of these factors, conventional microscopy, high resolution scanning electron microscopy, and wavelength dispersive element mapping were applied. Rock types were established accordingly, considering Poro/Perm data. Reservoir properties in shallow marine Cenomanian sandstones are mainly controlled by the degree of diagenetic calcite precipitation, Turonian rocks are characterized by reduced permeability, even for weakly cemented layers, due to higher matrix content as a result of lower depositional energy. Eocene subarkoses tend to be coarse-grained with minor matrix content as a result of their fluvio-deltaic and coastal deposition. Reservoir quality is therefore controlled by diagenetic clay and minor calcite cementation.Although Eocene rocks are often matrix free, occasionally a clay mineral matrix may be present and influence cementation of pores during early diagenesis. Oligo-/Miocene deep marine rocks exhibit excellent quality in cases when early cement is dissolved and not replaced by secondary calcite, mainly bound to the gas-water contact within hydrocarbon reservoirs. PMID:26365327

  14. Erosion surfaces and Neogene landscape evolution in the NE Duero Basin (north-central Spain)

    NASA Astrophysics Data System (ADS)

    Benito-Calvo, Alfonso; Pérez-González, Alfredo

    2007-08-01

    We present a chronological model of erosion surface development in the Iberian and Cantabrian Ranges of north-central Spain. We map four erosion surfaces and interpret these to be related to Duero basin continental sediments and tectonic activity from Upper Oligocene to Plio-Pleistocene. The oldest erosion surface, SE1, formed across Upper Oligocene-Lower Miocene synorogenic deposits; while surface SE2 was contemporaneous with the Middle Miocene alluvial systems, ending with an uplift stage in the Astaracian. The two most recent erosion surfaces, SE3 and SE4, developed during extensional tectonic episodes and are associated with the deposition of Upper Páramo sedimentary units at the end of the Miocene (Upper Turolian) and alluvial fan deposits, known as rañas (Plio-Pleistocene). With the exception of SE1, which seems to be associated with a relatively wet climate, the surfaces formed during periods of marked aridity and generally warm temperatures. Through geostatistical reconstruction of the best preserved surface (SE2), applying ordinary kriging method to the topography (DEM) of the erosion surface and its correlating sedimentary plains, we identify the deformation processes which occurred on this surface after its formation.

  15. Numerical modeling of fracking fluid migration through fault zones and fractures in the North German Basin

    NASA Astrophysics Data System (ADS)

    Pfunt, Helena; Houben, Georg; Himmelsbach, Thomas

    2016-04-01

    Gas production from shale formations by hydraulic fracturing has raised concerns about the effects on the quality of fresh groundwater. The migration of injected fracking fluids towards the surface was investigated in the North German Basin, based on the known standard lithology. This included cases with natural preferential pathways such as permeable fault zones and fracture networks. Conservative assumptions were applied in the simulation of flow and mass transport triggered by a high pressure boundary of up to 50 MPa excess pressure. The results show no significant fluid migration for a case with undisturbed cap rocks and a maximum of 41 m vertical transport within a permeable fault zone during the pressurization. Open fractures, if present, strongly control the flow field and migration; here vertical transport of fracking fluids reaches up to 200 m during hydraulic fracturing simulation. Long-term transport of the injected water was simulated for 300 years. The fracking fluid rises vertically within the fault zone up to 485 m due to buoyancy. Progressively, it is transported horizontally into sandstone layers, following the natural groundwater flow direction. In the long-term, the injected fluids are diluted to minor concentrations. Despite the presence of permeable pathways, the injected fracking fluids in the reported model did not reach near-surface aquifers, either during the hydraulic fracturing or in the long term. Therefore, the probability of impacts on shallow groundwater by the rise of fracking fluids from a deep shale-gas formation through the geological underground to the surface is small.

  16. Diagenetic Evolution and Reservoir Quality of Sandstones in the North Alpine Foreland Basin: A Microscale Approach.

    PubMed

    Gross, Doris; Grundtner, Marie-Louise; Misch, David; Riedl, Martin; Sachsenhofer, Reinhard F; Scheucher, Lorenz

    2015-10-01

    Siliciclastic reservoir rocks of the North Alpine Foreland Basin were studied focusing on investigations of pore fillings. Conventional oil and gas production requires certain thresholds of porosity and permeability. These parameters are controlled by the size and shape of grains and diagenetic processes like compaction, dissolution, and precipitation of mineral phases. In an attempt to estimate the impact of these factors, conventional microscopy, high resolution scanning electron microscopy, and wavelength dispersive element mapping were applied. Rock types were established accordingly, considering Poro/Perm data. Reservoir properties in shallow marine Cenomanian sandstones are mainly controlled by the degree of diagenetic calcite precipitation, Turonian rocks are characterized by reduced permeability, even for weakly cemented layers, due to higher matrix content as a result of lower depositional energy. Eocene subarkoses tend to be coarse-grained with minor matrix content as a result of their fluvio-deltaic and coastal deposition. Reservoir quality is therefore controlled by diagenetic clay and minor calcite cementation.Although Eocene rocks are often matrix free, occasionally a clay mineral matrix may be present and influence cementation of pores during early diagenesis. Oligo-/Miocene deep marine rocks exhibit excellent quality in cases when early cement is dissolved and not replaced by secondary calcite, mainly bound to the gas-water contact within hydrocarbon reservoirs.

  17. Discussions on the sedimentary-tectonic event and tectonic setting of the North Tarim Basin in Cryogenian-Cambrian

    NASA Astrophysics Data System (ADS)

    Zhou, X. B.; Li, J. H.; Li, W. S.

    2012-04-01

    Across the Tarim Basin, limited surface outcrops of Cryogenian to Cambrian sedimentary succession are completely exposed in the vicinity of Aksu area(Northwest Tarim), Kuruktag(Northeast Tarim)and Southwest Tarim, thus provides a unique, well preserved and accessible means by which to study the early development of the north Tarim Basin. Based on the field geological investigation in the northwestern and northeastern of Tarim Basin, with the referencing of paleomagnetism mapping and previous research, basin evolution process in Cryogenian-Cambrian is discussed according to sedimentary-tectonic event and other evidences. The major lithological types of Cryogenian-Cambrian system in Northeast Tarim are: tillite, clastic rocks(rich in organic matter) and carbonate ,with interbeds of volcanic rocks while in Northwest Tarim, the calstic rocks and carbonate are the common rock type, with tillite and volcanic interbeds in a small amount. The north margin of Tarim Block, which was a part of Rodinia supercontinent, neighboring the northwestern margin of Australia, was deeply rifted in Cryogenian-Ediacaran and developed into two rifts in the northwestern and northeastern margin, while formed a thick layer of the rift-passive margin deposits and the layer in the northwestern rift was not completely developed as the northeastern. The deepest rift-passive magin sediment which can be observed is Cryogenian-Middle Ordovician strata, and the period can be divided into Cryogenian faulted period (supercontinent rifting stage) and Ediacaran-Middle Ordovician subsidence period (plate drifting stage).

  18. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins

    PubMed Central

    McTaggart, Lisa R.; Brown, Elizabeth M.; Richardson, Susan E.

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  19. Mesozoic hydrocarbon source rock studies of north Tarim, south Junggar, and Turpan basins, Xinjiang Uygur autonomous region, northwestern China

    SciTech Connect

    Hendrix, M.S.; Xiao, Z.; Liang, Y.; Graham, S.A.; Carroll, A.R.; Chu, J.; McKnight, C.

    1989-03-01

    Ongoing outcrop and accompanying pyrolysis studies of Mesozoic strata of the north Tarim, south Junggar, and Turpan retroarc foreland basins, northwestern China, have demonstrated the existence of potential oil-prone and gas-prone petroleum source rocks. Lithologies include Jurassic coals from all three basins and Triassic coals from Tarim. Jurassic coals collected from the Mesozoic depocenters of the Junggar and Tarim basins are oil prone, yielding S/sub 2//S/sub 2+3/ values that range from 0.80 to 0.99 and average 0.96, hydrogen index (HI) values that range from 117.9 to 213.4 and average 150.8, and oxygen index (OI) values that range from 1.1 to 31.6 and average 7.67. In contrast, Triassic coals of Tarim and Jurassic coals of Turpan contain more conventional type III gas-prone kerogens and yield S/sub 2//S/sub 2+3/ values ranging from 0.04 to 0.52 and averaging 0.22, HI values ranging from 3.2 to 130.2 with a mean of 33.6, and OI values ranging from 30.9 to 223.7 and averaging 115.9. Coals of all three basins are slightly immature to mature with respect to oil generation, as indicated by T/sub max/ values ranging from 425/degrees/ to 449/degrees/C (average = 343/degrees/C) and vitrinite reflectance values ranging from 0.51 to 0.64 (average = 0.57). Thus, given the widespread abundance and significant thicknesses of Mesozoic and especially Jurassic coals in all three basins, it is very likely that Mesozoic contributions to Xinjiang's oil and gas reserves are significant. This is particularly important in the north Tarim basin, where recent Chinese oil and gas discoveries have been made and the existence of significant pre-Mesozoic source beds remains unproven.

  20. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins.

    PubMed

    McTaggart, Lisa R; Brown, Elizabeth M; Richardson, Susan E

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  1. Historic and unregulated monthly streamflow for selected sites in the Red River of the North basin in North Dakota, Minnesota, and South Dakota, 1931-99

    USGS Publications Warehouse

    Emerson, Douglas G.; Dressler, Valerie M.

    2002-01-01

    Operation of the Garrison Diversion Unit in North Dakota may have various effects on the quantity and quality of streamflow in the Sheyenne River and the Red River of the North. To model the effects that the Garrison Diversion Unit could have on water quality, gaged and estimated historic streamflow data and estimated unregulated streamflow data were compiled to develop a complete monthly streamflow record for January 1931 through September 1999 (the data-development period) for 35 sites in the Red River of the North Basin in North Dakota, Minnesota, and South Dakota.During the entire data-development period, gaged streamflow data were available for only 4 of the 35 sites, incomplete data of various length were available for 10 sites, and no data were available for 21 sites. Drainage- area ratio and Maintenance of Variance Extension Type 1 methods were used to estimate the historic streamflow for months when no data were available.Unregulated streamflow for the 35 sites was estimated by eliminating the hydrologic effects of Orwell Reservoir, Lake Traverse, Mud Lake, Lake Ashtabula, and surface-water withdrawals. Modeled flows at the Red River of the North at Wahpeton by the U.S. Army Corps of Engineers were used to eliminate the effects of Orwell Reservoir, Lake Traverse, and Mud Lake, and water-balance procedures were used to eliminate the effects of Lake Ashtabula.

  2. Volcanic Explosions, Seismicity, and Debris from the West and North Mata Volcano Complex, NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Haxel, J.; Walker, S.; Fowler, M.

    2010-12-01

    The discovery of the explosively erupting deep-ocean West Mata volcano in the northeast Lau Basin offers an unprecedented opportunity for in situ and near-field studies of the hydroacoustic wavefield produced by a submarine arc volcano, as well as the relationship between gas-driven explosions and the formation of volcanic-hydrothermal plumes. From December 2009 to April 2010, we re-initiated acoustic monitoring of the West Mata system by deploying four hydrophone moorings in a diamond-shaped geometry encompassing the summit and a set of nearby volcanic edifices known as the North Matas. Recent water column surveys over the North Matas found intense volcanic plumes suggesting that one or more of these volcanoes may be in an active eruption phase similar to West Mata. Each mooring contained a single sound-channel moored hydrophone (~1000 m depth) with a sample-rate of 1 kHz. The southern mooring in the array also included two optical backscatter and temperature sensors (MAPRs) attached to the mooring line (at 1800 m (data lost due to a battery failure) and 2250 m (~300 mab) depth) to detect plumes of volcanic debris that detach from the flank of West Mata. The acoustic record shows that West Mata volcano was continually erupting during the 5-month period of the experiment, producing broadband explosions every few seconds and long episodes of both mono- and poly-chromatic volcanic tremor. The MAPR record shows at least four major and several minor events, lasting from days to >week, that may correspond to debris flows. In most cases these episodes begin with a turbidity spike that slowly decreases while also fluctuating between elevated and ambient levels with the semidiurnal tides, as indicated by the temperature record. This linked temperature-turbidity fluctuation requires the events to be thin (<~100 m?) lenses that vertically oscillate around the MAPR depth while dissipating. High turbidity values (0.15-5 NTU) in some events imply these debris flows regularly

  3. Indications of Hydrocarbons in the Tjörnes Basin, North Iceland

    NASA Astrophysics Data System (ADS)

    Richter, B.; Brandsdóttir, B.; Detrick, R.; Helgadóttir, G.; Kjartansson, E.; Gunnarsson, K.; Driscoll, N.; Kent, G.

    2002-12-01

    The Tjörnes basin, located within the Tjörnes Fracture Zone (TFZ) was initiated during the Miocene (7-9 Ma), following an eastward jump of the spreading axis in N-Iceland. The roughly 150 km long (EW) and 50 km wide (NS) basin has since accumulated a 0.5-4 km thick sedimentary sequence within three extensional grabens, Eyjafjardaráll, Skjálfandadjúp and Öxarfjördur. The transtensional Húsavík-Flatey fault defines the southern margin of the basin. The hangingwalls within the westernmost and deepest graben (Eyjafjardaráll) are transected by series of synthetic and antithetic listric faults. These structures are affiliated with a crustal-scale, listric east- to north-easterly dipping master fault which soles out in the lower crust, at about 7500 m depth. Near shore sediments are exposed on the Tjörnes peninsula, at the eastern margin of the central graben, where a basal unit of Tertiary lava flows, up to 10 Ma old is overlain by 500 m thick Miocene-Pliocene sediments (Tjörnes Beds). Several lignite layers are present within this predominantly marine succession. Multichannel Seismic data show that the Tjörnes Beds extend westwards into the Skjálfandi Bay. In 1989, gas emissions of thermogenic hydrocarbons were detected during a core-drilling in the easternmost basin, Öxarfjördur. Analyses of natural gas-emissions within the geothermal areas at Skógarlón and Skógar in Öxarfjördur also revealed hydrocarbons (methane-hexane) in high concentrations. These gasses probably originate from marine sediments and lignites similar to those found in the Tjörnes Beds. The Tjörnes Beds, as seen in the Tjörnes horst, are thermally immature with respect to petroleum generation. However, based on the tectonic history, this is probably a minimum-maturity indication as organic geochemical analysis and maturation simulations indicate that high geothermal gradient enhances the formation of dry and wet gasses and waxy oil. In 2001 a sidescan sonar imaging was

  4. Study of the United States coal resources. [Appalachian Plateau, Interior Basins, Gulf Coastal Plain, Rocky Mountain Basins, High Plains, North Alaska

    SciTech Connect

    Ferm, J.C.; Muthig, P.J.

    1982-09-15

    The objectives of this study were: (1) the identification of geologically significant coal resources for the United States, including Alaska; and (2) the preparation of statistically controlled tonnage estimates for each resource type. Particular emphasis was placed on the identification and description of coals in terms of seam thickness, inclination, depth of cover, discontinuities caused by faulting and igneous intrusion, and occurrence as isolated or multiseam deposits. The national resource was organized into six major coal provinces: the Appalachian Plateau, the Interior Basins, the Gulf Coastal Plain, the Rocky Mountain Basins, the High Plains, and North Alaska. Total coal tonnage for a subarea was estimated from an analysis of the cumulative coal thickness derived from borehole or surface section records and subsequently categorized in terms of seam thickness, dip, overburden, multiseam proportions, coal quality, and tonnage impacted by severe faulting and igneous intrusions. Results indicate an aggregate resource in place of 11.6 trillion tons, of which North Alaska accounts for 3.5 trillion tons of subbituminous and bituminous coal; the Rocky Mountains, 2.2 trillion tons of bituminous and subbituminous deposits; and the Gulf Coast, 3.8 trillion tons of lignites. The Appalachian Plateau and Interior Basins are estimated to contain slightly less than 1 trillion tons each of bituminous coal, and the High Plains slightly more than 0.5 trillion tons of lignite. The Appalachian Plateau and Interior Basins are estimated to contain slightly less than 1 trillion tons each, and the High Plains Province is estimated to contain a bit more than 0.5 trillion tons. The implications of the results for research on advanced mining systems are discussed. 27 figures, 25 tables.

  5. Sedimentary record and climatic implications of recurrent deformation in the Tian Shan: Evidence from Mesozoic strata of the north Tarim, south Junggar, and Turpan basins, northwest China

    SciTech Connect

    Hendrix, M.S.; Graham, S.A.; Sobel, E.R.

    1992-01-01

    Detailed stratigraphic, sedimentologic, paleocurrent, and subsidence analyses were conducted on Mesozoic nonmarine sedimentary sections of the south Junggar, north Tarim, and Turpan basins, Xinjang Uygur Autonomous Region, northwest China. These three basins have been foreland basins throughout the Mesozoic and Cenozoic eras, as demonstrated by asymmetrically distributed basinwide sediment accumulations, foreland-style subsidence profiles, and a variety of outcrop and subsurface facies data. Mesozoic paleocurrent indicators measured in the south Junggar and north Tarim basins, as well as Mesozoic sandstone compositions from both basins, indicate that the intervening Tian Shan has existed as a positive physiographic feature partitioning the two basins throughout Mesozoic and Cenozoic time. Paleocurrent, facies, and subsurface isopach data suggest that the Turpan basin was established as a discrete feature by the Early Jurassic period. The timing and style of depositional systems within the north Tarim Mesozoic depocenter, the south Junggar Mesozoic depocenter, and the central Turpan basin are remarkably similar. Upper Triassic strata of each basin consist of alluvial conglomerate and associated braided-fluvial sandstone and siltstone which fine upward into lower through Middle Jurassic, locally organic-rich, meandering-fluvial, and lacustrine strata. Upper Jurassic braided-fluvial red beds in each basin are overlain by a distinct pulse of uppermost Jurassic alluvial conglomerate. Lower Cretaceous exposures consist of fine-grained red beds in north Tarim and Turpan and interbedded red and gray shale with local silty carbonates in south Junggar. Upper Cretaceous strata of the north Tarim and south Junggar basins are composed of alluvial conglomerate with associated braided-fluvial sandstone and siltstone. 94 refs., 17 figs.

  6. Chapter 44: Geology and petroleum potential of the Lincoln Sea Basin, offshore North Greenland

    USGS Publications Warehouse

    Sorensen, K.; Gautier, D.; Pitman, J.; Ruth, Jackson H.; Dahl-Jensen, T.

    2011-01-01

    A seismic refraction line crossing the Lincoln Sea was acquired in 2006. It proves the existence of a deep sedimentary basin underlying the Lincoln Sea. This basin appears to be comparable in width and depth to the Sverdrup Basin of the Canadian Arctic Islands. The stratigraphy of the Lincoln Sea Basin is modelled in analogy to the Sverdrup Basin and the Central Spitsbergen Basin, two basins between which the Lincoln Sea intervened before the onset of seafloor spreading in the Eurasian Basin. The refraction data indicates that the Lincoln Sea Basin is capped by a kilometre-thick, low-velocity layer, which is taken to indicate an uplift history similar to, or even more favourable than, the fairway part of the Sverdrup Basin. Tectonic activity in the Palaeogene is likely to constitute the major basin scale risk. We conclude that the Lincoln Sea Basin is likely to be petroliferous and contains risked resources on the order of 1 ?? 109 barrels of oil, to which comes an equivalent amount of (associated and nonassociated) gas. ?? 2011 The Geological Society of London.

  7. Waulsortian-type buildups in the lower carboniferous of the Bechar basin, northwestern Sahara of Algeria, North Africa

    SciTech Connect

    Setra, A. )

    1994-03-01

    The carboniferous strata in the Bechar basin can be subdivided into three major groups. The lower group is composed of bioclastic and perireefal carbonates. The middle group is exemplified by carbonate platform deposits that were eroded during episodes of emergence by channels of continental derived sediments. The upper group is represented by terrigenous deposits composed mainly of deltaic, fluvial, and lacustrine deposits, with the sporadic presence of coal seams. The carboniferous Waulsortian-type buildups within the Bechar basin occur in the lower group. They are exposed above the desert floor along a south to north-northwest-trending axis, with the younger buildups located to the south and the older ones to the north. These bioherms are apparently younger than those recognized in Europe and North America. These Algerian bioherms were initiated and persisted during the time interval represented by the conodont gnathodus bilineatus zone (lower Visean-upper Visean boundary). Although they are younger than their European and North American counterparts that are of Tournaisian-lower Visean age, these mounds appear to have formed in similar environmental and tectono-sedimentary conditions. Their areal extent, geometry, and facies relationships suggest that they were limited to a shelf edge. Their deposition environments range from shallow marine to deep sea.

  8. Gazetteer of hydrologic characteristics of streams in Massachusetts; coastal river basins of the North Shore and Massachusetts Bay

    USGS Publications Warehouse

    Wandle, S.W.

    1984-01-01

    The coastal river basins of the North Shore and Boston Bay include streams draining the Parker River (60.4 square miles), Rowley River (9.9 square miles), Ipswich River (156 miles), Mystic River (66.0 square miles), Charles River (311 square miles), Neponset River (117 square miles), Weymouth Fore and Weymouth Back Rivers (about 63 square miles) and Weir River (about 20 square miles) basins. The study area in eastern and northeastern Massachusetts also includes the minor river basins draining into Massachusetts Bay, Ipswich Bay, or the Atlantic Ocean. Drainage areas using the latest available 1:24,000 scale topographic maps were computed for the first time for streams draining more than 3 square miles and were recomputed for data-collection sites. Streamflow characteristics at 15 gaging stations were calculated using a new data base with daily flow records through 1981. These characteristics include annual and monthly flow statistics, duration of daily flow values, and the annual 7-day mean low flow at the 2-year and 10-year recurrence intervals. Seven-day low-flow statistics are presented for 95 partial-record sites and the procedures used to determine the hydrologic characteristics of a basin are summarized. Basin characteristics representing 14 commonly used indices to estimate various streamflows are presented for 15 gaged streams. This gazetteer will aid in the planning and siting of water-resources related activities and will provide a common data base for governmental agencies and the engineering and planning communities. (USGS)

  9. Nutrients, suspended sediment, and pesticides in water of the Red River of the North Basin, Minnesota and North Dakota, 1990-2004

    USGS Publications Warehouse

    Christensen, V.G.

    2007-01-01

    Nutrient, suspended sediment, and pesticide data from 1990 through 2004 in the Red River of the North Basin were compiled, summarized, and compared to historical data. Streamflow varied widely throughout the basin during the 1990-2004 study period. For 19 of 22 streamflow sites, median annual streamflow during the study period exceeded the long-term average streamflow. High streamflow can have a substantial effect on water quality. In water samples from selected surface-water sites, nitrite plus nitrate concentrations ranged from less than 0.005 to 7.7 milligrams per liter; total Kjeldahl nitrogen concentrations ranged from 0.1 to 7.5 milligrams per liter; total phosphorus concentrations ranged from less than 0.005 to 4.14 milligrams per liter; and dissolved phosphorus concentrations ranged from 0.003 to 4.13 milligrams per liter. Surface-water samples from the Pembina River basin generally had higher nitrite plus nitrate, total phosphorus, and suspended sediment concentrations compared to samples from other Red River Basin sites. Historical data from 1970 through 1990 showed relatively high nitrite plus nitrate and suspended sediment concentrations in samples from some Pembina River sites; in contrast to the 1990-2004 period, total phosphorus concentrations from the 1970-90 period generally were highest at Red River of the North sites. Nitrate concentrations in ground-water samples for the 1990-2004 period were highest in Sheridan County, North Dakota and Marshall and Otter Tail Counties in Minnesota. Concentrations of nitrate in ground water in Marshall and Otter Tail Counties corresponded to relatively high reported fertilizer applications during 2002; however, Sheridan County did not have the high fertilizer applications in 2002 compared to other North Dakota and Minnesota counties. The most frequently detected pesticides or pesticide metabolites were 2, 4-D, bentazon, de-ethylatrazine, metolachlor, picloram, and triallate in surface water and alachlor

  10. A review of tectonics and sedimentation in a forearc setting: Hellenic Thrace Basin, North Aegean Sea and Northern Greece

    NASA Astrophysics Data System (ADS)

    Maravelis, A. G.; Boutelier, D.; Catuneanu, O.; Seymour, K. St.; Zelilidis, A.

    2016-04-01

    Exposure of the forearc region of the North Aegean Sea, Greece, offers insight into evolving convergent margins. The sedimentary fill of the Thrace Basin during the Late Eocene to Oligocene time provides a record of subduction-driven processes, such as growth of magmatic arcs and construction of accretionary complexes. This large sediment repository received sediment from two sources. The southern (outboard) basin margin reflects the active influence of the exhumed accretionary prism (e.g. Pindic Cordillera or Biga peninsula), while the northern (inboard) margin records the effect of the magmatic arc in the Rhodope region. The forearc basin sedimentary fills shoal upward into shallow-marine strata but are dominated mainly by deep-marine facies. The depositional trend and stacking pattern are dominated by progradational patterns. This trend, which is observed in both basin margins, is related to tectonic deformation rather than sea-level fluctuations. Additional evidence for this tectonic uplift comes from the backstripping analysis. The accretionary complex provided material into the forearc basin. This material was transported northeast and formed a sand-rich turbidity system that evolved upslope into shallow-marine deposits. Stratigraphic data indicate that this turbidity system exhibits a successive landward (inboard) migration of the depocenter. Provenance data utilizing sandstone petrography, conglomerate clast composition, and bulk-rock geochemistry suggest that this system reflects an increased influx of mafic material into the basin. Volcanic arc-derived material was transported south and east and accumulated in deep-marine settings. Both stratigraphic and provenance data indicate a seaward (outboard) migration of the basin depocenter and a significant increase in felsic detritus into the forearc.

  11. Strategic development plan for integrated water resources management in Lake Manyara sub-basin, North-Eastern Tanzania

    NASA Astrophysics Data System (ADS)

    Ngana, J. O.; Mwalyosi, R. B. B.; Yanda, P.; Madulu, N. F.

    This paper reports that the core problem in the water resources management of the Lake Manyara sub-basin in north-eastern Tanzania is unsustainable utilization and management of natural resources. The subsequent effects observed in the sub-basin are natural resource use conflicts, poverty, low productivity, overcrowding, high siltation in rivers and lakes, degraded environment, decreased river flows, polluted water sources, etc. In order to establish strategies to arrest this situation, a strategic planning process has been used as a tool involving key stakeholders in the basin at various levels. Policy making officials at the district level i.e. planning officers, agricultural officers, water engineers and natural resources officers and grass root level experiences of respective wards in the basin were established through involving Ward executive officers. Water users of the key sectors in the basin were equally involved which included hotels, tented camps, irrigators and livestock keepers. Institutions working in natural resources management in the areas also participated including NGOs. The main causes leading to unsustainable utilization and management of natural resources were established as poverty, environment degradation, poor governance, weak enforcement of conservation laws, conflicting policies, inadequate experts at all levels, inadequate information on natural resources, high natural population growth rate, high immigration rates, high livestock population in comparison to land carrying capacity, political interference in implementation, limited water resources and lack of basin wide institution managing the natural resources in the basin. Various strategic objectives were identified by stakeholders and respective strategies, activities and verifiable indicators mapped for implementation. Stakeholders having owned the process and articulated the strategies themselves showed commitment and readiness to cooperate in the implementation of the plan.

  12. Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

    NASA Astrophysics Data System (ADS)

    Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

    2009-04-01

    Drained thaw lake basins in Western Siberia have a local name "khasyreis" [1]. Khasyreis as well as lakes, ponds and frozen mounds are invariable element of sub-arctic frozen peat bogs - palsas and tundra landscapes. In some areas of West-Siberian sub-arctic khasyreis occupy up to 40-50% of total lake area. Sometimes their concentration is so high that we call such places ‘khasyrei's fields". Khasyreis are part of the natural cycle of palsa complex development [1], but their origin is not continuous and uniform in time and, according to our opinion, there were periods of more intensive lake drainage and khasyrei development accordingly. These times were corresponding with epochs of climatic warming and today we have faced with one of them. So, last years this process was sufficiently activated in the south part of West-Siberian sub-arctic [2]. It was discovered that in the zone of continuous permafrost thermokarst lakes have expanded their areas by about 10-12%, but in the zone of discontinuous permafrost the process of their drainage prevails. These features are connected with the thickness of peat layers which gradually decreases to the North, and thus have reduced the opportunity for lake drainage in northern areas. The most typical way of khasyrei origin is their drainage to the bigger lakes which are always situated on the lower levels and works as a collecting funnels providing drainage of smaller lakes. The lower level of the big lake appeared when the lake takes a critical mass of water enough for subsidence of the lake bottom due to the melting of underlaying rocks [2]. Another one way of lake drainage is the lake intercept by any river. Lake drainage to the subsurface (underlaying rocks) as some authors think [3, 4] is not possible in Western Siberia, because the thickness of permafrost is at list 500 m here being safe confining bed. We mark out few stages of khasyrei development: freshly drained, young, mature and old. This row reflects stages of

  13. Sedimentation and chemical quality of surface water in the Heart River drainage basin, North Dakota

    USGS Publications Warehouse

    Maderak, Marion L.

    1966-01-01

    The Heart River drainage basin of .southwestern North Dakota comprises an area of 3,365 square miles and lies within the Missouri Plateau of the Great Plains province. Streamflow of the Heart River and its tributaries during 1949-58 was directly proportional to .the drainage area. After the construction of Heart Butte Dam in 1949 and Dickinson Dam in 1950, the mean annual streamflow near Mandan was decreased an estimated 10 percent by irrigation, evaporation from the two reservoirs, and municipal use. Processes that contribute sediment to the Heart River are mass wasting, advancement of valley heads, and sheet, lateral stream, and gully erosion. In general, glacial deposits, terraces, and bars of Quaternary age are sources of sand and larger sediment, and the rocks of Tertiary age are sources of clay, silt. and sand. The average annual suspended-sediment discharges near Mandan were estimated to be 1,300,000 tons for 1945-49 and 710,000 tons for 1970-58. The percentage composition of ions in water of the Heart River, based on average concentrations in equivalents per million for selected ranges of streamflow, changes with flow and from station to station. During extremely low flows the water contains a large percentage of sodium and about equal percentages of bicarbonate and .sulfate, and during extremely high flows the water contains a large percentage of calcium plus magnesium and bicarbonate. The concentrations, in parts per million, of most of the ions vary inversely with flow. The water in the reservoirs--Edward Arthur Patterson Lake and Lake Tschida--during normal or above-normal runoff is of suitable quality for public use. Generally, because of medium or high salinity hazards, the successful long-term use of Heart River water for irrigation will depend on a moderate amount of leaching, ,adequate drainage, ,and the growing of crops that have moderate or good salt tolerance.

  14. Lava and Life: New investigations into the Carson Volcanics, lower Kimberley Basin, north Western Australia

    NASA Astrophysics Data System (ADS)

    Orth, Karin; Phillips, Chris; Hollis, Julie

    2014-05-01

    The Carson Volcanics are the only volcanic unit in the Paleoproterozoic Kimberley Basin and are part of a poorly studied Large Igneous Province (LIP) that was active at 1790 Ma. New work focussing on this LIP in 2012 and 2013 involved helicopter-supported traverses and sampling of the Carson Volcanics in remote areas near Kalumburu in far north Western Australia's Kimberley region. The succession is widespread and flat lying to gently dipping. It consists of three to six basalt units with intercalated sandstone and siltstone. The basalts are 20-40 m thick, but can be traced up to 60 km along strike. The basalt can be massive or amygdaloidal and commonly display polygonal to subhorizontal and rare vertical columnar jointing. Features of the basalt include ropy lava tops and basal pipe vesicles consistent with pahoehoe lavas. The intercalated cross-bedded quartzofeldspathic sandstone and siltstone vary in thickness up to 40 m and can be traced up to 40 km along strike. Peperite is common and indicates interaction between wet, unconsolidated sediment and hot lava. Stromatolitic chert at the top of the formation represents the oldest life found within the Kimberley region. Mud cracks evident in the sedimentary rocks, and stromatolites suggest an emergent broad tidal flat environment. The volcanics were extruded onto a wide marginal margin setting subject to frequent flooding events. Thickening of the volcanic succession south and the palaeocurrents in the underlying King Leopold Sandstone and the overlying Warton Sandstone suggest that this shelf sloped to the south. The type of basalt and the basalt morphology indicate a low slope gradient of about 1°.

  15. Genetic sequence relationships of Winnipegosis platform carbonates, Southern Elk Point basin, North Dakota

    SciTech Connect

    Shanley, K.W.; Cross, T.A.

    1988-07-01

    Examination of cores and well-log data from the Winnipegosis Formation (Givetian) within a study area of approximately 11,500 mi/sup 2/ (30,000 km/sup 2/) in northern North Dakota allows recognition of seven time-stratigraphic progradational units within the Winnipegosis Formation. Together with the underlying Ashern Formation, these units are arranged in landward-stepping, vertical stacking, and seaward-stepping geometric patterns, which reflect changes in relative sea level. Abrupt juxtaposition of shallow over deeper water lithologies, evidence for subaerial exposure, and onlap geometries further suggest that these progradational units form two larger Vail-type sequences separated by regionally persistent unconformities or their correlative conformities. Sea level rise during the early Eifelian caused southeastward onlap of the Ashern Formation onto Middle Silurian carbonates of the Interlake Formation. Maximum flooding, expressed by deepest marine facies and a hardground surface, suggests the existence of a condensed section at the top of the Ashern Formation. This section was developed during the maximum rate of sea level rise. A decrease in the rate of sea level rise resulted in aggradation of lower Winnipegosis units on a gently dipping ramp. These units are presented by nodular and burrowed open-marine limestones with scattered stromatoporoid patch reefs and grainstone shoals. During the subsequent sea level fall, represented by Temple units, a shelf margin with pronounced depositional topography and adjacent starved basin were developed. Temple strata include coral-brachiopod-stromatoporoid reefs and productive fore-reef talus deposits along the shelf-margin rim. With increased rates of sea level fall, the platform interior and shelf margin were subaerially exposed, slope carbonates were dolomitized, and the E-shale was deposited as a lowstand wedge.

  16. Characterisation of the bacterial populations in a saline heat storage aquifer in the North German Basin

    NASA Astrophysics Data System (ADS)

    Alawi, M.; Lerm, S.; Vetter, A.; Vieth, A.; Mangelsdorf, K.; Seibt, A.; Wolfgramm, M.; Würdemann, H.

    2009-04-01

    The colonization and the ecology of microorganisms in the deep biosphere arouse increasing interest of scientists because of utilizing the subsurface for e.g. energy storage and recovery. The research project AquiScreen investigates the operational reliability of eight geothermally used groundwater systems in Germany under microbial, geochemical, mineralogical, and petrological aspects. This study shows the results of the heat storage in Neubrandenburg (depth: 1250 m), a typical site for saline fluids in the North German Basin. The seasonal alternation in charge and discharge mode enabled sampling the warm (75˚ C) and the cold (45˚ C) side of the geothermal doublet. The analyses focus on microbially induced corrosion on plant components and scaling resulting in filter and/or formation clogging. Microbiological analyses were carried out with fluid and solid phase samples by 16S rDNA based Single Strand Conformation Polymorphism (SSCP) fingerprinting. The analyses are utilized to evaluate the impact of microbial populations on such systems. The genetic fingerprinting revealed significant differences in the bacterial community structure between the warm and cold side of the heat storage. Since the geochemical analyses revealed no remarkable differences, the temperature might be crucial for the different community structures. At the warm side of the aquifer the identified bacteria are closely related to Variovorax and Sphingomonas. At the cold side of the heat storage sulphate reducing and fermentative bacteria were detected. These results correspond with locally observed iron sulphide precipitation and corrosion processes on plant components. Particularly the bacterial population of the cold side was studied over a period of two years. Thereby seasonal changes in the abundance of the identified bacteria, depending on the operational mode of the geothermal plant, were observed. After a malfunction in the pump system of the cold side of the heat storage changes in

  17. Application of magnetic proxies in reservoir characterization: a case study from the North German Basin

    NASA Astrophysics Data System (ADS)

    Scholger, Robert; Schleifer, Norbert; Gegenhuber, Nina; Rieckh, Veronika

    2014-05-01

    Porosity and permeability are key parameters for hydrocarbon reservoir characterization, but measurements are time consuming and expensive, and the demand for petrophysical proxies for these parameters is growing. In this study, the focus was laid on magnetic properties and their links with rock facies. Magnetic proxies can provide information about the concentration, grain size and type of magnetic minerals in soils and rocks. They are commonly used in environmental screening and mineral prospecting, but their potential for reservoir characterization is not yet fully understood. Sandstone samples from two elder drill cores from the North German Basin (Rotliegend) were examined. Natural remanent magnetization, frequency dependent magnetic susceptibility and anisotropy of magnetic susceptibility were measured before and after salt extraction, and the results were correlated with porosity and permeability. Acquisition of isothermal remanent magnetization and Curie point determinations were used to characterize the magnetic mineralogy in respect of the rock facies. Three ferr(o)magnetic minerals could be identified in the samples: magnetite, hematite and goethite. The occurrence of these three minerals was strongly dependant on the rock facies. Samples, which were characterised as aeolian mudflats, low energetic fluvial deposits and lake sediments typically yielded a significant magnetic anisotropy and relatively higher susceptibility values, whereas porosity and permeability was low. Hematite was found to be the most important magnetic mineral in these facies types. Contributions from goethite and a paramagnetic phase, probably illite, were also observable in most samples. In contrary, samples characterised as dry sandflats, damp sandflats and aeolian dunes showed elevated porosity and lower magnetic susceptibility values. Despite the lower bulk susceptibility values, the magnetic properties pointed towards magnetite as main magnetic mineral in these samples. The

  18. Habitat of oil in the Lindsborg field, Salina basin, north-central Kansas

    SciTech Connect

    Newell, K.D. )

    1991-03-01

    The Lindsborg field was discovered in 1938, and is now 14 mi in length and 1-2 mi in width. It has a projected ultimate recovery of 16 MMBO. Three pay zones (5-20 ft thick) produce in the field. The Simpson pay zone (Middle Ordovician) is a well-rounded, quartzitic sandstone that is interpreted to be a paralic, high-energy shelf deposit. The Viola pay (Middle Ordovician) appears to be a dolomitic, lime grainstone but no cores are available to confirm this. The uppermost pay zone, the Upper Ordovician Maquoketa, is a finely laminated, vuggy, cherry dolomite interpreted to have been deposited as a subtidal lime mudstone in a restricted lagoon. The Simpson and Viola pays are structurally trapped in culminations along the crest of the Lindsborg anticline. Although the Maquoketa pay is structurally trapped with the other pay zones in the southern half of the field, its locus of production in the north half of the fields extends 100 ft vertically down the western flank of the anticline. The trapping mechanism is unclear due to lack of core control and modern logging suites, but it may be subtle updip diagenetic change from vuggy to nonvuggy dolomite. The Simpson and Maquoketa oils are geochemically distinct. Both may reflect efficient local source-to-reservoir migration from originally rich but marginally mature Ordovician and Devonian shales that contact each pay zone. If oil in the Lindsborg field is locally generated, the prospectivity of the relatively unproductive and underexplored Salina basin may be enhanced.

  19. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2005-10-28

    The principal research effort for Year 2 of the project has been petroleum system characterization and modeling. Understanding the burial, thermal maturation, and hydrocarbon expulsion histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in hydrocarbon resource assessment. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and initial thermal maturation and hydrocarbon expulsion modeling indicated that an effective regional petroleum source rock in the onshore interior salt basins and subbasins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was Upper Jurassic Smackover lime mudstone. The initial modeling also indicated that hydrocarbon generation and expulsion were initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin and that hydrocarbon generation and expulsion were initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Refined thermal maturation and hydrocarbon expulsion modeling and additional petroleum source rock analysis have confirmed that the major source rock in the onshore interior salt basins and subbasins is Upper Jurassic Smackover lime mudstone. Hydrocarbon generation and expulsion were initiated in the Early to Late Cretaceous and continued into the Tertiary.

  20. Late Permian to Late Triassic basin evolution of North Vietnam: geodynamic implications for the South China and Indochina blocks

    NASA Astrophysics Data System (ADS)

    Rossignol, Camille; Bourquin, Sylvie; Hallot, Erwan; Poujol, Marc; Roger, Françoise

    2015-04-01

    The core of South East Asia is composed of a mosaic of continental blocks, among which the Indochina and the South China blocks (present day northern Vietnam), amalgamated during the Permian and/or the Triassic. Late Permian to Late Triassic geodynamic evolution of these two blocks remains controversial. The main discussion points concern the existence and the closure of an oceanic domain separating the Indochina and the South China blocks during this period. Especially, the polarity and the timing of the subduction zone that led to the collision between the blocks as well as the present location of the suture delimiting them are a matter of debate. Despite the valuable information they can provide, the sedimentary basins from northern Vietnam have been neglected in the previous studies dealing with the geodynamic evolution of South East Asia. To determine the geodynamic evolution of the area, the basins of Sam Nua and Song Da, presently located in North Vietnam, have been investigated using a combined approach involving sedimentology, geochronology (U-Pb/zircon) and geochemistry (whole-rock major and trace elements composition of both volcanic and volcaniclastic rocks). The palaeoenvironment evolution, the main unconformities, their age and the tectonic affinities of the interbedded volcanic and volcaniclastics series have been characterized for these two basins. Our results demonstrate (i) that the Song Da Basin exhibits a palaeogeographic affinity with the South China block, (ii) the occurrence of extensive calk-alkaline volcanism and associated volcaniclastic deposits in the Sam Nua Basin, related to the existence of an active magmatic arc during the Early and the lower Middle Triassic, (iii) a South dipping (present day coordinate) oceanic lithosphere beneath the Indochina block, deduced from the location of the magmatic arc south of the potential suture zones, (iv) that an angular unconformity postdates the lower Middle Triassic volcaniclastic deposits in the

  1. Gene lineages and eastern North American palaeodrainage basins: phylogeography and speciation in salamanders of the Eurycea bislineata species complex.

    PubMed

    Kozak, Kenneth H; Blaine, Russell A; Larson, Allan

    2006-01-01

    Contemporary North American drainage basins are composites of formerly isolated drainages, suggesting that fragmentation and fusion of palaeodrainage systems may have been an important factor generating current patterns of genetic and species diversity in stream-associated organisms. Here, we combine traditional molecular-phylogenetic, multiple-regression, nested clade, and molecular-demographic analyses to investigate the relationship between phylogeographic variation and the hydrogeological history of eastern North American drainage basins in semiaquatic plethodontid salamanders of the Eurycea bislineata species complex. Four hundred forty-two sequences representing 1108 aligned bases from the mitochondrial genome are reported for the five formally recognized species of the E. bislineata complex and three outgroup taxa. Within the in-group, 270 haplotypes are recovered from 144 sampling locations. Geographic patterns of mtDNA-haplotype coalescence identify 13 putatively independent population-level lineages, suggesting that the current taxonomy of the group underestimates species-level diversity. Spatial and temporal patterns of phylogeographic divergence are strongly associated with historical rather than modern drainage connections, indicating that shifts in major drainage patterns played a pivotal role in the allopatric fragmentation of populations and build-up of lineage diversity in these stream-associated salamanders. More generally, our molecular genetic results corroborate geological and faunistic evidence suggesting that palaeodrainage connections altered by glacial advances and headwater erosion occurring between the mid-Miocene and Pleistocene epochs explain regional patterns of biodiversity in eastern North American streams.

  2. Simulation of runoff and wetland storage in the Hamden and Lonetree watershed sites within the Red River of the North Basin, North Dakota and Minnesota

    USGS Publications Warehouse

    Vining, Kevin C.

    2004-01-01

    Re-establishment of wetlands has been promoted by various groups to control future floods in the Red River of the North Basin in North Dakota and Minnesota. Therefore, a study was conducted to simulate runoff and wetland storage in the Hamden and Lonetree watershed sites in the Red River of the North Basin. Data from geographic information system analyses, collected weather data, additional historic weather data, and geomorphology were used in a wetlands hydrologic model to simulate precipitation accumulation, snowmelt, evapotranspiration, soil infiltration, seepage to ground water, surface runoff, and streamflow. Simulated daily mean water volumes for the soil and wetlands in the Hamden and Lonetree watershed sites showed that the soils of the two sites stored as much water as the wetlands throughout most of the simulation period. Total simulated runoff for the Hamden watershed site for the period of record was reduced about 38 percent by increasing the Bisson Lake spillage threshold from 0.009 to 0.60. The additional simulated storage at the larger spillage threshold led to reductions in simulated runoff. Simulated daily mean streamflows for the Hamden watershed site at a Bisson Lake spillage threshold of 0.60 were less than those simulated for the same day at a Bisson Lake spillage threshold of 0.009. However, the peak streamflows simulated for June 2000 and April 2001 at a spillage threshold of 0.60 were about the same as those simulated at a spillage threshold of 0.009. Simulated runoff during flood conditions in April and June 2000 and March and April 2001 was reduced 1 to 6 percent for an increased spillage threshold. Total runoff for the period of record was reduced about 31 percent for the increased spillage threshold. Simulation results indicate total streamflow from a flood event may be reduced by wetland storage, but peak streamflows during a flood event may not be affected substantially.

  3. Late Jurassic to Early Cretaceous sedimentary-tectonic development in the Chengde Basin, Yanshan fold-thrust belt, North China Craton

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Zhao, Yue; Liu, Ankun; Ye, Hao

    2015-12-01

    The Chengde Basin is located in the central part of the Yanshan fold-thrust belt in the northern North China Craton. The sediments in the Upper Jurassic to Lower Cretaceous Tuchengzi Formation in the Chengde Basin provide a detrital record of basin dynamics and uplift of the basin margins during that time. We analyzed the sedimentary facies, paleocurrents, and provenance of the Tuchengzi Formation in the Chengde Basin for the period of the Late Jurassic and Early Cretaceous shortening in the Yanshan fold-thrust belt. Four sedimentary facies associations have been identified in the Tuchengzi Formation, corresponding to proximal fan, mid-fan, distal alluvial fan, and fluvial facies. The transport and distribution of the Upper Jurassic to Lower Cretaceous sediments in the Chengde Basin was controlled by the faults bounding the basin. Paleocurrent indicators and provenance data of conglomerate clasts reveal that the sediments of the Tuchengzi Formation in the northern part of the Chengde Basin were delivered from source regions to the north of the basin. The early sediments of the Tuchengzi Formation in the southern part of the basin comprise a suite of fluvial deposits, similar to the fluvial sediments in the northern part of the basin, and their paleocurrent data and the compositions of conglomerate clasts also suggest a northern source. However, the subsequent sedimentation in the Tuchengzi Formation in the southern part of the basin changed markedly to proximal fan facies, with sediments being derived from the south of the basin, according to the paleocurrent data and conglomerate clast lithology. The Sandaohe sheet, which is located in the southeast limb of the Chengde syncline, is not a klippe formed as a result of long-distance northward thrusting, but an autochthonous pop-up tectonic wedge generated by N-S shortening during the Early Cretaceous sedimentation of the Tuchengzi Formation. The sedimentation ended before the onset of the Early Cretaceous volcanic

  4. FISH COMMUNITIES AND HUMAN DISTURBANCE IN THE ALBEMARLE-PAMLICO BASIN OF NORTH CAROLINA AND VIRGINIA

    EPA Science Inventory

    Data on fish abundance, diversity, and habitat quality from the USGS and EPA were analyzed for patterns in the regional fish communities of the Albemarle-Pamlico drainage basin. The basin covers approximately 72,500 square kilometers and four physiographic provinces in Virginia ...

  5. Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina

    USGS Publications Warehouse

    Brown, C. Erwin

    1987-01-01

    Sixty-two Schlumberger electrical soundings were made in the Durham Triassic basin in an effort to determine basin structural geometry, depth of the sedimentary layers, and spatial distribution of individual rock facies. A digital computer program was used to invert the sounding curves of apparent resistivity versus distance to apparent resistivity versus depth. The apparent-resistivity-versus-depth data from the computer-modeling program were used to construct a geoelectric model of the basin that is believed to accurately represent the subsurface geology of the basin. The largest depth to basement in the basin along a resistivity profile (geoelectric section) was determined to be 1,800 m. A resistivity decrease was observed on certain soundings from depths of 100 to 1,000 m; below a 1,000-m depth, apparent resistivity increased to the bottom of the basin. Resistivity values for basement rocks were greater than 1,000 ohm-m and less than 350 ohm-m for the sedimentary layers in the basin. The data suggest that the basin contains a system of step faults near its eastern boundary. ?? 1987.

  6. Groundwater Quality in the North San Francisco Bay Groundwater Basins, CA

    NASA Astrophysics Data System (ADS)

    Kulongoski, J. T.; Belitz, K.

    2010-12-01

    Groundwater quality in the ~2,600 km2 North San Francisco Bay groundwater basins was investigated as part of the Priority Basin Project of the GAMA Program, a collaboration of the California State Water Resources Control Board, U.S. Geological Survey and Lawrence Livermore National Laboratory. Samples from 96 wells and 1 hydrothermal spring were analyzed for water chemistry, isotopic abundances, and dissolved gases. The study, designed to provide a spatially unbiased assessment of untreated groundwater quality in the primary aquifer systems, was based on water-quality and ancillary data from 84 of the wells sampled and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifers are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the CDPH database. Inorganic constituents with human-health benchmarks were present at high concentrations in 14%, moderate in 35.8%, and low in 50.2% of the primary aquifers. Arsenic, boron, and lead were the trace elements that most frequently occurred at high concentrations. Fluoride is a minor element, and nitrate, a nutrient were present at high concentrations in ~1% of the primary aquifers. In contrast, organic constituents (one or more) with human-health benchmarks were present at high concentrations in 1.4%, moderate in 4.9%, and low in 93.7% (not detected in 64.8%) of the primary aquifers. The high proportion of organic constituents primarily reflected high concentrations of PCE (1.3%), TCE (0.1%), and 1,1-dichloroethene (0.1%). Of the 255 organic constituents analyzed for, 26 constituents were detected. Two organic constituents were frequently detected (detected in 10% or more of samples): the trihalomethane chloroform and the herbicide simazine, but both were detected at low concentrations. In this study, arsenic is the constituent which most frequently exists at high concentrations (about 10%) in the primary aquifers. Natural sources

  7. Detailed geochemical study of the Dan River-Danville Triassic Basin, North Carolina and Virginia. National Uranium Resource Evaluation Program

    SciTech Connect

    Thayer, P. A.; Cook, J. R.

    1982-08-01

    This abbreviated data report presents results of surface geochemical reconnaissance in the Dan River-Danville Triassic Basin of north-central North Carolina and south-central Virginia. Unweathered rock samples were collected at 380 sites within the basin at a nominal sampling density of one site per square mile. Field measurements and observations are reported for each site; analytical data and field measurements are presented in tables and maps. A detailed four-channel spectrometric survey was conducted, and the results are presented as a series of symbol plot maps for eU, eTh, and eU/eTh. Data from rock sample sites (on microfiche in pocket) include rock type and color and elemental analyses for U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Na, Sc, Sm, Ti, V, and Yb. Elemental uranium in 362 sedimentary rock samples from the Dan River-Danville Basin ranges from a low of 0.1 to a maximum of 13.3 parts per million (ppM). The log mean uranium concentration for these same samples is 0.37 ppM, and the log standard deviation is 0.24 ppM. Elemental uranium in 10 diabase dike samples from within the basin is in the range 0.1 to 0.7 ppM. The log mean uranium concentration for diabase samples is -.65 ppM, and the log standard deviation is 0.27. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the NURE program.

  8. Floods of 1952 in the basins of the upper Mississippi River and Red River of the North

    USGS Publications Warehouse

    Wells, J.V.B.

    1955-01-01

    The flood of April 1952 on the Mississippi River between the Minnesota and Des Moines Rivers established many record-high stages. In the Minnesota River basin, the floods of April 1952 exceeded those of 1951 in many locations but generally were smaller than those of 1881. The timing of flows on the Mississippi and Minnesota Rivers was favorable for the highest possible peak flow at and downstream from St. Paul. Below the Wisconsin River, the 1951 and 1952 floods on the Mississippi River were of approximately equal size. The experiences gained in fighting the flood of 1951 proved valuable in preventing much flood damage in 1952. Because the floods generally moved slowly, few lives were lost, and there was ample time for construction of emergency levees. Many urban areas flooded in 1951 were not damaged by floods of equal or greater size in 1952. The total flood damage in the Mississippi River basin above Keokuk, Iowa, was estimated by the Corps of Engineers to be $19,376,000. Snow surveys made during mid-March did not show conclusively that major floods were to be expected. The snow surveys showed small areas of high water content at the headwaters of both the Mississippi and Minnesota Rivers and above-normal snow cover over most of the upper Mississippi River basin. Heavy snowfall occurred over most of Minnesota, especially in the southern part, on March 22-23, 1952. Cold weather delayed the breakup until a period when more rapid melt was probable. These factors definitely set the stage for the floods. A rapid rise in temperature at the end of March and early April started the melting of the snow. Because the topsoil had been frozen when wet during the preceding fall, very little of the snowmelt was absorbed by the ground. Runoff in southeastern Minnesota occurred earliest and with greatest rapidity; the Root River crested at Rushford on March 31. Runoff in the Minnesota River basin occurred later and at a slower rate. Floods on the Red River of the North and its

  9. Reconstruction of Cenozoic growth process in North Tibet: Source to sink relation between the Qaidam Basin and East Kunlun Mountains

    NASA Astrophysics Data System (ADS)

    Cheng, Feng; Jolivet, Marc; Guo, Zhaojie

    2015-04-01

    Understanding the source to sink relation through time between the East Kunlun Mountains that form the northern boundary of the Tibetan plateau and the actively deforming Qaidam Basin to the north has important implications for unravelling the growth history of the entire plateau. In this study, LA-ICP-MS U-Pb dating of detrital zircons from 22 sandstone samples (Palaeocene to Holocene) collected from 4 sections within the southwestern Qaidam Basin are combined with sediment petrology analysis and seismic profile interpretation to investigate the tectonic and topographic growth of the East Kunlun Mountains and its effects on the evolution of the Qaidam Basin. The occurrence of carbonate debris containing foraminifera fossils in the Palaeocene conglomerate sequences as well as a wide population of Palaeozoic to late Proterozoic grains in the age spectra of detrital grains from Palaeocene strata suggest the East Kunlun Mountains were already exhumed before the deposition of the Palaeocene Lulehe Formation. The topographic evolution of the southern edge of the Qaidam Basin can be separated in three phases: exhumation in the East Kunlun Mountains initiated during or possibly before the deposition of the Paleocene Lulehe Fm.. Erosion only affected the remaining Mesozoic cover and the Paleozoic basement without eroding the Mesozoic granitoids and the Precambrian basement. The southwestern Qaidam Basin was already separated from the Hoh Xil Basin to the south. During the middle Eocene to Oligocene, the Qaidam Basin widened towards the south and east. However the widening of the basin, uplift and erosion in the East Kunlun Mountains were still active and probably increased leading to the exhumation of the Mesozoic granitoids. This increase in exhumation is consistent with already published thermochronology data in the East Kunlun Mountains and sedimentology data in both the Qaidam and Hoh Xil basins. The occurrence of numerous early Proterozoic and Archean ages suggests

  10. Hydrocarbon seep-carbonates of a Miocene forearc (East Coast Basin), North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Campbell, Kathleen A.; Francis, David A.; Collins, Mike; Gregory, Murray R.; Nelson, Campbell S.; Greinert, Jens; Aharon, Paul

    2008-02-01

    An ancient hydrocarbon seep province of 14 isolated, authigenic carbonate deposits has been identified in fine-grained, deep-marine siliciclastic strata of the Miocene East Coast Basin, North Island, New Zealand. These forearc sediments have been uplifted and complexly deformed into accretionary ridges, adjacent to the still-active Hikurangi convergent margin. Older active and passive margin strata (mid-Cretaceous to Oligocene in age) underlie the Neogene sequence, and contain oil- and gas-prone source rocks. Older Mesozoic meta-sedimentary rocks constitute the backstop against which the current phase of subduction-related sedimentation has accumulated (~ 24 Ma-present). The seep-carbonates (up to 10 m thick, 200 m across) archive methane signatures in their depleted carbon isotopes (to δ13C -51.7‰ PDB), and contain chemosynthesis-based paleocommunities (e.g. worm tubes, bathymodioline mussels, and vesicomyid, lucinid and thyasirid bivalves) typical of other Cenozoic and modern seeps. Northern and southern sites are geographically separated, and exhibit distinct lithological and faunal differences. Structural settings are variable. Seep-associated lithologies also are varied, and suggest carbonate development in sub-seafloor, seafloor and physically reworked (diapiric expansion, gas explosion, gravity slide or debris flow) settings, similar to Italian Apennine seep deposits of overlapping ages. Peculiar attributes of the New Zealand Miocene seep deposits are several, including digitate thrombolites of clotted microbial micrite encased in thick, isopachous horizons and botryoids of aragonite. Seep plumbing features are also well-exposed at some sites, displaying probable gas-explosion breccias filled with aragonite, tubular concretions (fluid conduits), and carbonate-cemented, thin sandstone beds and burrows within otherwise impermeable mudstones. A few seeps were large enough to develop talus-debris piles on their flanks, which were populated by lucinid bivalves

  11. Phylogeography of the dark kangaroo mouse, Microdipodops megacephalus: cryptic lineages and dispersal routes in North America's Great Basin.

    PubMed

    Hafner, John C; Upham, Nathan S

    2011-06-01

    AIM: The rodent genus Microdipodops (kangaroo mice) includes two sand-obligate endemics of the Great Basin Desert: M. megacephalus and M. pallidus. The dark kangaroo mouse, M. megacephalus, is distributed throughout the Great Basin and our principal aims were to formulate phylogenetic hypotheses for this taxon and make phylogeographical comparisons with its congener. LOCATION: The Great Basin Desert of western North America. METHODS: DNA sequence data from three mitochondrial genes were examined from 186 individuals of M. megacephalus, representing 47 general localities. Phylogenetic inference was used to analyse the sequence data. Directional analysis of phylogeographical patterns was used to examine haplotype sharing patterns and recover routes of gene exchange. Haplotype-area curves were constructed to evaluate the relationship between genetic variation and distributional island size for M. megacephalus and M. pallidus. RESULTS: Microdipodops megacephalus is a rare desert rodent (trapping success was 2.67%). Temporal comparison of trapping data shows that kangaroo mice are becoming less abundant in the study area. The distribution has changed slightly since the 1930s but many northern populations now appear to be small, fragmented, or locally extinct. Four principal phylogroups (the Idaho isolate and the western, central and eastern clades) are evident; mean sequence divergence between phylogroups for cytochrome b is c. 8%. Data from haplotype sharing show two trends: a north-south trend and a web-shaped trend. Analyses of haplotype-area curves reveal significant positive relationships. MAIN CONCLUSIONS: The four phylogroups of M. megacephalus appear to represent morphologically cryptic species; in comparison, a companion study revealed two cryptic lineages in M. pallidus. Estimated divergence times of the principal clades of M. megacephalus (c. 2-4 Ma) indicate that these kangaroo mice were Pleistocene invaders into the Great Basin coincident with the formation

  12. Phylogeography of the dark kangaroo mouse, Microdipodops megacephalus: cryptic lineages and dispersal routes in North America's Great Basin.

    PubMed

    Hafner, John C; Upham, Nathan S

    2011-06-01

    AIM: The rodent genus Microdipodops (kangaroo mice) includes two sand-obligate endemics of the Great Basin Desert: M. megacephalus and M. pallidus. The dark kangaroo mouse, M. megacephalus, is distributed throughout the Great Basin and our principal aims were to formulate phylogenetic hypotheses for this taxon and make phylogeographical comparisons with its congener. LOCATION: The Great Basin Desert of western North America. METHODS: DNA sequence data from three mitochondrial genes were examined from 186 individuals of M. megacephalus, representing 47 general localities. Phylogenetic inference was used to analyse the sequence data. Directional analysis of phylogeographical patterns was used to examine haplotype sharing patterns and recover routes of gene exchange. Haplotype-area curves were constructed to evaluate the relationship between genetic variation and distributional island size for M. megacephalus and M. pallidus. RESULTS: Microdipodops megacephalus is a rare desert rodent (trapping success was 2.67%). Temporal comparison of trapping data shows that kangaroo mice are becoming less abundant in the study area. The distribution has changed slightly since the 1930s but many northern populations now appear to be small, fragmented, or locally extinct. Four principal phylogroups (the Idaho isolate and the western, central and eastern clades) are evident; mean sequence divergence between phylogroups for cytochrome b is c. 8%. Data from haplotype sharing show two trends: a north-south trend and a web-shaped trend. Analyses of haplotype-area curves reveal significant positive relationships. MAIN CONCLUSIONS: The four phylogroups of M. megacephalus appear to represent morphologically cryptic species; in comparison, a companion study revealed two cryptic lineages in M. pallidus. Estimated divergence times of the principal clades of M. megacephalus (c. 2-4 Ma) indicate that these kangaroo mice were Pleistocene invaders into the Great Basin coincident with the formation

  13. Glacier changes in the Ravi basin, North-Western Himalaya (India) during the last four decades (1971-2010/13)

    NASA Astrophysics Data System (ADS)

    Chand, Pritam; Sharma, Milap Chand

    2015-12-01

    A glacier inventory of the Ravi basin, north-western Himalaya has been generated for the year 2002 using Landsat ETM + and ASTER Global DEM (GDEM V2) as the baseline data for the change analysis. The Ravi basin consists of 285 glaciers (> 0.02 km2) covering an area of 164.5 ± 7.5 km2, including 71 debris-covered glaciers with an area of 36.1 ± 2.1 km2 (22% of total glacierized area) in 2002. Change analysis based on Corona KH-4B (1971), Worldview (2010) and Landsat 8 OLI/TRIS (2013) images was restricted to a subset of 157 glaciers (covering an area of 121.4 ± 5.4 km2 in 2002) due to cloud cover. Glacier area decreased from 125.8 ± 1.9 km2 (1971) to 119.9 ± 4.8 km2 (2010/13), a loss of 4.7 ± 4.1% or 0.1 ± 0.1% a- 1. The glacier recession rate has decreased, to a minimum for the recent decades (2002-2010/13). The debris-covered glacier area increased by 19.2 ± 2.2% (0.5 ± 0.05% a- 1) in the Ravi basin. However, there were significant variation in its sub-basins i.e. in Budhil and Upper Ravi sub-basin, where the debris-covered area increased by 28.6 ± 3.1% (0.7 ± 0.1% a- 1) and 14 ± 1.6% (0.3 ± 0.04% a- 1), respectively, between 1971 and 2010/13. Field investigation of selected glaciers (2010-2014) supports glacier recession trend from remote sensing data. Glacier retreat rates in the Ravi basin were lower than previously reported for selected glaciers in the similar basin and other basins (e.g. Chenab, Beas, Parbati, Baspa and Tirungkhad) of the Himachal Himalaya.

  14. Low-flow characteristics and profiles for the Deep River in the Cape Fear River basin, North Carolina

    USGS Publications Warehouse

    Weaver, J.C.

    1997-01-01

    An understanding of the magnitude and frequency of low-flow discharges is an important part of protecting surface-water resources and planning for municipal and industrial economic expansion. Low-flow characteristics are summarized for 7 continuous-record gaging stations and 23 partial-record measuring sites in the Deep River Basin in North Carolina. Records of discharge collected through the 1995 water year are used. Flow characteristics included in the summary are (1) average annual unit flow; (2) 7Q10 low-flow discharge, the minimum average discharge for a 7-consecutive-day period occurring, on average, once in 10 years; (3) 30Q2 low-flow discharge; (4) W7Q10 low-flow discharge, similar to 7Q10 discharge except only flow during the months of November through March is considered; and (5) 7Q2 low-flow discharge. The potential for sustained base flows in the upper half of the basin is higher than that for streams in the lower half of the basin. Much of the decrease in base-flow potential in the lower part of the basin is attributed to the underlying rock types of the Triassic basin. Soils in the lower part of the basin consist of clays which limit the infiltration of water into surficial aquifers for later release to streams during drought conditions. Correspondingly, many streams in the lower part of the basin have minimal (defined as less than 0.1 cubic foot per second) or zero 7Q10 discharges. Drainage area and low-flow discharge profiles are presented for the Deep River. The drainage-area profile shows downstream increases in basin size. At the mouth, the drainage area for the Deep River is 1,441 square miles. Low-flow discharge profiles for the Deep River include 7Q10, 30Q2, W7Q10, and 7Q2 discharges in a continuous profile with contributions from major tributaries included.

  15. Living on the edge: The oxygen isotope record of Eocene Basins at the margin of the Cenozoic North American plateau

    NASA Astrophysics Data System (ADS)

    Methner, Katharina; Mulch, Andreas; Chamberlain, Page

    2013-04-01

    Topography has a strong impact on atmospheric circulation and precipitation patterns and is a key element in reconstructing the dynamics of mountain building processes. The topographic evolution of the world's major orogens remains one of the most important questions when discussing the interactions among tectonics, climate, and Earth surface processes. Here, we focus on the spatial and temporal development of topography and relief in the western North American Cordillera and how changes in the topography may have affected precipitation patterns and vice versa. In this context, we sampled more than 20 sections in Eocene to Oligocene terrestrial (intermontane?) basins (Chumstick, Swauk, and Chuckanut) in western and central Washington (USA) to the W and E of the modern Cascades. Oxygen isotope analysis of pedogenic carbonate in these sections allows us to reconstruct the isotopic composition of ancient soilwater or groundwater, and ultimately precipitation. Oxygen isotope measurements of pedogenic concretions and calcic horizons interestingly yield uniformly low δ18O values of 10 to 13‰ SMOW despite the proximity of all sections to the Pacific moisture source. These extremely low oxygen isotope values can result from (1) highly 18O-depleted meteoric waters (soil- or groundwater), (2) burial diagenesis at moderate temperatures and interaction with 18O-depleted (ground)water, and (3) high burial temperatures and and exchange with basins brines. Vitrinite reflectance data and preservation of primary soil structures such as rootlets, root casts, burrows, or even preserved wood fragments clearly show that some of the low-d18O sections were not affected by high degrees of burial diagenesis. Thus, we believe that the primary isotopic signal of ancient soil- or groundwater is preserved at least in parts (if not in all) of these basins. Low δ18O values of pedogenic carbonate require highly 18O-depleted meteoric water, which in turn, would require high elevation either at

  16. Nutrient Loads and Ground-Water Residence Times in an Agricultural Basin in North-Central Connecticut

    USGS Publications Warehouse

    Mullaney, John R.

    2007-01-01

    Nutrient loads from ground-water discharge were studied in Broad Brook Basin, a 15.8-square mile basin in north-central Connecticut, dominated by agricultural activity. Loads were calculated, along with the travel times of ground water from recharge to discharge areas, to estimate the time required for the effects of Best Management Practices (BMPs) to be observed. Most concentrations of nitrogen and phosphorus in Broad Brook exceeded U.S. Environmental Protection Agency Ecoregion XIV nutrient criteria for streams. During the study period (1993-2004), annual loads of nitrogen from Broad Brook Basin ranged from 117,000 to 270,000 pounds (lb), and yields were about 10 times larger than those from forested basins in Connecticut. Ground-water discharge from the aquifer to the streams (base flow) during the study period was estimated with hydrograph separation and accounted for 82 percent of the total runoff from the basin. Nitrate nitrogen in base flow averaged 71 percent of the annual load of total nitrogen discharged from the basin, indicating that the largest source of nitrogen was likely from ground-water discharge. Annual loads of total phosphorus from the basin ranged from 2,330 to 14,400 lb, and yields were about five times higher than those from forested basins in Connecticut. Dissolved phosphorus averaged about 71 percent of the total phosphorus load, and ground-water discharge accounted for only as much as 40 percent of the annual load of dissolved phosphorus; therefore, phosphorus loads are dominated by stormwater-runoff events. Ground-water samples collected from 11 wells in the basin contained elevated concentrations of nitrite plus nitrate nitrogen. Dissolved gas analyses indicated that little denitrification was occurring in the aquifer. Apparent ages of the ground-water samples ranged from greater than 2 to more than 50 years based on sulfur hexafluoride, tritium, and tritium/helium-3 analyses. A three-dimensional ground-water-flow model was used in

  17. Evolution of Meso-Cenozoic lithospheric thermal-rheological structure in the Jiyang sub-basin, Bohai Bay Basin, eastern North China Craton

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Qiu, Nansheng; Wang, Ye; Chang, Jian

    2016-07-01

    The Meso-Cenozoic lithospheric thermal-rheological structure and lithospheric strength evolution of the Jiyang sub-basin were modeled using thermal history, crustal structure, and rheological parameter data. Results indicate that the thermal-rheological structure of the Jiyang sub-basin has exhibited obvious rheological stratification and changes over time. During the Early Mesozoic, the uppermost portion of the upper crust, middle crust, and the top part of the upper mantle had a thick brittle layer. During the early Early Cretaceous, the top of the middle crust's brittle layer thinned because of lithosphere thinning and temperature increase, and the uppermost portion of the upper mantle was almost occupied by a ductile layer. During the late Early Cretaceous, the brittle layer of the middle crust and the upper mantle changed to a ductile one. Then, the uppermost portion of the middle crust changed to a thin brittle layer in the late Cretaceous. During the early Paleogene, the thin brittle layer of the middle crust became even thinner and shallower under the condition of crustal extension. Currently, with the decrease in lithospheric temperature, the top of the upper crust, middle crust, and the uppermost portion of the upper mantle are of a brittle layer. The total lithospheric strength and the effective elastic thickness (T e) in Meso-Cenozoic indicate that the Jiyang sub-basin experienced two weakened stages: during the late Early Cretaceous and the early Paleogene. The total lithospheric strength (approximately 4-5 × 1013 N m-1) and T e (approximately 50-60 km) during the Early Mesozoic was larger than that after the Late Jurassic (2-7 × 1012 N m-1 and 19-39 km, respectively). The results also reflect the subduction, and rollback of Pacific plate is the geodynamic mechanism of the destruction of the eastern North China Craton.

  18. Solutions for North American Water Security Challenge: Colorado and Bravo transboundary basins cases

    NASA Astrophysics Data System (ADS)

    López Pérez, M.

    2013-12-01

    The transboundary basins of Colorado (Baja California) and Rio Bravo (Grande) have low water availability figures and water will be appreciated as a highly valued good. In the Rio Grande basin, the strategies and actions have been developed with the River Basin Council: a new surface water management, new water allocation rules for different rainfall and runoff scenarios (climate change included), new sources of water and establishment of water reserves for human consumption and for environmental purposes. In the Colorado River, with an integrated watershed management vision, Mexican and US federal, state and non-governmental organizations representatives signed Minute 319 for 5 years without changing the 1944 Water Treaty. Concepts and rules for surplus, shortage, Intentionally Created Mexican Water (ICMA), salinity, water for the environment and international projects were included and are been implemented. Parallel drinking water and sanitation services in both sides of the border through the Joint Investment Program, EPA-CONAGUA invested 979.2 million dollars from grants to improve the quality of the environment and the inhabitants. Accomplishments are high and the reduction in river health is a good indicator. The implementation of this binational cooperation actions under the framework of the 1944 Water Treaty are considered global solutions in the field of integrated water management in transboundary basins and for creating water security in highly pressured basins. Keywords: Colorado River, Rio Grande or Bravo River, water security, Transboundary basins, environmental water reserves

  19. Geology of the Williston basin, North Dakota, Montana, and South Dakota, with reference to subsurface disposal of radioactive wastes

    USGS Publications Warehouse

    Sandberg, C.A.

    1962-01-01

    The southern Williston basin, which underlies about 110,000 square miles #n North Dakota, South Dakota, and eastern Montana, is part of a large structural and sedimentary basin. Its surface is a flat to gently rolling plain, standing about 1,500 to 3,500 feet above sea level and locally studded by a few high buttes. The sedimentary sequence that fills the basin has a maximum thickness of about 16,700 feet and rests on Precambrian metamorphic rocks at depths of 500 to 13,900 feet below sea level. It contains rocks of every geologic system, from Cambrian to Quaternary. Rocks of Middle Cambrian through Middle Ordovician age are largely shale and sandstone, as much as 1,200 feet thick; rocks of Late Ordovician through Pennsylvanian age are largely limestone and dolomite, as much as 7,500 feet thick; and rocks of Permian through Tertiary age are predominantly shale and siltstone, as much as 8,000 feet thick. Pleistocene glacial drift mantles the northern and eastern parts of the area. Rocks of the Williston basin are gently folded and regional dips are 1? or less from the margins to the basin center. Dips on the flanks of the major anticlinal folds, the Nesson and cedar Creek anticlines and the Poplar and Bowdoin domes, generally are about 1? to 3? except on the steep west limb of the Cedar Creek anticline. The basin was shaped by Laramide orogeny during latest Cretaceous and early Tertiary time. Most of the present structural features, however, were initiated during the Precambrian and reactivated by several subsequent orogenies, of which the latest was the Laramide. The most important mineral resource of the area is oil, which is produced predominantly from the Paleozoic carbonate sequence and largely on three of the major anticlinal folds, and lignite, which is present near the surface in Paleocene rocks. The subsurface disposal of radioactive wastes at some places in the Williston basin appears to be geographically and geologically feasible. Many sites, at which

  20. Historic and naturalized monthly streamflow for selected sites in the Red River of the North Basin in North Dakota, Minnesota, and South Dakota, 1931-2001

    USGS Publications Warehouse

    Emerson, Douglas G.

    2005-01-01

    Historic monthly streamflow data were compiled and missing historic and naturalized monthly streamflow data were estimated to develop a database of updated streamflow data for January 1931 through December 2001 (the data-development period) for 35 sites in the Red River of the North Basin. Of the 35 sites, 4 had gaged historic monthly streamflow data for the entire data-development period, 10 had gaged historic monthly streamflow data for part of the data-development period, and 21 had no gaged historic monthly streamflow data. To develop the database, a modified drainage-area ratio method, a maintenance of variance extension type 1 method, and a water-balance method were used to estimate the missing historic monthly streamflow data. Naturalized streamflow for the 35 sites was estimated by eliminating the hydrologic effects of Orwell Dam, Reservation Dam, White Rock Dam, Baldhill Dam, surfacewater withdrawals, and return flows.

  1. Streamflow characteristics of streams in the Upper Red River of the North basin, North Dakota, Minnesota, and South Dakota

    USGS Publications Warehouse

    Wiche, G.J.; Williams-Sether, Tara

    1997-01-01

    Statistical summaries of streamflow data for all active and inactive gaging stations for the Red River Basin upstream of and including Halstad, Minnesota, are presented in this report. The summaries for each streamflow-gaging station include (1) manuscript (station description), (2) graph of the annual mean discharge for the period of record, (3) statistics of monthly and annual mean discharges, (4) graph of the annual flow duration, (5) monthly and annual flow duration, (6) probability of annual high discharges, (7) probability of annual low discharges, (8) probability of seasonal low discharges, (9) annual peak discharge and corresponding gage height for the period of record, and (10) monthly and annual mean discharges for the period of record.

  2. Structural style in a young flexure-induced oblique extensional system, north-western Bonaparte Basin, Australia

    NASA Astrophysics Data System (ADS)

    Saqab, Muhammad Mudasar; Bourget, Julien

    2015-08-01

    In the north-western Bonaparte Basin (North West Shelf of Australia) Neogene to Recent flexure-induced extension superimposed obliquely over the Mesozoic rift structures. Thus, the area offers a good opportunity to investigate the dynamics and architecture of oblique extension fault systems. Analysis of basin-scale 2D and 3D seismic data along the Vulcan sub-basin shows that Neogene deformation produced a new set of extensional, en échelon faults, at places accompanied by the reactivation of the Mesozoic faults. The pre-existing Mesozoic structures strongly control the distribution of the Neogene-Recent deformation, both at regional and local scales. Main controls on the Neogene-Recent fault style, density and segmentation/linkage include: (1) the orientation of the underlying Mesozoic structures, (2) the obliqueness of the younger extension relative to the rift-inherited faults, and (3) the proximity to the Timor Trough. Three types of vertical relationships have been observed between Mesozoic and Neogene-Recent faults. Hard linkages seems to develop when both fault systems trend parallel, therefore increasing risks for trap integrity. It is suggested that the orientation of maximum horizontal stress (SHmax) relative to the Mesozoic faults, forming hydrocarbon traps, is critical for their potential seal/leak behaviour. Stratigraphic growth across the faults indicates that main fault activity occurred during the Plio-Pleistocene, which corresponds to the timing of tectonic loading on Timor Island and the development of lithospheric flexure. Synchronism of normal faulting with flexural bending suggests that extensional deformation on the descending Australian margin accompanied the formation of the Timor Trough.

  3. Low-Flow Characteristics and Discharge Profiles for Selected Streams in the Cape Fear River Basin, North Carolina, Through 1998

    USGS Publications Warehouse

    Weaver, J.C.; Pope, B.F.

    2001-01-01

    An understanding of the magnitude and frequency of low-flow discharges is an important part of evaluating surface-water resources and planning for municipal and industrial economic expansion. Low-flow characteristics are summarized in this report for 67 continuous-record gaging stations and 121 partial-record measuring sites in the Cape Fear River Basin of North Carolina. Records of discharge collected through the 1998 water year were used in the analyses. Flow characteristics included in the summary are (1) average annual unit flow; (2) 7Q10 low-flow discharge, the minimum average discharge for a 7-consecutive-day period occurring, on average, once in 10 years; (3) 30Q2 low-flow discharge; (4) W7Q10 low-flow discharge, similar to 7Q10 discharge except that only flow during November through March is considered; and (5) 7Q2 low-flow discharge. Low-flow characteristics in the Cape Fear River Basin vary widely in response to changes in geology and soil types. The area of the basin with the lowest potentials for sustained base flows is underlain by the Triassic basin in parts of Durham, Wake, and Chatham Counties. Typically, these soils are derived from basalt and fine-grained sedimentary rocks that allow very little infiltration of water into the shallow aquifers for storage and later release to streams during periods of base flow. The area of the basin with the highest base flows is the Sand Hills region in parts of Moore, Harnett, Hoke, and Cumberland Counties. Streams in the Sand Hills have the highest unit low flows in the study area as well as in much of North Carolina. Well-drained sandy soils in combination with higher topographic relief relative to other areas in the Coastal Plain contribute to the occurrence of high potentials for sustained base flows. A number of sites in the upper part of the Cape Fear River Basin underlain by the Carolina Slate Belt and Triassic basin, as well many sites in lower areas of the Coastal Plain (particularly the Northeast Cape

  4. Changes in flow in the upper North Canadian river basin of western Oklahoma, pre-development to 2000

    USGS Publications Warehouse

    Wahl, K.L.

    2001-01-01

    Water levels have declined in the southern part of the High Plains aquifer of the central USA since the mid-1960s in response to extensive irrigation development. The North Canadian River originates in western Oklahoma, and most of the basin is underlain by the High Plains aquifer. Average river flow in the headwaters near Guymon, Oklahoma, has decreased from about 0.9 m3/s before 1970 to near zero at present. Canton Lake, on the North Canadian River near Seiling, about 250 km downstream from Guymon, is a source of water supply for Oklahoma City. Precipitation data and streamflow data for gages upstream from Canton Lake were divided into an "early" period ending in 1971 and a "recent" period that begins in 1978. The early period represents conditions before ground-water levels had declined appreciably in the High Plains aquifer, and the recent period reflects the current condition, including the effects of storage reservoirs. Tests for trend and comparisons of flows between the early and recent periods show that the total annual volume of flow and the magnitudes of instantaneous annual peak discharges measured at most locations in the North Canadian River basin have decreased. Precipitation records for the area, however, show no corresponding changes. The decreases in average annual flow, expressed as a percentage of the average flows for the early period, ranged from 91 percent near Guymon to 37 percent near Canton Lake. A major contributing factor in the decreased flows appears to be the large declines in water levels in the High Plains aquifer.

  5. Remote Sensing Observations of Snow and Soil Moisture for Snowmelt Flood Predictions in the Red River of the North Basin

    NASA Astrophysics Data System (ADS)

    Tuttle, S. E.; Jacobs, J. M.; Vuyovich, C.; Cho, E.; Restrepo, P. J.; Jia, X.; Cosh, M. H.; Deweese, M. M.; Connelly, B.; Buan, S.

    2015-12-01

    The northward-flowing Red River of the North Basin (RRB), located in eastern North Dakota and western Minnesota, is vulnerable to frequent floods due to its flat terrain and low permeability soil. A vast majority of floods in the basin occur during the snowmelt season, when the winter snowpack thaws and spring rains fall onto saturated soils. This causes the Red River to spill over shallow banks and across the floodplain. The region has sparse in situ observations of snow and soil moisture, making flood prediction in the RRB difficult. Remote sensing data can help to capture magnitude, timing, and spatial distribution of watershed scale snow, soil moisture, and snowmelt parameters in the RRB, which will allow for better characterization of the watershed's hydrologic state. This research examines snow water equivalent (SWE; from the AMSR-E, AMSR2, and SSM/I satellite instruments), soil moisture (from AMSR-E, SMOS, and SMAP), and snow covered area (SCA; from MODIS), along with modeled SWE and snow depth from NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) SNOw Data Assimilation System (SNODAS). These data are compared with observations from local and federal snow surveys, NOHRSC Airborne Gamma Radiation Snow Survey Program flights, NOAA National Climate Data Center (NCDC) cooperative network sites, Natural Resource Conservation Service (NRCS) Soil Climate Analysis Network (SCAN) sites, and the North Central River Forecast Center's (NCRFC) model states, in order to determine data quality as well as strengths and weaknesses of satellite observations for RRB flood forecasting. Future analyses will include evaluation of freeze/thaw state information from the Soil Moisture Active-Passive (SMAP) satellite, and explore the potential for flood forecasting improvement by updating state variables of the NOAA National Weather Service (NWS) operational forecasting models with remotely sensed fields.

  6. Aminostratigraphy of Middle and Late Pleistocene deposits in The Netherlands and the southern part of the North Sea Basin

    NASA Astrophysics Data System (ADS)

    Meijer, T.; Cleveringa, P.

    2009-09-01

    A review of all available amino acid racemization D (alloisoleucine)/L (isoleucine) data from the whole shell of four molluscan species from Late and late Middle Pleistocene deposits of the Netherlands is presented. The data allow the distinction of 5 aminostratigraphical units, NAZ (Netherlands Amino Zone) A-E, each representing a temperate stage. The zones are correlated with marine isotope stages 1, 5e, 7, 9, and 11 respectively. Apart from NAZ-D (MIS 9), in all aminozones the marine transgression reached the present-day onshore area of the Netherlands. The transgression during NAZ-C (Oostermeer Interglacial: MIS 7) seems to be at least as widespread as its counterpart during NAZ-B (Eemian: MIS 5e) in the southern bight of the North Sea Basin. The stratigraphic position of the Oostermeer Interglacial is just below deposits of the Drente phase of the Saalian and because of this position the interglacial marine deposits have formerly erroneously considered to be of Holsteinian age. Neede, the 'classic' Dutch Holsteinian site, is dated in NAZ-E (MIS 11), like Noordbergum. Although the validity of these zones has been checked with independent data, some overlap between succeeding zones may occur. The relation between amino acid data from elsewhere in the North Sea Basin and the Netherlands amino zonation is discussed. The deposits at the Holsteinian stratotype Hummelsbüttel in North West Germany are dated in NAZ-D. This interglacial correlates with MIS 9. The Belvédère Interglacial, which is of importance for its archaeology, is in NAZ-D (MIS 9) and therefore of Holsteinian age as well. The lacustroglacial 'pottery clays' in the Noordbergum area are deposits from two glacial stages, which can be correlated with MIS 8 and 10 (the Elsterian). The pottery clay that is considered equivalent to the German 'Lauenburger Ton' correlates with MIS 10.

  7. An experimental peri-urban basin in North-western France

    NASA Astrophysics Data System (ADS)

    Chancibault, K.; Rodriguez, F.; Mosini, M.-L.; Furusho, C.; Bocher, E.; Palaccio, M.; Palma-Lopes, S.; Letellier, L.; Benot, R.; Andrieu, H.

    2009-04-01

    Basins located in the suburbs, known as peri-urban basins, face a quick land-use change, increasing pollution and flood risks. Being neither urban nor rural basins, they have been left apart by hydrologists. Improving hydrological models taking into account both natural and anthropogenic surfaces and pathways is the objective of the French project AVuPUR. One of the two peri-urban basins chosen for this project is the Chézine basin, located in northwestern France, in the suburbs of Nantes. The Chézine basin is subject to an oceanic climate and has a quite flat topography. Whereas the upstream part of the catchment remains essentially rural, the urbanization is dense in the downstream part and under development in the medium part. The mean urbanization over the basin is about 18%. A first part of the project consists of collecting geographical and hydrological data, followed by a first hydrological data analysis. Then different spatial segmentation methods are tested based on a geomorphological analysis and ultimately hydrological models well adapted for these particular basins will be developed. Nantes Metropole supplies geographical data as roads, buildings, land-use, sewer networks, Digital Elevation Model, etc. They also have monitored Chézine basin since 2001, with a water level recorder and a rain gauge. The outlet, at the water level recorder, defines a 29 km² basin with a 15km long river. During summer 2008, additional recorders were installed, in the medium part of the basin, at the outlet of the rural subcatchment : a rain gauge and a flow meter. This will help to analyse the hydrological behaviour of the catchment, by characterizing the rainfall spatial variability over the basin and by pointing out the rural surface contribution. In autumn 2008, a geophysical experimental study was carried out, using different geophysical methods: ground penetrating radar, DC-electrical resistivity tomography and EM31 electromagnetic profiling method. The aim of this

  8. Landscape Based Modeling of Nonpoint Source Nitrogen Loading in the Neuse River Basin, North Carolina

    SciTech Connect

    Garten, C.T.

    2001-01-11

    The objective of this research was to arrive at a quantitative and qualitative assessment of nonpoint sources of potential excess N under different land use/land cover (LULC) categories in the Neuse River Basin on a seasonal time scale. This assessment is being supplied to EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, for inclusion in a hydrologic model to predict seasonal fluxes of N from the terrestrial landscape to surface receiving waters and groundwater in the Neuse River Basin. The analysis was performed in the following five steps: (1) development of a conceptual model to predict potential excess N on land, (2) a literature review to parameterize N fluxes under LULC categories found in the Neuse River Basin, (3) acquisition of high resolution (15-m pixel) LULC data from EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, (4) acquisition of a soil N inventory map for the Neuse River Basin, (5) calculations of potential excess N on a seasonal basis for the entire Neuse River Basin.

  9. Flood of April 1989 in the Wahpeton-Breckenridge and Fargo-Moorhead areas, Red River of the North Basin, North Dakota and Minnesota

    USGS Publications Warehouse

    Ryan, Gerald L.; Harkness, R.E.

    1994-01-01

    The most severe flooding during the April 1989 flood in the Red River of the North Basin in North Dakota and Minnesota occurred in the Wahpeton-Breckenridge area. Flood stage on April 5, 1989, was the highest stage that has been reported in almost 100 years. The 1989 peak flow was not as large as that of the 1969 flood, which had the largest peak flow since the Wahpeton gage was installed in 1942. The 1989 peak stage, however, was more than 1 foot higher than during the 1969 flood because of backwater from ice. Cooler weather subsequent to the peak at Wahpeton slowed the snowmelt and allowed the peak to attenuate as it moved downstream; thus, the severity of flooding in the Fargo-Moorhead area and in areas farther downstream was reduced. Advance flood warning allowed communities downstream from the Wahpeton-Breckenridge area to prepare for the flood and was instrumental in reducing flood damage. Aerial photographs were used to delineate the extent of the April 1989 flood in the Wahpeton-Breckenridge and the Fargo-Moorhead areas on topographic maps. The aerial photographs of the Wahpeton-Breckenridge area were taken during the flood peak on April 5 and those of the Fargo-Moorhead area were taken during the flood peak on April 9.

  10. Analysis of trends in streamflow and its linkages with rainfall and anthropogenic factors in Gomti River basin of North India

    NASA Astrophysics Data System (ADS)

    Abeysingha, N. S.; Singh, Man; Sehgal, V. K.; Khanna, Manoj; Pathak, Himanshu

    2016-02-01

    Trend analysis of hydro-climatic variables such as streamflow, rainfall, and temperature provides useful information for effective water resources planning, designing, and management. Trends in observed streamflow at four gauging stations in the Gomti River basin of North India were assessed using the Mann-Kendall and Sen's slope for the 1982 to 2012 period. The relationships between trends in streamflow and rainfall were studied by correlation analyses. There was a gradual decreasing trend of annual, monsoonal, and winter seasonal streamflow ( p < 0.05) from the midstream to the downstream of the river and also a decreasing trend of annual streamflow for the 5-year moving averaged standardized anomalies of streamflow for the entire basin. The declining trend in the streamflow was attributed partly to the increased water withdrawal, to increased air temperature, to higher population, and partly to significant reducing trend of post monsoon rainfall especially at downstream. Upstream gauging station showed a significant increasing trend of streamflow (1.6 m3/s/year) at annual scale, and this trend was attributed to the significant increasing trend of catchment rainfall (9.54 mm/year). It was further evident in the significant coefficient of positive correlation ( ρ = 0.8) between streamflow and catchment rainfall. The decreasing trend in streamflow and post-monsoon rainfall especially towards downstream area with concurrent increasing trend of temperature indicates a drying tendency of the Gomti River basin over the study period. The results of this study may help stakeholders to design streamflow restoration strategies for sustainable water management planning of the Gomti River basin.

  11. Vitrinite reflectance data for Cretaceous marine shales and coals in the Bighorn Basin, north-central Wyoming and south-central Montana

    USGS Publications Warehouse

    Pawlewicz, Mark J.; Finn, Thomas M.

    2012-01-01

    The Bighorn Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 10,400 square miles in north-central Wyoming and south-central Montana. The purpose of this report is to present new vitrinite reflectance data collected from Cretaceous marine shales and coals in the Bighorn Basin to better characterize the thermal maturity and petroleum potential of these rocks. Ninety-eight samples from Lower Cretaceous and lowermost Upper Cretaceous strata were collected from well cuttings from wells stored at the U.S. Geological Survey (USGS) Core Research Center in Lakewood, Colorado.

  12. Preliminary study of the uranium potential of the northern part of the Durham Triassic Basin, North Carolina

    SciTech Connect

    Harris, W.B.; Thayer, P.A.

    1981-09-01

    This report presents results of a four-channel spectrometric survey of the northern part of the Durham Triassic basin and adjacent Piedmont, North Carolina. Gamma-ray spectrometric measurements were obtained at 112 localities from 136 different lithologies. The nominal sampling density in the Durham Basin is one site per 2 mi/sup 2/. Surface radiometric surveys reveal no anomalous radioactivity in the northern part of the Durham Basin. Uranium concentrations in Triassic rocks are from 0.6 to 9.7 ppM and average 2.9 ppM. Mudrocks contain from 1.3 to 9.7 ppM, and the average is 4.5 ppM. Sandstones contain from 0.6 to 8.8 ppM, and the average is 2.5 ppM. Fanglomerates contain the lowest concentrations of uranium, from 1.4 to 2.0 ppM, for an average of 1.8 ppM. Uranium/thorium ratios average 0.27 for Triassic rocks and are from 0.04 to 1.85. The mean log uranium/log thorium for Triassic rocks is 0.37. Mudrock has the highest average uranium/thorium ratio (0.32), and the range is 0.09 to 0.66. Sandstones have an average uranium/thorium ratio of 0.26, and the range is 0.04 to 1.85. Fanglomerates have the lowest range uranium/thorium ratio (0.19), and the range is 0.12 to 0.19. On the basis of surface radiometric surveys and geologic studies, it is believed that sedimentary strata in the northern part of the Durham Basin are poor targets for further uranium exploration. This conclusion is based on the lack of favorable characteristics commonly present in fluvial uranium deposits. Among these are: (1) carbonaceous material is absent in Triassic rocks of the northern basin, (2) indicators of a reduzate facies in sandstones are not present, and (3) no tuffaceous beds are associated with sediments in the northern Durham Basin.

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

    USGS Publications Warehouse

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

    1999-01-01

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

  14. Dissolved Organic Carbon Distribution, Export and Subsequent Remineralization in the Mesopelagic and Bathypelagic Realms of the North Atlantic Basin

    NASA Astrophysics Data System (ADS)

    Carlson, C. A.; Hansell, D. A.; Nelson, N. B.; Siegel, D. A.; Smethie, W. M.; Khatiwala, S.

    2010-12-01

    Dissolved organic carbon (DOC) was measured for three meridional transects in the North Atlantic as part of the US CLIVAR Repeat Hydrography program in 2003.The hydrographic sections covered a latitudinal range of 6°S to 63° N along longitudes 20°W (CLIVAR line A16), 52°W (A20) and 66°W (A22). Over 3700 individual measurements reveal unprecedented detail in the DOC distribution and systematic variations in the mesopelagic and bathypelagic zones of the North Atlantic basin. Latitudinal gradients in DOC concentrations combined with published estimates of ventilation rates for the main thermocline and North Atlantic Deep Water (NADW) indicate a net DOC export rate of 0.081 Pg C yr-1 from of the epipelagic zone into the mesopelagic and bathypelagic zones. Model II regression and multiple linear regression models applied to pairwise measures of DOC and chlorofluorocarbon (CFC-12) ventilation age, retrieved from major water masses within the main thermocline and NADW, indicate decay rates for exported DOC ranging from 0.13 to 0.94 µmol kg-1 yr-1, with higher DOC concentrations driving higher rates. The contribution of DOC oxidation to oxygen consumption ranged from 5 to 29% while mineralization of sinking biogenic particles drove the balance of the apparent oxygen utilization.

  15. Dissolved organic carbon export and subsequent remineralization in the mesopelagic and bathypelagic realms of the North Atlantic basin

    NASA Astrophysics Data System (ADS)

    Carlson, Craig A.; Hansell, Dennis A.; Nelson, Norman B.; Siegel, David A.; Smethie, William M.; Khatiwala, Samar; Meyers, Meredith M.; Halewood, Elisa

    2010-08-01

    Dissolved organic carbon (DOC) data are presented from three meridional transects conducted in the North Atlantic as part of the US Climate Variability (CLIVAR) Repeat Hydrography program in 2003. The hydrographic sections covered a latitudinal range of 6°S to 63°N along longitudes 20°W (CLIVAR line A16), 52°W (A20) and 66°W (A22). Over 3700 individual measurements reveal unprecedented detail in the DOC distribution and systematic variations in the mesopelagic and bathypelagic zones of the North Atlantic basin. Latitudinal gradients in DOC concentrations combined with published estimates of ventilation rates for the main thermocline and North Atlantic Deep Water (NADW) indicate a net DOC export rate of 0.081 Pg C yr -1 from the epipelagic zone into the mesopelagic and bathypelagic zones. Model II regression and multiple linear regression models applied to pairwise measures of DOC and chlorofluorocarbon (CFC-12) ventilation age, retrieved from major water masses within the main thermocline and NADW, indicate decay rates for exported DOC ranging from 0.13 to 0.94 μmol kg -1 yr -1, with higher DOC concentrations driving higher rates. The contribution of DOC oxidation to oxygen consumption ranged from 5 to 29% while mineralization of sinking biogenic particles drove the balance of the apparent oxygen utilization.

  16. The Holocene palaeogeography and relative sea level for two tidal basins of the German North Sea coast

    NASA Astrophysics Data System (ADS)

    Bungenstock, Friederike; Wartenberg, Wolfram; Mauz, Barbara; Freund, Holger; Frechen, Manfred; Weerts, Henk J. T.; Berner, Heinrich

    2014-05-01

    The response of coasts to global sea-level rise is highly variable. Knowledge of driving coastal parameters alongside the regional sea-level history is therefore indispensable when the response to global sea-level rise is to be assessed. Here, we study the Holocene relative sea-level of the south coast of the North Sea which is controlled by a number of very local parameters, as well as by regional glacio-isostatic adjustments. It is therefore crucial to restrict the data acquisition and evaluation to small coastal sections, ideally to single tidal basins, to minimize the sources of uncertainties (Bungenstock & Weerts 2010, 2012). We present data from two tidal basins, Langeoog and Jade Bay. For Langeoog a database derived from 600 cores, 68 km of Boomer seismic data, 33 radiocarbon ages and 8 OSL dates is available. (Bungenstock & Schäfer 2009, Mauz & Bungenstock 2007). For the Jade bay, the database comprises sedimentary markers, pollen and macro remains derived from 68 cores. The sedentary chronology is based on 54 radiocarbon ages and pollen constraints (Wartenberg & Freund 2011, Wartenberg et al. 2013). For both tidal basins the sedimentological record was interpreted in terms of the local paleogeographical development since about 7000 cal BP and its influence on the local relative sea-level curve. While the trend of the relative sea level is similar for both tidal basins, it shows a different altitude. The timing of the main marine transgression within the Langeoog area takes place ~3000 cal. BP whereas the sedimentological record of the Jade Bay shows two prominent transgressions, one for ~5000 cal. BP and one for ~3000 cal. BP. The Langeoog palaeo-environment is continuously characterised by marine influence. Within the Jade Bay two different palaeo-environments could be identified, documenting that from the West to the centre the landscape development in the Jade Bay was drainage driven feeding the associated fen peat with minerogenic water but being

  17. Water quality of streams in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1970-2001

    USGS Publications Warehouse

    Tornes, Lan H.

    2005-01-01

    Data for the Red River of the North (Red River) Basin in Minnesota, North Dakota, and South Dakota were analyzed to determine whether the water quality of streams in the basin is adequate to meet future needs. For the Red River at Emerson, Manitoba, site, pH values, water temperatures, and dissolved-oxygen concentrations generally were within the criteria established for the protection of aquatic life. Dissolved-solids concentrations ranged from 245 to 1,100 milligrams per liter. Maximum sulfate and chloride concentrations were near, but did not exceed, the established secondary maximum contaminant level. The trace elements considered potentially harmful generally were at concentrations that were less than the established guidelines, standards, and criteria. The concentrations of lead that were detected may have occurred as a result of sample contamination. For the Red River upstream from Emerson, Manitoba, sites, pH and other field values rarely exceeded the criteria established for the protection of aquatic life. Many constituent concentrations for the Red River below Fargo, N. site exceeded water-quality guidelines, standards, and criteria. However, the trace-element exceedances could be natural or could be related to pollution or sample contamination. Many of the tributaries in the western part of the Red River Basin had median specific-conductance values that were greater than 1,000 microsiemens per centimeter. Sulfate concentrations occasionally exceeded the established drinking-water standard. Median arsenic concentrations were 6 micrograms per liter or less, and maximum concentrations rarely exceeded the 10-microgram-per-liter drinking-water standard that is scheduled to take effect in 2006. The small concentrations of lead, mercury, and selenium that occasionally were detected may have been a result of sample contamination or other factors. The tributaries in the eastern part of the Red River Basin had median specific-conductance values that were less than

  18. Integrated well log and 2-D seismic data interpretation to image the subsurface stratigraphy and structure in north-eastern Bornu (Chad) basin

    NASA Astrophysics Data System (ADS)

    Isyaku, Aminu A.; Rust, Derek; Teeuw, Richard; Whitworth, Malcolm

    2016-09-01

    Structural and stratigraphic mapping within the Bornu Basin in north east Nigeria was commonly carried out using traditional field geological methods. However, such traditional approaches remain inadequate in the semi-arid region characterised by topographically flat areas and lack of continuous bedrock outcrops that are mostly concealed beneath sand cover. Previous studies in the north-eastern part of the basin carried out using ditch cuttings from few wells and disconnected seismic data were largely inadequate and the resulting stratigraphic analyses were more often generalised. This paper presents an integrated structural and stratigraphic study of the basin using combined subsurface geophysical datasets. A Combined Log Pattern (CLP) method is a well log analysis, which utilises various well log data including gamma ray, resistivity, bulk density and sonic logs to identify lithology and stratigraphic boundaries of subsurface formations. This method is applied to constrain the subsurface stratigraphy of the north-eastern part of the Bornu Basin bordering the Lake Chad. In addition to qualitative combined well log analysis, the time-depth relationship of the sonic log and seismic data was quantitatively determined by tying a well with an intersecting seismic section to validate the stratigraphic facies horizons identified. Four well log facies and their environments of deposition were characterised from the combined well log analysis of the different log types. It is discovered that the Cretaceous basement structural features controlled the deposition of overlying formations in the basin. Without intact core data, the shallower wells were discovered to have bottomed over subsurface horst features while deeper wells penetrated into the basal facies contained mainly within the grabens. Main subsurface structural lineaments in the area include NW-SE, NE-SW and NNW-SSE trending faults, which mainly formed the horst and graben features. Some stratigraphic formations

  19. Nutrient mass balance for the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia, 1990

    USGS Publications Warehouse

    McMahon, G.; Woodside, M.D.

    1997-01-01

    A 1990 nitrogen and phosphorus mass balance calculated for eight National Stream Quality Accounting Network (NASQAN) basins in the Albemarle-Pamlico Drainage Basin indicated the importance of agricultural nonpoint sources of nitrogen and phosphorus and watershed nitrogen retention and processing capabilities. Basin total nitrogen and phosphorus input estimates were calculated for atmospheric deposition (which averaged 27 percent of total nitrogen inputs and 22 percent of total phosphorus inputs); crop fertilizer (27 and 25 percent); animal-waste (22 and 50 percent, respectively); point sources (3 percent each of total nitrogen and total phosphorus inputs); and biological nitrogen fixation (21 percent of total nitrogen inputs). Highest in-stream nitrogen and phosphorus loads were measured in predominantly agricultural drainage areas. Intermediate loads were observed in mixed agricultural/urban drainage areas; the lowest loads were measured in mixed agricultural/forested drainage areas. The difference between the sum of the nutrient input categories and the sum of the instream nutrient loads and crop-harvest nutrient removal was assigned to a residual category for the basin. The residual category averaged 51 percent of total nitrogen inputs and 54 percent of total phosphorus inputs.

  20. Pesticides detected in surface waters and fish of the Red River of the North drainage basin

    USGS Publications Warehouse

    Brigham, Mark E.

    1994-01-01

    Pesticide data have been collected in the Red River Basin by various Federal, State, and local agencies. Tornes and Brigham (1994) recently summarized many of these historical data. This paper summarizes selected data collected as part of the NAWQA program during 1992-93, and briefly compares these data to historical data and to pesticide usage.

  1. Magma genesis during early stages of lithospheric extension: Great Basin of western North America

    SciTech Connect

    Leeman, W.P.; Harry, D.L. . Dept. of Geology Geophysics)

    1993-04-01

    Models for extension-related magmatism based on decompression melting of asthenosphere mantle are in conflict with geological and geochemical observations in the Great Basin. First, assuming a dry'' peridotite source, a substantial lag time (ca. 20 Ma) between onset of extension and first manifestations of magmatism is predicted, whereas magmatism was syn-extensional over a large part of the eastern Great Basin. Second, a gradual increase in magmatic intensity with time is predicted, whereas the observed pattern is characterized by voluminous early volcanism and diminishing melt production with time. Third, the models predict initially deep magma production ([approximately] 80 km) followed by progressive shoaling of the magma production zone. In contrast, compositions of the magmas suggest significant involvement of shallower lithospheric sources (incl. crust) in the earliest magmas, and dominance of deeper asthenospheric sources only in the latest Cenozoic, particularly in the southern portion of the Great Basin -- i.e. a duality of mantle sources. The authors suggest that melting of mafic lithologies within lithospheric mantle is physically plausible and can account for many aspects of early extensional magmatism. Only after lithospheric stretching nears [approximately] 100% does asthenospheric mantle become a dominant source of Great Basin basaltic magmas. There is no need to invoke a plume heat source. This model is tested by comparing the thermo-mechanical behavior of extending lithosphere with phase equilibria results for mafic compositions.

  2. Brittle Deformation in the Ordos Basin in response to the Mesozoic destruction of the North China Craton

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Jiang, L.

    2012-12-01

    Craton is continental block that has been tectonically stable since at least Proterozoic. Some cratons, however, become unstable for some geodynamic reasons. The North China Craton (NCC) is an example. Structure geological, geochemical, and geophysical works have revealed that the NCC was destructed in Cretaceous and that lithosphere thickness beneath the eastern NCC were thinned by 120 km. The present study will focus on deformation of the western NCC, and to understand the effect of the Mesozoic destruction of the North China Craton (NCC). Structural partitioning of the Ordos Basin, which is located in the western NCC, from the eastern NCC occurred during the Mesozoic. Unlike the eastern NCC where many Cretaceous metamorphic core complexes developed, sedimentary cover of the NCC remains nearly horizontal and deformation is manifested by joint. We visited 216 sites of outcrops and got 1928 joints measurements, among which 270 from Jurassic sandstones, 1378 from the Upper Triassic sandstones, 124 from the Middle and Lower Triassic sandstones, and 156 from Paleozoic sandstones. In the interior of the Ordos Basin, joints developed quite well in the Triassic strata, while joints in the Jurassic stata developed weakly and no joint in the Cretaceous strata. The Mesozoic stratigraphic thickness are: 1000 meters for the Lower Triassic, the Middle Triassic sandstone with thickness of 800 meters, 3000 meters for the Upper Triassic, 4000 meters for the Jurassic, and 1100 meters for the Lower Cretaceous. The vertical difference in joint development might be related to the burying depth of the strata: the higher the strata, the smaller the lithostatic stress, and then the weaker the joint. Joints in all stratigraphic levels showed a similar strain direction with the sigma 1 (the maximum pressure stress) vertical and the sigma 3 (the minimum pressure stress) horizontal and running N-S. The unconformity below the Cretaceous further indicates that joints in Jurassic and Triassic

  3. Water Masses and Currents in Orphan Basin of the North Atlantic

    NASA Astrophysics Data System (ADS)

    Loder, J.; Yashayaev, I.; Geshelin, Y.

    2006-12-01

    Over the past three years (2004-2006), the Bedford Institute of Oceanography (BIO) has conducted three annual hydrographic surveys and current-meter mooring deployments in Orphan Basin. Located at the southern end of the Labrador Sea, this region is a large continental-margin basin where portions of subpolar outflows such as the Labrador Current, the Deep Western Boundary Current (DWBC) and Labrador Sea Water approach the topographic promontory of Flemish Cap before exiting the Subpolar Gyre. Hydrographic sections across Orphan Basin occupied in June 2004, May 2005 and May 2006 reveal significant basin-wide changes, which are largely in agreement with the changes in the corresponding layers of the central Labrador Sea. Both the intermediate (Labrador Sea Water) and deep (Northeast Atlantic Deep Water) waters of the basin became warmer and saltier over the past three years. In contrast, the bottom waters - representing the densest limb of the DWBC - became ~0.2°C colder and ~0.015 fresher between 2004 and 2005. This change is most likely associated with the passing of a fresh and cold event around the Labrador Sea, observed about a year earlier in May 2004 on the eastern side of the Labrador Sea, yielding an average DWBC speed of ~10cm/s. The 2006 survey mapped a strong cyclonic eddy in the central Orphan Basin with its radial geostrophic velocities reaching 0.6 m/sec between 500 and 1000 m. Another phenomenon seen in the 2006 temperature, salinity, density and dissolved oxygen profiles at a 2900 m deep station is a distinct near-bottom layer (~150 m thick) bound by an extraordinarily sharp transition to a layer above (with a density step of 0.03 over 10 m). This feature indicates complex dynamics in the basin, possibly associated with a change in vorticity when the flow passes the saddle-shaped topography at its northern boundary. The moored current measurements indicate the structure and magnitude of the major throughflows, as well as episodic temporal

  4. Hydrologic Sensitivities of Upper Indus Basin (North Pakistan) Rivers to Multi-Decadal Climatic Variability

    NASA Astrophysics Data System (ADS)

    Farhan, S. B.; Zhang, Y.; Ma, Y.; Haifeng, G.; Jilani, R.; Hashmi, D.; Rasul, G.

    2014-12-01

    Thermal inputs play a vital role in the management and seasonal distribution of stream-flows particularly in snow and glacier fed basins, therefore the signatures of the recent climate trends can also be observed in various hydrological variables in those basins. Upper Indus Basin (UIB) is located in the western part of Tibetan Plateau, and most of its flows are dependent on snow- and glacier-melt produced water, thus the analyses of historical stream-flows and climatic indicators in the snow-melt dominated rivers of UIB was carried out, which points towards an advance in the spring flow onset time over the past few decades. Trend results reveal that warm temperature spells in spring have occurred much earlier in recent years, which explains in part the trend in the timing of spring peak stream-flows owing to earlier occurrence of snow melt onset. The observed increase in spring stream-flows and decrease in summer stream-flows suggests a broad shift of snow-melt yield and spring peak flows. These trends are found to be strongest at lower elevations basins where winter temperatures are closer to the melting point, even modest variation in temperatures are capable to enforce large shifts in the basin hydrologic feedback. In addition, it appears that in recent years due to winter and spring warming, more of the precipitation is falling as rain rather than snow particularly in late winter and early spring seasons, consequently it is speculated that this shift in precipitation ratio (snow vs rain) and early warming spells might also affect local (basin-scale) Albedo via early recession and systematic decrease of snow cover area, which tends in lowering Albedo from an increased fraction of snow-free area, which instigate positive feedback on radiative balance that can perhaps causes local-scale heat redistribution, which collectively in turn augmented winter and early spring stream-flows in those basins. These observed hydro-climatological trends over UIB can have

  5. Water quality in the Yellowstone River Basin, Wyoming, Montana, and North Dakota, 1999-2001

    USGS Publications Warehouse

    Peterson, David A.; Bartos, Timothy T.; Clark, Melanie L.; Miller, Kirk A.; Porter, Stephen D.; Quinn, Thomas L.

    2004-01-01

    This report contains the major findings of a 1999?2001 assessment of water quality in the Yellowstone River Basin. It is one of a series of reports by the National Water-Quality Assessment (NAWQA) Program that present major findings in 51 major river basins and aquifer systems across the Nation. In these reports, water quality is discussed in terms of local, State, and regional issues. Conditions in a particular basin or aquifer system are compared to conditions found elsewhere and to selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms. This report is intended for individuals working with water-resource issues in Federal, State, or local agencies, universities, public interest groups, or in the private sector. The information will be useful in addressing a number of current issues, such as the effects of agricultural and urban land use on water quality, human health, drinking water, source-water protection, hypoxia and excessive growth of algae and plants, pesticide registration, and monitoring and sampling strategies. This report also is for individuals who wish to know more about the quality of streams and ground water in areas near where they live, and how that water quality compares to the quality of water in other areas across the Nation. The water-quality conditions in the Yellowstone River Basin summarized in this report are discussed in detail in other reports that can be accessed from http://wy.water.usgs.gov/YELL/index.htm. Detailed technical information, data and analyses, collection and analytical methodology, models, graphs, and maps that support the findings presented in this report, in addition to reports in this series from other basins, can be accessed from the national NAWQA Web site (http://water.usgs.gov/nawqa).

  6. Crustal structures of the Boreas Basin and the Knipovich Ridge, North Atlantic

    NASA Astrophysics Data System (ADS)

    Hermann, Tobias; Jokat, Wilfried

    2013-06-01

    The Boreas Basin is located in the Norwegian-Greenland Sea between Northeast Greenland and Svalbard. Towards the east, it is bounded by the ultraslow mid-ocean Knipovich Ridge. Here, we present a 340-km-long seismic refraction line acquired during the expedition ARK-XXIV/3 of research vessel Polarstern in 2009, using 18 ocean bottom seismometers. It crosses the central Boreas Basin from the Knipovich Ridge to the Northeast Greenland margin. Thus, the line provides the first reliable crustal structure information of this basin. In addition, the gravity data acquired parallel to the seismic refraction line are used to calculate a 2.5-D gravity model. The P-wave velocity model shows an unusual ˜3-km-thin oceanic crust with seismic velocities less than 6.3 km s-1, indicating the absence of a significant oceanic layer 3. Mantle velocities vary between 7.5 km s-1 in the uppermost mantle and 8.0 km s-1 at approximately 15 km depth. The low velocities within the upper mantle may be explained by 13 per cent serpentinisation, which is negligible at about 15 km depth. Furthermore, the S-wave velocity model shows low Vp/Vs ratios in the mantle, indicating a highly serpentinised mantle at shallow depths. The gravity model has crustal densities between 2.3 and 2.9 g cm-3, which also point towards the absence of a significant thick oceanic layer 3. The results of our seismic refraction line and other geophysical data indicate that the entire Boreas Basin opened at ultraslow spreading rates since at least ˜28 Ma. No evidence for an extinct spreading ridge in the centre of the Boreas Basin was found.

  7. Seismic structure of the crust and uppermost mantle of north America and adjacent oceanic basins: A synthesis

    USGS Publications Warehouse

    Chulick, G.S.; Mooney, W.D.

    2002-01-01

    We present a new set of contour maps of the seismic structure of North America and the surrounding ocean basins. These maps include the crustal thickness, whole-crustal average P-wave and S-wave velocity, and seismic velocity of the uppermost mantle, that is, Pn and Sn. We found the following: (1) The average thickness of the crust under North America is 36.7 km (standard deviation [s.d.] ??8.4 km), which is 2.5 km thinner than the world average of 39.2 km (s.d. ?? 8.5) for continental crust; (2) Histograms of whole-crustal P- and S-wave velocities for the North American crust are bimodal, with the lower peak occurring for crust without a high-velocity (6.9-7.3 km/sec) lower crustal layer; (3) Regions with anomalously high average crustal P-wave velocities correlate with Precambrian and Paleozoic orogens; low average crustal velocities are correlated with modern extensional regimes; (4) The average Pn velocity beneath North America is 8.03 km/sec (s.d. ?? 0.19 km/sec); (5) the well-known thin crust beneath the western United States extends into northwest Canada; (6) the average P-wave velocity of layer 3 of oceanic crust is 6.61 km/ sec (s.d. ?? 0.47 km/sec). However, the average crustal P-wave velocity under the eastern Pacific seafloor is higher than the western Atlantic seafloor due to the thicker sediment layer on the older Atlantic seafloor.

  8. New Vitrinite Reflectance Data for the Bighorn Basin, North-Central Wyoming and South-Central Montana

    USGS Publications Warehouse

    Finn, Thomas M.; Pawlewicz, Mark J.

    2007-01-01

    Introduction The Bighorn Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 10,400 mi2 in north-central Wyoming and south-central Montana (fig. 1). Important conventional oil and gas resources have been discovered and produced from reservoirs ranging in age from Cambrian through Tertiary (Fox and Dolton, 1989, 1996a, b; De Bruin, 1993). In addition, a potential unconventional basin-centered gas accumulation may be present in Cretaceous reservoirs (Johnson and Finn, 1998; Johnson and others, 1999). The purpose of this report is to present new vitrinite reflectance data to be used in support of the U.S Geological Survey's assessment of undiscovered oil and gas resources of the Bighorn Basin. These new data supplement previously published data by Nuccio and Finn (1998), and Yin (1997), and lead to a better understanding and characterization of the thermal maturation and burial history of potential source rocks. Eighty-nine samples of Cretaceous and Tertiary strata (fig. 2) were collected and analyzed - 15 samples were from outcrops around the margins of the basin and 74 samples were well cuttings (fig. 1). Forty-one of the samples were shale, two were carbonaceous shale, and the remainder from coal. All samples were analyzed by vitrinite reflectance to determine levels of thermal maturation. Preparation of samples for reflectance analysis required (1) crushing the larger pieces into 0.25-to 1-mm pieces, (2) casting the pieces with epoxy in pre-cut and drilled plugs, and (3) curing the samples overnight. Subsequently, a four-step grinding and polishing process was implemented that included sanding with progressively finer sandpaper (60 and 600 grit) followed with a two-step polishing process (0.3 and 0.05 micron). Vitrinite reflectance measurements were determined at 500 X magnification using plane-polarized incident white light and a 546-nm monochromatic filter in immersion oil. For samples containing

  9. Inelastic yielding and forebulge shape across a modern foreland basin: North West Shelf of Australia, Timor Sea

    NASA Astrophysics Data System (ADS)

    Lorenzo, Juan M.; O'Brien, Geoffrey W.; Stewart, Jonathan; Tandon, Kush

    The Timor Trough is a modern ‘underfilled’ foreland basin created by partial subduction of the outer north west continental shelf of Australia beneath Timor Island in the Outer Banda Arc of eastern Indonesia during the Cenozoic. A change of the effective elastic thickness (EET) of the continental foreland lithosphere from ˜80±20 km to ˜25 km over a distance of ˜300 km explains (1) the high curvature (˜10-7 m-1) on the outer Trough wall, (2) the low shelf forebulge (˜200 m) as measured along a reference base Pliocene unconformity, and (3) observed gravity. An inelastically yielding quartzite-quartz-diorite-dunite continental rheology can explain the EET gradient. New, shallow crustal (<8 km), seismic reflection images indicate that Jurassic basement normal faults are reactivated during bending of the foreland.

  10. Ecological data collected in the Santee River basin and coastal drainages, North and South Carolina, 1996-98

    USGS Publications Warehouse

    Abrahamsen, Thomas A.

    2001-01-01

    As part of the National Water-Quality Assessment Program, ecological investigations were conducted in 23 reaches of 16 streams in the Santee River Basin and Coastal Drainages study unit in North and South Carolina during 1996-98. Habitat characteristics, such as stream width and depth, bank composition, bank vegetative cover, stream shading by overhanging vegetation, and streambed composition were recorded. Algal and benthic invertebrate communities were sampled using quantitative and qualitative techniques. These data will provide information needed to: (1) support findings of the effects of human landuse activities on water quality by augmenting or enhancing physical and chemical water-quality data, (2) provide a basic overview of aquatic community structure in selected stream reaches in the study unit, and (3) provide a means for comparing aquatic communities in subsequent years of the assessment program.

  11. Freshwater fish faunas, habitats and conservation challenges in the Caribbean river basins of north-western South America.

    PubMed

    Jiménez-Segura, L F; Galvis-Vergara, G; Cala-Cala, P; García-Alzate, C A; López-Casas, S; Ríos-Pulgarín, M I; Arango, G A; Mancera-Rodríguez, N J; Gutiérrez-Bonilla, F; Álvarez-León, R

    2016-07-01

    The remarkable fish diversity in the Caribbean rivers of north-western South America evolved under the influences of the dramatic environmental changes of neogene northern South America, including the Quechua Orogeny and Pleistocene climate oscillations. Although this region is not the richest in South America, endemism is very high. Fish assemblage structure is unique to each of the four aquatic systems identified (rivers, streams, floodplain lakes and reservoirs) and community dynamics are highly synchronized with the mono-modal or bi-modal flooding pulse of the rainy seasons. The highly seasonal multispecies fishery is based on migratory species. Freshwater fish conservation is a challenge for Colombian environmental institutions because the Caribbean trans-Andean basins are the focus of the economic development of Colombian society, so management measures must be directed to protect aquatic habitat and their connectivity. These two management strategies are the only way for helping fish species conservation and sustainable fisheries.

  12. Freshwater fish faunas, habitats and conservation challenges in the Caribbean river basins of north-western South America.

    PubMed

    Jiménez-Segura, L F; Galvis-Vergara, G; Cala-Cala, P; García-Alzate, C A; López-Casas, S; Ríos-Pulgarín, M I; Arango, G A; Mancera-Rodríguez, N J; Gutiérrez-Bonilla, F; Álvarez-León, R

    2016-07-01

    The remarkable fish diversity in the Caribbean rivers of north-western South America evolved under the influences of the dramatic environmental changes of neogene northern South America, including the Quechua Orogeny and Pleistocene climate oscillations. Although this region is not the richest in South America, endemism is very high. Fish assemblage structure is unique to each of the four aquatic systems identified (rivers, streams, floodplain lakes and reservoirs) and community dynamics are highly synchronized with the mono-modal or bi-modal flooding pulse of the rainy seasons. The highly seasonal multispecies fishery is based on migratory species. Freshwater fish conservation is a challenge for Colombian environmental institutions because the Caribbean trans-Andean basins are the focus of the economic development of Colombian society, so management measures must be directed to protect aquatic habitat and their connectivity. These two management strategies are the only way for helping fish species conservation and sustainable fisheries. PMID:27401480

  13. A QUANTITATIVE ASSESSMENT OF A COMBINED SPECTRAL AND GIS RULE-BASED LAND-COVER CLASSIFICATION IN THE NEUSE RIVER BASIN OF NORTH CAROLINA

    EPA Science Inventory

    The 14,582 km2 Neuse River Basin in North Carolina was characterized based on a user defined land-cover (LC) classification system developed specifically to support spatially explicit, non-point source nitrogen allocation modeling studies. Data processing incorporated both spect...

  14. Hydrology of the Chicod Creek basin, North Carolina, prior to channel improvements

    USGS Publications Warehouse

    Simmons, Clyde E.; Aldridge, Mary C.

    1980-01-01

    Extensive modification and excavation of stream channels in the 6-square mile Chicod Creek basin began in mid-1979 to reduce flooding and improve stream runoff conditions. The effects of channel improvements on this Coastal Pain basin 's hydrology will be determined from data collected prior to, during, and for several years following channel alternations. This report summarizes the findings of data collected prior to these improvements. During the 3-year study period, flow data collected from four stream gaging stations in the basin show that streams are dry approximately 10 percent of the time. Chemical analyses of water samples from the streams and from eight shallow groundwater observation wells indicate that water discharge from the surficial aquifer is the primary source of streamflow during rainless periods. Concentrations of Kjeldahl nitrogen, total nitrogen, and total phosphorus were often 5 to 10 times greater at Chicod Creek sites than those at nearby baseline sites. It is probable that runoff from farming and livestock operations contributes significantly to these elevated concentrations in Chicod Creek. The only pesticides detected in stream water were low levels of DDT and dieldrin, which occurred during storm runoff. A much wider range of pesticides, however, are found associated with streambed materials. The ratio of fecal coliform counts to those of fecal streptococcus indicate that the streams receive fecal wastes from livestock and poultry operations.

  15. Assessment of Undiscovered Technically Recoverable Oil and Gas Resources of the Bakken Formation, Williston Basin, Montana and North Dakota, 2008

    USGS Publications Warehouse

    Pollastro, R.M.; Roberts, L.N.R.; Cook, T.A.; Lewan, M.D.

    2008-01-01

    The U.S. Geological Survey (USGS) has completed an assessment of the undiscovered oil and associated gas resources of the Upper Devonian to Lower Mississippian Bakken Formation in the U.S. portion of the Williston Basin of Montana and North Dakota and within the Williston Basin Province. The assessment is based on geologic elements of a total petroleum system (TPS), which include (1) source-rock distribution, thickness, organic richness, maturation, petroleum generation, and migration; (2) reservoir-rock type (conventional or continuous), distribution, and quality; and (3) character of traps and time of formation with respect to petroleum generation and migration. Framework studies in stratigraphy and structural geology and modeling of petroleum geochemistry, combined with historical exploration and production analyses, were used to estimate the undiscovered, technically recoverable oil resource of the Bakken Formation. Using this framework, the USGS defined a Bakken-Lodgepole TPS and seven assessment units (AU) within the system. For the Bakken Formation, the undiscovered oil and associated gas resources were quantitatively estimated for six of these AUs.

  16. A record of astronomically forced climate change in a late Ordovician (Sandbian) deep marine sequence, Ordos Basin, North China

    NASA Astrophysics Data System (ADS)

    Fang, Qiang; Wu, Huaichun; Hinnov, Linda A.; Wang, Xunlian; Yang, Tianshui; Li, Haiyan; Zhang, Shihong

    2016-07-01

    The late Ordovician Pingliang Formation on the southwestern margin of the Ordos Basin, North China, consists of rhythmic alternations of shale, limestone, and siliceous beds. To explore the possible astronomical forcing preserved in this lithological record, continuous lithological rank and magnetic susceptibility (MS) stratigraphic series were obtained from a ~ 34 m thick section of the Pingliang Formation at Guanzhuang. Power spectral analysis of the MS and rank series reveal 85.5 cm to 124 cm, 23 cm to 38 cm, and 15 cm to 27 cm thick sedimentary cycles that in ratio match that of late Ordovician short eccentricity, obliquity and precession astronomical cycles. The power spectrum of the MS time series, calibrated to interpreted short orbital eccentricity cycles, aligns with spectral peaks to astronomical parameters, including 95 kyr short orbital eccentricity, 35.3 kyr and 30.6 kyr obliquity, and 19.6 kyr and 16.3 kyr precession cycles. The 15 cm to 27 cm thick limestone-shale couplets mainly represent precession cycles, and siliceous bed deposition may be related to both precession and obliquity forcing. We propose that precession-forced sea-level fluctuations mainly controlled production of lime mud in a shallow marine environment, and transport to the basin. Precession and obliquity controlled biogenic silica productivity, and temperature-dependent preservation of silica may have been influenced by obliquity forcing.

  17. Selected water-quality and biological characteristics of streams in some forested basins of North Carolina, 1985-88

    USGS Publications Warehouse

    Caldwell, W.S.

    1992-01-01

    Selected physical, chemical and biological components of streams draining undeveloped, forested basins in North Carolina were characterized on the basis of samples collected at nine sites on streams in basins that ranged in size from 0.67 to 11.2 sq mi. Water analysis included specific conductance, dissolved oxygen, water temperature, suspended sediment, pH, major dissolved constituents, nutrients, minor constituents, organochlorine insecticides, and biochemical oxygen demand. Biological characteristics included fish tissue analysis for minor constituents and synthetic organic compounds, fish community structure, and benthic macroinvertebrates. Precipitation is the source of 10 to 40% of the chloride concentration and 20 to 30% of the sulfate concentration in stormflow. Mean total nitrogen concentrations ranged from 0.16 mg/L during low-flow conditions to 1.2 mg/L during stormflow. Organic nitrogen was 60 to 85% of the total nitrogen concentration. Stream water was free of organochlorine insecticides. DDD, DDE, DDT, Lindane, and Mirex were detected in 18 of 60 samples of streambed material. About 35% of fish tissue analyses showed detectable concentrations of copper, lead, mercury and nickel. Synthetic organic chemicals were not detected in fish tissue. Fish community structure data were rated using Karr's Index of Biotic Integrity. Streams rated poor to good because of natural stresses on fish communities. Five streams in the Piedmont and mountains received excellent bioclassification ratings based on benthic macroinvertebrtate data. Two streams in the Coastal Plain rated good to fair because of natural stresses.

  18. Multi-disciplinary approach to biostratigraphic mapping - two case studies: Bass basin, Australia, and North Soldado, Trinidad

    SciTech Connect

    Aquing, F.R.

    1984-04-01

    Palynologic zones were used to subdivide the Late Cretaceous to late eocene beds in the Bass basin, Tasmania, Australia and the Late Miocene to Pliocene beds in the S.484/S.498 area, North Soldado, Trinidad. These zones are related to discrete genetic sedimentary cycles bounded by unconformities which are marked by abrupt changes in the environment of deposition. In both areas, the environments range from shallow marine to continental. Owing to wide sample spacing (up to several hundred feet in some wells), it was impossible to locate precisely each biostratigraphic boundary, based on palynological data alone. The composite use of sedimentology, wire-line log characteristics, dipmeter interpretation, and reservoir fluid properties was integrated with the palynologic data, providing a practical technique that was used to delineate the sequence boundaries in wells where spore-pollen data was inadequate. This method enabled the development of accurate zonation and a detailed correlation between wells within both the Bass basin and the S.484/S.498 area.

  19. Deposition of selenium and other constituents in reservoir bottom sediment of the Solomon River Basin, north-central Kansas

    USGS Publications Warehouse

    Christensen, Victoria G.

    1999-01-01

    The Solomon River drains approximately 6,840 square miles of mainly agricultural land in north-central Kansas. The Bureau of Reclamation, U.S. Department of the Interior, has begun a Resource Management Assessment (RMA) of the Solomon River Basin to provide the necessary data for National Environmental Policy Act (NEPA) compliance before renewal of long-term water-service contracts with irrigation districts in the basin. In May 1998, the U.S. Geological Survey (USGS) collected bottom-sediment cores from Kirwin and Webster Reservoirs, which are not affected by Bureau irrigation, and Waconda Lake, which receives water from both Bureau and non-Bureau irrigated lands. The cores were analyzed for selected physical properties, total recoverable metals, nutrients, cesium-137, and total organic carbon. Spearman's rho correlations and Kendall's tau trend tests were done for sediment concentrations in cores from each reservoir. Selenium, arsenic, and strontium were the only constituents that showed an increasing trend in concentrations for core samples from more than one reservoir. Concentrations and trends for these three constituents were compared to information on historical irrigation to determine any causal effect. Increases in selenium, arsenic, and strontium concentrations can not be completely explained by Bureau irrigation. However, mean selenium, arsenic, and strontium concentrations in sediment from all three reservoirs may be related to total irrigated acres (Bureau and non-Bureau irrigation) in the basin. Selenium, arsenic, and strontium loads were calculated for Webster Reservoir to determine if annual loads deposited in the reservoir were increasing along with constituent concentrations. Background selenium, arsenic, and strontium loads in Webster Reservoir are significantly larger than post-background loads.

  20. Pre-Variscan back-arc extension of Avalonia: The genesis of the Southern North Sea Basin

    NASA Astrophysics Data System (ADS)

    Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

    2016-04-01

    The Devonian-Early Carboniferous was a period of intense rifting in the Avalonia microplate in between the Caledonian and the Hercynian-Alleghanian collision phases. This rifting phase created the typical horst-and-graben structure of much of East Avalonia's crust that is best known from the UK and Ireland where the horsts and the graben infill are located at or near the surface. In the Southern North Sea, the Netherlands and northwest Germany, the Late Devonian-Early Carboniferous rift structure and units are obliterated by the thick cover of Late Carboniferous-to-Recent basin fill and by the recurrent fault reactivation. Although this rifting created the basis for 350 Ma of lithospheric memory, its dynamics remains relatively unknown. Major open questions include the mode and total amount of extension as well as the age and origin of the Central Graben and the relation between structures located east and west of it. This study addresses these issues by integrating existing data from lithosphere to basin scales and a map-view restoration. We have revised the crustal map of the Thor Suture Zone. The newly defined northern margin of Avalonia and the Thor Suture Zone are key elements in the reconstruction of Devonian-Carboniferous rifting of Avalonian lithosphere. We present a revised map of Devonian-Carboniferous basin structures including the main horsts and grabens and the governing faults east of the Central Graben. Based on these maps, we present a new paleotectonic reconstruction and a novel geodynamic scenario for the Devonian- Carboniferous rifting. These findings are key for better understanding of long-lived tectonic compartmentalisation and post-rifting deformation phases.

  1. Simulation of Constituent Transport in the Red River of the North Basin, North Dakota and Minnesota, During Unsteady-Flow Conditions, 1977 and 2003-04

    USGS Publications Warehouse

    Nustad, Rochelle A.; Bales, Jerad D.

    2006-01-01

    The Bureau of Reclamation identified eight water-supply alternatives for the Red River Valley Water Supply Project. Of those alternatives, six were considered for this study. Those six alternatives include a no-action alternative, two in-basin alternatives, and three interbasin alternatives. To address concerns of stakeholders and to provide information for an environmental impact statement, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, developed and applied a water-quality model to simulate the transport of total dissolved solids, sulfate, chloride, sodium, and total phosphorus during unsteady-flow conditions and to simulate the effects of the water-supply alternatives on water quality in the Red River and the Sheyenne River. The physical domain of the model, hereinafter referred to as the Red River model, includes the Red River from Wahpeton, North Dakota, to Emerson, Manitoba, and the Sheyenne River from below Baldhill Dam, North Dakota, to the confluence with the Red River. Boundary conditions were specified for May 15 through October 31, 2003, and January 15 through June 30, 2004. Measured streamflow data were available for August 1 through October 31, 2003, and April 1 through June 30, 2004, but water-quality data were available only for September 15 through 16, 2003, and May 10 through 13, 2004. The water-quality boundary conditions were assumed to be time invariant for the entire calibration period and to be equal to the measured value. The average difference between the measured and simulated streamflows was less than 4 percent for both calibration periods, and most differences were less than 2 percent. The average differences are considered to be acceptable because the differences are less than 5 percent, or the same as the error that would be expected in a typical streamflow measurement. Simulated total dissolved solids, sulfate, chloride, and sodium concentrations generally were less than measured concentrations for both

  2. Water-quality trend analysis and sampling design for streams in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1970-2001

    USGS Publications Warehouse

    Vecchia, Aldo V.

    2005-01-01

    The Bureau of Reclamation is considering several alternatives to meet the future municipal, rural, and industrial water-supply needs in the Red River of the North (Red River) Basin, and an environmental impact statement is being prepared to evaluate the potential effects of the various alternatives on the water quality and aquatic health in the basin in relation to the historical variability of streamflow and constituent concentration. Therefore, a water-quality trend analysis was needed to determine the amount of natural water-quality variability that can be expected to occur in the basin, to determine if significant water-quality changes have occurred as a result of human activities, to explore potential causal mechanisms for water-quality changes, and to establish a baseline from which to monitor future water-quality trends. This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, to analyze historical water-quality trends in two dissolved major ions, dissolved solids, three nutrients, and two dissolved trace metals for nine streamflow-gaging stations in the basin. Annual variability in streamflow in the Red River Basin was high during the trend-analysis period (1970-2001). The annual variability affects constituent concentrations in individual tributaries to the Red River and, in turn, affects constituent concentrations in the main stem of the Red River because of the relative streamflow contribution from the tributaries to the main stem. Therefore, an annual concentration anomaly, which is an estimate of the interannual variability in concentration that can be attributed to long-term variability in streamflow, was used to analyze annual streamflow-related variability in constituent concentrations. The concentration trend is an estimate of the long-term systematic changes in concentration that are unrelated to seasonal or long-term variability in streamflow. Concentrations that have both

  3. Water resources of the Yadkin-Pee Dee River Basin, North Carolina

    USGS Publications Warehouse

    Fish, Robert Eugene; LeGrand, H.E.; Billingsley, G.A.

    1957-01-01

    Sufficient water is available in the basin of the Yadkin and Pee Dee Rivers to meet present requirements and those for many years to come if water use increases at about the present rate. Data presented in this report show that the average annual streamflow from approximately 82 percent of the basin area during the 25-year period, 1929-53, was about 6,200 mgd, representing essentially the total available water supply. Comparison of the available water supply to the estimated withdrawal use (excluding water power) of both surface and ground water of 600 mgd indicates the relative utilization of the water resources of the basin at present. If proper pollution controls are observed and practiced so that water in the various streams may be reused several times, the potential water available is even greater than indicated by the above comparison. Preliminary studies indicate that the quantity of water now being withdrawn from ground-water reservoirs in the basin is only a fraction of the total that may be obtained from this source. Twenty-eight of the 64 municipalities having public water-supply systems use surface water; however, as the largest cities in the area use surface supplies, about 85 percent of the water used for public supplies is from surface sources. Of the 20 complete-record stream-gaging stations now in operation in this area 7 have been in operation for 24 years or longer. Periodic measurements of the rate of flow have been made at 31 additional sites on streams scattered widely over the basin. All available streamflow data including those for 1953 are summarized in either graphic or tabular form, or both. Because of the critically low flows occurring during the drought of 1954, several illustrations include data for 1954 and the early months of 1955 for comparison with the minima of previous years. Adequate water for domestic use is available from wells throughout the basin. The consolidated rocks of the Piedmont furnish water for small industries and

  4. Constraints on post Mid-Jurassic basin evolution in the North Sea from 3D numerical modelling of basin initiation and subsidence.

    NASA Astrophysics Data System (ADS)

    Petersen, K. D.; Nielsen, S. B.

    2007-12-01

    The North Sea sedimentary basin contains more than 3km of post Mid-Jurassic sediments. These are located in a trilete graben system consisting of the Moray Firth and the Viking and Central grabens, but also in a broad region surrounding the grabens, corresponding to the post-mid Cretaceous sediment deposits During the Mid- Jurassic the area was exposed to volcanism, domal regional uplift and erosion, followed by crustal thinning and normal faulting in the grabens. We use a numerical model considering 3D thermal evolution, flexural isostasy, erosion, sedimentation and compaction together with isopach data to simulate the geodynamic evolution of the area since the Mid-Jurassic. Our modelling studies show that the broad distribution of post Jurassic sediments cannot be explained by uniform stretching in the graben areas alone. Regional Mid-Jurassic thinning of the subcrustal lithosphere producing first uplift and erosion and later accommodation space for Cretaceous and Cenozoic sediments is also required. The uniform crustal thinning factor in the grabens amounts to a maximum of 1.14. The required subcrustal lithospheric thinning amounts to about 15 km. Our results are in accordance with observations from recent rift systems such as the Rhine Graben, Eastern Africa and the Baikal Rift, which show that crustal thinning is restricted to the graben areas while thinning of the subcrustal lithosphere (up to 100 km) and the associated domal surface uplift are more regionally distributed.

  5. Constraints on post Mid-Jurassic basin evolution in the North Sea from 3D numerical modelling of basin initiation and subsidence.

    NASA Astrophysics Data System (ADS)

    Petersen, K. D.; Nielsen, S. B.

    2004-12-01

    The North Sea sedimentary basin contains more than 3km of post Mid-Jurassic sediments. These are located in a trilete graben system consisting of the Moray Firth and the Viking and Central grabens, but also in a broad region surrounding the grabens, corresponding to the post-mid Cretaceous sediment deposits During the Mid- Jurassic the area was exposed to volcanism, domal regional uplift and erosion, followed by crustal thinning and normal faulting in the grabens. We use a numerical model considering 3D thermal evolution, flexural isostasy, erosion, sedimentation and compaction together with isopach data to simulate the geodynamic evolution of the area since the Mid-Jurassic. Our modelling studies show that the broad distribution of post Jurassic sediments cannot be explained by uniform stretching in the graben areas alone. Regional Mid-Jurassic thinning of the subcrustal lithosphere producing first uplift and erosion and later accommodation space for Cretaceous and Cenozoic sediments is also required. The uniform crustal thinning factor in the grabens amounts to a maximum of 1.14. The required subcrustal lithospheric thinning amounts to about 15 km. Our results are in accordance with observations from recent rift systems such as the Rhine Graben, Eastern Africa and the Baikal Rift, which show that crustal thinning is restricted to the graben areas while thinning of the subcrustal lithosphere (up to 100 km) and the associated domal surface uplift are more regionally distributed.

  6. Relations among land cover, streamflow, and water quality in the North Canadian River Basin near Oklahoma City, Oklahoma: 1968-2009

    USGS Publications Warehouse

    Esralew, Rachel A.; Andrews, William J.; Smith, S. Jerrod

    2011-01-01

    The U.S. Geological Survey, in cooperation with the city of Oklahoma City, has collected water-quality samples at the North Canadian River near Harrah, Oklahoma (the Harrah station), since 1968, and the North Canadian River at Britton Road at Oklahoma City, Oklahoma (the Britton Road station), since 1988. The North Canadian municipal wastewater-treatment plant, managed by the city of Oklahoma City, is the largest wastewater-treatment plant in the North Canadian River Basin and discharges effluent between the Britton Road and Harrah stations. Water-quality constituent concentrations were summarized, and trends in concentrations and frequencies of detection of selected constituents with time were evaluated to determine if changes in land cover, streamflow, and other potential sources of constituents in water had significant effects on water quality in the North Canadian River downstream from Oklahoma City.

  7. Mercury accumulation in Devils Lake, North Dakota effects of environmental variation in closed-basin lakes on mercury chronologies

    USGS Publications Warehouse

    Lent, R.M.; Alexander, C.R.

    1997-01-01

    Sediment cores were collected from lakes in the Devils Lake Basin in North Dakota to determine if mercury (Hg) accumulation chronologies from sediment-core data are good indicators of variations in Hg accumulation rates in saline lakes. Sediment cores from Creel Bay and Main Bay, Devils Lake were selected for detailed analysis and interpretation. The maximum Hg concentration in the Creel Bay core was 0.15 micrograms per gram at 8 to 9 centimeters. The maximum Hg concentration in the Main Bay core was 0.07 micrograms per gram at 5 to 7 centimeters. The general decreases in Hg concentrations with depth are attributed to historic variations in atmospheric Hg deposition rate. Hg stratigraphies combined with 210Pb and 137Cs dating analyses yield Hg chronologies that indicate a general increase in Hg accumulation rates in Devils Lake since the middle of the 19th century. Mean modern Hg accumulation rates in Creel Bay were 4.9 nanograms per square centimeter per year, and rates in Main Bay were 1.8 nanograms per square centimeter per year. Mean preindustrial Hg accumulation rates in Creel Bay were 1.2 nanograms per square centimeter per year, and rates in Main Bay were 1.6 nanograms per square centimeter per year. Relatively low Hg concentrations in recent sediments in the Devils Lake Basin, along with similarities in Hg accumulation rates between lakes in the Devils Lake Basin and other lakes in the northern interior of North America, indicate that local sources of Hg are not important sources of Hg. Results of the study indicate that accurate Hg chronologies are discernible in sediment cores collected from saline lakes. However, spatial and temporal variations in lake level and water chemistry common to saline lakes make interpretation of radioisotopic and geochemical chronologies difficult. Hg geochemistry in Devils Lake, and presumably in other saline lakes, is dynamic. The results of this study indicate that the absolute amount of sediment transported to Devils Lake

  8. Petroleum system of the sourth-eastern portion of the Maracaibo basin: Ceuta-North Andean Flank

    SciTech Connect

    Marcano, F.; Boesi, T.; Pirela, B.; Alcala, L.; Violino, R.

    1996-08-01

    The South Eastern portion of the Maracaibo basin encompasses a giant field (Ceuta) that carries ultimate recoverable oil reserves of more than 2.5 billion barrels and areas with little or no drilling. Oil in the area has been found in Cretaceous and Tertiary sediments and, in seeps along the North Andean Flank, where oil-source rock correlation based on biomarker fingerprints relates the existing crude to the Cretaceous La Luna source rock. A main tectonic constituent of the area is represented by the Merida arch, controlling the sedimentation until the end of the Cretaceous passive margin. Also, the Middle Eocone rifting and its associated structures have determined important thickness variations of deltaic eocene prograding sediments. A significant sequence boundary is associated to compression, uplifting, erosion or non deposition from the late Eocene to the early Miocene. A gradual tilting towards the southeast developed as a consequence of the Andean foredeep in the southern area. Heat flow field is found to be different from one area to another, as given by estimations taking into account well temperature measurements, rock maturity and the calculation of thermal conductivities of the rock formations as a function of their lithologies, porosities and temperature. Kinetic modelling of the hydrocarbon generation indicates a complex history starting in the northeastern area during the Eocene with the generation of oil and still ongoing nowadays in the north Andean Flank with the generation of gas.

  9. Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam

    PubMed Central

    Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J.; Janeau, J.-L.; Rochelle-Newall, E.

    2016-01-01

    The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013–June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml−1 and 15300 colonies 100 ml−1, respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d−1 to a maximum of 1.13 d−1 for EC and from 0.17 d−1 to 1.33 d−1 for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system. PMID:26869451

  10. Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam.

    PubMed

    Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J; Janeau, J-L; Rochelle-Newall, E

    2016-02-12

    The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml(-1) and 15300 colonies 100 ml(-1), respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d(-1) to a maximum of 1.13 d(-1) for EC and from 0.17 d(-1) to 1.33 d(-1) for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system.

  11. Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam.

    PubMed

    Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J; Janeau, J-L; Rochelle-Newall, E

    2016-01-01

    The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml(-1) and 15300 colonies 100 ml(-1), respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d(-1) to a maximum of 1.13 d(-1) for EC and from 0.17 d(-1) to 1.33 d(-1) for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system. PMID:26869451

  12. Using LiDAR datasets to improve HSPF water quality modeling in the Red River of the North Basin

    NASA Astrophysics Data System (ADS)

    Burke, M. P.; Foreman, C. S.

    2013-12-01

    The Red River of the North Basin (RRB), located in the lakebed of ancient glacial Lake Agassiz, comprises one of the flattest landscapes in North America. The topography of the basin, coupled with the Red River's direction of flow from south to north results in a system that is highly susceptible to flooding. The magnitude and frequency of flood events in the RRB has prompted several multijurisdictional projects and mitigation efforts. In response to the devastating 1997 flood, an International Joint Commission sponsored task force established the need for accurate elevation data to help improve flood forecasting and better understand risks. This led to the International Water Institute's Red River Basin Mapping Initiative, and the acquisition LiDAR Data for the entire US portion of the RRB. The resulting 1 meter bare earth digital elevation models have been used to improve hydraulic and hydrologic modeling within the RRB, with focus on flood prediction and mitigation. More recently, these LiDAR datasets have been incorporated into Hydrological Simulation Program-FORTRAN (HSPF) model applications to improve water quality predictions in the MN portion of the RRB. RESPEC is currently building HSPF model applications for five of MN's 8-digit HUC watersheds draining to the Red River, including: the Red Lake River, Clearwater River, Sandhill River, Two Rivers, and Tamarac River watersheds. This work is being conducted for the Minnesota Pollution Control Agency (MPCA) as part of MN's statewide watershed approach to restoring and protecting water. The HSPF model applications simulate hydrology (discharge, stage), as well as a number of water quality constituents (sediment, temperature, organic and inorganic nitrogen, total ammonia, organic and inorganic phosphorus, dissolved oxygen and biochemical oxygen demand, and algae) continuously for the period 1995-2009 and are formulated to provide predictions at points of interest within the watersheds, such as observation gages

  13. Multiple Magmatic Events Over 40 Ma in the Fish Creek Mountains, North-central Great Basin, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Cousens, B.; Henry, C. D.; Stevens, C.; Varve, S.

    2011-12-01

    The Fish Creek Mountains, located in north-central Nevada south of Battle Mountain, is a site of multiple igneous events ranging from ca. 35 Ma to 1 Ma, covering most of the igneous history of the Great Basin of the western United States. Such extended volcanic activity allows for documentation of mantle sources and petrogenetic processes over time. Beginning approximately 50 Ma, the Great Basin experienced a magmatic front that began migrating southwestward across southern Idaho, central Oregon and into northern Nevada and Utah. Intermediate, "arc-like" andesite and dacite dominated volcanic activity in northeastern Nevada between about 45 and 36 Ma. By 34 Ma, a northwest-trending belt of rhyolitic ash-flow calderas began to develop through central Nevada, the "ignimbrite flare-up". Volcanism then migrated westwards towards the Sierra Nevada. In north-central Nevada, the oldest lavas are ca. 35 Ma basaltic andesites through rhyolites that are exposed in the western Shoshone Range, the eastern Tobin Range, and the northern and eastern Fish Creek Mountains. Plagioclase-rich andesites, dacite intrusions, and volcanic breccias occur in a belt along the western side of the Fish Creek Mountains. The bulk of the Fish Creek Mountains is composed of the 24.7 Ma Fish Creek Mountains rhyolitic tuff that is largely confined to an undeformed caldera structure. The caldera and tuff are anomalously young compared to nearby felsic centers such as the Caetano caldera (33.8Ma) and Shoshone Range (39-35 Ma) and relative to the southwest to west magmatic migration. The basal tuff is unwelded, with abundant pumice and lithic (primarily volcanic) fragments but only rare crystals. Sanidine and smoky quartz phenocrysts become more abundant upsection and glassy fiamme (hydrated to devitrified) are common, but the abundance of lithic fragments diminishes. 16-15 Ma volcanic rocks of the Northern Nevada Rift are exposed in the Battle Mountain area, ranging in composition from subalkaine

  14. Basin-scale estimates of oceanic primary production by remote sensing: The North Atlantic

    NASA Astrophysics Data System (ADS)

    Platt, Trevor; Caverhill, Carla; Sathyendranath, Shubha

    1991-08-01

    The estimation by remote sensing of annual primary production at ocean basin scales is illustrated for the Atlantic Ocean, using the monthly averaged Coastal Zone Color Scanner data for 1979. The principal supplementary data used were some 873 vertical profiles of chlorophyll and some 248 sets of parameters derived from photosynthesis-light experiments. This information was used to parametrize the local algorithm for calculation of primary production in 12 subregions of the entire domain for each of the four seasons. Four different procedures were tested for calculation of primary production. These differed according to whether the autotrophic biomass distribution was uniform with depth and whether the irradiance was resolved with respect to wavelength: the spectral model with nonuniform biomass was considered as the benchmark for comparison against the other three models. At particular locations and times, the less complete models gave results that differed by as much as 50% from the benchmark. After integration to basin scale, vertically uniform models tended to underestimate primary production by about 20% compared to the nonuniform models. At large horizontal scale, the differences between spectral and nonspectral models were negligible, a result that was believed to follow from mutual compensation of underestimates and overestimates, according to the local biomass, in different parts of the domain. Calculation of primary production is highly sensitive to the algorithm used to retrieve the biomass. The linear correlation between biomass and estimated production was poor outside the tropics, suggesting caution against the indiscriminate use of biomass as a proxy variable for primary production. The annual primary production for the Atlantic between 20°S and 70°N was 9 ± 3 Gt yr-1, higher than previous estimates made without reference to remotely sensed data. It is argued that the remote-sensing method is the method of choice for calculation of primary

  15. A New Troodontid Theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America

    PubMed Central

    Zanno, Lindsay E.; Varricchio, David J.; O'Connor, Patrick M.; Titus, Alan L.; Knell, Michael J.

    2011-01-01

    Background Troodontids are a predominantly small-bodied group of feathered theropod dinosaurs notable for their close evolutionary relationship with Avialae. Despite a diverse Asian representation with remarkable growth in recent years, the North American record of the clade remains poor, with only one controversial species—Troodon formosus—presently known from substantial skeletal remains. Methodology/Principal Findings Here we report a gracile new troodontid theropod—Talos sampsoni gen. et sp. nov.—from the Upper Cretaceous Kaiparowits Formation, Utah, USA, representing one of the most complete troodontid skeletons described from North America to date. Histological assessment of the holotype specimen indicates that the adult body size of Talos was notably smaller than that of the contemporary genus Troodon. Phylogenetic analysis recovers Talos as a member of a derived, latest Cretaceous subclade, minimally containing Troodon, Saurornithoides, and Zanabazar. MicroCT scans reveal extreme pathological remodeling on pedal phalanx II-1 of the holotype specimen likely resulting from physical trauma and subsequent infectious processes. Conclusion/Significance Talos sampsoni adds to the singularity of the Kaiparowits Formation dinosaur fauna, which is represented by at least 10 previously unrecognized species including the recently named ceratopsids Utahceratops and Kosmoceratops, the hadrosaurine Gryposaurus monumentensis, the tyrannosaurid Teratophoneus, and the oviraptorosaurian Hagryphus. The presence of a distinct troodontid taxon in the Kaiparowits Formation supports the hypothesis that late Campanian dinosaurs of the Western Interior Basin exhibited restricted geographic ranges and suggests that the taxonomic diversity of Late Cretaceous troodontids from North America is currently underestimated. An apparent traumatic injury to the foot of Talos with evidence of subsequent healing sheds new light on the paleobiology of deinonychosaurians by bolstering

  16. Relation of physical and chemical characteristics of streams to fish communities in the Red River of the North basin, Minnesota and North Dakota, 1993-95

    USGS Publications Warehouse

    Goldstein, R.M.; Stauffer, J.C.; Larson, P.R.; Lorenz, D.L.

    1996-01-01

    Within the instream habitat data set, measures of habitat volume (channel width and depth) and habitat diversity were most significant in explaining the variability of the fish communities. The amount of nonagricultural land and riparian zone integrity from the terrestrial habitat data set were also useful in explaining fish community composition. Variability of mean monthly discharge and the frequency of high and low discharge events during the three years prior to fish sampling were the most influential of the hydrologic variables.The first two axes of the canonical correspondence analysis accounted for 43.3 percent of the variation in the fish community and 52.5 percent of the variation in the environmental-species relation. Water-quality indicators such as the percent of fine material in suspended sediment, minimum dissolved oxygen concentrations, minimum concentrations of dissolved organic carbon, and the range of concentrations of major ions and nutrients were the variables that were most important in the canonical correspondence analysis of water-quality data with fish. No single environmental variable or data set appeared to be more important than another in explaining variation in the fish community. The environmental factors affecting the fish communities of the Red River of the North are interrelated. For the most part, instream environmental conditions (instream habitat, hydrology, and water chemistry) appear to be more important in explaining variability in fish community composition than factors related to the agricultural nature of the basin.

  17. Shallow ground-water quality beneath cropland in the Red River of the North Basin, Minnesota and North Dakota, 1993-95

    USGS Publications Warehouse

    Cowdery, Timothy K.

    1997-01-01

    Land-use factors that increased nitrate and herbicide concentrations were greater tilled area, chemical application, irrigation, and cropland contiguity. Hydrogeological factors that increased these concentrations were a deeper watertable (higher oxygen concentration and less organic carbon), larger grain-size and degree of sorting of aquifer material (shorter time in the soil zone and aquifer), and fewer sulfur-containing minerals (lignite and pyrite) composing the aquifer. High rainfall, just before sampling of the Sheyenne Delta aquifer, contributed to the relatively low nitrate and pesticide concentrations in the shallow ground water of this aquifer by raising the water table higher into the soil zone, increasing ponded water (increasing biodegradation), preventing some chemical application (flooded fields), and leaching and then displacing nitrate-rich water downward, beneath new recharge. The shallow ground-water quality measured beneath cropland in these land-use study areas covers a large range. The land-use, hydrogeological, and rainfall factors controlling this quality also control shallow ground-water quality in other surficial aquifers in the Red River of the North Basin. Although not used for drinking water, 43% of the shallow ground water from the Otter Tail outwash aquifer was above the U.S. Environmental Protection Agency's nitrate maximum contaminant level of 10 mg/L-N, reducing its potential uses. These high nitrate concentrations do not threaten the Otter Tail outwash aquifer's surface-water bodies with eutrophication however, because significant denitrification occurs beneath riparian wetlands before ground water discharges to surface waters.

  18. Water-Quality Trend Analysis and Sampling Design for the Devils Lake Basin, North Dakota, January 1965 Through September 2003

    USGS Publications Warehouse

    Ryberg, Karen R.; Vecchia, Aldo V.

    2006-01-01

    This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota State Water Commission, the Devils Lake Basin Joint Water Resource Board, and the Red River Joint Water Resource District, to analyze historical water-quality trends in three dissolved major ions, three nutrients, and one dissolved trace element for eight stations in the Devils Lake Basin in North Dakota and to develop an efficient sampling design to monitor the future trends. A multiple-regression model was used to detect and remove streamflow-related variability in constituent concentrations. To separate the natural variability in concentration as a result of variability in streamflow from the variability in concentration as a result of other factors, the base-10 logarithm of daily streamflow was divided into four components-a 5-year streamflow anomaly, an annual streamflow anomaly, a seasonal streamflow anomaly, and a daily streamflow anomaly. The constituent concentrations then were adjusted for streamflow-related variability by removing the 5-year, annual, seasonal, and daily variability. Constituents used for the water-quality trend analysis were evaluated for a step trend to examine the effect of Channel A on water quality in the basin and a linear trend to detect gradual changes with time from January 1980 through September 2003. The fitted upward linear trends for dissolved calcium concentrations during 1980-2003 for two stations were significant. The fitted step trends for dissolved sulfate concentrations for three stations were positive and similar in magnitude. Of the three upward trends, one was significant. The fitted step trends for dissolved chloride concentrations were positive but insignificant. The fitted linear trends for the upstream stations were small and insignificant, but three of the downward trends that occurred during 1980-2003 for the remaining stations were significant. The fitted upward linear trends for dissolved

  19. Optimum interpolation analysis of basin-scale ¹³⁷Cs transport in surface seawater in the North Pacific Ocean.

    PubMed

    Inomata, Y; Aoyama, M; Tsumune, D; Motoi, T; Nakano, H

    2012-12-01

    ¹³⁷Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of ¹³⁷Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of ¹³⁷Cs that revealed the basin-scale circulation of Cs ¹³⁷Cs in surface seawater in the North Pacific Ocean: ¹³⁷Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, ¹³⁷Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre. PMID:23117411

  20. Optimum interpolation analysis of basin-scale ¹³⁷Cs transport in surface seawater in the North Pacific Ocean.

    PubMed

    Inomata, Y; Aoyama, M; Tsumune, D; Motoi, T; Nakano, H

    2012-12-01

    ¹³⁷Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of ¹³⁷Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of ¹³⁷Cs that revealed the basin-scale circulation of Cs ¹³⁷Cs in surface seawater in the North Pacific Ocean: ¹³⁷Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, ¹³⁷Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre.

  1. New Constraints on Buried Triassic Basins of the Eastern North American Margin and Implications for Regional Tectonics from Reanalysis of SeisData6 Seismic Profile

    NASA Astrophysics Data System (ADS)

    Knapp, C. C.; Akintunde, O. M.; Knapp, J. H.

    2012-12-01

    The Eastern North American Margin (ENAM) is most significant due to the complexity and regional extent of this mature Mesozoic passive margin rift system encompassing: (1) a large volume and regional extent of related magmatism, (2) a preserved complete stratigraphic column that records the post-rift evolution in several basins, (3) preserved lithospheric-scale pre-rift structures including Paleozoic sutures, and (4) a wide-range of geological, geochemical, and geophysical studies both onshore and offshore. The short-lived but most voluminous magmatic event associated with the initiation of rifting, the Central Atlantic Magmatic Province (CAMP), is one of the most significant magmatic events in North America. The South Georgia Rift (SGR) basin is believed to be the largest and probably the most geologically complex Mesozoic graben of the ENAM formed during crustal extension associated with the breakup of Pangea and later opening of the North Atlantic Ocean. The separation of the African and North American plates, the formation of the Atlantic Ocean and the associated zones of weakness in eastern North America have been stated as the initial events in the breakup of Pangea. At least four major unanswered questions of regional tectonic significance derive from a previous study of the USGS SeisData6 seismic profile across the Coastal Plain of South East Georgia and are now addressed through reprocessing. These issues are: (1) the stratigraphy, structural composition, extent and thickness of this buried basin which have remained unknown, (2) whether or not the SGR basin is connected with the Riddleville and Dunbarton basins in Georgia and South Carolina, (3) whether or not the Augusta fault, an inferred crustal scale thrust fault which approximately represents the Piedmont-Coastal Plain boundary in Georgia and South Carolina, extends underneath the Coastal Plain sediments, and (4) weather there is evidence of CAMP basalt flows or sills within the SGR basin along this

  2. Effects of channel modifications on the hydrology of Chicod Creek basin, North Carolina, 1975-87

    USGS Publications Warehouse

    Mason, R.R.; Simmons, C.E.; Watkins, S.A.

    1990-01-01

    Drainage modifications in this Coastal Plain basin from 1978 to 1981 consisted of channel excavation and clearing of blockages. A study was begun in 1975 to define hydrologic conditions of the basin before, during, and after modifications and to determine what changes were attributed to modifications. Surface-water conditions were altered during and following modifications. Minimum flow at Juniper Branch was increased from less than 0.1 cu ft/sec to 0.4 cu ft/second;streamflow variability was reduced from an index of 0.87 to 0.49. In-channel velocity at Chicod Creek was increased from a mean of 0.4 ft/sec to 1.5 ft/sec. Substantial groundwater level declines were observed in wells 180 and 250 ft from Juniper Branch during the modifications phase;these were 0.4 and 0.2 ft, respectively. However, most surface-water and groundwater conditions returned nearly to premodification levels by 1987. Water-quality characteristics monitored during the investigation included physical, chemical, and bacteriological characteristics. Physical characteristics monitored were suspended sediment, temperature, dissolved oxygen, and pH. Of these physical characteristics, only sediment concentrations increased substantially during channel modifications. Chemical characteristics studied were major dissolved constituents, nutrients, trace metals, and pesticides. Substantial changes ranged from a decline in total iron concentrations of 77% to an increase in total nitrite concentrations of 130%. Changes in many chemical characteristics persisted following channel modifications. Bacterial counts did not change substantially.

  3. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W.

    1996-12-31

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  4. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W. )

    1996-01-01

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  5. Sediment flux history of Pearl River mouth basin, North margin of South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, S.

    2004-12-01

    This work estimates the solid sediment flux in Pearl River mouth basin from Cenozoic (42Ma). The estimates were derived from isopach maps, seismic reflection profiles and drill holes. Average solid sediment fluxes were calculated for six epochs approximately corresponding to geological periods: Eocene-Lower Oligocene (42-29.3), Upper Oligocene (29.3-23.8), Lower Miocene (23.8-16.4), Middle Miocene (16.4-11.2), Upper Miocene (11.2-5.32), and Pliocene-Pleistocene (5.32-0). The total sediment flux from 42 Ma is 392071.3 km3 and 0.89 km of erosion formed from the onshore drainage basin area. The average erosion rate is 22 m/ Ma. The sediment flux curve shows 3 episodes massive increase in sediment supply, i.e. Upper Oligocene, Middle Miocene and Pliocene-Pleistocene. The first increase related to the break up activity and is the product of elevated rift shoulder. The other two increase peak link to the changing of climate.

  6. Climate change impact on soil erosion in the Mandakini River Basin, North India

    NASA Astrophysics Data System (ADS)

    Khare, Deepak; Mondal, Arun; Kundu, Sananda; Mishra, Prabhash Kumar

    2016-05-01

    Correct estimation of soil loss at catchment level helps the land and water resources planners to identify priority areas for soil conservation measures. Soil erosion is one of the major hazards affected by the climate change, particularly the increasing intensity of rainfall resulted in increasing erosion, apart from other factors like landuse change. Changes in climate have an adverse effect with increasing rainfall. It has caused increasing concern for modeling the future rainfall and projecting future soil erosion. In the present study, future rainfall has been generated with the downscaling of GCM (Global Circulation Model) data of Mandakini river basin, a hilly catchment in the state of Uttarakhand, India, to obtain future impact on soil erosion within the basin. The USLE is an erosion prediction model designed to predict the long-term average annual soil loss from specific field slopes in specified landuse and management systems (i.e., crops, rangeland, and recreational areas) using remote sensing and GIS technologies. Future soil erosion has shown increasing trend due to increasing rainfall which has been generated from the statistical-based downscaling method.

  7. Antiphasing Between Rainfall in Africa's Rift Valley and North America's Great Basin

    NASA Technical Reports Server (NTRS)

    Broecker, Wallace S.; Pettet, Dorothy; Hajdas, Irena; Lin, Jo; Clark, Elizabeth

    1998-01-01

    The beginning of the Bolling-Allerod warm period is marked in Greenland ice by an abrupt rise in (Delta)O-18, an abrupt drop in dust rain, and an abrupt increase in atmospheric methane content. The surface waters in the Norwegian Sea underwent a simultaneous abrupt warming. At about this time, a major change in the pattern of global rainfall occurred. Lake Victoria (latitude 0deg), which prior to this time was dry, was rejuvenated. The Red Sea, which prior to this time was hypersaline, freshened. Lake Lahontan, which prior to this time had achieved its largest size, desiccated. Whereas the chronologic support for the abruptness of the hydrologic changes is firm only for the Red Sea, in keeping with evidence obtained well away from the nor-them Atlantic in the Santa Barbara basin and the Cariaco Trench, the onset and end of the millennial-duration climate events were globally abrupt. If so, the proposed linkage between the size of African closed basin lakes and insolation cycles must be reexamined.

  8. Tectonic controls of the North Anatolian Fault System (NAFS) on the geomorphic evolution of the alluvial fans and fan catchments in Erzincan pull-apart basin; Turkey

    NASA Astrophysics Data System (ADS)

    Sarp, Gulcan

    2015-02-01

    The Erzincan pull-apart basin is located in the eastern section of the North Anatolian Fault System (NAFS). The tectonic evolution of this basin is mostly controlled by strike slip master faults of the NAFS. This study examines the topography-structure relationships in an effort to evaluate the tectonic signatures in the landscape, paying special attention to recent tectonic activity. In the study, the main focus is on the tectonic controls of the NAFS on the geomorphic evolution of alluvial fans and fan catchments in the Erzincan pull-apart basin. The observations of the amount of tilting of the alluvial fans (β) and its relation with morphometric (Asymmetry Factor (AF), Hypsometric Integral (HI), Fractal analysis of drainage networks (D)) properties of the fan catchments provide valuable information about the tectonic evolution of the basin area. The results of the analyses showed that the alluvial fan and fan catchment morphology in the pull-apart basin are mainly controlled by the ongoing tectonic activity of the NAFS. The fault system in the basin has controlled the accommodation space by causing differential subsidence of the basin, and aggradation processes by causing channel migration, channel incision and tilting the alluvial fans.

  9. Provenance and composition of Eocene-Oligocene mudrocks of the Thrace Basin (North-east Greece)

    NASA Astrophysics Data System (ADS)

    Perri, Francesco; Caracciolo, Luca; Critelli, Salvatore; Dominici, Rocco; Muto, Francesco; Manetti, Piero

    2013-04-01

    The aim of this study is to provide new insights on Middle Eocene to Oligocene clastics of the Thrace Basin in Greece, recording synchronously phases of post-Cretaceous collision and subsequent Tertiary extension. Sedimentological and stratigraphic studies associated to the distribution of major and trace elements and the mineralogical composition of the analyzed mudrocks, are pivotal factors to reconstruct the sedimentary evolution of the Thrace Basin. The distribution of some major and trace elements (such as Fe, Mg Cr and Ni, typical of mafic source, and Al, Ti, La and Nb, typical of felsic source) for the studied samples, reflects heterogeneous source areas characterized by both felsic and mafic composition. The mineralogical composition, mainly characterized by variations in 10 Å-minerals (illite and micas), mixed-layers phases, kaolinite and chlorite amounts, coupled with the A-CN-K plot suggest a complex evolution. This may be related to (1) different source areas characterized by different conditions of weathering rates, (2) different conditions of balance between physical (tectonism/uplift/erosion) and chemical processes. The studied samples are characterized by a linear trend subparallel to A-CN join reflecting weathering from granitoid rocks, and a linear trend subparallel to A-K join and plot near the A apex reflecting the abundance of secondary clay minerals (e.g., kaolinite) over primary minerals (e.g., feldspars). The higher values of Avdira samples are anticipated because of the increased production of aluminous minerals during chemical weathering, as also showed in the mineralogical analyses. The observed trends may be result of non-steady state weathering conditions where active tectonism and uplift allow erosion of all zones within weathering profiles developed on source rocks. The occurrence of variable amount of labile minerals in studied rocks corresponds to variable degree of weathering in the source terrain. By the way, the CIA values

  10. Deformation History of the Haymana Basin: Structural Records of Closure-Collision and Subsequent Convergence (Indentation) Events at the North-Central Neotethys (Central Anatolia, Turkey)

    NASA Astrophysics Data System (ADS)

    Gülyüz, Erhan; Özkaptan, Murat; Kaymakcı, Nuretdin

    2016-04-01

    Gondwana- (Tauride Platfrom and Kırşehir Block) and Eurasia (Pontides) - derived continental blocks bound the Haymana basin, in the south and north, respectively. Boundaries between these blocks are signed by İzmir-Ankara-Erzincan and debatable Intra-Tauride Suture zones which are straddled by the Haymana Basin in the region. In this regard, deformation recorded in the upper Cretaceous to middle Eocene deposits of the basin is mainly controlled by the relative movements of these blocks. Therefore, understanding the structural evolution of the Haymana Basin in a spatio-temporal concept is crucial to shed some light on some debatable issues such as ; (1) timing of late stage subduction histories of various branches of Neotethys and subsequent collision events, (2) effects of post-collisional tectonic activity in the Haymana region. Fault kinematic analyses (based on 623 fault-slip data from 73 stations) indicate that the basin was subjected to initially N-S to NNE-SSW extension until middle Paleocene and then N-S- to NNE-SSW- directed continuous compression and coeval E-W to ESE-WNW extension up to middle Miocene. These different deformation phases correspond to the fore-arc (closure) and foreland (collision and further convergence) stages of the basin. Additionally, fold analyses (based on 1017 bedding attitudes) and structural mapping studies show that development of folds and major faults are coeval and they can be explained by principle stress orientations of the second deformation phase. The Haymana basin is, based on the trends of E-W- and WNW-ESE- directed structures at the south-eastern and the north-western parts of the basin, respectively, divided into two structural segments. The balanced cross-sections also indicate ~4% and ~25% shortening at the north-western and south-eastern segments, respectively. The differences in amounts of shortenings are explained by reduce in effectiveness zone of basin-bounding thrust faults towards west. On the other hand

  11. Regression Equations for Estimating Concentrations of Selected Water-Quality Constituents for Selected Gaging Stations in the Red River of the North Basin, North Dakota, Minnesota, and South Dakota

    USGS Publications Warehouse

    Williams-Sether, Tara

    2004-01-01

    The Dakota Water Resources Act, passed by the U.S. Congress on December 15, 2000, authorized the Secretary of the Interior to conduct a comprehensive study of future water-quantity and quality needs of the Red River of the North Basin in North Dakota and possible options to meet those water needs. Previous Red River of the North Basin studies conducted by the Bureau of Reclamation used streamflow and water-quality data bases developed by the U.S. Geological Survey that included data for 1931-84. As a result of the recent congressional authorization and results of previous studies by the Bureau of Reclamation, redevelopment of the streamflow and water-quality data bases with current data through 1999 are needed in order to evaluate and predict the water-quantity and quality effects within the Red River of the North Basin. This report provides updated statistical summaries of selected water-quality constituents and streamflow and the regression relations between them. Available data for 1931-99 were used to develop regression equations between 5 selected water-quality constituents and streamflow for 38 gaging stations in the Red River of the North Basin. The water-quality constituents that were regressed against streamflow were hardness (as CaCO3), sodium, chloride, sulfate, and dissolved solids. Statistical summaries of the selected water-quality constituents and streamflow for the gaging stations used in the regression equations development and the applications and limitations of the regression equations are presented in this report.

  12. Pliocene facies trends and controls on deposition of lower gusher shallow gas reservoirs, North Coles Levee Field, San Joaquin Basin, California

    SciTech Connect

    Steward, D.C.; Gillespie, J.M. )

    1994-04-01

    Net sand isochore maps of three Pliocene-age Lower Gusher sands in the Etchegoin Formation at North Coles Levee field, southern San Joaquin basin, California display geometries suggestive of deposition in delta front settings. The north-south depositional strike of these sands approximately parallels the orientation of the paleoshoreline. The sands thicken and display greater lateral continuity near distributary channel sands, which are oriented east-northeast approximately perpendicular to the shoreline. A comparison of the isochore maps of each of the three sand bodies show that they are stacked vertically above each other, indicating that the position of the shoreline remained stationary during deposition of the Gusher interval. This apparent stillstand of the shoreline is superimposed on an overall regression of the sea from the San Joaquin basin during the Pliocene. Therefore, we believe that the Lower Gusher sands were deposited during a period of relatively rapid basin subsidence, which negated the effects of the marine regression and caused vertical aggradation of shoreline facies in the North Coles Levee area. The Lower Gusher interval at North and South Coles Levee contains the most prolific shallow gas reservoirs on the Bakersfield Arch. A thorough knowledge of depositional trends in the Lower Gusher interval increases the probability of encountering reservoir-quality facies in exploration programs focusing on Pliocene gas.

  13. Sequestration of Carbon Dioxide with Enhanced Gas Recovery-CaseStudy Altmark, North German Basin

    SciTech Connect

    Rebscher, Dorothee; Oldenburg, Curtis M.

    2005-10-12

    Geologic carbon dioxide storage is one strategy for reducingCO2 emissions into the atmosphere. Depleted natural gas reservoirs are anobvious target for CO2 storage due to their proven record of gascontainment. Germany has both large industrial sources of CO2 anddepleting gas reservoirs. The purpose of this report is to describe theanalysis and modeling performed to investigate the feasibility ofinjecting CO2 into nearly depleted gas reservoirs in the Altmark area inNorth Germany for geologic CO2 storage with enhanced gasrecovery.

  14. Export of dissolved organic carbon from the Penobscot River basin in north-central Maine

    USGS Publications Warehouse

    Huntington, Thomas G.; Aiken, George R.

    2013-01-01

    Dissolved organic carbon (DOC) flux from the Penobscot River and its major tributaries in Maine was determined using continuous discharge measurements, discrete water sampling, and the LOADEST regression software. The average daily flux during 2004–2007 was 71 kg C ha−1 yr−1 (392 Mt C d−1), an amount larger than measured in most northern temperate and boreal rivers. Distinct seasonal variation was observed in the relation between concentration and discharge (C–Q). During June through December (summer/fall), there was a relatively steep positive C–Q relation where concentration increased by a factor of 2–3 over the approximately 20-fold range of observed stream discharge for the Penobscot River near Eddington, Maine. In contrast, during January through May (winter/spring), DOC concentration did not increase with increasing discharge. In addition, we observed a major shift in the C–Q between 2004–2005 and 2006–2007, apparently resulting from unprecedented rainfall, runoff, and soil flushing beginning in late fall 2005. The relative contribution to the total Penobscot River basin DOC flux from each tributary varied dramatically by season, reflecting the role of large regulated reservoirs in certain basins. DOC concentration and flux per unit watershed area were highest in tributaries containing the largest areas in palustrine wetlands. Tributary DOC concentration and flux was positively correlated to percentage wetland area. Climatic or environmental changes that influence the magnitude or timing of river discharge or the abundance of wetlands will likely affect the export of DOC to the near-coastal ocean.

  15. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data.

    PubMed

    Jiao, Jiu Jimmy; Zhang, Xiaotao; Liu, Yi; Kuang, Xingxing

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003-2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km3 in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes.

  16. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data.

    PubMed

    Jiao, Jiu Jimmy; Zhang, Xiaotao; Liu, Yi; Kuang, Xingxing

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003-2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km3 in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes. PMID:26506230

  17. Upper Jurassic and Lower Cretaceous facies relationships in a passive margin basin, western North Atlantic

    SciTech Connect

    Prather, B.E.

    1988-02-01

    Correlation of facies from hydrocarbon-bearing continental and transitional marine sandstones to time-equivalent high-energy shelf-margin carbonates provide insight into hydrocarbon habitats of the Baltimore Canyon basin. These facies occur within a thick (> 10,000 ft) prograded wedge of shelf sediments in this passive margin basin. Wells drilled to test structural closures in shallow-water (< 600 ft) areas of Baltimore Canyon penetrate clastic facies which are time-equivalent to the downdip carbonate facies tested in deep-water wells. Numerous hydrocarbon shows, including a noncommercial gas and gas-condensate accumulation, occur with sandstone units that were deposited in prograding continental/fluvial and transitional marine environments located updip of the Oxfordian/Kimmeridgian carbonate shelf edge. The continental and transitional facies are overlain by a fine-grained deltaic complex which forms a regionally extensive top seal unit. The deltaic complex was deposited during aggradation of the Kimmeridgian through Berriasian shelf-margin carbonates penetrated by the deep-water wells. Deep-water wells (> 5000 ft) drilled off the continental shelf edge to test large structural closures along the downdip termination of the Upper Jurassic/Lower Cretaceous carbonate shelf edge encountered no significant hydrocarbon shows. Reservoir rocks in these wells consist of (1) oolite grainstone which was deposited within a shoal-water complex located at the Aptian shelf edge, and (2) coral-stromatoporoid grainstone and boundstone which formed an aggraded shelf-margin complex located at the Kimmeridgian through Berriasian shelf edge. Structural closures with reservoir and top seals are present in both updip and downdip trends. The absence of hydrocarbon shows in downdip carbonate reservoirs suggests a lack of source rocks available to charge objectives at the shelf margin.

  18. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data

    PubMed Central

    Jiao, Jiu Jimmy; Zhang, Xiaotao; Liu, Yi; Kuang, Xingxing

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003–2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km3 in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes. PMID:26506230

  19. Can mima-like mounds be Vertisol relics (Far North Region of Cameroon, Chad Basin)?

    NASA Astrophysics Data System (ADS)

    Diaz, Nathalie; Dietrich, Fabienne; Cailleau, Guillaume; Sebag, David; Ngounou Ngatcha, Benjamin; Verrecchia, Eric P.

    2016-05-01

    Non-anthropogenic earth mounds, defined as mima-like mounds in this study, have recently been observed in non-carbonate watersheds along the Sudano-Sahelian belt in the Chad Basin. In the Diamare piedmont (northern Cameroon) they are particularly well developed within stream networks. In less eroded areas, they occur as whaleback, flattened morphologies, or even as buried features. All these shapes are composed of clay-rich sediment associated with high proportions of secondary carbonate nodules and Fesbnd Mn micro-nodules. Their soil structure is prismatic to massive and vertical cracks are observed locally. Grain-size distributions emphasize the clay-rich nature of the sediment, with average clay contents of 32% ± 12.8% (n = 186), which is significantly higher than the clay content in the adjacent sediments in the landscape (mean = 10% ± 4%, n = 21). Moreover, high proportions of smectite characterize the soil, with average contents of 34 ± 7% (n = 25). At the micro-scale, the groundmass has a cross-striated b-fabric, with embedded smooth subangular quartz and feldspar grains of the silt-size fraction. All the characteristics point to altered vertic properties in the clay-rich sediment composing the mima-like mounds. Mima-like mounds are thus interpreted as degraded Vertisols. Compared to present-day Vertisols occurring in the piedmont, mima-like mounds are located upstream. It is thus proposed that the Vertisol areas were more extensive during a former and wetter period than the present-day. Subsequent changing climatic conditions increased erosion, revealing the gilgai micro-relief by preferential erosion in micro-lows rather than in micro-highs. Mima-like mounds of the Chad Basin might thus result from pedogenesis combined with later erosion. These local processes can be inherited from regional climatic variations during the Late Pleistocene-Holocene and likely be related to the African Humid Period.

  20. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-04-26

    The principal research effort for the first half of Year 3 of the project has been resource assessment. Emphasis has been on estimating the total volume of hydrocarbons generated and the potential amount of this resource that is classified as deep (>15,000 ft) gas in the North Louisiana Salt Basin, the Mississippi Interior Salt Basin, the Manila Subbasin and the Conecuh Subbasin. The amount of this resource that has been expelled, migrated and entrapped is also the focus of the first half of Year 3 of this study.

  1. Phylogeography of the pallid kangaroo mouse, Microdipodops pallidus: a sand-obligate endemic of the Great Basin, western North America

    PubMed Central

    Hafner, John C; Upham, Nathan S; Reddington, Emily; Torres, Candice W

    2008-01-01

    Aim Kangaroo mice, genus Microdipodops Merriam, are endemic to the Great Basin and include two species: M. pallidus Merriam and M. megacephalus Merriam. The pallid kangaroo mouse, M. pallidus, is a sand-obligate desert rodent. Our principal intent is to identify its current geographical distribution and to formulate a phylogeographical hypothesis for this taxon. In addition, we test for orientation patterns in haplotype sharing for evidence of past episodes of movement and gene flow. Location The Great Basin Desert region of western North America, especially the sandy habitats of the Lahontan Trough and those in south-central Nevada. Methods Mitochondrial DNA sequence data from portions of three genes (16S ribosomal RNA, cytochrome b, and transfer RNA for glutamic acid) were obtained from 98 individuals of M. pallidus representing 27 general localities sampled throughout its geographical range. Molecular sequence data were analysed using neighbour-joining, maximum-parsimony, maximum-likelihood and Bayesian methods of phylogenetic inference. Directional analysis of phylogeographical patterns, a novel method, was used to examine angular measurements of haplotype sharing between pairs of localities to detect and quantify historical events pertaining to movement patterns and gene flow. Results Collecting activities showed that M. pallidus is a rather rare rodent (mean trapping success was 2.88%), and its distribution has changed little from that determined three-quarters of a century ago. Two principal phylogroups, distributed as eastern and western moieties, are evident from the phylogenetic analyses (mean sequence divergence for cytochrome b is c. 8%). The western clade shows little phylogenetic structure and seems to represent a large polytomy. In the eastern clade, however, three subgroups are recognized. Nine of the 42 unique composite haplotypes are present at two or more localities and are used for the orientation analyses. Axial data from haplotype sharing

  2. Cenozoic lithospheric evolution of the Bohai Bay Basin, eastern North China Craton: Constraint from tectono-thermal modeling

    NASA Astrophysics Data System (ADS)

    Liu, Qiongying; He, Lijuan; Huang, Fang; Zhang, Linyou

    2016-01-01

    It is well established that the lithosphere beneath the eastern North China Craton (NCC) had been thinned before the Cenozoic. A 2D multi-phase extension model, in which the initial crustal and lithospheric thicknesses are variable, is presented to reconstruct the initial thicknesses of the crust and lithosphere in the early Cenozoic and to further investigate the lithospheric evolution beneath the eastern NCC through the Cenozoic. We conduct thermal modeling along three profiles from east to west in the Bohai Bay Basin, which is the center of the lithospheric destruction and thinning of the NCC. Using multiple constraints, such as tectonic subsidence, the present-day heat flow and the Moho depth, we determine the initial crustal and lithospheric thicknesses of the Bohai Bay Basin before the Cenozoic rift to be 33-36 km and 80-105 km, respectively. The model results show that the most rapid lithospheric thinning during the Cenozoic occurred in the middle Eocene for most depressions, and the thinning activity ceased at the end of the Oligocene, reaching a minimum lithospheric thickness of 53-74 km, followed by a thermal relaxation phase. Combined with previous studies, we infer that the lithosphere beneath the eastern NCC experienced two stages of alternating thinning and thickening: notable thinning in the Early Cretaceous and Paleogene, and thickening in the Late Cretaceous and late Cenozoic. We believe that thermo-chemical erosion, together with extension, was probably the major mechanism of the significant lithospheric removal during the Mesozoic, whereas the Cenozoic lithospheric thinning was mainly dominated by tectonic extension in the eastern NCC; lithospheric thickening was generally a result of thermal cooling.

  3. Water budget estimates for the 14 hydrographic areas in the middle Humboldt River basin, north-central Nevada

    USGS Publications Warehouse

    Berger, David L.

    2000-01-01

    Water budgets were developed for the 14 hydrographic areas in the middle Humboldt River Basin of north-central Nevada. The water budgets include estimates of average annual precipitation, runoff, water yield, ground-water recharge and subsurface flow, and evapotranspiration (ET) determined from recently developed or revised methods. Ground-water pumping is not included in the budget estimates. The estimated budgets represent average annual volumes over a 30-year reference period ( 1961-90) and are compared to water budgets developed more than 30 years ago. Annual inflow to the middle Humboldt River basin is about 5 million acre-feet. An estimated 4.6 million is from precipitation in the 14 hydrographic areas and about 350,000 acre-feet is inflow from the Humboldt River. Annual outflow is about 5.1 million acre-feet, of which ET accounts for 4.8 million acre-feet, and outflow of the Humboldt River is about 300,000 acre-feet. Average annual precipitation in the hydrographic areas for 1961-90 ranged from 105 to 128 percent of that for the 1912-63 period. The annual volume ofET in the 14 areas was 102 to almost 134 percent of that previously estimated, although the percentage of annual precipitation lost to ET is similar. About 15 percent of the annual precipitation in mountain-block areas becomes water yield (either ground water or runoff) as compared to previous estimates of 11 percent. On the basis of mass-balance calculations, ground-water recharge on average is about 145 percent of previous estimates.

  4. Element concentrations in bed sediment of the Yellowstone River basin, Montana, North Dakota, and Wyoming; a retrospective analysis

    USGS Publications Warehouse

    Peterson, D.A.; Zelt, R.B.

    1999-01-01

    Chemical data for bed sediment were analyzed as part of the U.S. Geological Survey National Water-Quality Assessment Program investigation of the Yellowstone River Basin in parts of Montana, North Dakota, and Wyoming. The primary data set consisted of about 13,000 samples collected during 1974-79 for the National Uranium Resource Evaluation program. Data were available for 50 elements, although not all samples were analyzed for all elements. Element concentrations varied spatially and were associated with geologic settings or ecoregions. Factor analysis indicated three groups of associated elements: factor 1 elements were strongly correlated with basaltic rocks, factor 2 elements were strongly correlated with granitic rocks, and factor 3 elements were strongly correlated with carbonate rocks. Scores for factor 1 were highest for bed-sediment samples associated with volcanic rocks of Tertiary and Cretaceous age in the Absaroka volcanic field and crystalline rocks of Precambrian age in the Beartooth Mountains. Scores for factor 2 were highest for samples associated with volcanic rocks of Quaternary age on the Yellowstone Plateau, crystalline rocks of Precambrian age, and sedimentary rocks of Tertiary age in the Wyoming Basin ecoregion. Scores for factor 3 were highest in samples associated with sedimentary rocks of Paleozoic age and volcanic rocks of Cretaceous and Tertiary age. Descriptive statistics are presented to serve as a baseline for element concentrations in bed sediment associated with eight geologic settings or ecoregions in the study unit. Some of the concentrations of chromium, copper, lead, nickel, and zinc in bed-sediment samples from areas of crystalline rocks in the Beartooth Mountains and other formations in the western part of the study unit exceeded sediment-quality assessment values associated with toxic effects to aquatic life.

  5. Many objective optimization and impact assessment of water management options in the Jaguaribe Basin of North East Brazil

    NASA Astrophysics Data System (ADS)

    Hurford, A. P.; Huskova, I.; Matrosov, E.; Harou, J. J.

    2012-12-01

    The Jaguaribe river basin in the north east of Brazil lies in the country's driest state, Ceará. Rainfall is concentrated in six months of the year, evapotranspiration can reach 2000 mm per year and a high proportion of the population relies on irrigated agriculture for their subsistence or livelihood. The current water management strategy involves negotiating monthly release rates from each of the basin's three major reservoirs twice a year. The state water management company leads these negotiations with representatives of various water user groups; releases are decided based on the currently stored volume and limited modelling of release scenarios. Presently reservoirs are managed such that municipal demands are guaranteed for 30 months from the date of negotiation. We use multi-objective optimization to search for the pareto-optimal number of months of municipal demand to be guaranteed, and the shape of release rules (based on stored volume). System performance is assessed by comparing flow-duration curves and livelihood factors, such as riparian farm land availability and fishery quality , in addition to the satisfaction of demands in the region supplied by each reservoir. Historical monthly flows are used to simulate the system over 90 years. Results shows the trade-offs between different performance measures and the effects of management option combinations on different water users. A few climate change projections of reservoir inflows are used to assess how a selection of the resulting release rules might perform against the same measures under altered future hydrological conditions. The proposed approach helps planners evaluate the impacts of management options and allows finding balanced stakeholder-backed ways to reduce negative impacts on the environment and the region's vulnerable groups while maintaining overall system performance.

  6. Major Crustal Fault Zone Trends and Their Relation to Mineral Belts in the North-Central Great Basin, Nevada

    USGS Publications Warehouse

    Rodriguez, Brian D.; Sampson, Jay A.; Williams, Jackie M.

    2007-01-01

    The Great Basin physiographic province covers a large part of the western United States and contains one of the world's leading gold-producing areas, the Carlin Trend. In the Great Basin, many sedimentary-rock-hosted disseminated gold deposits occur along such linear mineral-occurrence trends. The distribution and genesis of these deposits is not fully understood, but most models indicate that regional tectonic structures play an important role in their spatial distribution. Over 100 magnetotelluric (MT) soundings were acquired between 1994 and 2001 by the U.S. Geological Survey to investigate crustal structures that may underlie the linear trends in north-central Nevada. MT sounding data were used to map changes in electrical resistivity as a function of depth that are related to subsurface lithologic and structural variations. Two-dimensional (2-D) resistivity modeling of the MT data reveals primarily northerly and northeasterly trending narrow 2-D conductors (1 to 30 ohm-m) extending to mid-crustal depths (5-20 km) that are interpreted to be major crustal fault zones. There are also a few westerly and northwesterly trending 2-D conductors. However, the great majority of the inferred crustal fault zones mapped using MT are perpendicular or oblique to the generally accepted trends. The correlation of strike of three crustal fault zones with the strike of the Carlin and Getchell trends and the Alligator Ridge district suggests they may have been the root fluid flow pathways that fed faults and fracture networks at shallower levels where gold precipitated in favorable host rocks. The abundant northeasterly crustal structures that do not correlate with the major trends may be structures that are open to fluid flow at the present time.

  7. Statistical Aspects of North Atlantic Basin Tropical Cyclones During the Weather Satellite Era, 1960-2013: Part 1

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2014-01-01

    A tropical cyclone is described as a warm-core, nonfrontal, synoptic-scale system that originates over tropical or subtropical waters, having organized deep convection and closed surface wind circulation (counterclockwise in the Northern Hemisphere) about a well defined center. When its sustained wind speed equals 34-63 kt, it is called a tropical (or subtropical) storm and is given a name (i.e., alternating male and female names, beginning in 1979); when its sustained wind speed equals 64-95 kt, it is called a hurricane (at least in the Eastern Pacific and North Atlantic basin); and when its sustained wind speed equals 96 kt or higher, it is called an intense or major hurricane (i.e., categories 3-5 on the Saffir-Simpson Hurricane Wind Scale). Although tropical cyclones have been reported and described since the voyages of Columbus, a detailed record of their occurrences extends only from 1851 to the present, with the most reliable portion extending only from about 1945 to the present, owing to the use of near-continuous routine reconnaissance aircraft monitoring flights and the use of satellite imagery (beginning in 1960; see Davis). Even so, the record may still be incomplete, possibly missing at least one tropical cyclone per yearly hurricane season, especially prior to the use of continuous satellite monitoring. In fact, often an unnamed tropical cyclone is included in the year-end listing of events at the conclusion of the season, following post-season analysis (e.g., as happened in 2011 and 2013, each having one unnamed event). In this two-part Technical Publication (TP), statistical aspects of the North Atlantic basin tropical cyclones are examined for the interval 1960-2013, the weather satellite era. Part 1 examines some 25 parameters of tropical cyclones (e.g., frequencies, peak wind speed (PWS), accumulated cyclone energy (ACE), etc.), while part 2 examines the relationship of these parameters against specific climate-related factors. These studies are

  8. Geology and physiography of the continental margin north of Alaska and implications for the origin of the Canada Basin

    USGS Publications Warehouse

    Grantz, Arthur; Eittreim, Stephen L.; Whitney, O.T.

    1979-01-01

    The continental margin north of Alaska is of Atlantic type. It began to form probably in Early Jurassic time but possibly in middle Early Cretaceous time, when the oceanic Canada Basin of the Arctic Ocean is thought to have opened by rifting about a pole of rotation near the Mackenzie Delta. Offsets of the rift along two fracture zones are thought to have divided the Alaskan margin into three sectors of contrasting structure and stratigraphy. In the Barter Island sector on the east and the Chukchi sector on the west the rift was closer to the present northern Alaska mainland than in the Barrow sector, which lies between them. In the Barter Island and Chukchi sectors the continental shelf is underlain by prisms of clastic sedimentary rocks that are inferred to include thick sections of Jurassic and Neocomian (lower Lower Cretaceous) strata of southern provenance. In the intervening Barrow sector the shelf is underlain by relatively thin sections of Jurassic and Neocomian strata derived from northern sources that now lie beneath the outer continental shelf. The rifted continental margin is overlain by a prograded prism of Albian (upper Lower Cretaceous) to Tertiary clastic sedimentary rocks that comprises the continental terrace of the western Beaufort and northern Chukchi Seas. On the south the prism is bounded by Barrow arch, which is a hingeline between the northward-tilted basement surface beneath the continental shelf of the western Beaufort Sea and the southward-tilted Arctic Platform of northern Alaska. The Arctic platform is overlain by shelf clastic and carbonate strata of Mississippian to Cretaceous age, and by Jurassic and Cretaceous clastic strata of the Colville foredeep. Both the Arctic platform and Colville foredeep sequences extend from northern Alaska beneath the northern Chukchi Sea. At Herald fault zone in the central Chukchi Sea they are overthrust by more strongly deformed Cretaceous to Paleozoic sedimentary rocks of Herald arch, which trends

  9. Identifying hydrological pathways in the north basin of Lake Kivu using stable isotope ratios of meteoric recharge and surface water

    NASA Astrophysics Data System (ADS)

    Balagizi, Charles M.; Kasereka, Marcellin M.; Terzerand, Stefan; Cuoco, Emilio; Liotta, Marcello

    2016-04-01

    A rain-gauge network of 12 stations was installed at different altitudes at Nyiragongo volcano (DR Congo) and surroundings and sampled on monthly basis between December 2013 and June 2015 to evaluate the isotopic signature of the meteoric recharge. Additional samples were collected on monthly basis from 5 rivers, 7 springs, 3 profiles in Kabuno bay and 2 others in the Main Basin of Lake Kivu to determine their water isotope compositions (δ18O and δ2H). The precipitation, surface and groundwater δ18O and δ2H values were thereafter used to estimate the groundwater recharge area, surface and groundwater inflow level to Lake Kivu, and for modeling water circulation in the north basin of Lake Kivu. The monthly precipitation isotope composition varied in a large range, whereas mean precipitation-weighed values ranged between -12.39‰ and 6.52‰ for δ2H, and from -4.02‰ to -0.91‰ for δ18O. Monthly values allowed to define a Local Meteoric Water Line of equation δ2H=7.96δ18O + 16.96. Our dataset, the first time series in the Virunga, implies that the δ18O and δ2H of precipitation are predominantly determined by the recycled moisture source area, while their clearly defined seasonality is driven by wind direction and precipitation amount changes. The δ18O, δ2H and deuterium-excess values revealed a convergence zone around Nyiragongo where the N-NE and S-SW trade winds come together. Moisture from the Nile River basin brought by the N-NE originating winds yielded depleted precipitation at local highlands, while that from the Congo River basin brought by the S-SW wind yielded enriched precipitation at lowlands. Rivers and springs monthly are included in the range of monthly precipitation values, and are thus indicative of lack of significant evaporation during aquifer recharge. The mean rivers and springs δ2H and δ18O, and the mean precipitation-weighed values revealed the presence of shallow groundwater recharged between 2100 and 2700m a.s.l., and deep

  10. Trace elements and organic chemicals in stream-bottom sediments and fish tissues, Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1992-95

    USGS Publications Warehouse

    Brigham, M.E.; Goldstein, R.M.; Tornes, L.H.

    1998-01-01

    Stream-bottom sediment and fish-tissue samples from the Red River of the North Basin, were analyzed for a large suite of chemical elements and organic chemicals. Cadmium, lead, and mercury were widespread in sediments, at concentrations not indicative of acute contamination. Mercury, the element of greatest health concern in the region, was detected at low concentrations in 38 of 43 sediment samples (<0.02-0.13 micrograms per gram) and all of eleven fish-liver samples (0.03-0.6 micrograms per gram dry weight, or 0.0066-0.13 micrograms per gram wet weight). Concentrations of many elements appeared to be controlled by mineral rather than anthropogenic sources. DDT and its metabolites were the most frequently detected synthetic organochlorines: p,p'-DDE was detected in 9 of 38 sediment samples (concentration range: <1-16 nanograms per gram) and also frequently in whole-fish samples. Total DDT (the sum of DDT and its metabolites) concentrations ranged from <5 to 217 nanograms per gram, and at least one component of total DDT was detected in 19 of 23 fish samples. Concentrations of DDT and its metabolites in stream sediments were significantly higher in the intensively cropped Red River Valley Lake Plain, compared to upland areas, probably because of greater historical DDT usage in the lake plain. Several polycyclic aromatic hydrocarbons were detected in stream-bottom sediments. Although the potentially toxic chemicals measured in this study were at low levels, relative to more contaminated areas of the Nation, maximum concentrations of some chemicals are of concern because of their possible effects on aquatic biota and human health.

  11. Simulation of conservative-constituent transport in the Red River of the North Basin, North Dakota and Minnesota, 2003-04

    USGS Publications Warehouse

    Nustad, Rochelle A.; Bales, Jerad D.

    2005-01-01

    Population growth along with possible future droughts in the Red River of the North (Red River) Basin will create an increasing need for reliable water supplies. Therefore, as a result of the Dakota Water Resources Act of 2000, the Bureau of Reclamation identified eight water-supply alternatives (including a no-action alternative) to meet future water needs in the basin. Because of concerns about the possible effects of the alternatives on water quality in the Red River and the Sheyenne River and in Lake Winnipeg, Manitoba, the Bureau of Reclamation needs to prepare an environmental impact statement that describes the specific environmental effects of each alternative. To provide information for the environmental impact statement, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, conducted a study to develop and apply a water-quality model, hereinafter referred to as the Red River water-quality model, to part of the Red River and the Sheyenne River to simulate conservative-constituent transport in the Red River Basin. The Red River water-quality model is a one-dimensional, steady-state flow and transport model for selected constituents in the Red River and the Sheyenne River. The model simulates the flow and transport of total dissolved solids, sulfate, and chloride during steady-state conditions. The physical model domain includes the Red River from the confluence of the Bois de Sioux and Otter Tail Rivers to the Red River at Emerson, Manitoba, and the Sheyenne River from above Harvey, N. Dak., to the confluence with the Red River. The Red River water-quality model was calibrated and tested using data collected at 34 sites from September 15 through 16, 2003, and from May 10 through 13, 2004. Water-quality samples were collected during low, steady-flow conditions from September 15 through 16, 2003, and during medium, unsteady-flow conditions from May 10 through 13, 2004. The simulated total dissolved-solids, sulfate, and chloride

  12. Buried-hill discoveries in Damintan depression of North China basin

    SciTech Connect

    Xiaoguang, T.; Zuan, H.

    1988-01-01

    The Damintan fault depression is about 20 km west of Shenyang, Liaoning Province, North China, and is a small Tertiary continental depression, covering only about 800 km/sup 2/. In the depression, the Tertiary system unconformably overlies upper-middle Proterozoic sedimentary rocks and Archean metamorphic rocks. The Tertiary system is up to 6,600 m in thickness. Source rocks are in the third and fourth members of the Eocens Shahejie Formation. Buried-hill traps were formed in Proterozoic carbonates and metamorphic rocks of the Archean. Fault block, stratigraphic, and lithologic traps also occur in sandstones of the Shahejie Formation, especially in those of the third member. Several buried-hill-drape traps occur in the depression. The various types of oil pole in each buried-hill-drape trap constitute a complex hydrocarbon accumulation zone. A series of oil fields have been found in the depression. The crude oil is characterized by high wax content and high pour point.

  13. Basin-scale coherence in phenology of shrimps and phytoplankton in the North Atlantic Ocean.

    PubMed

    Koeller, P; Fuentes-Yaco, C; Platt, T; Sathyendranath, S; Richards, A; Ouellet, P; Orr, D; Skúladóttir, U; Wieland, K; Savard, L; Aschan, M

    2009-05-01

    Climate change could lead to mismatches between the reproductive cycles of marine organisms and their planktonic food. We tested this hypothesis by comparing shrimp (Pandalus borealis) egg hatching times and satellite-derived phytoplankton bloom dynamics throughout the North Atlantic. At large spatial and long temporal (10 years or longer) scales, hatching was correlated with the timing of the spring phytoplankton bloom. Annual egg development and hatching times were determined locally by bottom water temperature. We conclude that different populations of P. borealis have adapted to local temperatures and bloom timing, matching egg hatching to food availability under average conditions. This strategy is vulnerable to interannual oceanographic variability and long-term climatic changes.

  14. Atmospheric wet deposition of soluble macro-nutrients in the Cilician Basin, north-eastern Mediterranean sea.

    PubMed

    Ozsoy, Türkan

    2003-12-01

    In order to estimate wet deposition atmospheric fluxes of macro-nutrients into the eastern Mediterranean coastal waters, soluble inorganic phosphate (PO4(3-)), nitrate (NO3-) and nitrite (NO2-) concentrations in precipitation (from February 1996 to June 1997) have been measured at a coastal sampling site, Erdemli, Turkey. Water-soluble inorganic PO4(3)-P, a reactive, bioavailable, limiting macro-nutrient in the oligotrophic waters of the eastern Mediterranean was studied with respect to its contribution to biological productivity. Reactive PO4(3-)-P and NO2(-) + NO3(-)-N concentrations were found to be highly variable in rainwater samples. One of the aims of the study was to determine the contribution of dust transport to the soluble macro-nutrient budget of the eastern Mediterranean. No differences were found between the mean reactive P and NO(2-) + NO3(-)-N concentrations of "red rain" and normal rain events. Most likely as a result of low solubility of crustal phosphorus, dust episodes were not found to be important sources of reactive P, in terms of wet deposition. The annual wet deposition fluxes of reactive PO4(3-)-P and NO2(-) + NO3(-)-N into the Cilician Basin were respectively estimated to be 0.010 g P m(-2) per year and 0.23 g N m(-2) per year, which are comparable to the fluxes from land-based sources in the north-eastern Mediterranean. The incorporation of water soluble bioavailable PO4(3-)-P and NO2(-) + NO3(-)-N delivered via atmospheric wet deposition could be responsible for approximately 3.3% (0.40 g C m(-2) per year) and 11.0% (1.31 g C m(-2) per year) respectively, of the mean annual new production in the north-eastern Mediterranean.

  15. Statistical Aspects of North Atlantic Basin Tropical Cyclones During the Weather Satellite Era, 1960-2013. Part 2

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2014-01-01

    This Technical Publication (TP) is part 2 of a two-part study of the North Atlantic basin tropical cyclones that occurred during the weather satellite era, 1960-2013. In particular, this TP examines the inferred statistical relationships between 25 tropical cyclone parameters and 9 specific climate-related factors, including the (1) Oceanic Niño Index (ONI), (2) Southern Oscillation Index (SOI), (3) Atlantic Multidecadal Oscillation (AMO) index, (4) Quasi-Biennial Oscillation (QBO) index, (5) North Atlantic Oscillation (NAO) index of the Climate Prediction Center (CPC), (6) NAO index of the Climate Research Unit (CRU), (7) Armagh surface air temperature (ASAT), (8) Global Land-Ocean Temperature Index (GLOTI), and (9) Mauna Loa carbon dioxide (CO2) (MLCO2) index. Part 1 of this two-part study examined the statistical aspects of the 25 tropical cyclone parameters (e.g., frequencies, peak wind speed (PWS), accumulated cyclone energy (ACE), etc.) and provided the results of statistical testing (i.e., runs-testing, the t-statistic for independent samples, and Poisson distributions). Also, the study gave predictions for the frequencies of the number of tropical cyclones (NTC), number of hurricanes (NH), number of major hurricanes (NMH), and number of United States land-falling hurricanes (NUSLFH) expected for the 2014 season, based on the statistics of the overall interval 1960-2013, the subinterval 1995-2013, and whether the year 2014 would be either an El Niño year (ENY) or a non-El Niño year (NENY).

  16. Geology and hydrocarbon potential of Dawson Bay Formation carbonate unit (Middle Devonian), Williston basin, North Dakota

    SciTech Connect

    Pound, W.

    1988-07-01

    The Middle Devonian Dawson Bay Formation carbonate unit is present in the subsurface of North Dakota except where truncated by postdepositional erosion. The carbonate unit thickens from the erosional limit to a maximum thickness of 47.5 m (156 ft) in Renville County and reaches a maximum depth of 3798 m (12,460 ft) below the surface in McKenzie County. In North Dakota, a submarine hardground separates the carbonate unit from the underlying second red bed member of the Dawson Bay Formation. The upper contact with the Souris River Formation is conformable except in those areas where the Dawson Bay Formation was exposed to subaerial erosion prior to deposition of the Souris River sediments. The Dawson Bay carbonate unit is predominantly dolomitic and fossiliferous limestone or fossiliferous dolostone. The carbonate unit can be subdivided into five lithofacies on the basis of characteristic fossil fauna, flora, and other lithologic features. Lithofacies analysis of the Dawson Bay carbonates suggests a shallowing-upward succession of depositional environments and associated energy zones as follows: shallow epeiric sea (very low energy), stromatoporoid biostrome/bioherm (low energy), very shallow epeiric sea (very low energy), restricted shallow epeiric sea (extremely low energy), and shallow epeiric sea shoreline (variable energy). Eogenetic diagenesis includes color-mottling, dolomitization of micrite to microcrystalline dolomite with penecontemporaneous anhydrite replacement of cryptalgal mudstones and boundstones, cementation by sparry calcite, and vuggy porosity development. Mesogenetic diagenesis includes formation of mosaic dolomites, cementation by blocky equant calcite, neomorphism, pressure-solution, fracturing, halite cementation, and hydrocarbon emplacement.

  17. Crustal thickness anomalies in the North Atlantic Ocean basin from gravity analysis

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Lin, Jian; Tucholke, Brian; Chen, Yongshun John

    2011-03-01

    Gravity-derived crustal thickness models were calculated for the North Atlantic Ocean between 76°N and the Chain Fracture Zone and calibrated using seismically determined crustal thickness. About 7% of the ocean crust is <4 km thick (designated as thin crust), and 58% is 4-7 km thick (normal crust); the remaining 35% is >7 km thick and is interpreted to have been affected by excess magmatism. Thin crust probably reflects reduced melt production from relatively cold or refractory mantle at scales of up to hundreds of kilometers along the spreading axis. By far the most prominent thick crust anomaly is associated with Iceland and adjacent areas, which accounts for 57% of total crustal volume in excess of 7 km. Much smaller anomalies include the Azores (8%), Cape Verde Islands (6%), Canary Islands (5%), Madeira (<4%), and New England-Great Meteor Seamount chain (2%), all of which appear to be associated with hot spots. Hot spot-related crustal thickening is largely intermittent, suggesting that melt production is episodic on time scales of tens of millions of years. Thickened crust shows both symmetrical and asymmetrical patterns about the Mid-Atlantic Ridge (MAR) axis, reflecting whether melt anomalies were or were not centered on the MAR axis, respectively. Thickened crust at the Bermuda and Cape Verde rises appears to have been formed by isolated melt anomalies over periods of only ˜20-25 Myr. Crustal thickness anomalies on the African plate generally are larger than those on the North American plate; this most likely results from slower absolute plate speed of the African plate over relatively fixed hot spots.

  18. Geoelectric investigation to delineate groundwater potential and recharge zones in Suki river basin, north Maharashtra

    NASA Astrophysics Data System (ADS)

    Gupta, Gautam; Patil, S. N.; Padmane, S. T.; Erram, Vinit C.; Mahajan, S. H.

    2015-10-01

    Suki river basin of Raver sub-division is located towards the northeastern part of Jalgaon district in Maharashtra State. The existing land use pattern of the region clearly shows that more than 60% of the area is utilized for agricultural sector. Groundwater is the major source of irrigation and domestic purposes. To assess the overall water resources development of Raver area for better environment in future, investigation was carried out with the help of geophysical indicators. Vertical electrical sounding studies were conducted at 17 stations in the study area using Wenner configuration. The study was aimed at characterizing the aquifer in the area as well as assessing its potential risk to contaminant seepage in terms of protective capacity of the overburden rock materials using Dar- Zarrouk (D-Z) parameters, viz., the transverse resistance ( T), longitudinal conductance ( S), transverse resistivity ( ρ t ) and longitudinal resistivity ( ρ l ). These were computed to generate the resistivity regime of freshwater-bearing formations and its movement. The central-western part of the study area reflects very good to good protective capacity rating as can be seen from the high longitudinal conductance values. The low value of the protective capacity in the eastern part is making the aquifer system in the area highly vulnerable to surface contamination. This indicates that the ground water quality may have been deteriorated in the area and borehole water samples should be randomly sampled for contaminant loads based on this analysis.

  19. Data for selected gaging stations in the upper Red River of the North Basin in Minnesota, September 2001 through September 2003

    USGS Publications Warehouse

    Damschen, William C.; Nustad, Rochelle A.

    2005-01-01

    Surface-water and water-quality data were collected to use in development of upper Red River of the North Basin Total Maximum Daily Loads (TMDLs). This report presents the data that were collected. During September 2001 through September 2003, data were collected at 13 selected gaging stations in the upper Red River of the North Basin. Continuous streamflow data were collected at three of the gaging stations. Water-quality samples were collected at all 13 gaging stations; and, simultaneous with sample collection, in-stream specific conductance, pH, water temperature, dissolved oxygen, and turbidity were measured. Samples were analyzed for selected nutrients, selected bacteria, chlorophyll a, and suspended sediment. Continuous in-stream water-quality monitors were installed at two gaging stations to measure specific conductance, pH, water temperature, dissolved oxygen, and turbidity.

  20. Jurassic-Cretaceous Composite Total Petroleum System and Geologic Assessment of Oil and Gas Resources of the North Cuba Basin, Cuba

    USGS Publications Warehouse

    ,

    2008-01-01

    The purpose of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment is to develop geologically based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the world. The U.S. Geological Survey (USGS) completed an assessment of the undiscovered oil and gas potential of the North Cuba Basin. The assessment is based on the geologic elements of the total petroleum system (TPS) defined in the province, including petroleum source rocks (source-rock maturation, generation, and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and petroleum traps (Trap formation and timing). Using this geologic framework, the USGS defined a Jurassic-Cretaceous Total Petroleum System in the North Cuba Basin Province. Within this TPS, three assessment units were defined and assessed for undiscovered oil and gas resources.

  1. Deep phylogeographic divisions and long-term persistence of forest invertebrates (Hexapoda: Collembola) in the North-Western Mediterranean basin.

    PubMed

    Cicconardi, F; Nardi, F; Emerson, B C; Frati, F; Fanciulli, P P

    2010-01-01

    The North-Western Mediterranean basin is well known for its high number of relictual endemic taxa, and has been indicated as one of the world's major biodiversity hotspots at the species level. A possible contributing factor may be long-term persistence of populations and their prolonged stability. This study was designed to investigate the phylogeographic structure of three common species of the genus Lepidocyrtus (Hexapoda: Collembola), soil-dwelling arthropods characterized by limited dispersal capabilities and generally associated with forest habitats. We observed a remarkable geographic structure, with numerous deeply divergent genetic lineages occupying islands as well as mainland sites with no apparent gene flow among most sites, even across distances of only tens of kilometres. The reconstructed time frame for the evolution of these lineages suggests divergence between 5 and 15 Ma. This indicates a remarkably ancient origin and long-term persistence of individual lineages over a fine geographic scale despite the occurrence of abrupt sea level and climatic fluctuations in the area. This further suggests that currently recognized morphological species might be a serious underestimation of the true springtail biodiversity within this region. PMID:20015142

  2. Development and application of a pollen-based paleohydrologic reconstruction from the lower Roanoke River Basin, North Carolina, USA

    USGS Publications Warehouse

    Willard, D.; Bernhardt, C.; Brown, R.; Landacre, B.; Townsend, P.

    2011-01-01

    We used pollen assemblages to reconstruct late-Holocene paleohydrologic patterns in floodplain deposits from the lower Roanoke River basin (North Carolina, southeastern USA). Using 120 surface samples from 38 transects, we documented statistical relationships between pollen assemblages, vegetation, and landforms. Backswamp pollen assemblages (long hydroperiods) are dominated by Nyssa (tupelo) and Taxodium (cypress) and have high pollen concentrations. Sediments from elevated levees and seasonally flooded forests (shorter hydroperiods) are characterized by dominant Pinus (pine) pollen, variable abundance of hardwood taxa, and low pollen concentrations. We apply the calibration data set to interpret past vegetation and paleohydrology. Pollen from a radiocarbon-dated sediment core collected in a tupelo-cypress backswamp indicates centennial-scale fluctuations in forest composition during the last 2400 years. Backswamp vegetation has occupied the site since land clearance began ~300 years ago. Recent dam emplacement affected sedimentation rates, but vegetation changes are small compared with those caused by pre-Colonial climate variability. The occurrence of wetter conditions from ~2200 to 1800 cal. yr BP, ~1100 to 750 cal. yr BP, and ~400 to 250 cal. yr BP may indicate changes in cyclonic circulation patterns related to shifts in the position of the Bermuda High and jet stream.

  3. Governing change: land-use change and the prevention of nonpoint source pollution in the north coastal basin of California.

    PubMed

    Short, Anne G

    2013-01-01

    Many rural areas in the United States and throughout much of the postindustrial world are undergoing significant ecological, socioeconomic, and political transformations. The migration of urban and suburban dwellers into rural areas has led to the subdivision of large tracts of land into smaller parcels, which can complicate efforts to govern human-environmental problems. Non-point source (NPS) pollution from private rural lands is a particularly pressing human-environmental challenge that may be aggravated by changing land tenure. In this article, I report on a study of the governance and management of sediment (a common NPS pollutant) in the North Coastal basin of California, a region undergoing a transition from traditional extractive and agricultural land uses to rural residential and other alternative land uses. I focus on the differences in the governance and management across private timber, ranch, residential, vacation, and other lands in the region. I find that (1) the stringency and strength of sediment regulations differ by land use, (2) nonregulatory programs tend to target working landscapes, and (3) rural residential landowners have less knowledge of sediment control and report using fewer sediment-control techniques than landowners using their land for timber production or ranching. I conclude with an exploration of the consequences of these differences on an evolving rural landscape.

  4. Late Cretaceous to Miocene phosphatic sediments in the Georges Bank Basin, U.S. North Atlantic outer continental shelf

    USGS Publications Warehouse

    Poppe, L.J.; Manheim, F. T.; Popenoe, P.

    1992-01-01

    Phosphorite and phosphatic sediments are present in the Georges Bank Basin in marine, Late Cretaceous to Miocene strata equivalent to the Dawson Canyon Formation and Banquereau Formation of offshore Nova Scotia. The Late Cretaceous to Paleocene phosphorite occurs predominantely as sand- and gravel-sized pellets and as cement in conglomeratic aggregates. The Eocene and Miocene phosphate occurs mainly as fine-very fine sand-size spheroidal-avoidal pellets in unconsolidated clayey silts. The older phosphorites form intraformational conglomerates that are the result of a winnowed finer-grained matrix, leaving lag deposits of phosphorite. We present evidence that most of the Eocene and Miocene phosphate is primary and formed during marine trangressions. Our observations extend the geographic and temporal limits of the major phosphogenic system of the Western North Atlantic northward and through time. However, compared to the well-known phosphorite deposits along the southeastern margin of the U.S.A., these northern deposits are not of commercial scale due to a high terrigenous input and the lack of a mechanism capable of driving persistant upwelling. ?? 1992.

  5. Lithospheric rheology and Moho upheaval control the generation mechanism of the intraplate earthquakes in the North China Basin

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Zhu, Bojing; Shi, Yaolin

    2016-05-01

    Many devastating intraplate earthquakes, such as the 1966 Xingtai earthquake (Ms 7.2) and the 1976 Tangshan earthquake (Ms 7.8), occurred in the North China Basin (NCB). This study aims to investigate the generation mechanism of the large intraplate earthquakes in the NCB and the spatial distribution of earthquake activity through numerical experiments. In order to simulate the interseismic stress accumulation process in the NCB, we set up several 3D finite element models based on different lithospheric rheological structure and apply boundary conditions of horizontal compression. We find that stress concentration with high rate in the regions where Moho upheaves is responsible for the large earthquakes in the NCB. During the interseismic period large stress rate is located nearly around the bottom of the brittle upper crust, where stress accumulates fast to reach fault strength and active the main shocks. Aftershocks in the seismogenic layers could be triggered by the main shocks. Two factors are critical to the crustal stress accumulation process. (1) The first is Moho upheaval in the seismic zones. (2) The second is viscosity contrast among the crustal layers. Our results support the lithospheric rheological structure in the NCB as following: the brittle upper crust, brittle-ductile transition in the middle crust, the ductile lower crust, and the ductile lithospheric upper mantle.

  6. Heat flow and subsurface temperature as evidence for basin-scale ground-water flow, North Slope of Alaska

    USGS Publications Warehouse

    Deming, D.; Sass, J.H.; Lachenbruch, A.H.; De Rito, R. F.

    1992-01-01

    Several high-resolution temperature logs were made in each of 21 drillholes and a total of 601 thermal conductivity measurements were made on drill cuttings and cores. Near-surface heat flow (??20%) is inversely correlated with elevation and ranges from a low of 27 mW/m2 in the foothills of the Brooks Range in the south, to a high of 90 mW/m2 near the north coast. Subsurface temperatures and thermal gradients estimated from corrected BHTs are similarly much higher on the coastal plain than in the foothills province to the south. Significant east-west variation in heat flow and subsurface temperature is also observed; higher heat flow and temperature coincide with higher basement topography. The observed thermal pattern is consistent with forced convection by a topographically driven ground-water flow system. Average ground-water (Darcy) velocity in the postulated flow system is estimated to be of the order of 0.1 m/yr; the effective basin-scale permeability is estimated to be of the order of 10-14 m2. -from Authors

  7. Uncertainty analysis of a spatially explicit annual water-balance model: case study of the Cape Fear basin, North Carolina

    NASA Astrophysics Data System (ADS)

    Hamel, P.; Guswa, A. J.

    2015-02-01

    There is an increasing demand for assessment of water provisioning ecosystem services. While simple models with low data and expertise requirements are attractive, their use as decision-aid tools should be supported by uncertainty characterization. We assessed the performance of the InVEST annual water yield model, a popular tool for ecosystem service assessment based on the Budyko hydrological framework. Our study involved the comparison of 10 subcatchments ranging in size and land-use configuration, in the Cape Fear basin, North Carolina. We analyzed the model sensitivity to climate variables and input parameters, and the structural error associated with the use of the Budyko framework, a lumped (catchment-scale) model theory, in a spatially explicit way. Comparison of model predictions with observations and with the lumped model predictions confirmed that the InVEST model is able to represent differences in land uses and therefore in the spatial distribution of water provisioning services. Our results emphasize the effect of climate input errors, especially annual precipitation, and errors in the ecohydrological parameter Z, which are both comparable to the model structure uncertainties. Our case study supports the use of the model for predicting land-use change effect on water provisioning, although its use for identifying areas of high water yield will be influenced by precipitation errors. While some results are context-specific, our study provides general insights and methods to help identify the regions and decision contexts where the model predictions may be used with confidence.

  8. Assessment of undiscovered oil resources in the Bakken and Three Forks Formations, Williston Basin Province, Montana, North Dakota, and South Dakota, 2013

    USGS Publications Warehouse

    Gaswirth, Stephanie B.; Marra, Kristen R.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Higley, Debra K.; Klett, Timothy R.; Lewan, Michael D.; Lillis, Paul G.; Schenk, Christopher J.; Tennyson, Marilyn E.; Whidden, Katherine J.

    2013-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 7.4 billion barrels of oil, 6.7 trillion cubic feet of associated/dissolved natural gas, and 0.53 billion barrels of natural gas liquids in the Bakken and Three Forks Formations in the Williston Basin Province of Montana, North Dakota, and South Dakota.

  9. Results of U-Pb (LA-ICPMS) dating of detrital zircons from metaterrigenous rocks of the basement of the North Kara basin

    NASA Astrophysics Data System (ADS)

    Ershova, V. B.; Prokopiev, A. V.; Khudoley, A. K.; Shneider, G. V.; Andersen, T.; Kullerud, K.; Makar'ev, A. A.; Maslov, A. V.; Kolchanov, D. A.

    2015-10-01

    The U-Pb (LA-ICPMS) age was established for detrital zircons from the oldest, intensely deformed metasedimentary complexes without reliable fossils' record, which represent the folded basement of the North Kara basin and are exposed on Bol'shevik and Troinoi islands (Severnaya Zemlya and Izvestii TSIK archipelagoes, respectively). Our data suggest the common evolution of the Cambrian-Ordovician sequences exposed on the islands of both archipelagoes.

  10. Water quality in the Albemarle-Pamlico drainage basin, North Carolina and Virginia, 1992-95

    USGS Publications Warehouse

    Spruill, Timothy B.; Harned, Douglas A.; Ruhl, Peter M.; Eimers, Jo Leslie; McMahon, Gerard; Smith, Kelly E.; Galeone, David R.; Woodside, Michael D.

    1998-01-01

    The NAWQA Program is assessing the water-quality conditions of more than 50 of the Nation's largest river basins and aquifers, known as Study Units. Collectively, these Study Units cover about one-half of the United States and include sources of drinking water used by about 70 percent of the U.S. population. Comprehensive assessments of about one-third of the Study Units are ongoing at a given time. Each Study Unit is scheduled to be revisited every decade to evaluate changes in water-quality conditions. NAWQA assessments rely heavily on existing information collected by the USGS and many other agencies as well as the use of nationally consistent study designs and methods of sampling and analysis. Such consistency simultaneously provides information about the status and trends in water-quality conditions in a particular stream or aquifer and, more importantly, provides the basis to make comparisons among watersheds and improve our understanding of the factors that affect water-quality conditions regionally and nationally. This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Albemarle-Pamlico Drainage Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

  11. Correlation of Plio-Pleistocene deposits of the Lower Rhine Basin (North-West Germany) and the Valle Ricca pits (Central Italy)

    NASA Astrophysics Data System (ADS)

    Arias, Claudio; Bigazzi, Giulio; Bonadonna, Francescopaolo; Brunnacker, Karl; Urban, Brigitte

    Biostratigraphic and palaeomagnetic research has been carried out on selected profiles in North-Western Germany and Central Italy in order to correlate Plio-Pleistocene sections. Around the Réunion subchronozone, vegetation in the Valle Ricca was dominated by a mountain forest type pointing to cool climatic conditions. In the Lower Rhine Basin vegetation had a slightly warmer character, but was also dominated strongly by a mountain type of forest vegetation, characteristic of cooler summers and higher precipitation than at present. Two warmer periods have been determined in the Central Italian profiles; the youngest around the Olduvai reversal, should correspond to the youngest Tiglian beds of the Lower Rhine Basin. Deposits older than the Réunion subzone have not been found in the Valle Ricca. In the Lower Rhine Basin, on the other hand, the Gauss-Matuyama boundary is located between the uppermost Pliocene, the Reuverian C and the Praetiglian.

  12. Morphotectonic setting of the Gölpazari pull-apart basin: Implications on the region between the North Anatolian and Eskişehir fault zones, NW Turkey

    NASA Astrophysics Data System (ADS)

    Önde, E.; Gürbüz, A.

    2010-05-01

    The Gölpazarı basin is a rhomb-shaped pull-apart basin that situated on the region between the right-lateral North Anatolian and Eskişehir fault zones in NW Turkey at an altitude of ~500 m a.s.l. with a size of 12 km in length and 4.5 km in width. The main structural elements controlling the morphological features in and around the study area are the strike-slip motion of these fault zones. The North Anatolian fault zone is one of the best known faults in the world because of its remarkable high seismicity and importance for the tectonics of Eastern Mediterranean region. This fault zone seperates the Eurasian plate from the Anatolian plate and splays into two major strands to the north of the Gölpazarı basin.The Eskişehir fault zone that located to the south of the studied area is a WNW-ESE-trending strike-slip deformation area with a normal component that extends from Uludağ in the west to Sivrihisar in the east and separates the western Anatolia region from the central Anatolia. The morphotectonic framework of the study area was mainly set in the Quaternary period by the tectonics of these fault zones. The fault-generated mountain fronts are the most characteristic landforms. As a result of this the surrounding topography of the Gölpazarı basin being steeper along the boundaries where mountains rises steeply to over 700 m from the depression floor. The faults along the northern and southern sides of the depression, indicate mainly oblique normal faulting whereas the SE and NW margins indicate mainly strike-slip faulting. The gradient of the basin floor is towards west. There was a shallow lake in the west of the depression until 1963. There are several boreholes in the floor of the Gölpazarı basin that were drilled by General Directorate of State Hydraulic Works of Turkey that represents an alluvium thickness of ~300 m. In the Early Quaternary the Gölpazarı basin was a closed depression and then the openning of a strait in the south of the basin by

  13. Assessment of sediments in the riverine impoundments of national wildlife refuges in the Souris River Basin, North Dakota

    USGS Publications Warehouse

    Tangen, Brian A.; Laubhan, Murray K.; Gleason, Robert A.

    2014-01-01

    Accelerated sedimentation of reservoirs and riverine impoundments is a major concern throughout the United States. Sediments not only fill impoundments and reduce their effective life span, but they can reduce water quality by increasing turbidity and introducing harmful chemical constituents such as heavy metals, toxic elements, and nutrients. U.S. Fish and Wildlife Service national wildlife refuges in the north-central part of the United States have documented high amounts of sediment accretion in some wetlands that could negatively affect important aquatic habitats for migratory birds and other wetland-dependent wildlife. Therefore, information pertaining to sediment accumulation in refuge impoundments potentially is important to guide conservation planning, including future management actions of individual impoundments. Lands comprising Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges, collectively known as the Souris River Basin refuges, encompass reaches of the Des Lacs and Souris Rivers of northwestern North Dakota. The riverine impoundments of the Souris River Basin refuges are vulnerable to sedimentation because of the construction of in-stream dams that interrupt and slow river flows and because of post-European settlement land-use changes that have increased the potential for soil erosion and transport to rivers. Information regarding sediments does not exist for these refuges, and U.S. Fish and Wildlife Service personnel have expressed interest in assessing refuge impoundments to support refuge management decisions. Sediment cores and surface sediment samples were collected from impoundments within Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges during 2004–05. Cores were used to estimate sediment accretion rates using radioisotope (cesium-137 [137Cs], lead-210 [210Pb]) dating techniques. Sediment cores and surface samples were analyzed for a suite of elements and agrichemicals, respectively. Examination of

  14. Changes in flow in the Beaver-North Canadian River basin upstream from Canton Lake, western Oklahoma

    USGS Publications Warehouse

    Wahl, Kenneth L.; Tortorelli, Robert L.

    1997-01-01

    This report presents the results of an evaluation of hydrologic data for the Beaver-North Canadian River basin upstream from Canton Lake in western Oklahoma. It examines the climatic and hydrologic data for evidence of trends. The hydrologic data examined includes total annual flow, base flow, and annual peak discharges. This study was conducted to determine if there is evidence of trends present in hydrologic and climatic data. All available streamflow-gaging station data, with at least 10 or more years of record, were examined for trends. In addition, the data were divided into an 'early' period (ending in 1971), representing conditions before ground-water levels had declined appreciably, and a 'recent' period (1978-1994), reflecting the condition of declining ground-water levels, including the effects of storage reservoirs. Tests for trend, moving averages, and comparisons of median and average flows for an early period (ending in 1971) with those for the recent period (1978-1994) show that the total annual volume of flow and the magnitudes of instantaneous annual peak discharges measured at most gaging stations in the Beaver- North Canadian River basin have decreased in recent years. Precipitation records for the panhandle, however, show no corresponding changes. The changes in flow are most pronounced in the headwaters upstream from Woodward, but also are evident at Woodward and near Seiling, which represents the inflow to Canton Lake. The average annual discharge decreased between the early period and the recent period by the following amounts: near Guymon, 18,000 acre-feet; at Beaver, 68,000 acre-feet; at Woodward, 72,000 acre-feet; and near Seiling, 63,000 acre-feet. These decreases, expressed as a percentage of the average flows for the early period, were 91 percent near Guymon, 82 percent at Beaver, 49 percent at Woodward, and 37 percent near Seiling. The medians of the annual peak discharges decreased from the early period to the recent period by the

  15. Climatic impacts of the Middle Route of the South-to-North Water Transfer Project over the Haihe River basin in North China simulated by a regional climate model

    NASA Astrophysics Data System (ADS)

    Zou, Jing; Zhan, Chesheng; Xie, Zhenghui; Qin, Peihua; Jiang, Shanshan

    2016-08-01

    The Middle Route of the South-to-North Water Transfer Project (MSWTP) was constructed to ease the water crisis over the North China Plain. In this study, we incorporated a water transfer scheme into the regional climate model RegCM4 and investigated the climatic impacts of the MSWTP over the Haihe River Basin in North China. Four 10 year simulation tests were conducted from 2001 to 2010 where different volumes of water were transferred. The results demonstrated that before the MSWTP was conducted the original groundwater exploitation and consumption over the Haihe River Basin led to wetting and cooling at the land surface with rapidly falling groundwater depth. The extra water input from the MSWTP slightly enhanced the wetting and cooling effects over the basin, as well as reduced the falling rate in the groundwater depth along the conveyance line. However, the weak climatic effects of the MSWTP were limited at a local scale and had no obvious interannual trends, because the transfer volume of the MSWTP was far lower than the total demand which has been conventionally satisfied through local water exploitation. In terms of seasonal variations, the greatest changes due to the MSWTP occurred in the summer for precipitation and soil moisture and in the spring for energy-related variables (heat fluxes and 2 m air temperature).

  16. Wabek and Plaza fields: Carbonate shoreline traps in the Williston basin of North Dakota

    SciTech Connect

    Sperr, T. ); Hendricks, M.L. ); Stancel, S.G.

    1991-06-01

    Wabek and Plaza fields in Mountrail and Ware counties, North Dakota, will ultimately produce 8 million and 3 million bbl of oil, respectively, from reservoirs in the Sherwood and Bluell intervals of the Mississippian Mission Canyon Formation. Both fields produce from porous, oolitic, and pisolitic lime packstones and grainstones deposited as shoals along a low-energy shoreline. A facies change to impermeable dolomitic and salina/sabkha environments to the east provides the updip trap. The Sherwood at Wabek has more than 100 ft of oil column driven by solution gas and water influx. Effective porosity consists of interparticle, vuggy, and minor dolomitic intercrystalline porosity. Log porosities range from 6 to 26%, averaging about 10%, and net pay averages about 26 ft. One mile west of Wabek, Plaza field produces from the Bluell, stratigraphically overlying the Sherwood. Log porosities range from 6 to 16%, averaging about 9%. Net pay averages about 6 ft. An oil-water contact is not yet defined, but at least 120 ft of oil column are present. Regional depositional slope and local depositional topography were major controls on Mission Canyon shoreline trends and the development of reservoir facies. In the Wabek-Plaza complex, the position and trend of the Sherwood and Bluell shorelines can be related to structural trends indentified in the crystalline basement from aeromagnetic data. Locally, thickness variations in the underlying Mohall interval amplified relief on the Wabek-Plaza structure and influenced the deposition of shoreline reservoirs.

  17. Subsurface structure of the north Summit gas field, Chestnut Ridge anticline of the Appalachian Basin

    SciTech Connect

    Zhou, G.; Shumaker, R.C.; Staub, W.K.

    1996-09-01

    The Chestnut Ridge anticline is the westernmost of the High Plateau folds in southwestern Pennsylvania and north-central West Virginia that are detached primarily in the Marcellus Shale, and the Martinsburg, Salina, and Rome Formations. The primary, basal detachment at the Summit field occurs in the Salina salt. Production from fracture porosity in the Devonian Oriskany Sandstone commenced in 1936. During the late 1980s and early 1990s, 14 wells were drilled preparatory to conversion of the reservoir to gas storage. Schlumberger`s Formation MicroScanner (FMS) logs were run in each of these wells to provide information on the structural configuration and fracture patterns of the reservoir. These data indicate that two inward-facing, tight folds at the Oriskany level form the upper flanks and core of the anticline at the northern end of the field, whereas the main part of the field to the south is a comparatively simple, broad closure at the Oriskany level. The structure is a broad, slightly asymmetric open fold in the Mississippian Greenbrier Formation at the surface. Fracture patterns mapped using FMS logs indicate a complex fracture system which varies slightly along the trend of the fold and among the units analyzed, including the Helderberg Formation, Huntersville Chert, Oriskany Sandstone, and Onondaga Formation. An orthogonal joint system strikes toward the northwest and northeast slightly askew to the trend of the fold`s crestal trace. A similar, but more complex fracture pattern is found in an oriented core of these units.

  18. Buried-hill discoveries in Damintan depression of north China basin

    SciTech Connect

    Xiaoguang, Tong; Huang Zuan

    1988-02-01

    The Damintan fault depression is about 20 km west of Shenyang, Liaoning Province, North China, and is a small Tertiary continental depression, covering only about 800 km/sup 2/. In the depression, the Tertiary system unconformably overlies upper-middle Proterozoic sedimentary rocks and Archean metamorphic rocks. The Tertiary system is up to 6,600 m in thickness. Source rocks are in the third and fourth members of the Eocene Shahejie Formation. Buried-hill traps were formed in Proterozoic carbonates and metamorphic rocks of the Archean. Fault block, stratigraphic, and lithologic traps also occur in sandstones of the Shahejie Formation, especially in those of the third member. Several buried-hill-drape traps occur in the depression. The various types of oil pools in each buried-hill-drape trap constitute a complex hydrocarbon accumulation zone. A series of oil fields have been found in the depression. The crude oil is characterized by high wax content and high pour point. Hydrocarbon exploration began in 1971, but only a few small oil fields were found in the 1970s. Recently, by applying digital seismic techniques, the subsurface geological structure has been accurately mapped and new production technology has enabled the high-our-point oil to be produced. Thus, important achievements in hydrocarbon exploration were made during the 1980s.

  19. A space-time statistical climate model for hurricane intensification in the North Atlantic basin

    NASA Astrophysics Data System (ADS)

    Fraza, Erik; Elsner, James B.; Jagger, Thomas H.

    2016-08-01

    Climate influences on hurricane intensification are investigated by averaging hourly intensification rates over the period 1975-2014 in 8° × 8° latitude-longitude grid cells. The statistical effects of hurricane intensity and sea-surface temperature (SST), along with the climatic effects of El Niño-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the Madden-Julian Oscillation (MJO), are quantified using a Bayesian hierarchical model fit to the averaged data. As expected, stronger hurricanes tend to have higher intensification rates, especially over the warmest waters. Of the three climate variables considered, the NAO has the largest effect on intensification rates after controlling for intensity and SST. The model shows an average increase in intensification rates of 0.18 [0.06, 0.31] m s-1 h-1 (95 % credible interval) for every 1 standard deviation decrease in the NAO index. Weak trade winds associated with the negative phase of the NAO might result in less vertical wind shear and thus higher mean intensification rates.

  20. Nonlinear vegetation cover changes in the North Ethiopian Highlands: Evidence from the Lake Ashenge closed basin.

    PubMed

    Lanckriet, Sil; Rucina, Stephen; Frankl, Amaury; Ritler, Alfons; Gelorini, Vanessa; Nyssen, Jan

    2015-12-01

    Vegetation cover changes in African drylands are often thought to result from population growth, social factors and aridification. Here we show that long-term vegetation proxy records can help disentangling these main driving factors. Taking the case of North Ethiopia, we performed an integrated investigation of land cover changes over the last four centuries around the endorheic Lake Ashenge, as derived from pollen analysis and repeat photography complemented with information from historical sources. Pollen and sediment analysis of radiocarbon-dated lake deposits shows a phase of environmental destabilization during the 18th century, after a more stable previous period. This is evidenced by decreases of tree pollen (Juniperus, Olea, Celtis, Podocarpus<5%), increases in Poaceae (>40%) and deposition of coarser silt lake sediments (>70%). Quantitative analysis of 30 repeated landscape photographs around the lake indicates a gradual decline of the vegetation cover since a relative maximum during the mid-19th Century. Vegetation cover declined sharply between the 1950s and the 1980s, but has since begun to recover. Overall, the data from around Lake Ashenge reveal a nonlinear pattern of deforestation and forest regrowth with several periods of vegetation cover change over the past four centuries. While there is forcing of regional drought and the regional land tenure system, the cyclic changes do not support a simplified focus on aridification or population growth. PMID:26117500

  1. Nonlinear vegetation cover changes in the North Ethiopian Highlands: Evidence from the Lake Ashenge closed basin.

    PubMed

    Lanckriet, Sil; Rucina, Stephen; Frankl, Amaury; Ritler, Alfons; Gelorini, Vanessa; Nyssen, Jan

    2015-12-01

    Vegetation cover changes in African drylands are often thought to result from population growth, social factors and aridification. Here we show that long-term vegetation proxy records can help disentangling these main driving factors. Taking the case of North Ethiopia, we performed an integrated investigation of land cover changes over the last four centuries around the endorheic Lake Ashenge, as derived from pollen analysis and repeat photography complemented with information from historical sources. Pollen and sediment analysis of radiocarbon-dated lake deposits shows a phase of environmental destabilization during the 18th century, after a more stable previous period. This is evidenced by decreases of tree pollen (Juniperus, Olea, Celtis, Podocarpus<5%), increases in Poaceae (>40%) and deposition of coarser silt lake sediments (>70%). Quantitative analysis of 30 repeated landscape photographs around the lake indicates a gradual decline of the vegetation cover since a relative maximum during the mid-19th Century. Vegetation cover declined sharply between the 1950s and the 1980s, but has since begun to recover. Overall, the data from around Lake Ashenge reveal a nonlinear pattern of deforestation and forest regrowth with several periods of vegetation cover change over the past four centuries. While there is forcing of regional drought and the regional land tenure system, the cyclic changes do not support a simplified focus on aridification or population growth.

  2. Confederated Tribes of the Umatilla Indian Reservation North Fork John Day River Basin Anadromous Fish Enhancement Project, Annual Report for FY 2000.

    SciTech Connect

    Macy, Tom L.; James, Gary A.

    2003-03-01

    The CTUIR North Fork John Day River Basin Anadromous Enhancement Project (NFJDAFEP) identified and prioritized stream reaches in The North Fork John day River basin for habitat improvements during the 2000 project period. Public out reach was emphasized during this first year of the project. We presented multiple funding and enhancement options to landowners. We concentrated on natural recovery methods, riparian fencing and off-stream livestock water developments. Under this BPA contract four riparian easements were signed protecting almost 5 miles of tributary streams. There are nine offstream water developments associated with these easements. Some landowners chose to participate in other programs based on Tribal outreach efforts. Two landowners chose NRCS programs for enhancement and one chose OWEB as a funding source. Two landowners implemented there own enhancement measures protecting 3 miles of stream. Cooperation between the NRCS/FSA/SWCDs and the Tribe to create joint projects and develop alternative funding scenarios for riparian enhancement was a major effort. The Tribe also worked with the North Fork John Day Watershed Council, USFS and ODFW to coordinate projects and support similar projects throughout the John Day Basin. We provided input to the John Day Summary prepared for the NWPPC by ODFW. The Tribe worked with the Umatilla National Forest on the Clear Creek Dredgetailings Rehabilitation project and coordinated regularly with USFS Fisheries, Hydrology and Range staff.

  3. Confederated Tribes of the Umatilla Indian Reservation North Fork John Day River Basin Anadromous Fish Enhancement Project, Annual Report for FY 2001.

    SciTech Connect

    Macy, Tom L.; James, Gary A.

    2003-03-01

    The CTUIR North Fork John Day River Basin Anadromous Enhancement Project (NFJDAFEP) identified and prioritized stream reaches in The North Fork John day River basin for habitat improvements during the 2000 project period. Public outreach was emphasized during this first year of the project. During the past year we concentrated on satisfying landowner needs, providing cost share alternatives, providing joint projects and starting implementation. We presented multiple funding and enhancement options to landowners. We concentrated on natural recovery methods, riparian fencing and offstream livestock water developments. Under this BPA contract four riparian easements have been signed protecting almost 5 miles of tributary streams. There are nine offstream water developments associated with these easements. Some landowners chose to participate in other programs based on Tribal outreach efforts. Some landowners chose NRCS programs for enhancement and others chose OWEB as a funding source. The exact amount of stream protection due to other funding sources probably exceeds that by BPA, however most would not have entered any program without initial Tribal outreach. Cooperation between the NRCS/FSA/SWCDs and the Tribe to create joint projects and develop alternative funding scenarios for riparian enhancement was a major effort. The Tribe also worked with the North Fork John Day Watershed Council, USFS and ODFW to coordinate projects and support similar projects throughout the John Day Basin.

  4. Final monitoring plan for the Utica aquifer-North Lake Basin restoration project at Utica, Nebraska.

    SciTech Connect

    LaFreniere, L. M.

    2005-10-05

    On March 9, 2001, representatives of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) and Argonne National Laboratory met with representatives from a number of federal and Nebraska state agencies (the wetlands agencies; see Table 1.1) to discuss the CCC/USDA's proposed aquifer remediation and wetlands restoration project at Utica, Nebraska. As part of those discussions, Argonne outlined preliminary recommendations for a long-term monitoring program to verify and document (1) the performance of the spray irrigation treatment process for the removal of carbon tetrachloride from extracted groundwater, (2) the geochemical quality of the extracted and treated groundwater delivered to the wetlands, and (3) the hydrogeologic and inorganic geochemical impacts of the groundwater delivery. General activities recommended included the following: (1) Periodic sampling and analysis for volatile organic compounds (VOCs) in groundwater extracted at each pumping well and in water discharged from the spray irrigation treatment units. (2) Periodic sampling of groundwater from each pumping well and directly from the sprinkler discharge, for analysis for selected inorganic water quality parameters. The CCC/USDA and Argonne also requested at the March 2001 meeting that the wetlands agencies accept responsibility for developing the ecological and biological monitoring programs needed to meet environmental requirements for the wetlands restoration program. The preliminary recommendations for monitoring outlined above were generally accepted by the wetlands agencies. Since the March 2001, meeting, however, no further discussions have taken place (to Argonne's knowledge) regarding potential monitoring at this site. As the design of the Utica project has evolved, more detailed technical information has become available regarding the specific restoration activities to be performed in association with the aquifer and the wetlands basin. The scope of the aquifer

  5. Prospect evaluation of BED 3 and Sitra oilfields, Abu Gharadig Basin, North Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Salem, Ibrahim; Ghazala, Hosni; El Diasty, Waleed

    2015-12-01

    The occurrence of hydrocarbons is closely linked to the elements of petroleum system history of the BED 3 and Sitra 8 oilfields, which has created multiple reservoir and seal combinations. BED 3 Field and Sitra concessions occupy the northwestern part of the Abu Gharadig Basin and extends between latitudes 29°45‧ and 30°05‧N and longitudes 27°30‧ and 28°10‧E. The comprehensive integration of the geo-related data and the interpretation of the well logging, geochemical, seismic data in time domain and depth and sealing mechanisms explain the occurrence of hydrocarbons in some certain reservoirs during cretaceous age and other reservoirs in the same fields don't have any hydrocarbon accumulation. Detailed seismic data interpretation was performed for the target units of BED 3 and Sitra 8 oilfields in time domain and converted to depth domain. Sitra 8 Field is a three-way dip closure bounded by NW-SE faults while BED 3 field is represented by a WNW-ESE trending horst dipping to the east. The Albian-Cenomanian Kharita Formation has a high energy shallow marine shelf environment and considered as the main pay zone in the BED 3 oilfield. On the other hand, Kharita sands are dry in the Sitra 8 Field. Also, the shallow marine shale, sandstone, limestone and dolomite interbeds of the Abu Roash G Member are another hydrocarbon bearing reservoir in the Sitra 8 Field. Sealing mechanisms were applied to explain why certain reservoirs have hydrocarbon and others don't. Allan's juxtaposition diagram for the main faults in the study area shows that Kharita sands in BED 3 area have excellent juxtaposition as Kharita juxtapose to upper Bahariya and intra Bahariya, which consist of shale and limestone. Abu Roash G sands in BED 3 area have bad juxtaposition as the Abu Roash G juxtapose to Abu Roash C sand (sand juxtaposed sand). Allan's diagram shows that the Abu Roash G reservoir (main target) in Sitra 8 is juxtaposing Abu Roash D which is composed of limestone and shale

  6. Distribution and variation of the inorganic fraction of Devonian to Bashkirian black shales in the north-western part of the Dniepr-Donets Basin, Ukraine

    NASA Astrophysics Data System (ADS)

    Wegerer, Eva; Sachsenhofer, Reinhard; Misch, David; Aust, Nicolai

    2016-04-01

    Mineralogical data of 112 core samples from 12 wells are used to investigate lateral and vertical variations in the lithofacies of Devonian to Bashkirian black shales in the north-western part of the Dniepr-Donets-Basin. Sulphur and carbonate contents as well as organic geochemical parameters, including TOC and Hydrogen Index have been determined on the same sample set within the frame of an earlier study (Sachsenhofer et al. 2010). This allows the correlation of inorganic and organic composition of the black shales. Aims of the study are to distinguish between detrital and authigenic minerals, to relate the lithofacies of the black shales with the tectono-stratigraphic sequences of the Dniepr-Donets Basin, to contribute to the reconstruction of the depositional environment and to relate diagenetic processes with the thermal history of the basin. Mineral compositions were determined primarily using XRD-measurements applying several measurement procedures, e.g. chemical and temperature treatment, and specific standards. Major differences exist in the mineralogical composition of the black shales. For example, clay mineral contents range from less than 20 to more than 80 Vol%. Kaolinite contents are significantly higher in rocks with a Tournaisian or Early Visean age than in any other stratigraphic unit. This is also true for two Lower Visean coal samples from the shallow north-westernmost part of the basin. Chlorite contents reach maxima in uppermost Visean and overlying rocks. Quartz contents are often high in Upper Visean rocks and reach maxima in Bashkirian units. Feldspar-rich rocks are observed in Devonian sediments from the north-western part of the study area and may reflect the proximity to a sediment source. Carbonate contents are typically low, but reach very high values in some Tournaisian, Lower Visean and Serpukhovian samples. Pyrite contents reach maxima along the basin axis in Tournaisian and Visean rocks reflecting anoxic conditions. Mixed layer

  7. High-resolution records of Bonneville Basin paleohydrology offer new insights into changing atmospheric circulation patterns over North America from 26 ka through the Holocene

    NASA Astrophysics Data System (ADS)

    Steponaitis, E.; McGee, D.; Quade, J.; Andrews, A.; Edwards, R.; Hsieh, Y.; Broecker, W. S.; Cheng, H.

    2013-12-01

    The tremendous lateral extent of the Bonneville Basin, which covers much of western Utah, makes paleoclimate records from this region highly sensitive to global-scale changes in atmospheric circulation and hydrology. New paleoclimate records from speleothems and lacustrine carbonates offer insight into the hydrology the Bonneville Basin spanning from 26 ka through the Holocene. Anchored by high-precision U-Th dates, Sr records from crystalline lacustrine carbonates from throughout the basin provide a mechanism for constraining zonal variations in precipitation over time. To accomplish this, we exploit spatial variations in the 87Sr/86Sr ratios of fluvial inputs to Lake Bonneville (Hart et al. 2004). Paired with stable isotope records, these Sr records give a spatially detailed view of the response of Great Basin to global climate change, and by extension, insight into atmospheric circulation patterns over North America during abrupt climate changes. Stable isotope and trace metal records from Lehman Cave speleothems provide a high-resolution extension of these Great Basin hydrological records into the Holocene. Here we provide an overview of these unique paired records, focusing particular attention on the region's response to the Younger Dryas and Heinrich events 1 and 2. Hart, W.S. et al., The 87Sr/86Sr ratios of lacustrine carbonates and lake-level history of the Bonneville paleolake system. GSA Bulletin. 2004; 116: 1107-1119.

  8. Benthic invertebrate communities and their responses to selected environmental factors in the Kanawha River basin, West Virginia, Virginia, and North Carolina

    USGS Publications Warehouse

    Chambers, Douglas B.; Messinger, Terence

    2001-01-01

    The effects of selected environmental factors on the composition and structure of benthic invertebrate communities in the Kanawha River Basin of West Virginia, Virginia and North Carolina were investigated in 1997 and 1998. Environmental factors investigated include physiography, land-use pattern, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics. Land-use patterns investigated include coal mining, agriculture, and low intensity rural-residential patterns, at four main stem and seven tributary sites throughout the basin. Of the 37 sites sampled, basin size and physiography most strongly affected benthic invertebrate-community structure. Land-use practices also affected invertebrate community structure in these basins. The basins that differed most from the minimally affected reference condition were those basins in which coal mining was the dominant nonforest land use, as determined by comparing invertebrate- community metric values among sites. Basins in which agriculture was important were more similar to the reference condition. The effect of coal mining upon benthic invertebrate communities was further studied at 29 sites and the relations among invertebrate communities and the selected environmental factors of land use, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics analyzed. Division of coal-mining synoptic-survey sites based on invertebrate-community composition resulted in two groups?one with more than an average production of 9,000 tons of coal per square mile per year since 1980, and one with lesser or no recent coal production. The group with significant recent coal production showed higher levels of community impairment than the group with little or no recent coal production. Median particle size of streambed sediment, and specific conductance and sulfate concentration of streamwater were most strongly correlated with effects on invertebrate communities. These characteristics were

  9. Geology and undiscovered oil and gas resources in the Madison Group, Williston Basin, North Dakota and Montana

    USGS Publications Warehouse

    Gaswirth, Stephanie B.; Lillis, Paul G.; Pollastro, Richard M.; Anna, Lawrence O.

    2010-01-01

    Two of the total petroleum systems (TPS) defined as part of the U.S. Geological Survey (USGS) assessment of the Williston Basin contain Mississippian Madison Group strata: 1) the Bakken-Lodgepole TPS, which includes the Lodgepole Formation; and 2) the Madison TPS, which includes the Mission Canyon, Charles, and Spearfish formations. The Bakken-Lodgepole TPS is defined as the area in which oil generated from the upper and lower shales of the Upper Devonian-Lower Mississippian Bakken Formation has accumulated in reservoirs in the Three Forks, Bakken, and Lodgepole formations. Two conventional assessment units (AU) have been identified within the Bakken-Lodgepole TPS, including one in the Bakken Formation and another in the Waulsortian mound reservoirs of the lower Lodgepole Formation. Lodgepole Formation Waulsortian mound oil production has been restricted to a small part of Stark County, North Dakota. Reservoirs are sealed by middle and upper Lodgepole Formation tight argillaceous limestones. Several nonproductive mounds and mound-like structures have also been identified in the Lodgepole Formation. Productivity correlates closely with the oil window of the Bakken Formation shales, and also indicates the likelihood of limited lateral migration of Bakken Formation oil into Lodgepole Formation reservoirs in North Dakota and Montana. Such considerations limit the estimated mean of undiscovered, technically recoverable resources to 8 million barrels of oil (MMBO) for the Lodgepole Formation conventional reservoirs. The Madison TPS is defined as the area where oil generated from Mission Canyon and Charles formation source rocks has accumulated in reservoirs of the Mission Canyon and Charles formations and in reservoirs within the Triassic Spearfish Formation. One continuous reservoir AU, the Mission Canyon-Charles AU, was defined within the Madison TPS; its boundary coincides with the TPS boundary. There is extensive conventional production throughout the AU on major

  10. Investigation of dioxin concentrations in the lower Roanoke River basin, North Carolina, February 26-March 7, 2001

    USGS Publications Warehouse

    Miller, K.F.; Walters, D.A.

    2001-01-01

    Dioxin is a toxic chemical that, when present in the environment, can cause cancer and birth defects in humans. Dioxin is of particular concern because concentrations of dioxin that were released into the environment many years ago remain a contributing factor to current exposure. Dioxin exposure often occurs in surface-water systems downstream from contaminated sites and is detrimental to aquatic life. For these reasons and because the U.S. Geological Survey has expertise in conducting high-volume dioxin sampling, the U.S. Environmental Protection Agency and the State of North Carolina asked the U.S. Geological Survey to collect water samples in the lower Roanoke River to be analyzed for the presence of dioxin. Water quality of the lower Roanoke River Basin in North Carolina was assessed at eight sites during February 26-March 7, 2001. Water- quality samples were collected for analysis of suspended-sediment and dioxin concentrations; high-volume (750-liter) water samples were collected for dioxin analysis. Discharge measurements were made at or near the high-volume sampling sites. Suspended-sediment sampling and water-quality measurements of specific conductance, pH, water temperature, and dissolved-oxygen concentrations made at each sampling site included multidepth measurements at two cross-section transects and hourly measurements at the point of high-volume sampling. Multidepth measurements were made near the surface, mid-depth, and near the bottom of the water column. These values were averaged for each cross section. During the sampling period, all sites sampled had dioxin concentrations above detection limits (1 part per quintillion) for both suspended and dissolved dioxin. Suspended dioxin ranged from 5.1 to 900 femtograms per liter, and dissolved dioxin values ranged from 0.31 to 41 femtograms per liter. Suspended-sediment concentrations ranged from 1.1 to 14 milligrams per liter. Specific conductance values ranges from 111 to 340 microsiemens per

  11. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2006-09-30

    The objectives of the study were: (1) to perform resource assessment of the thermogenic gas resources in deeply buried (>15,000 ft) natural gas reservoirs of the onshore interior salt basins of the north central and northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling; and (2) to use the petroleum system based resource assessment to estimate the volume of the deep thermogenic gas resource that is available for potential recovery and to identify those areas in the interior salt basins with high potential for this thermogenic gas resource. Petroleum source rock analysis and petroleum system characterization and modeling, including thermal maturation and hydrocarbon expulsion modeling, have shown that the Upper Jurassic Smackover Formation served as the regional petroleum source rock in the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin. Thus, the estimates of the total hydrocarbons, oil, and gas generated and expelled are based on the assumption that the Smackover Formation is the main petroleum source rock in these basins and subbasins. The estimate of the total hydrocarbons generated for the North Louisiana Salt Basin in this study using a petroleum system approach compares favorably with the total volume of hydrocarbons generated published by Zimmermann (1999). In this study, the estimate is 2,870 billion barrels of total hydrocarbons generated using the method of Schmoker (1994), and the estimate is 2,640 billion barrels of total hydrocarbons generated using the Platte River software application. The estimate of Zimmermann (1999) is 2,000 to 2,500 billion barrels of total hydrocarbons generated. The estimate of gas generated for this basin is 6,400 TCF using the Platte River software application, and 12,800 TCF using the method of Schmoker (1994). Barnaby (2006) estimated that the total gas volume generated for this basin ranges from 4,000 to 8,000 TCF. Seventy

  12. Controls on early retention and late enhancement of microporosity in reefal gas reservoirs, offshore north Sumatra basin

    SciTech Connect

    Moshier, S.O.

    1989-03-01

    Chalky lime-matrix texture is pervasive in 300 m of coralgal and skeletal carbonates in the NSB-A (North Sumatra basin-A) gas field (lower-middle Miocene), offshore northern Sumatra. Much of the reservoir quality can be attributed to matrix with abundant intercrystalline, vuggy, and channel-form micropores. Matrix is composed of calcite microrhombs which are interpreted to have developed during stabilization of the precursor mud. On the same shelf, the smaller NSB-H oil field is composed of more than 45-m thick buildup of similar lithofacies which lack abundant microporosity. In both fields, early diagenesis included dissolution of aragonitic skeletal material, matrix neomorphism, and precipitation of nonluminescent calcite followed by zoned, luminescent calcite cements. Stable isotopes from matrix reflect a more open or water-dominated matrix diagenesis at NSB-H field. More active flushing of oversaturated, organically charged meteoric waters was responsible for thorough matrix cementation and microporosity occlusion at NSB-H field. Calcite cements show progressive enrichment of iron and manganese and depletion of magnesium and strontium during growth. The matrix at NSB-H field contains iron-rich dolomite. At A field, remnant matrix microporosity and intraparticle microporosity in calcitic skeletal material were greatly enhanced after all phases of cementation. Some pore-rimming cements are partially dissolved. At NSB-H field, late-phase dissolution is limited to the vicinity of open fractures where matrix-calcite and dolomite crystals are leached. Reservoir brines have a limey marine origin but are depleted in Ca and Mg relative to seawater, and carbon dioxide accounts for 31% of reservoir gas. If present brines are carbonate undersaturated, they may be substantially enhanced microporosity at NSB-A field. Late-stage dissolution is insignificant at NSB-H field due to the lack of early formed matrix microporosity.

  13. Plant-water relationships in the Great Basin Desert of North America derived from Pinus monophylla hourly dendrometer records.

    PubMed

    Biondi, Franco; Rossi, Sergio

    2015-08-01

    Water is the main limiting resource for natural and human systems, but the effect of hydroclimatic variability on woody species in water-limited environments at sub-monthly time scales is not fully understood. Plant-water relationships of single-leaf pinyon pine (Pinus monophylla) were investigated using hourly dendrometer and environmental data from May 2006 to October 2011 in the Great Basin Desert, one of the driest regions of North America. Average radial stem increments showed an annual range of variation below 1.0 mm, with a monotonic steep increase from May to July that yielded a stem enlargement of about 0.5 mm. Stem shrinkage up to 0.2 mm occurred in late summer, followed by an abrupt expansion of up to 0.5 mm in the fall, at the arrival of the new water year precipitation. Subsequent winter shrinkage and enlargement were less than 0.3 mm each. Based on 4 years with continuous data, diel cycles varied in both timing and amplitude between months and years. Phase shifts in circadian stem changes were observed between the growing season and the dormant one, with stem size being linked to precipitation more than to other water-related indices, such as relative humidity or soil moisture. During May-October, the amplitude of the phases of stem contraction, expansion, and increment was positively related to their duration in a nonlinear fashion. Changes in precipitation regime, which affected the diel phases especially when lasting more than 5-6 h, could substantially influence the dynamics of water depletion and replenishment in single-leaf pinyon pine. PMID:25281029

  14. Plant-water relationships in the Great Basin Desert of North America derived from Pinus monophylla hourly dendrometer records

    NASA Astrophysics Data System (ADS)

    Biondi, Franco; Rossi, Sergio

    2015-08-01

    Water is the main limiting resource for natural and human systems, but the effect of hydroclimatic variability on woody species in water-limited environments at sub-monthly time scales is not fully understood. Plant-water relationships of single-leaf pinyon pine ( Pinus monophylla) were investigated using hourly dendrometer and environmental data from May 2006 to October 2011 in the Great Basin Desert, one of the driest regions of North America. Average radial stem increments showed an annual range of variation below 1.0 mm, with a monotonic steep increase from May to July that yielded a stem enlargement of about 0.5 mm. Stem shrinkage up to 0.2 mm occurred in late summer, followed by an abrupt expansion of up to 0.5 mm in the fall, at the arrival of the new water year precipitation. Subsequent winter shrinkage and enlargement were less than 0.3 mm each. Based on 4 years with continuous data, diel cycles varied in both timing and amplitude between months and years. Phase shifts in circadian stem changes were observed between the growing season and the dormant one, with stem size being linked to precipitation more than to other water-related indices, such as relative humidity or soil moisture. During May-October, the amplitude of the phases of stem contraction, expansion, and increment was positively related to their duration in a nonlinear fashion. Changes in precipitation regime, which affected the diel phases especially when lasting more than 5-6 h, could substantially influence the dynamics of water depletion and replenishment in single-leaf pinyon pine.

  15. Geological framework of an active hydrothermal site in the North Fiji Basin: Starmer cruise of the submersible Nautile

    SciTech Connect

    Auzende, J. )

    1990-06-01

    During the summer of 1989 the French submersible Nautile carried out a diving cruise on the North Fiji Basin ridge axis in the frame of the Starmer French-Japanese joint project. The diving sites were selected using the Seapso 3, Kaiyo 87, and Kaiyo 88 cruises Seabeam surveys. They are located around 17{degree}S in the axial graben at the northern end of the N15 ridge. The axis consists of an 18 km wide, N15 elongated dome cut by a 2 km wide axial graben. The elevation of the dome with respect to adjacent oceanic floor is 500-600 m. It culminates at less than 1,900 m, which is higher than a normal oceanic ridge. The axial graben width (2 km) is also unusual compared to oceanic ridge with intermediate spreading rates such as the EPR at 21{degree}N. Six Nautile dives have been devoted to the detailed exploration of the axial graben between 16{degree}58'S and 17{degree}00'S in order to locate the hydrothermal vents in the inferred most active part of the axial graben. A structural map has been established on the basis of dive observation. Between 17{degree}S and 16{degree}58'S, the axis shows a succession of N15-trending horsts and grabens paralleling the main orientation of the ridge. Two main lateral grabens and a central graben can be recognized. The central graben shows remarkably constant width (200 m) and depth (2,000 m). It is bounded by two small horsts, few tens of meters wide. Observed tectonic features include N15 normal fault scarps and abundant open fissures with the same direction. The whole area is dusted with sediments indicating that volcanism was not active recently. Evidence of recent hydrothermal activity such as oxide staining, dead munch, dead chimney is abundant all along the central graben.

  16. Absolute probability estimates of lethal vessel strikes to North Atlantic right whales in Roseway Basin, Scotian Shelf.

    PubMed

    van der Hoop, Julie M; Vanderlaan, Angelia S M; Taggart, Christopher T

    2012-10-01

    Vessel strikes are the primary source of known mortality for the endangered North Atlantic right whale (Eubalaena glacialis). Multi-institutional efforts to reduce mortality associated with vessel strikes include vessel-routing amendments such as the International Maritime Organization voluntary "area to be avoided" (ATBA) in the Roseway Basin right whale feeding habitat on the southwestern Scotian Shelf. Though relative probabilities of lethal vessel strikes have been estimated and published, absolute probabilities remain unknown. We used a modeling approach to determine the regional effect of the ATBA, by estimating reductions in the expected number of lethal vessel strikes. This analysis differs from others in that it explicitly includes a spatiotemporal analysis of real-time transits of vessels through a population of simulated, swimming right whales. Combining automatic identification system (AIS) vessel navigation data and an observationally based whale movement model allowed us to determine the spatial and temporal intersection of vessels and whales, from which various probability estimates of lethal vessel strikes are derived. We estimate one lethal vessel strike every 0.775-2.07 years prior to ATBA implementation, consistent with and more constrained than previous estimates of every 2-16 years. Following implementation, a lethal vessel strike is expected every 41 years. When whale abundance is held constant across years, we estimate that voluntary vessel compliance with the ATBA results in an 82% reduction in the per capita rate of lethal strikes; very similar to a previously published estimate of 82% reduction in the relative risk of a lethal vessel strike. The models we developed can inform decision-making and policy design, based on their ability to provide absolute, population-corrected, time-varying estimates of lethal vessel strikes, and they are easily transported to other regions and situations.

  17. Using of Spatial multi criteria evaluation for landslide zoning Case study Malach Aram basin -north of Iran

    NASA Astrophysics Data System (ADS)

    Naeimi-Nezamabad, A.; Hoseini Sarrafi, N.; Sadat Mousavi, S. H.

    2009-04-01

    Land slide is one of the major disasters which usually happens in specific area and causes different kinds of financial damage and loss of lives. Different places in IRAN are susceptible for occurring landslide. The study area, Malach Aram basin in Ramian County which is located in north part of Iran, is extended about 3500 hectare. Ever different methods are using for zoning and evaluation this natural disaster. Spatial multi criteria evaluation (SMCE) is a structure that implements statistical analysis of multi criteria evaluation on the Georefrence data. This model can be implemented on the GIS software, Ilwis and ArcGIS are major software for running this study. With defining criterion and sub criteria that are effective in occurring landslide and also specifying in groups and inter groups weight of values on the data layers and defining objectives in this classification and with using different effective criteria that are related to this issue, landslide zoning in the case study area has been prepared. The most important criteria that have been used for running this model are Topography, Slope, Aspect, Hillshade,landuse, climate (mouthy, seasonal and annual precipitation during 15 years ago from 2001 until 2007), state of earth dynamic ( earthquake density, distance of faults and others factors), state of existing flora ( density and percentage flora, kind of specious) geomorphology (geomorphology unit , landforms and fancies geomorphologic). After running the this model, output of this model is classification and part of area defined with height potential of landslide occurring. Output of classification landslide zoning with survey GPS pointes that defined real position landslide used in artificial neural network with supervised learning (Multi-Layer Perceptions) . Recently have defined that 5 area of total of suitable area with height potential landslide occurring are important areas with highly positional landslide occurring. Key words: Land slide- Natural

  18. The Early Miocene-Early Pliocene Vegetation and Climate Changes at the north to northwest Çankırı -Çorum Basin (Central Anatolian Plateau)

    NASA Astrophysics Data System (ADS)

    Atalar, Müge; Kováčová, Marianna; Sezgül Kayseri Ozer, Mine; Utescher, Torsten; Mazzini, Ilaria; Gliozzi, Elsa; Cosentino, Domenico

    2016-04-01

    The ALErT project targets on climate and tectonic hazards in the densely populated regions in the Central Anatolian Plateau (CAP), within the framework of the Marie Curie FP7-PEOPLE-2013-ITN program, The CAP extends in a wide area in between zone the Aegean extensional zone and Bitlis /Zagros compressional zone. Çankırı Basin (in the middle CAP) is a key to understand aridification plateau interior and it was a deep pelagic Basin from Late Cretaceous -Early Tertiary as a result of the closure of Neo- Tethyan till the Middle Eocene. North to south of the Çankırı Basin; the Plio - Quaternary Deǧim formation (fluvial deposits) consist of massive mudstones and sandstones and it unconformable overlies the Bozkır formation (lacustrine deposits). That is a Messinian succession mainly by a 200 m-thick cyclic sequence of continental gypsum layers, clays and sandy clays in gypsum with different thicknesses crops. Bozkır formation, the lower being the contact with the Süleymanlı formation. It is overlay the Tuǧlu formation with uncomformably, which is an Upper Miocene succession mainly composed of dark grey silty and organic rich clays. Following formation, which outcrops in the northwest of Çankırı basin, is Hançili formation. The unit is covered by grey sediments of the Hançili Formation, showing alternations of channel sandstones and clay stones over 100 m thick in Early - Middle Miocene in the Çankırı basin. In this study, samples were analyzed for biotic proxy data (palynology) to figure the paleo-environmental and paleoclimate changes. Additionally only for Bozkir formation (longest section in the study area) were sampled for geochemical (δ18O - δ13C isotopes analyses and CaCO3) analysis and the rest of the formations were interpreted using the previous study. In the most pollen spectra the herbs and shrubs prevail: in Deǧim formation (50%), in Bozkır formation (75%), in Süleymanlı formation (47%), in Tuǧlu formation (60%) and in Han

  19. From the North American Great Basin to the planet Mars: Taking Lacustrine Geomorphology into the 21st Century

    NASA Astrophysics Data System (ADS)

    Edgett, Kenneth S.; Parker, Timothy J.

    1997-09-01

    Introduction. The entire planet Mars is presently a desert more arid than any on Earth. The planet appears to have had more water in the past, and some of this water affected the surface geology and geomorphology by carving a variety of channels. Despite the evidence for running water in the martian past, the presence of sanding bodies of water (lakes, oceans) has been a topic of considerable controversy in the past two decades. The issue is still not settled, but evidence has mounted to suggest that lakes and oceans were indeed a major factor in shaping the present geomorphology of the martian surface. Although there remains uncertainty as to whether lakes were present on Mars, major efforts to seek evidence for fossil martian organisms are focused on the search for lake sediments and tufa deposits [1]. In 2001 and 2003, the NASA Mars Surveyor Program will launch mobile rovers designed to explore the surface and collect samples for return to Earth. The first set of samples will reach Earth in 2008. The types of landing sites being considered for the '01 and '03 missions include areas interpreted as ancient lacustrine deposits. Knowledge and experience with the geomorphology of lacustrine features in the North American Great Basin is crucial for identifying lake features on Mars. Martian Lakes and Oceans: Prior to spacecraft exploration of Mars, many early astronomers though that the low-albedo surfaces of Mars could be seas or lakes, others considered these to be vast tracts of vegetation [2]. The low-albedo surfaces are now known to be the result of aeolian action on the distribution of sand and dust. The Mariner 4, 6, and 7 spacecraft in 1965 and 1969 stunned the world by showing a cratered, lunar-like martian surface. In 1972, Mariner 9 showed a more Earth-like surface - indeed, there were numerous channels, some carved by massive floods, others perhaps by fluvial run-off or sapping. The Viking orbiters (1976-1980) provided additional images; these formed the

  20. Buried paleo-sedimentary basins in the north-eastern Black Sea-Azov Sea area and tectonic implications (DOBRE-2)

    NASA Astrophysics Data System (ADS)

    Starostenko, Vitaly; Stephenson, Randell; Janik, Tomasz; Tolkunov, Anatoly

    2014-05-01

    A number of independent but inter-related projects carried out under the auspices of various national and international programmes in Ukraine including DARIUS were aimed at imaging the upper lithosphere, crustal and sedimentary basin architecture in the north-eastern Black Sea, southern Crimea and Kerch peninsulas and the Azov Sea. This region marks the transition from relatively undisturbed Precambrian European cratonic crust and lithosphere north of the Azov Sea to areas of significant Phanerozoic tectonics and basin development, in both extensional as well as compressional environments, to the south, including the eastern Black Sea rift, which is the main sedimentary basin of the study area. The wide-angle reflection and refraction (WARR) profile DOBRE-2, a Ukrainian national project with international participation (see below), overlapping some 115 km of the southern end of the DOBREfraction'99 profile (that crosses the intracratonic Donbas Foldbelt) in the north and running to the eastern Black Sea basin in the south, utilised on- and offshore recording and energy sources. It maps crustal velocity structure across the craton margin and documents, among other things, that the Moho deepens from 40 km to ~47 km to the southwest below the Azov Sea and Crimean-Caucasus deformed zone. A regional CDP seismic profile coincident with DOBRE-2, crossing the Azov Sea, Kerch Peninsula and the north-eastern Black Sea southwest to the Ukraine-Turkey border, acquired by Ukrgeofisika (the Ukrainian national geophysical company) reveals in its inferred structural relationships the ages of Cretaceous and younger extensional and subsequent basin inversion tectonic events as well as the 2D geometry of basement displacement associated with post mid-Eocene inversion. A direct comparison of the results of the WARR velocity model and the near-vertical reflection structural image has been made by converting the former into the time domain. The results dramatically demonstrate that

  1. Use of a watershed-modeling approach to assess hydrologic effects of urbanization, North Fork Pheasant Branch basin near Middleton, Wisconsin

    USGS Publications Warehouse

    Steuer, Jeffrey J.; Hunt, R.J.

    2001-01-01

    The North Fork Pheasant Branch Basin in Dane County, Wisconsin is expected to undergo development. There are concerns that development will adversely affect water resources with increased flood peaks, increased runoff volumes, and increased pollutant loads. To provide a scientific basis for evaluating the hydrologic system response to development the Precipitation Runoff Modeling System (PRMS) was used to model the upper Pheasant Branch Creek watershed with an emphasis on the North Fork Basin. The upper Pheasant Branch Creek (18.3 mi2; 11,700 acres) Basin was represented with 21 Hydrologic Response Units (daily time step) and 50 flow planes (5-minute time steps). Precipitation data from the basin outlet streamflow-gaging station located at Highway 12 and temperature data from a nearby airport were used to drive the model. Continuous discharge records at three gaging stations were used for model calibration. To qualitatively assess model representation of small subbasins, periodic reconnaissance, often including a depth measurement, was made after precipitation to determine the occurrence of flow in ditches and channels from small subbasins. As a further effort to verify the model on a small subbasin scale, continuous-stage sensors (15-minute intervals) measured depth at the outlets of three small subbasins (500 to 1,200 acres). Average annual precipitation for the simulation period from 1993 to 1998 was 35.2 inches. The model simulations showed that, on average, 23.9 inches were intercepted by vegetation, or lost to evapotranspiration, 6.0 inches were infiltrated and moved to the regional ground-water system, and 4.8 inches contributed to the upper Pheasant Branch streamflow. The largest runoff event during the calibration interval was in July 1993 (746 ft3/sec; with a recurrence interval of approximately 25 years). Resulting recharge rates from the calibrated model were subsequently used as input into a ground-water-flow model. Average annual recharge varied

  2. Flow path of the 1993 Hokkaido-Nansei-oki earthquake seismoturbidite, suthern margin of the Japan sea north basin, inferred from anisotropy of magnetic susceptibility

    USGS Publications Warehouse

    Abdeldayem, A.L.; Ikehara, K.; Yamazaki, T.

    2004-01-01

    A magnetic fabric analysis has been carried out on standard cube samples from one gravity and three multiple cores extracted from the Shiribeshi trough and Okushiri basin in the southern margin of the Japan sea north basin. It is aimed at tracing the flow path of turbidites that are assumed to have deposited in response to the 1993 Hokkaido-Nansei-oki earthquake. Magnetic remanence was used for reorientation to the geographic coordinates. Magnetomineralogical investigations including low-temperature magnetometry, magnetic hysteresis loops and isothermal remanent magnetization (IRM) acquisition experiments indicate that pseudosingle domain to multidomain magnetite is the principal magnetic carrier and is, therefore, capable of providing reliable anisotropy of magnetic susceptibility (AMS) palaeocurrent direction estimates. A well-developed near-horizontal magnetic foliation and minimum susceptibility axes lying close to vertical are recorded at all sites reflecting an original depositional fabric. Clearly defined magnetic lineation was observed at all sites and is considered to reflect the palaeocurrent direction. Down-core changes of susceptibility and key AMS parameters show good correspondence to occurrences of turbidite layers marking the increase of input of influx materials. In agreement with results from recent marine surveys and IZANAGI side-scan sonar images, an NNE transportation trend has been estimated for sediments at sites from the Shiribeshi trough with a possible depositing path initiating from the slope bounding the south and southeastern margin down to the trough floor. Similarly, a SSE palaeocurrent direction has been estimated for sediments from the Okushiri basin with evidence for a relatively strong transporting current flowing through the canyons along the steep slope bounding the north and northeastern margins of the basin. The present results agree with the view that slope failure is the most probable mechanism for the down-slope transport

  3. A giant submarine slope failure on the insular slope north of Puerto Rico: A response of Arecibo basin strata to tectonic stress

    SciTech Connect

    Schwab, W.C.; Danforth, W.W.; Scanlon, K.M. )

    1990-06-01

    An amphitheater-shaped scarp, approximately 55 km across in water depths from about 3,000 m to 6,700 m was imaged on the northern insular slope of Puerto Rico (southern slope of the Puerto Rico Trench) using the GLORIA side-scan sonar system. This scarp represents the removal of more than 1,500 m{sup 3} of Tertiary Arecibo basin strata. The head of the scarp coincides with the location of a fault zone observed on nearby seismic-reflection profiles. Interpretation of the GLORIA imagery, and a review of available bathymetric, geophysical, and stratigraphic data and tectonic-framework models suggest that the scarp formed as a consequence of slope failure induced by tectonic oversteepening of the insular slope. The oversteepening may be a result of the most recent episode of convergence of the Caribbean and North American plates, which began approximately 4 million years ago. The Arecibo basin strata have been tilted approximately 4{degree} to the north and are apparently gravitationally unstable under the present seismic regime. The volume of material involved in this slope failure is comparable to the material displaced in tsunamogenic submarine landslides along the Peru Trench and Hawaiian Ridge. Therefore, if the slope failure north of Puerto Rico was catastrophic, it was large enough to have generated a tsunami that would have flooded the low ground of northern Puerto Rico.

  4. Effect of meteorological conditions on interannual variability in timing and magnitude of the spring bloom in the Irminger Basin, North Atlantic

    NASA Astrophysics Data System (ADS)

    Henson, Stephanie A.; Robinson, Ian; Allen, John T.; Waniek, Joanna J.

    2006-10-01

    Interannual variability in the spring bloom in the Irminger Basin, northern North Atlantic, is investigated using SeaWiFS-derived chlorophyll- a (chl- a) concentration and satellite or model-derived meteorological data. Variability in the timing and magnitude of the spring bloom in the basin is evaluated. A method for estimating a time series of Sverdrup's critical depth from satellite-derived data is introduced. Comparison with modelled mixed layer depth and chlorophyll concentration demonstrates that Sverdrup's critical depth model is valid for the Irminger Basin spring bloom. The dependence of the timing and magnitude of the spring bloom on winter pre-conditioning is investigated. We find that in the Irminger Basin the start of the spring bloom can be estimated from the preceding winter's mean wind speed and net heat flux. We also find that the maximum chl- a concentration during the bloom can be estimated from the frequency of winter storms. Increased storm activity results in a reduced bloom chlorophyll maximum by delaying the development of spring stratification, resulting in the bloom missing the 'window of opportunity' for optimum phytoplankton growth.

  5. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard

    2004-10-28

    The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification.

  6. A Backarc Basin Origin for the Eocene Volcanic Rocks North of Abbas Abad, East of Shahrud, Northeast Iran

    NASA Astrophysics Data System (ADS)

    Khalatbari Jafari, M.; Mobasher, K.; Davarpanah, A.; Babaie, H.; La Tour, T.

    2008-12-01

    The region in northeastern Iran, bordered by the Miami fault and the Doruneh fault, mainly exposes the Eocene volcanic and Tertiary sedimentary rocks and sporadic outcrops of pre- Jurassic metamorphic rocks such as gneiss and mica-schist. We have divided the volcanic and volcanic-sedimentary rocks into six main units: E1 through the youngest E6. North of Abbas Abad, the Lower Eocene is conglomerate, sandstone, and red shale with lenses of nummulite-bearing limestone at the base, and dacitic lava (E1) at the top. The nummulites give an Early Eocene age for the limestone lenses. The E2 unit includes vesicular basalt, intercalated, intraformational conglomerate, and lenses of nummulite-bearing limestone. E3 is volcanic- sedimentary, and is made of green tuff, tuffite, shale, and nummulite bearing limestone. E4 includes basalt and vesicular trachy-basalt, and E5 is mostly sedimentary, made of tan marl, sandstone, shale, and lenses of Middle Eocene nummulite-bearing limestone. The E6 unit is the most extensive, with at least three levels of nummulite-bearing limestone lenses which give a Middle to Early Eocene age. The volcanic rocks of the E6 unit include few hundred meters of epiclastic to hyaloclastic breccia, with intercalations of lava at the base. These are overlain by four horizons of aphyric olivine basalt and basalt, and phyric trachy-andesite and trachy-basalt. The volume of the aphyric lavas decreases, and that of the phyric lavas increases upsection. The Eocene volcanic sequence is covered by turbidite; the marl washings give an Eocene-Oligocene age range. Chondrite-normalized multi-element plots indicate enrichment of the Eocene Abbas Abad volcanic rocks in the LILE elements, with variable ratios of La/Yb (4.36-19.33) and La/Sm (3.10-7.91). These plots show a gentle slope, and the volcanic rocks in the E1 to E4 units are less enriched than those in the E6 unit, probably reflecting the difference in the original source for the melt. The multi-element plots

  7. RESOURCE ASSESSMENT OF THE IN-PLACE AND POTENTIALLY RECOVERABLE DEEP NATURAL GAS RESOURCE OF THE ONSHORE INTERIOR SALT BASINS, NORTH CENTRAL AND NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-04-16

    The University of Alabama and Louisiana State University have undertaken a cooperative 3-year, advanced subsurface methodology resource assessment project, involving petroleum system identification, characterization and modeling, to facilitate exploration for a potential major source of natural gas that is deeply buried (below 15,000 feet) in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas. The project is designed to assist in the formulation of advanced exploration strategies for funding and maximizing the recovery from deep natural gas domestic resources at reduced costs and risks and with minimum impact. The results of the project should serve to enhance exploration efforts by domestic companies in their search for new petroleum resources, especially those deeply buried (below 15,000 feet) natural gas resources, and should support the domestic industry's endeavor to provide an increase in reliable and affordable supplies of fossil fuels. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification. The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The project objectives will be achieved through a 3-year effort. First, emphasis is on petroleum system identification and characterization in the North

  8. Investigation of fluvial landforms in the north-eastern Pannonian Basin, using cartographic materials from the XIX-XXI Centuries

    NASA Astrophysics Data System (ADS)

    Robu, Delia; Niga, Bogdan; Perşoiu, Ioana

    2015-04-01

    The study area is located in the north-eastern Pannonian Basin, and covers approximately 3700 km2. Using cartographic materials for the last 155 years, we analyzed and defined river network and relict fluvial morphologies created by the rivers Tur, Someş, Homorod and Crasna. Database extraction from each set of historical maps was performed by field verification and validation, associated to GIS techniques. Relict fluvial morphologies on the Someş alluvial cone comprise a wide variety of channel typologies and sizes, drainage directions and their consequent typology, which indicates a complex fluvial evolution. The dominant category of relict fluvial morphology is represented by the meander loop. Following the quantitative analysis on the successive sets of maps we identified and delimited meander loops and meandering paths formed prior to the reference year 1860. Generally, the post-1860 relict fluvial morphologies are secondary morphologies, as the keynote is given by those formed previous to the reference moment 1860. An analysis of the share of the relict fluvial morphologies on the three sets of reference cartographic materials (the second Austro-Hungarian topographic survey, Google Earth and orthophotoplans) highlights that most relict fluvial morphologies were identified on the second Austro-Hungarian topographic survey, followed by those identified in Google Earth and orthophotoplans. The map of fluvial morphologies constructed in this study enables a discussion on drainage directions, based on the observation that a series of abandoned meander loops and segments follow clear directions. We applied several quantitative indices in assessing the relict fluvial morphology (radius of curvature, paleochannel width). Consequently, we identified underfit stream sectors with meander loops larger than the modern ones Someş meanders (on the Racta River), uncharacteristic features such as braided riverbed reaches, a high frequency of meander scrolls present on the

  9. Basin-scale population genetic structure of the planktonic copepod Calanus finmarchicus in the North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Unal, Ebru; Bucklin, Ann

    2010-10-01

    Pelagic marine invertebrates have extensive potential for gene flow, although barriers to gene flow and entrainment in ocean currents may lead to reproductive isolation or drift, and thus to genetic differentiation of populations. The planktonic calanoid copepod Calanus finmarchicus shows significant geographic variation in life history traits across subarctic zones of the N. Atlantic Ocean. Population genetic analysis of C. finmarchicus examined allelic variation at 24 single nucleotide polymorphic (SNP) sites in three nuclear protein-coding genes: citrate synthase, heat-shock protein-70, and AMP-activated protein kinase. Samples were collected during 2005 from 10 areas representing the Northwest (NW), North Central (NC), and Northeast (NE) Atlantic gyres. Hypotheses of two or more distinct populations of C. finmarchicus were examined based on SNP variation within the three genes analyzed both separately and together using AMOVA ( Arlequin Ver. 3.11), CLUMPP (Ver. 1.1), GENALEX (Ver. 6.2), Genepop (Ver. 4.0.10), and Structure (Ver. 2.3). All analyses revealed evidence of small but significant differentiation among areas within gyres (e.g., FSC = 0.0306, p < 0.0001 for two populations; FSC = 0.0344, p < 0.0001 for three populations; pairwise FST values for all 10 areas ranged from 0.0000 to 0.2400), which may reflect ecologically-important, short-term (on the order of months) variation driven by geographic variation in life history traits. Support for underlying large-scale differentiation, which may reflect persistent barriers to gene flow associated with entrainment in ocean gyres, was provided by various analyses, with numbers of distinct C. finmarchicus populations ranging from two to four. Analysis of molecular variation supported two populations, while clustering and population assignment supported two, three, or four populations. The Barents Sea sample was especially distinctive: one test using AMOVA was non-significant among gyres without this sample and

  10. Water quality in Reedy Fork and Buffalo Creek basins in the Greensboro area, North Carolina, 1986-87

    USGS Publications Warehouse

    Davenport, M.S.

    1989-01-01

    Water and bottom-sediment samples were collected from April 1986 through September 1987 at 19 sites in Guilford County and the City of Greensboro, North Carolina. Sampling locations included 13 stream sites, two lakes that supply the City of Greensboro with drinking water, two City of Greensboro finished drinking-water filtration plants, and effluent from the two municipal wastewater plants prior to outfall into receiving streams. Water sampling consisted of six surveys during various stages of steady ground-water flow at all sites and high-flow-event sampling during two storms at six sites. Bottom-sediment samples were collected at three sites during two routine sampling surveys. A summary of nearly 22, 000 separate chemical or physical analyses of water samples or bottom sediment is presented and discussed as individual values, ranges of values, or median values with respect to the locations of sampling sites, streamflow conditions, or other information bearing on water-quality conditions under discussion. The results include discussions of general water-quality indicators; major ion, nutrient, and trace-element concentrations; acid and base/neutral extractable organic compounds; volatile organic compounds; and organochlorine and organophosphorus pesticides detected at each sampling site. Loadings of selected constituents are also estimated on a yearly and daily basis. The quality of the raw and finished water, municipal effluents, and streams in the Greensboro area are characterized by using State and Federal water-quality standards. Inorganic constituents most commonly found in excess of standards were iron, copper, zinc, arsenic, phosphorus, manganese, cyanide, and mercury. Relatively few organic compounds were detected; however, those consistently reported were phthalate, thihalomethane, organophosphorus pesticide, benzol, and phenolic compounds. Selected inorganic, physical, and total organic carbon data are used in a Wilcoxon test for two independent

  11. Towards A 3d Retro-deformation of The Rotliegend Strata of The 'tight Gas' Area, North German Basin

    NASA Astrophysics Data System (ADS)

    Tanner, D.; Krawczyk, C. M.; Oncken, O.

    This work is concerned with the subsurface Rotliegend strata beneath the `Tight-Gas' area (10 × 20 km2) of the North German Basin, Lower Saxony. We aim to: 1. construct a detailed three-dimensional, geometrical model of the Rotliegend from 3D seismic and borehole data. 2. compile an incremental tectonic history of the area from structure maps for specific Rotliegend horizons, i.e. Top Rotliegend, Top Dethlingen Fm. and Base Rotliegend. 3. retro-deform the model in time and 3D space. This will demonstrate the strain caused during the tectonic history, which will give insight into the position of tectonic fracturing and thus secondary porosity. The database for our model comes from 3D reflection seismic data (25 m resolution) and 11 boreholes. In the working area, the Rotliegend is approximately 200­300 m thick. The structure is dominated by an arcuate wall/dome of Zechstein salt in the middle of the area. Assuming no movement of salt in or out of the area, we estimate the original thickness of salt was 497 m. In general, the Top Rotliegend is highest in the S-SW and lowest in the N-NE of the area, split NW­SE, apparently by faults. The most prominent feature is a N­S graben. This cross-cuts a NW­SE trending (east-dipping) fault, which loses throw eastwards. To the west, there is a large N­S trending, east-dipping fault with a prominent footwall bulge. Structures to the east of the main graben are more complex. NW­SE, NE­SW and N­S striking faults can seen with few cross-cutting relationships and small, if any, throws. The N­S faults are correlated with the major graben. Fault traces are visible in dip, azimuth and amplitude maps of the Top Rotliegend, and in most cases faults can be picked in inline and crossline sections. Additional information is won from dip, amplitude and coherence maps of Rotliegend horizons. 1 Allan Maps are constructed to demonstrate the vertical and horizontal throw (of var- ious stratigraphic horizons) on the faults. In order to

  12. Physical characteristics of stream subbasins in the upper Minnesota River basin, west-central Minnesota, northeastern South Dakota and southeastern North Dakota

    USGS Publications Warehouse

    Sanocki, C.A.

    1995-01-01

    Data that describe the physical characteristics of stream subbasins upstream from selected points on streams in the Upper Minnesota River Basin, located in west-central Minnesota, north-eastern South Dakota, and southeastern North Dakota, are presented in this report. The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both laker and wetlands, the main-channel length, and the main-channel slope. The points on the stream include outlets of subbasins of at least 5 square miles, outlets of sewage treatment plants, and locations of U.S. Geological Survey low-flow, highflow, and continuous-record gaging stations.

  13. The lithospheric-scale 3D structural configuration of the North Alpine Foreland Basin constrained by gravity modelling and the calculation of the 3D load distribution

    NASA Astrophysics Data System (ADS)

    Przybycin, Anna M.; Scheck-Wenderoth, Magdalena; Schneider, Michael

    2014-05-01

    The North Alpine Foreland Basin is situated in the northern front of the European Alps and extends over parts of France, Switzerland, Germany and Austria. It formed as a wedge shaped depression since the Tertiary in consequence of the Euro - Adriatic continental collision and the Alpine orogeny. The basin is filled with clastic sediments, the Molasse, originating from erosional processes of the Alps and underlain by Mesozoic sedimentary successions and a Paleozoic crystalline crust. For our study we have focused on the German part of the basin. To investigate the deep structure, the isostatic state and the load distribution of this region we have constructed a 3D structural model of the basin and the Alpine area using available depth and thickness maps, regional scale 3D structural models as well as seismic and well data for the sedimentary part. The crust (from the top Paleozoic down to the Moho (Grad et al. 2008)) has been considered as two-parted with a lighter upper crust and a denser lower crust; the partition has been calculated following the approach of isostatic equilibrium of Pratt (1855). By implementing a seismic Lithosphere-Asthenosphere-Boundary (LAB) (Tesauro 2009) the crustal scale model has been extended to the lithospheric-scale. The layer geometry and the assigned bulk densities of this starting model have been constrained by means of 3D gravity modelling (BGI, 2012). Afterwards the 3D load distribution has been calculated using a 3D finite element method. Our results show that the North Alpine Foreland Basin is not isostatically balanced and that the configuration of the crystalline crust strongly controls the gravity field in this area. Furthermore, our results show that the basin area is influenced by varying lateral load differences down to a depth of more than 150 km what allows a first order statement of the required compensating horizontal stress needed to prevent gravitational collapse of the system. BGI (2012). The International

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

    USGS Publications Warehouse

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

    2013-01-01

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

  15. Mapping the hydraulic connection between a coalbed and adjacent aquifer: example of the coal-seam gas resource area, north Galilee Basin, Australia

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenjiao; Mariethoz, Gregoire; Schrank, Christoph; Cox, Malcolm; Timms, Wendy

    2016-07-01

    Coal-seam gas production requires groundwater extraction from coal-bearing formations to reduce the hydraulic pressure and improve gas recovery. In layered sedimentary basins, the coalbeds are often separated from freshwater aquifers by low-permeability aquitards. However, hydraulic connection between the coalbed and aquifers is possible due to the heterogeneity in the aquitard such as the existence of conductive faults or sandy channel deposits. For coal-seam gas extraction operations, it is desirable to identify areas in a basin where the probability of hydraulic connection between the coalbed and aquifers is low in order to avoid unnecessary loss of groundwater from aquifers and gas production problems. A connection indicator, the groundwater age indictor (GAI), is proposed, to quantify the degree of hydraulic connection. The spatial distribution of GAI can indicate the optimum positions for gas/water extraction in the coalbed. Depressurizing the coalbed at locations with a low GAI would result in little or no interaction with the aquifer when compared to the other positions. The concept of GAI is validated on synthetic cases and is then applied to the north Galilee Basin, Australia, to assess the degree of hydraulic connection between the Aramac Coal Measure and the water-bearing formations in the Great Artesian Basin, which are separated by an aquitard, the Betts Creek Beds. It is found that the GAI is higher in the western part of the basin, indicating a higher risk to depressurization of the coalbed in this region due to the strong hydraulic connection between the coalbed and the overlying aquifer.

  16. Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; characterization of suspended sediment, nutrients, and pesticides

    USGS Publications Warehouse

    Harned, Douglas; McMahon, Gerard; Spruill, T.B.; Woodside, M.D.

    1995-01-01

    The 28,000-square-mile Albemarle-Pamlico drainage basin includes the Roanoke, Dan, Chowan Tar, and Neuse Rivers. The basin extends through four physiographic provinces in North Carolina and Virginia-Valley and Ridge, Blue Ridge, Piedmont and Coastal Plain. The spatial and temporal trends in ground-water and riverine water quality in the study area were characterized by using readily available data sources The primary data sources that were used included the U.S. Geological Survey's National Water Data Storage and Retrieval System (WATSTORE) database, the U.S. Environmental Protection Agency's Storage and Retrieval System (STORET) database, and results of a few investigations of pesticide occurrence. The principal water-quality constituents examined were suspended sediment, nutrients, and pesticides. The data examined generally spanned the period from 1950 to 1993. The only significant trends in suspended sediment were detected at three Chowan River tributary sites which showed long-term decreases. Suspended- and total-solids concentrations have decreased throughout the Albemarle-Pamlico drainage basin. The decreases are probably a result of (1) construction of new lakes and ponds in the basin, which trap solids, (2) improved agricultural soil management, and (3) improved wastewater treatment. Nutrient point sources are much less than nonpoint nutrient sources at the eight NASQAN basins examined for nutrient loads. The greatest nitrogen inputs are associated with crop fertilizer and biological nitrogen fixation by soybeans and peanuts, whereas atmospheric and animal-related nitrogen inputs are comparable in magnitude. The largest phosphorus inputs are associated with animal wastes. The most commonly detected pesticides in surface water in the STORET database were atrazine and aldrin.Intensive organonitrogen herbicide sampling of Chicod Creek in 1992 showed seasonal variations in pesticide concentration. The most commonly detected herbicides were atrazine, alachlor

  17. Relating seasonal dynamics of enhanced vegetation index to the recycling of water in two endorheic river basins in north-west China

    NASA Astrophysics Data System (ADS)

    Matin, M. A.; Bourque, C. P.-A.

    2015-08-01

    This study associates the dynamics of enhanced vegetation index in lowland desert oases to the recycling of water in two endorheic (hydrologically closed) river basins in Gansu Province, north-west China, along a gradient of elevation zones and land cover types. Each river basin was subdivided into four elevation zones representative of (i) oasis plains and foothills, and (ii) low-, (iii) mid-, and (iv) high-mountain elevations. Comparison of monthly vegetation phenology with precipitation and snowmelt dynamics within the same basins over a 10-year period (2000-2009) suggested that the onset of the precipitation season (cumulative % precipitation > 7-8 %) in the mountains, typically in late April to early May, was triggered by the greening of vegetation and increased production of water vapour at the base of the mountains. Seasonal evolution of in-mountain precipitation correlated fairly well with the temporal variation in oasis-vegetation coverage and phenology characterised by monthly enhanced vegetation index, yielding coefficients of determination of 0.65 and 0.85 for the two basins. Convergent cross-mapping of related time series indicated bi-directional causality (feedback) between the two variables. Comparisons between same-zone monthly precipitation amounts and enhanced vegetation index provided weaker correlations. Start of the growing season in the oases was shown to coincide with favourable spring warming and discharge of meltwater from low- to mid-elevations of the Qilian Mountains (zones 1 and 2) in mid-to-late March. In terms of plant requirement for water, mid-seasonal development of oasis vegetation was seen to be controlled to a greater extent by the production of rain in the mountains. Comparison of water volumes associated with in-basin production of rainfall and snowmelt with that associated with evaporation seemed to suggest that about 90 % of the available liquid water (i.e. mostly in the form of direct rainfall and snowmelt in the mountains

  18. REGIONAL ASSESSMENT OF FISH HEALTH: A PROTOTYPE METHODOLOGY AND CASE STUDY FOR THE ALBEMARLE-PAMLICO RIVER BASIN, NORTH CAROLINA

    EPA Science Inventory

    BASE (Basin-Scale Assessments for Sustainable Ecosystems) is a research program developed by the Ecosystems Research Division of the National Exposure Research Laboratory to explore and formulate approaches for assessing the sustainability of ecological resources within watershed...

  19. Volcanic activities in the Southern part of East African rift initiation: Melilitites and nephelinites from the Manyara Basin (North Tanzania rift axis)

    NASA Astrophysics Data System (ADS)

    Baudouin, Celine; Parat, Fleurice; Tiberi, Christel; Gautier, Stéphanie; Peyrat, Sophie

    2016-04-01

    The East African Rift exposes different stages of plate boundary extension, from the initiation of the rift (North (N) Tanzania) to oceanic accretion (Afar). The N Tanzania rift-axis (north-south (S) trend) is divided into 2 different volcanic and seismic activities: (1) the Natron basin (N) with shallow seismicity and intense volcanism and (2) the Manyara basin (S) with deep crustal earthquakes and sparse volcanism. The Natron basin is characterized by extinct volcanoes (2 Ma-0.75 Ma) and active volcano (Oldoinyo Lengai) and a link between seismicity and volcanism has been observed during the Oldoinyo Lengai crisis in 2007. In the S part of the N Tanzanian rift, volcanoes erupted in the Manyara basin between 0.4 and 0.9 Ma. In this study, we used geochemical signature of magmas and deep fluids that percolate into the lithosphere beneath Manyara basin, to define the compositions of magmas and fluids at depth beneath the S part of the N Tanzania rift, compare to the Natron basin and place constrain on the volcanic and seismic activities. The Manyara basin has distinct volcanic activities with mafic magmas as melilitites (Labait) and Mg-nephelinites (carbonatite, Kwaraha), and more differentiated magmas as Mg-poor nephelinites (Hanang). Melilitites and Mg-nephelinites are primary magmas with olivine, clinopyroxene (cpx), and phlogopite recording high-pressure crystallization environment, (melilitites >4 GPa and Mg-nephelinites>1 GPa) with high volatile contents (whole rock: 0.7-4.6 wt% CO2, 0.1-0.3 wt% F and 0.1 wt% Cl). FTIR analyses of olivine constrained the water content of Labait and Kwaraha magmas at 0.1 and 0.4 wt% H2O, respectively. Geochemical modelling suggests that mafic magmas result from a low degree of partial melting (1-2%) of a peridotitic source with garnet and phlogopite (high Tb/Yb (>0.6) and Rb/Sr (0.03-0.12) ratio). Mg-poor nephelinites from Hanang volcano crystallized cpx, Ti-garnet, and nepheline as phenocrysts. Magmas result from fractional

  20. Multi-parameter analysis of seismoturbidites in the Kumburgaz Basin of Sea of Marmara: Implications for creeping versus locked Central High segment of the North Anatolian Fault

    NASA Astrophysics Data System (ADS)

    Yakupoǧlu, Nurettin; Uçarkuş, Gülsen; Eriş, K. Kadir; Çaǧatay, M. Namık; Henry, Pierre; Yalamaz, Burak; Sabuncu, Asen; Acar, Dursun

    2016-04-01

    Sediment sequences deposited in active transform basins provide valuable archives of earthquake-triggered co-seismic sedimentation. A better understanding of the relationship between offshore fault ruptures and Seismoturbidites would have direct implications for earthquake hazard assessment. Submerged section of the North Anatolian Fault in the northern Sea of Marmara basin, which experienced more than 55 (Ms>6.8) earthquakes in the last 2000 years, poses a unique laboratory to study such kind of sync-tectonic history. Following the devastating 1999 Izmit and Duzce earthquakes (Mw = 7.4/7.2 respectively), a major seismic gap is now along the offshore branch of the NAF in the Sea of Marmara. The segments that control the Cinarcik and Kumburgaz basins in the Sea of Marmara have not ruptured during the 20th century. This study focusses on the Kumburgaz basin, which is located along the central segment of the NAF, and its less-known linkage to historical earthquakes, particularly to Ms>7 1509 and 1766 earthquakes. The main objective of this study is to test the two alternative hypotheses of a creeping versus locked central High segment by determining the frequency and timing of earthquake triggered turbidite units in the Kumburgaz basin. A 21-m-long piston core recovered in Kumburgaz basin during the Marsite cruise in 2014 is analysed at high resolution in order to identify the discrete turbidite-homogenite units (T-H units). The piston core reveals 22 T-H units where several packages consist of a sharp basal contact and multiple fining upward beds of sand to coarse silt as characteristically seen in most Seismoturbidite units. We initiated a systematic study of T-H units with the objectives of establishing criteria for identification of Seismoturbidites by analysing the physical, mineralogical and chemical composition of the piston core. The density and magnetic susceptibility changes along the core are analysed by Multi-Sensor Core Logger (MSCL). High detrital input

  1. The impact of the spatial variability in bottom roughness on tidal dynamics and energetics, a case study: the M 2 surface tide in the North European Basin

    NASA Astrophysics Data System (ADS)

    Kagan, Boris A.; Sofina, Ekaterina V.; Rashidi, Ebrahim

    2012-12-01

    A modified version of the 3D finite-element hydrostatic model QUODDY-4 is used to quantify the changes in the dynamics and energetics of the M 2 surface tide in the North European Basin, induced by the spatial variability in bottom roughness. This version differs from the original one, as it introduces a module providing evaluation of the drag coefficient in the bottom boundary layer (BBL) and by accounting for the equilibrium tide. The drag coefficient is found from the resistance laws for an oscillatory rotating turbulent BBL over hydrodynamically rough and incompletely rough underlying surfaces, describing how the wave friction factor as well as other resistance characteristics depend on the dimensionless similarity parameters for the BBL. It is shown that the influence of the spatial variability in bottom roughness is responsible for some specific changes in the tidal amplitudes, phases, and the maximum tidal velocities. These changes are within the model noise, while the changes in the averaged (over a tidal cycle) horizontal wave transport and the averaged dissipation of barotropic tidal energy may be of the same orders of magnitude as are the above energetic characteristics as such. Thus, contrary to present views, ignoring the spatial variability in bottom roughness at least in the North European Basin is only partially correct: it is valid for the tidal dynamics, but is liable to break down for the tidal energetics.

  2. Structural evolution of the Kopet Dagh fold-and-thrust belt (North-East Iran) and interactions with the South Caspian Sea Basin and Amu Darya Basin

    NASA Astrophysics Data System (ADS)

    Robert, Alexandra M. M.; Letouzey, Jean; Kavoosi, Mohammad A.; Sherkati, Sharham; Müller, Carla; Vergés, Jaume

    2014-05-01

    We present a detailed stratigraphic and structural study of the Kopet Dagh fold-and-thrust belt in NE Iran, which is an investigation of the complex polyphased tectonic history of this belt and its links with the adjacent South Caspian Sea and Amu Darya basins. Based on numerous field surveys, a large amount of 2D and 3D seismic data, borehole data and more than 150 new biostratigaphic datings, a new detailed biostratigraphic chart and 4 main regional cross-sections illustrate the importance of lateral facies variations and structural inheritance in the present-day structure of the belt. After the Cimmerian orogeny corresponding to the closure of the Paleotethys Ocean in Late Triassic-Early Jurassic times, a post-collisional rifting event was associated with the deposition of one of the main source rocks of the Kopet Dagh and the Amu Darya Basin (Kashafrud Formation). Following this rifting event, over 7 km of sediments were accumulated until the Tertiary above a regional post-Triassic unconformity. The occurrence of local uplifts during the Late Cretaceous-Early Paleocene is interpreted as a consequence of regional-scale modification of plate-slab coupling in the Neotethys subduction zone. The structures associated with the Late Eocene/Oligocene folding phase are sealed in the western part of the belt by a major Eocene-Oligocene unconformity at the base of the thick sedimentary series belonging to the South Caspian Sea Basin. The rapid subsidence of the South Caspian Sea Basin is probably related to syn-compressional downward flexure of the resistant basement basin at the onset of the Alpine phase. In the eastern part of the Kopet Dagh, this deformation is characterized by Middle Jurassic graben inversion with evidences of forced-folding, short-cuts and present-day slip partitioning, and as well by larger scale basement uplift. In contrast, the northwestern part of the belt shows thrust faults involving basement and fault-propagation folds within the sedimentary

  3. Syn-Rift Stratigraphic Architecture Reveals the Growth History of a Sub-basinal Fault Population in the Outer Moray Firth, North Sea

    NASA Astrophysics Data System (ADS)

    Kane, K.; Gupta, S.; Trudgill, B.; Johnson, H.

    2003-12-01

    Processes of normal fault propagation and linkage are recorded in the stratigraphic record by syn-rift sedimentary deposits that fill the generated accommodation volume. Using 3D seismic stratigraphic analysis, supported by well log and core interpretation, we investigate how the growth of an intrabasinal fault population led to the progressive development of an extensional sub-basin in the Moray Firth rift arm of the North Sea. The North Halibut Graben sub-basin has an E-W to WNW-ESE orientation and formed through the interaction of two main structural trends during late Jurassic rifting. E-W trending structural barriers bound the sub-basin to the north (Tartan and Petronella Ridges) and south (Halibut Horst Spur) whilst major NE-SW trending structures occur at the eastern margin. Spatial and temporal changes in syn-rift stratigraphic architecture reflect the history of faulting within the North Halibut Graben sub-basin. Fault parallel seismic profiles and intra-syn rift isochron maps demonstrate how faults initially developed as separate segments and subsequently linked to form longer strands through progressive growth and propagation. They also provide clear evidence that a major change in the structural framework occurred during rifting, supporting earlier studies advocating sequential rather than synchronous normal fault activity. The syn-rift sequence can be divided into at least two phases based on shifts in sedimentary packages and reorganistation of sequence thicknesses. Isochron maps illustrate that from late Oxfordian times (syn-rift phase I), early syn-rift sedimentation was controlled solely by NE-SW trending faults at the eastern margin of the basin. Strain was initially accommodated across several distributed, highly segmented faults but, with progressive linkage, stress became localised on one or two major through-going fault strands whilst shorter surrounding segments were switched off. From early-mid Volgian times we observe a progressive switch

  4. Estimation of successive coseismic vertical offsets using coeval sedimentary events - application to the southwestern limit of the Sea of Marmara's Central Basin (North Anatolian Fault)

    NASA Astrophysics Data System (ADS)

    Beck, C.; Campos, C.; Eriş, K. K.; Çağatay, N.; Mercier de Lepinay, B.; Jouanne, F.

    2015-02-01

    In the deep part of the Sea of Marmara (Turkey), the sedimentation developing upon the North Anatolian Fault is strongly influenced by the associated seismic activity, through gravity reworking (fluidized landslides) and tsunamis. Specific layers (homogenites + turbidites, HmTu), representing individual sedimentary events, have been characterized along three giant piston cores retrieved from the Çinarcik and Central (or Orta) basins. Pre-Holocene, nonmarine sediments, were analyzed, representing the last 12-17 kyr BP (before present). For a 2 kyr long interval, 11 events could be precisely correlated on both sides of the Central Basin's southwestern scarp. For each of them, based on the specific depositional process, the thickness difference between the two sites was considered as a direct estimation of the vertical component of a coeval coseismic offset. The homogenite (upper) component accounts for the major part of the thickness difference (ranging from 36 to 144 cm). These offsets were considered as likely representing dominantly vertical throws, along the transtensional southwestern boundary of the inner, pull-apart Central Basin. In terms of natural hazards, further investigations on this local behavior should rather be directed to tsunami genesis.

  5. New insights into the origin of late Neogene sediments in the Umatilla Basin, north-central Oregon and south-central Washington

    SciTech Connect

    Lindsey, K.A. ); Tolan, T.L. . Dept. of Geology); Reidel, S.P. )

    1993-04-01

    The study of late Miocene-aged terrigenous clastic sediments in the Umatilla Basin of north-central Oregon and adjacent Klickitat Valley of southern Washington reveal important, previously unrecognized stratigraphic and lithologic trends. These sediments, comprising the upper Ellensburg and the Alkali Canyon Formations (14 to 8.5 Ma) previously have been characterized as basaltic gravels deposited in localized alluvial fans and minor air fall tuffs produced by Cascade volcanism. A minor extrabasinal (exotic) component to these sediments has been noted in some previous studies. The authors' data challenges these interpretations. Pebble counts reveal a variety of exotic clast types, including metavolcanics, laminated metasediments, quartzites, and intermediate to silicic volcanics. This assemblage of lithologies is different than those that characterize the ancestral Columbia and Salmon-Clearwater Rivers. Sedimentologic trends suggest fluvial rather than alluvial fan deposition dominated. They interpret that a major fluvial system flowed from SE to NW across the western third of the Umatilla Basin. This river exited the Umatilla Basin via the Rock Creek water gap in the Columbia Hills, flowed across the Klickitat Valley and the Horse Heaven Hills, and then intersected the ancestral Columbia River. The abundance and stratigraphic distribution of exotic clast types suggests that this river drained terranes south and east of the Blue Mountains and persisted for a significant period of time, from approximately 14.5 to 8.5 Ma.

  6. Streamflow Simulations and Percolation Estimates Using the Soil and Water Assessment Tool for Selected Basins in North-Central Nebraska, 1940-2005

    USGS Publications Warehouse

    Strauch, Kellan R.; Linard, Joshua I.

    2009-01-01

    The U.S. Geological Survey, in cooperation with the Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North Natural Resources Districts, used the Soil and Water Assessment Tool to simulate streamflow and estimate percolation in north-central Nebraska to aid development of long-term strategies for management of hydrologically connected ground and surface water. Although groundwater models adequately simulate subsurface hydrologic processes, they often are not designed to simulate the hydrologically complex processes occurring at or near the land surface. The use of watershed models such as the Soil and Water Assessment Tool, which are designed specifically to simulate surface and near-subsurface processes, can provide helpful insight into the effects of surface-water hydrology on the groundwater system. The Soil and Water Assessment Tool was calibrated for five stream basins in the Elkhorn-Loup Groundwater Model study area in north-central Nebraska to obtain spatially variable estimates of percolation. Six watershed models were calibrated to recorded streamflow in each subbasin by modifying the adjustment parameters. The calibrated parameter sets were then used to simulate a validation period; the validation period was half of the total streamflow period of record with a minimum requirement of 10 years. If the statistical and water-balance results for the validation period were similar to those for the calibration period, a model was considered satisfactory. Statistical measures of each watershed model's performance were variable. These objective measures included the Nash-Sutcliffe measure of efficiency, the ratio of the root-mean-square error to the standard deviation of the measured data, and an estimate of bias. The model met performance criteria for the bias statistic, but failed to meet statistical adequacy criteria for the other two performance measures when evaluated at a monthly time

  7. Deep Crustal Magma Conduits, Diabase Internal Structure, and Coupled Hydrothermal Processes in Mesozoic Basins of Eastern North America

    NASA Astrophysics Data System (ADS)

    Ryan, M. P.; Ingerov, A.; Daniels, D. L.; Carr, P. M.; Elliott, G.; Fox, L.; Pierce, H. A.; Sutphin, D. M.

    2004-05-01

    Integrated geophysical, geological, and hydrological studies of the Culpeper (VA) and Gettysburg (PA) basins have shown fundamental new relationships among the internal structure of their plutonic rocks and have constrained the structural controls on paleo- and contemporary subsurface fluid flow within their ancient rift zone intrusive centers. Deep sub-basin igneous structure and the cross-sectional structure of the Culpeper basin. Magnetotelluric (MT) measurements along two basin-crossing transects have been inverted to reveal the basin cross-sectional structure and the structure of the primary conduit that transported tholeiitic magma through the crust during the Lower Jurassic. In cross-section, the basin deepens abruptly east of the Bull Run and Catoctin mountains, reaching a maximum depth of 2.5 to 2.75 km. The basin then shallows gradually towards the east. Basin rocks span the range 25 to 8,000 Ohm-m and range from fluid-saturated siltstones to unsaturated diabase, respectively. The crustal conduit for the Belmont diabase sheet has been resolved to 20 km depth. At that depth, it is characterized by a vertical region of relatively low resistivity (150 to 4,000 Ohm-m) embedded in relatively resistive (~10,000+ Ohm-m) crystalline Proterozoic rocks. At 4--5 km depth, the conduit width is ~2 km, flaring outward to a mean width of 6 km at 20 km depth. The conduit is inferred to be a laminate-like resistivity ``composite,'' with a central core resistivity of ~150 Ohm-m grading outwards through zones of 103, 2×103, and finally 4×103 Ohm-m near the outer margins. Based on the phase equilibria of ultramafic rocks and the petrology of diabase, the conduit is inferred to be olivine gabbro +/- dunite, and to be compositionally-zoned from core to margin. In general, the resistivity structure of the conduit is bilaterally-symmetric. Intra-basin igneous structure of the Gettysburg basin. The structure and geometry of the diabase sheets, lopoliths, and dikes of the

  8. Petrographic and geochemical characteristics of the Paleogene sedimentary rocks from the North Jiangsu Basin, Eastern China: implications for provenance and tectonic setting

    NASA Astrophysics Data System (ADS)

    Zhang, Ni; Lin, Chun-Ming; Zhang, Xia

    2014-08-01

    The petrography and geochemistry (major, trace, and rare earth elements) of clastic sedimentary rocks from the Paleogene Dainan Formation (E2 d) in the North Jiangsu Basin, eastern China, are investigated to trace their provenance and to constrain their tectonic setting. The studied samples are characterized by LREE enrichment, flat HREE, and negative Eu anomaly similar to the upper continental crust composed chiefly of felsic components in the source area. Petrographic observation indicates that the sandstones contain predominant metamorphic and sedimentary clasts that were derived from peripheral recycled orogen and intrabasinal materials. The trace element ratios (Co/Th, La/Sc, La/Th, and Th/U) and the La-Th-Sc ternary plot further confirm that the sandstones are derived from granitic gneiss sources from recycled orogen and the intrabasinal mixed sedimentary provenance. The granitic gneiss source rocks may have derived from the Proterozoic granitic gneiss denuded in the eastern Dabie-Sulu orogen; and the intrabasinal provenance may come from the underlying strata during the Late Paleocene Wubao movement. The chemical index of alteration (CIA) and A-CN-K plot show that these source rocks may have experienced weak to medium chemical weathering. Analysis on tectonic setting of the source area suggests an active continental margin, which is intimate with tectonic feature of the Dabie-sulu orogen and the Yangtze block. In summary, we suggest that the North Jiangsu Basin is an ideal site for the study of the coupling between the uplift of the orogen and the subsidence of the foreland basin.

  9. An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

    2013-12-01

    Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as

  10. Cenozoic stratigraphic development in the north Chilean forearc: Implications for basin development and uplift history of the Central Andean margin

    NASA Astrophysics Data System (ADS)

    Hartley, Adrian J.; Evenstar, Laura

    2010-11-01

    Analysis of the Cenozoic stratigraphic development of the forearc of northern Chile between 18°S and 23°30'S, allows constraints to be placed on the timing and nature of basin formation and the uplift history of the Central Andes. Chronostratigraphic charts have been constructed from 20 lithostratigraphic sections distributed throughout the forearc. Sections were taken from the Longitudinal Valley, Central Depression, Calama Basin, Salar de Atacama, Precordillera and the western flank of the Western Cordillera. Correlation and timing of events is largely based on the presence of dated volcanic horizons in all the studied sections. Three chronostratigraphic units are defined based upon the presence of regional unconformities. Deposition of the Late Eocene to Early Miocene chronostratigraphic unit (38-19 Ma) commenced across an irregular unconformity surface between ˜ 38 and 30 Ma with alluvial fan and fluvial sediments derived from the east interbedded with rhyolitic ignimbrites. Aggradation after 25 Ma resulted in development of a large broad basin over much of northern Chile that expanded eastwards through onlap onto basement. Deposition terminated around 19 Ma with the development of an angular unconformity over much, but not all of the study area. During deposition of the Early to Late Miocene chronostratigraphic unit (18-10 Ma) emergent volcanic source areas to the east provided catchments for large fluvial systems that drained westwards into endorheic ephemeral lacustrine basins. Fold growth affected sedimentation restricting accommodation space to small intra-thrust basins in the Precordillera and localised disruption and unconformity development in the Longitudinal Valley. The Late Miocene to present day chronostratigraphic unit (10-0 Ma) followed the development of a regional angular unconformity at 10 Ma. Sedimentation was restricted to a series of thrust-bounded endorheic basins in both the Central Depression and the Precordillera sourced from the east

  11. Illite/Smectite diagenesis in the NanXiang, Yitong, and North China Permian-carboniferous basins: Application to petroleum exploration in China

    SciTech Connect

    Xinhua Deng; Youngchuan Sun; Xinrong Lei

    1996-02-01

    The NanXiang basin in Henan Province and the Yitong basin in Jilin Province, located in the eastern part of China, are composed mainly of Tertiary nonmarine clastic sequences that thicken to more than 4000-5000 m. The North China Permian-Carboniferous basin consists of Permian-Carboniferous systems composed of marine and nonmarine coal-bearing sequences. Clay diagenesis in these basins was studied by systematic x-ray diffraction analysis. The clay mineralogy consists of illite, smectite, mixed-layered illite/smectite (I/S), kaolinite, and chlorite. The major clay reaction is the illitization of smectite with depth and temperature. The reactions generally involve discrete smectite stage to smectite, plus the randomly interstratified I/S (R = 0 in the Reichweite nomenclature), followed by the first rapid change (1) to the ordered I/S of short-range stacking (R = 1) and the second rapid change (11) to the metastable stage (with the ordered I/S of long-range stacking-R {ge}3). The first rapid change leads to the appearance of I/S-ordered I/S and disappearance of discrete smectite. The proportion of smectite layers (Ps) in the I/S in the metastable stage remained unchanged (15-20%) over a thick burial interval. The discrete illite stage finally occurs in highly mature areas. Potassium-feldspar (K-feldspar) in rocks and K ions in present formation waters are available for the I/S reactions; I/S reactions in these areas responded mainly to temperature. The I/S transition from the randomly interstratified I/S (R = 0) to the ordered I/S occurred at 80-95{degrees}C and coincided with the onset of the oil window in source rocks and with secondary porosity enhancement of sand-stones. Integrating the I/S reactions with thermal histories, hydrological regimes, structure, sedimentation, and sandstone diagenesis of each basin allows formulation of clay diagenetic models for each specific basin.

  12. Detailed north-south cross section showing environments of deposition, organic richness, and thermal maturities of lower Tertiary rocks in the Uinta Basin, Utah

    USGS Publications Warehouse

    Johnson, Ronald C.

    2014-01-01

    , and North Horn Formations since 1970. Datum for the cross section is sea level so that hydrocarbon source rocks and reservoir rocks could be integrated into the structural framework of the basin.

  13. A new species of Ischyodus (Chondrichthyes: Holocephali: Callorhynchidae) from Upper Maastrichtian Shallow marine facies of the Fox Hills and Hell Creek Formations, Williston basin, North Dakota, USA

    USGS Publications Warehouse

    Hoganson, J.W.; Erickson, J.M.

    2005-01-01

    A new species of chimaeroid, Ischyodus rayhaasi sp. nov., is described based primarily upon the number and configuration of tritors on palatine and mandibular tooth plates. This new species is named in honour of Mr Raymond Haas. Fossils of I. rayhaasi have been recovered from the Upper Maastrichtian Fox Hills Formation and the Breien Member and an unnamed member of the Hell Creek Formation at sites in south-central North Dakota and north-central South Dakota, USA. Ischyodus rayhaasi inhabited shallow marine waters in the central part of the Western Interior Seaway during the latest Cretaceous. Apparently it was also present in similar habitats at that time in the Volga region of Russia. Ischyodus rayhaasi is the youngest Cretaceous species Ischyodus known to exist before the Cretaceous/Tertiary extinction, and the species apparently did not survive that event. It was replaced by Ischyodus dolloi, which is found in the Paleocene Cannonball Formation of the Williston Basin region of North Dakota and is widely distributed elsewhere. ?? The Palaeontological Association.

  14. Hydrogeology and simulation of ground-water flow in the thick regolith-fractured crystalline rock aquifer system of Indian Creek basin, North Carolina

    USGS Publications Warehouse

    Daniel, Charles C.; Smith, Douglas G.; Eimers, Jo Leslie

    1997-01-01

    The Indian Creek Basin in the southwestern Piedmont of North Carolina is one of five type areas studied as part of the Appalachian Valleys-Piedmont Regional Aquifer-System analysis. Detailed studies of selected type areas were used to quantify ground-water flow characteristics in various conceptual hydrogeologic terranes. The conceptual hydrogeologic terranes are considered representative of ground-water conditions beneath large areas of the three physiographic provinces--Valley and Ridge, Blue Ridge, and Piedmont--that compose the Appalachian Valleys-Piedmont Regional Aquifer-System Analysis area. The Appalachian Valleys-Piedmont Regional Aquifer-System Analysis study area extends over approximately 142,000 square miles in 11 states and the District of Columbia in the Appalachian highlands of the Eastern United States. The Indian Creek type area is typical of ground-water conditions in a single hydrogeologic terrane that underlies perhaps as much as 40 percent of the Piedmont physiographic province. The hydrogeologic terrane of the Indian Creek model area is one of massive and foliated crystalline rocks mantled by thick regolith. The area lies almost entirely within the Inner Piedmont geologic belt. Five hydrogeologic units occupy major portions of the model area, but statistical tests on well yields, specific capacities, and other hydrologic characteristics show that the five hydrogeologic units can be treated as one unit for purposes of modeling ground-water flow. The 146-square-mile Indian Creek model area includes the Indian Creek Basin, which has a surface drainage area of about 69 square miles. The Indian Creek Basin lies in parts of Catawba, Lincoln, and Gaston Counties, North Carolina. The larger model area is based on boundary conditions established for digital simulation of ground-water flow within the smaller Indian Creek Basin. The ground-water flow model of the Indian Creek Basin is based on the U.S. Geological Survey?s modular finite

  15. Nutrients, suspended sediment, and pesticides in streams in the Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1993-95

    USGS Publications Warehouse

    Tornes, L.H.; Brigham, M.E.; Lorenz, D.L.

    1997-01-01

    The most heavily used herbicides, 2,4-D and MCPA, were infrequently detected in stream-water samples. Of the estimated applications of atrazine, triallate, and 2,4-D, about 0.9, 0.06, and 0.02 percent of each of these compounds, respectively, was carried out of the study unit by the Red River of the North during 1993-95.

  16. An integrated approach to investigate the hydrological behavior of the Santa Fe River Basin, north central Florida

    NASA Astrophysics Data System (ADS)

    Vibhava, F.; Graham, W. D.; De Rooij, R.; Maxwell, R. M.; Martin, J. B.; Cohen, M. J.

    2011-12-01

    The Santa Fe River Basin (SFRB) consists of three linked hydrologic units: the upper confined region (UCR), semi-confined transitional region (Cody Escarpment, CE) and lower unconfined region (LUR). Contrasting geological characteristics among these units affect streamflow generation processes. In the UCR, surface runoff and surficial stores dominate whereas in the LCR minimal surface runoff occurs and flow is dominated by groundwater sources and sinks. In the CE region the Santa Fe River (SFR) is captured entirely by a sinkhole into the Floridan aquifer, emerging as a first magnitude spring 6 km to the south. In light of these contrasting hydrological settings, developing a predictive, basin scale, physically-based hydrologic simulation model remains a research challenge. This ongoing study aims to assess the ability of a fully-coupled, physically-based three-dimensional hydrologic model (PARFLOW-CLM), to predict hydrologic conditions in the SFRB. The assessment will include testing the model's ability to adequately represent surface and subsurface flow sources, flow paths, and travel times within the basin as well as the surface-groundwater exchanges throughout the basin. In addition to simulating water fluxes, we also are collecting high resolution specific conductivity data at 10 locations throughout the river. Our objective is to exploit hypothesized strong end-member separation between riverine source water geochemistry to further refine the PARFLOW-CLM representation of riverine mixing and delivery dynamics.

  17. Hydrologic conditions in the Chicod Creek basin, North Carolina, before and during channel modifications, 1975-81

    USGS Publications Warehouse

    Watkins, S.A.; Simmons, C.E.

    1984-01-01

    Beginning in late 1978, stream channels throughout the 60-square mile Chicod Creek basin underwent extensive modification to increase drainage efficiency and reduce flooding potential. Drainage modifications in this Coastal Plain basin, consisting primarily of channel excavation and clearing of channel blockages, were completed in December 1981. The hydrologic condition of the basin before and during modification was determined from observed data. Observed data indicate hydrologic changes occurred in selected basin characteristics. For example, water levels in the surficial aquifer within 250 feet of Juniper Branch declined as much as 0.4 feet during modifications; at distances greater than 250 feet from the stream, ground-water levels did not change. Base flows increased, and suspended-sediment concentrations for high flows were several times greater than before channel modifications. Increases in selected chemical constituent concentrations in stream water during modifications were as follows: calcium, 12 percent; sodium, 18 percent; bicarbonate, 84 percent; and phosphorous, 80 percent. Significant changes were not found in either pesticide concentrations or coliform bacteria counts.

  18. Low-flow characteristics and profiles for the Rocky River in the Yadkin-Pee Dee River basin, North Carolina, through 2002

    USGS Publications Warehouse

    Weaver, J. Curtis; Fine, Jason M.

    2003-01-01

    An understanding of the magnitude and frequency of low-flow discharges is an important part of protecting surface-water resources and planning for municipal and industrial economic expansion. Low-flow characteristics are summarized for 12 continuous-record gaging stations and 44 partial-record measuring sites in the Rocky River basin in North Carolina. Records of discharge collected through the 2002 water year at continuous-record gaging stations and through the 2001 water year at partial-record measuring sites were used. Flow characteristics included in the summary are (1) average annual unit flow; (2) 7Q10 low-flow discharge, the minimum average discharge for a 7-consecutive-day period occurring, on average, once in 10 years; (3) 30Q2 low-flow discharge; (4) W7Q10 low-flow discharge, which is similar to 7Q10 discharge but is based only on flow during the winter months of November through March; and (5) 7Q2 low-flow discharge. The Rocky River basin drains 1,413 square miles (mi2) of the southern Piedmont Province in North Carolina. The Rocky River is about 91 miles long and merges with the Yadkin River in eastern Stanly County to form the Pee Dee River, which discharges into the Atlantic Ocean in South Carolina. Low-flow characteristics compiled for selected sites in the Rocky River basin indicated that the potential for sustained base flows in the upper half of the basin is relatively higher than for streams in the lower half of the basin. The upper half of the basin is underlain by the Charlotte Belt, where streams have been identified as having moderate potentials for sustained base flows. In the lower half of the basin, many streams were noted as having little to no potential for sustained base flows. Much of the decrease in base-flow potential is attributed to the underlying rock types of the Carolina Slate Belt. Of the 19 sites in the basin having minimal (defined as less than 0.05 cubic foot per second) or zero 7Q10 discharges, 18 sites are located in the

  19. Mississippian Barnett Shale, Fort Worth basin, north-central Texas: Gas-shale play with multi-trillion cubic foot potential

    USGS Publications Warehouse

    Montgomery, S.L.; Jarvie, D.M.; Bowker, K.A.; Pollastro, R.M.

    2005-01-01

    The Mississippian Barnett Shale serves as source, seal, and reservoir to a world-class unconventional natural-gas accumulation in the Fort Worth basin of north-central Texas. The formation is a lithologically complex interval of low permeability that requires artificial stimulation to produce. At present, production is mainly confined to a limited portion of the northern basin where the Barnett Shale is relatively thick (>300 ft; >92 m), organic rich (present-day total organic carbon > 3.0%), thermally mature (vitrinite reflectance > 1.1%), and enclosed by dense limestone units able to contain induced fractures. The most actively drilled area is Newark East field, currently the largest gas field in Texas. Newark East is 400 mi2 (1036 km2) in extent, with more than 2340 producing wells and about 2.7 tcf of booked gas reserves. Cumulative gas production from Barnett Shale wells through 2003 was about 0.8 tcf. Wells in Newark East field typically produce from depths of 7500 ft (2285 m) at rates ranging from 0.5 to more than 4 mmcf/day. Estimated ultimate recoveries per well range from 0.75 to as high as 7.0 bcf. Efforts to extend the current Barnett play beyond the field limits have encountered several challenges, including westward and northward increases in oil saturation and the absence of lithologic barriers to induced fracture growth. Patterns of oil and gas occurrence in the Barnett, in conjunction with maturation and burial-history data, indicate a complex, multiphased thermal evolution, with episodic expulsion of hydrocarbons and secondary cracking of primary oils to gas in portions of the basin where paleotemperatures were especially elevated. These and other data imply a large-potential Barnett resource for the basin as a whole (possibly > 200 tcf gas in place). Recent assessment by the U.S. Geological Survey suggests a mean volume of 26.2 tcf of undiscovered, technically recoverable gas in the central Fort Worth basin. Recovery of a significant portion of

  20. Water-quality and algal conditions in the North Umpqua River basin, Oregon, 1992-95, and indications for resource management

    USGS Publications Warehouse

    Anderson, Chauncey W.; Carpenter, Kurt D.

    1998-01-01

    Water quality in the Wild and Scenic reach is dominated by water released from the hydroelectric project area during summer. Effects of the hydroelectric project include seasonal control of streamflow, water temperature, and phosphorus concentrations, and the possible release of low but ecologically important concentrations of organic nitrogen. A review of available data and literature suggests that the reservoirs can increase the interception of sediments and large organic debris, and promote their conversion into fine-grained particulate and dissolved organic matter for downstream transport. These effects could be compounded by the effects of forestry in the basin, including alteration of hydrologic cycles, changes in sediment and nutrient runoff, reductions of the transport of large woody debris, and degradation of habitat quality. It is hypothesized that, in the North Umpqua River, these processes have induced a fundamental shift in the river’s food web, from a detritus-based system to a system with a 2 higher emphasi

  1. Coupled ocean-atmosphere model system for studies of interannual-to-decadal climate variability over the North Pacific Basin and precipitation over the Southwestern United States

    SciTech Connect

    Lai, Chung-Chieng A.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The ultimate objective of this research project is to make understanding and predicting regional climate easier. The long-term goals of this project are (1) to construct a coupled ocean-atmosphere model (COAM) system, (2) use it to explore the interannual-to-decadal climate variability over the North Pacific Basin, and (3) determine climate effects on the precipitation over the Southwestern United States. During this project life, three major tasks were completed: (1) Mesoscale ocean and atmospheric model; (2) global-coupled ocean and atmospheric modeling: completed the coupling of LANL POP global ocean model with NCAR CCM2+ global atmospheric model; and (3) global nested-grid ocean modeling: designed the boundary interface for the nested-grid ocean models.

  2. Extending the life of mature basins in the North Sea and imaging sub-basalt and sub-intrusive structures using seismic intensity monitoring.

    NASA Astrophysics Data System (ADS)

    De Siena, Luca; Rawlinson, Nicholas

    2016-04-01

    Non-standard seismic imaging (velocity, attenuation, and scattering tomography) of the North Sea basins by using unexploited seismic intensities from previous passive and active surveys are key for better imaging and monitoring fluid under the subsurface. These intensities provide unique solutions to the problem of locating/tracking gas/fluid movements in the crust and depicting sub-basalt and sub-intrusives in volcanic reservoirs. The proposed techniques have been tested in volcanic Islands (Deception Island) and have been proved effective at monitoring fracture opening, imaging buried fluid-filled bodies, and tracking water/gas interfaces. These novel seismic attributes are modelled in space and time and connected with the lithology of the sampled medium, specifically density and permeability with as key output a novel computational code with strong commercial potential.

  3. A resource evaluation of the Bakken Formation (Upper Devonian and Lower Mississippian) continuous oil accumulation, Williston Basin, North Dakota and Montana

    USGS Publications Warehouse

    Schmoker, J.W.

    1996-01-01

    The Upper Devonian and Lower Mississippian Bakken Formation in the United States portion of the Williston Basin is both the source and the reservoir for a continuous oil accumulation - in effect a single very large field - underlying approximately 17,800 mi2 (46,100 km2) of North Dakota and Montana. Within this area, the Bakken Formation continuous oil accumulation is not significantly influenced by the water column and cannot be analyzed in terms of conventional, discrete fields. Rather, the continuous accumulation can be envisioned as a collection of oil-charged cells, virtually all of which are capable of producing some oil, but which vary significantly in their production characteristics. Better wellperformance statistics are linked regionally to higher levels of thermal maturity and to lower levels of reservoir heterogeneity. Although portions of the Bakken Formation continuous oil accumulation have reached a mature stage of development, the accumulation as a whole is far from depleted.

  4. Thermococcus fumicolans sp. nov., a new hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent in the north Fiji Basin.

    PubMed

    Godfroy, A; Meunier, J R; Guezennec, J; Lesongeur, F; Raguénès, G; Rimbault, A; Barbier, G

    1996-10-01

    An extremely thermophilic archaeon, strain ST557T (T = type strain), was isolated from a deep-sea hydrothermal vent in the North Fiji Basin. This strain is a strictly anaerbic coccus whose cells are about 0.8 to 2 microns in diameter. The optimum temperature, pH and sea salt concentration for growth are 85 degrees C, 8.5, and 20 to 40 g/liter, respectively. Strain ST557T grows preferentially in the presence of elemental sulfur on proteinaceous substrates and on a mixture of 20 amino acids. It grows slowly on pyruvate and maltose. Growth is inhibited by rifampin. The DNA G + C content is 54 to 55 mol%. Sequencing of the 16S rRNA gene revealed that strain ST557T belongs to the genus Thermococcus. We propose that this organism should be placed in a new species, Thermococcus fumicolans.

  5. Effects of highway runoff on streamflow and water quality in the Sevenmile Creek basin, a rural area in the Piedmont Province of North Carolina, July 1981 to July 1982

    SciTech Connect

    Harned, D.A.

    1988-01-01

    The effects of highway runoff on streamflow and water quality in the Sevenmile Creek basin, a rural area in the Piedmont Province of North Carolina is presented. The U.S. Geological Survey study was conducted between July 1981 and July 1982.

  6. On the Sizes of the North Atlantic Basin Tropical Cyclones Based on 34- and 64-kt Wind Radii Data, 2004-2013

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2014-01-01

    At end of the 2012 hurricane season the National Hurricane Center retired the original HURDAT dataset and replaced it with the newer version HURDAT2, which reformatted the original data and included additional information, in particular, estimates of the 34-, 50, and 64-kt wind radii for the interval 2004-2013. During the brief 10-year interval, some 164 tropical cyclones are noted to have formed in the North Atlantic basin, with 77 becoming hurricanes. Hurricane Sandy (2012) stands out as being the largest individual storm that occurred in the North Atlantic basin during the 2004 -2013 timeframe, both in terms of its 34- and 64-kt wind radii and wind areas, having maximum 34- and 64-kt wind radii, maximum wind areas, and average wind areas each more than 2 standard deviations larger than the corresponding means. In terms of the largest yearly total 34-kt wind area (i.e., the sum of all individual storm 34-kt wind areas during the year), the year 2010 stands out as being the largest (about 423 × 10(exp 6) nmi(exp 2)), compared to the mean of about 174 × 10(exp 6) nmi(exp 2)), surpassing the year 2005 (353 x 10(exp 6) nmi(exp 2)) that had the largest number of individual storms (28). However, in terms of the largest yearly total 64-kt wind area, the year 2005 was the largest (about 9 × 10(exp 6) nmi(exp 2)), compared to the mean of about 3 × 106 nmi(exp 2)). Interesting is that the ratio of total 64-kt wind area to total 34-kt wind area has decreased over time, from 0.034 in 2004 to 0.008 in 2013.

  7. Geochemical study (major, trace elements and Pb-Sr-Nd isotopes) of mantle material obducted onto the North African margin (Edough Massif, North Eastern Algeria): Tethys fragments or lost remnants of the Liguro-Provençal basin?

    NASA Astrophysics Data System (ADS)

    Bosch, Delphine; Hammor, Dalila; Mechati, Mehdi; Fernandez, Laure; Bruguier, Olivier; Caby, Renaud; Verdoux, Patrick

    2014-06-01

    The Maghrebides, Betics and some parts of the Calabrian, NE Sicilian and Tuscan allochtons constitute dismembered fragments of the Alpine belt that resulted from the Cenozoic collision between Africa and Eurasia and the opening of the Western Mediterranean basin. Mineral and whole-rock geochemical analyses have been performed on three distinct outcrops of mantle material from the Edough Massif of NE Algeria, namely the Bou Maiza (BM) gabbros, the La Voile Noire (LVN) amphibolites and the Sidi Mohamed (SM) peridotites. In all samples, Sr isotopes are largely affected by seawater alteration (87Sr/86Sract. > 0.70384 and up to 0.70888) and cannot be used to evaluate the nature of the source reservoirs. SM peridotites display variable depleted mantle Nd isotopic signatures (εNdact. from + 7.0 to + 12.2) and geochemical features suggesting no significant chemical depletion as a result of partial melting and melt extraction (Mg# < 90; slightly LREE-depleted patterns with La/YbN = 0.33-0.39). These rocks are interpreted as parts of the subcontinental lithospheric mantle incorporated into the crustal units of the Edough Massif during the early stages of opening of the Algerian basin. BM gabbros and LVN amphibolites show geochemical signatures indicating derivation from a common depleted mantle reservoir (εNd > + 7.9) and are likely cogenetic, but without filiation with the SM peridotites. Pb isotopes indicate a contribution of sediments in the source reservoir, which is attributed to contamination solely by hydrous fluids released from a sedimentary component. This observation, together with a LILE-enrichment, suggests a back-arc basin environment. These results indicate that BM and LVN units were obducted onto the North African margin and subsequently fragmented, probably during doming and exhumation of the lower continental crust of the Edough massif. Doming resulted in opposite movements of the overlying oceanic units, southward for the BM units and northward for LVN

  8. Regional and Local Trends in helium isotopes, basin and rangeprovince, western North America: Evidence for deep permeablepathways

    SciTech Connect

    Kennedy, B. Mack; van Soest, Matthijs C.

    2005-07-15

    Fluids from the western margin of the Basin and Range have helium isotope ratios as high as {approx}6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to ''background'' values of around 0.6 Ra, and then gradually decrease toward the east to low values of {approx}0.1 Ra at the eastern margin of the Basin and Range. Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and local geology indicate that these ''He-spikes'' are not related to current or recent magmatic activity, suggesting that the spikes may reflect either localized zones deep mantle melting or deep permeable pathways (faults) with high vertical fluid flowrates. A detailed study of one of the He-spikes (Dixie Valley and the Stillwater Range Front Fault system), indicates that features with high 3He/4He ratios are confined to the range front normal faults characteristic of the extensional regime in the Basin and Range, suggesting that these faults are deep permeable pathways. However, not all range front fault systems transmit fluids with a mantle signature, implying that not all have deep permeable pathways.

  9. Petrology and diagenetic history of the upper shale member of the Late Devonian–Early Mississippian Bakken Formation, Williston Basin, North Dakota

    USGS Publications Warehouse

    Neil S. Fishman,; Sven O. Egenhoff,; Boehlke, Adam; Lowers, Heather

    2015-01-01

    The organic-rich upper shale member of the upper Devonian–lower Mississippian Bakken Formation (Williston Basin, North Dakota, USA) has undergone significant diagenetic alteration, irrespective of catagenesis related to hydrocarbon generation. Alteration includes precipitation of numerous cements, replacement of both detrital and authigenic minerals, multiple episodes of fracturing, and compaction. Quartz authigenesis occurred throughout much of the member, and is represented by multiple generations of microcrystalline quartz. Chalcedonic quartz fills radiolarian microfossils and is present in the matrix. Sulfide minerals include pyrite and sphalerite. Carbonate diagenesis is volumetrically minor and includes thin dolomite overgrowths and calcite cement. At least two generations of fractures are observed. Based on the authigenic minerals and their relative timing of formation, the evolution of pore waters can be postulated. Dolomite and calcite resulted from early postdepositional aerobic oxidation of some of the abundant organic material in the formation. Following aerobic oxidation, conditions became anoxic and sulfide minerals precipitated. Transformation of the originally opaline tests of radiolaria resulted in precipitation of quartz, and quartz authigenesis is most common in more distal parts of the depositional basin where radiolaria were abundant. Because quartz authigenesis is related to the distribution of radiolaria, there is a link between diagenesis and depositional environment. Furthermore, much of the diagenesis in the upper shale member preceded hydrocarbon generation, so early postdepositional processes were responsible for occlusion of significant original porosity in the member. Thus, diagenetic mineral precipitation was at least partly responsible for the limited ability of these mudstones to provide porosity for storage of hydrocarbons.

  10. Tectonic development of the North Patagonian Andes and their related Miocene foreland basin (41°30‧-43°S)

    NASA Astrophysics Data System (ADS)

    Orts, DaríO. Leandro; Folguera, AndréS.; Encinas, Alfonso; Ramos, Miguel; Tobal, Jonathan; Ramos, VíCtor A.

    2012-06-01

    The Northern Patagonian Andes have been constructed through multiple mechanisms that range from tectonic inversion of extensional structures of Early to Middle Jurassic age in the Main Andes to Oligocene in the Precordilleran region. These have acted during two distinctive orogenic stages, first in late Early Cretaceous and later in Miocene times Late Oligocene extension separates these two contractional periods and is recorded by half-grabens developed in the retroarc region. The last contractional stage coexists with an eastward foreland expansion of the late Miocene arc whose roots are presently exposed as minor granitic stocks and volcanic piles subordinately in the Main Andes, east of the present arc. As a consequence of this orogenic stage a foreland basin has developed, having progressed from 18 Ma in the main North Patagonian Andes, where the mountain front was flooded by a marine transgression corresponding to the base of the Ñirihuau Formation, to 11 Ma in the foreland area. Cannibalization of this foreland basin occurred initially in the hinterland and then progressed to the foreland zone. Blind structures formed a broken foreland at the frontal zone inferred from growth strata geometries. During Pliocene to Quaternary times most of the contractional deformation was dissipated in the orogenic wedge at the time when the arc front retracted to its present position.

  11. Estimation of successive co-seismic vertical offsets using coeval sedimentary events - application to the Sea of Marmara's Central Basin (North Anatolian Fault)

    NASA Astrophysics Data System (ADS)

    Beck, C.; Campos, C.; Eriş, K.; Çağatay, N.; Mercier de Lepinay, B.; Jouanne, F.

    2014-06-01

    In the deep part of the Sea of Marmara (Turkey), the sedimentation developing upon the North Anatolian Fault is strongly influenced by the associated seismic activity. Specific layers (homogenites-turbidites), representing individual sedimentary events, have been characterized along three giant piston cores retrieved from Çinarcik and Central (or Orta) basins. Analyzed sediments represent the last 12 to 17 kyr BP. For a 2 kyr-lasting interval, 11 events could be precisely correlated on both sides of the Central Basin's southern scarp. For each of them, based on the specific depositional process, the thickness difference between the two sites was considered as a direct estimation of the vertical component of a coeval co-seismic offset. The homogenite (upper) term accounts for the major part of the thickness difference. The 6 most significant values range from 36 cm to 144 cm and are likely representing dominantly normal throws, with estimated paleomagnitudes (Mw) ranging from 5.9 to 6.6.

  12. Water-quality and algal conditions in the North Umpqua River basin, Oregon, 1992-95, and indications for resource management

    USGS Publications Warehouse

    Anderson, Chauncey W.; Carpenter, Kurt D.

    1998-01-01

    Water quality in the Wild and Scenic reach is dominated by water released from the hydroelectric project area during summer. Effects of the hydroelectric project include seasonal control of streamflow, water temperature, and phosphorus concentrations, and the possible release of low but ecologically important concentrations of organic nitrogen. A review of available data and literature suggests that the reservoirs can increase the interception of sediments and large organic debris, and promote their conversion into fine-grained particulate and dissolved organic matter for downstream transport. These effects could be compounded by the effects of forestry in the basin, including alteration of hydrologic cycles, changes in sediment and nutrient runoff, reductions of the transport of large woody debris, and degradation of habitat quality. It is hypothesized that, in the North Umpqua River, these processes have induced a fundamental shift in the river’s food web, from a detritus-based system to a system with a 2 higher emphasis on algal production. Confirmation of these changes and their effects on higher trophic levels are needed to properly manage the aquatic resources for all designated beneficial uses in the basin.

  13. Impacts of agricultural intensification through upscaling of suitable rainwater harvesting technologies in the upper Ewaso Ng'iro North basin, Kenya

    NASA Astrophysics Data System (ADS)

    Mutiga, J. K.; Zhongbo, S.; Woldai, T.

    2011-03-01

    Changes in land cover and land use can lead to significant impacts to hydrology by affecting the amount of runoff, soil moisture and groundwater recharge over a range of temporal and spatial scales. However, hydrologic effects of these changes are still an unknown at watershed scale. Moreover, predicting the effects of land cover/use and climate change on hydrological cycle has remained a major challenge. This is because of the complexity and uncertainty of future climate changes making it difficult to predict the consequences. It is against this backdrop that, for sustainable water resources management, assessment of the impacts of land cover/use change on hydrological regime at all scales becomes critical. During this study, we applied the SWAT model to assess the impacts of area hydrology between baseline and alternative scenario (upscaling of rainwater harvesting technologies). Specifically, our overall objective was to quantitatively evaluate the effects of land use changes on watershed hydrology in the upper Ewaso Ng'iro North basin in Kenya. This was achieved by estimating hydrological responses under historical land use scenarios obtained from the multi-temporal satellite imageries of 1987, 1995 and 2003. The model performance was found to be relatively good (Nash and Sutcliffe efficient of 70%). Stream flow analysis was carried out for different parts of the basin to understand its hydrological responses, especially, the behavior of base flow. The results show a decrease in base flow during 1987-2003 period with decreasing forest, bush and grass covers, which can be attributed to poor natural vegetation emanating mainly from overgrazing and deforestation for agricultural activities. In conclusion, the study clearly shows that, assessment of hydrologic effects of land use changes is critical for a sustainable water resources planning and management of the basin.

  14. Effects of groundwater lateral flow on land surface processes: a case study in Heihe River Basin, north-west of China

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Zeng, Y.; Yu, Y.

    2015-12-01

    As an important component of hydrologic cycle, groundwater is affected by topography, vegetation, climate condition, and anthropogenic activity. Groundwater horizontal convergence and divergence and vertical interaction with soil water result in variations of soil moisture, water and energy exchanges between the land surface and the atmosphere, which ultimately influences climate. In this work, a two-dimensional groundwater lateral flow scheme based on groundwater mass equation, is developed and incorporated into the land surface model CLM4.5 to investigate effects of groundwater lateral flow on land surface processes in a river basin. A 30-year simulation with groundwater lateral flow and a control run without the horizontal movement are conducted over Heihe River Basin, north-west China, from 1979 to 2012 using the developed model. Results show that with groundwater lateral flow, equilibrium distribution of groundwater table shows more spatial variability following topography rather than the water balance between local precipitation and evapotranspiration, and are much closer to well observations especially over middle reaches area. Along with shallower groundwater table over piedmont areas in the middle reaches, increased soil moisture is shown which alleviates the underestimation of CLM4.5 at here. Changes in evapotranspiration are occurred and it is mainly controlled by the variation of local surface soil moisture, since water is the major limitation factor of evapotranspiration over this arid area. Besides, groundwater lateral flow can change the distribution of surface runoff by changing the saturated area fraction of each model grid cell. Energy cycle also responds to the changes of hydrological cycle which redistributes the sensible heat flux and latent heat flux in the entire basin.

  15. Seasonal Dynamics of a Drained Thermokarst Lake Basin on the North Slope of Alaska From InSAR

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Liu, L.; Schaefer, K. M.; Parsekian, A.; Grosse, G.; Jones, B. M.; Zebker, H. A.

    2012-12-01

    Thermokarst lakes (or thaw lakes) are ubiquitous and dynamic landscape features on the Arctic coastal plain of Alaska. They form as ice-rich permafrost thaws and grow laterally and vertically, coalesce with other lakes, and often rapidly drain, forming a dry and depressed basin denoted as drained thermokarst lake basins (DTLBs). Vertical deformation of the ground from settlement and heave occurs during thermokarst evolution. These morphological variations are a result of changes in the thermal regime of the landscape and mechanical and hydrological changes in the sediment and surface vegetation. These changes also affect carbon exchange and stability of the permafrost carbon pool. We apply radar interferometry (InSAR) techniques using data acquired over a 100 km by 70 km area by the Advanced Land Observing Satellite (ALOS-PALSAR) to monitor surface deformation of DTLBs near Prudhoe Bay from space. Over the period 2007-2010, the entire tundra area experienced thaw settlement and frost heave on the order of 3 cm due to melting and refreezing of pore ice in the active layer. A vast majority of the DTLBs appear to be moving along with the surrounding tundra area, however our study in fine spatial and temporal detail reveals a unique and significant seasonal settlement and heave at one basin located at (70.138621N, 148.649614W). The area of deformation is bounded by a historical lake shore on its west edge and a residual low pond on its east side. The seasonal deformation increases from about 2 cm near the center of the basin to about 9 cm near the west edge, well exceeding the measurement precision that is of the order of 1 cm. The spatial pattern and magnitude of subsidence repeated in all four years. We attribute the seasonal deformation at this DTLB to one or more of three possible mechanisms: a thick active layer (> 1 m) over the DTLB, a thick talik (unfrozen) layer beneath the DTLB, and seasonal surface drainage and flooding as the DLTB is connected to a thaw lake

  16. Geophysical anomalies and quartz microstructures, Eastern Warburton Basin, North-east South Australia: Tectonic or impact shock metamorphic origin?

    NASA Astrophysics Data System (ADS)

    Glikson, Andrew Y.; Uysal, I. Tonguç; Fitz Gerald, John D.; Saygin, Erdinc

    2013-03-01

    The Eastern Warburton Basin, Northeast South Australia, features major geophysical anomalies, including a magnetic high of near-200 nT centred on a 25 km-wide magnetic low (< 100 nT), interpreted in terms of a magmatic body below 6 km depth. A distinct seismic tomographic low velocity anomaly may reflect its thick (9.5 km) sedimentary section, high temperatures and possible deep fracturing. Scanning electron microscope (SEM) analyses of granites resolves microbreccia veins consisting of micron-scale particles injected into resorbed quartz grains. Planar and sub-planar elements in quartz grains (Qz/PE) occur in granites, volcanics and sediments of the > 30,000 km-large Eastern Warburton Basin. The Qz/PE include multiple intersecting planar to curved sub-planar elements with relic lamellae less than 2 μm wide with spacing of 4-5 μm. Qz/PE are commonly re-deformed, displaying bent and wavy patterns accompanied with fluid inclusions. U-stage measurements of a total of 243 planar sets in 157 quartz grains indicate dominance of ∏{10-12}, ω{10-13} and subsidiary §{11-22}, {22-41}, m{10-11} and x{51-61} planes. Transmission Electron Microscopy (TEM) analysis displays relic narrow ≤ 1 μm-wide lamellae and relic non-sub grain boundaries where crystal segments maintain optical continuity. Extensive sericite alteration of feldspar suggests hydrothermal alteration to a depth of 500 m below the unconformity which overlies the Qz/PE-bearing Warburton Basin terrain. The data are discussed in terms of (A) Tectonic-metamorphic deformation and (B) impact shock metamorphism producing planar deformation features (Qz/PDF). Deformed Qz/PE are compared to re-deformed Qz/PDFs in the Sudbury, Vredefort, Manicouagan and Charlevoix impact structures. A 4-5 km uplift of the Big Lake Granite Suite during 298-295 Ma is consistent with missing of upper Ordovician to Devonian strata and possible impact rebound. The occurrence of circular seismic tomography anomalies below the east

  17. The nonmarine Lower Cretaceous of the North American Western Interior foreland basin: New biostratigraphic results from ostracod correlations and early mammals, and their implications for paleontology and geology of the basin—An overview

    NASA Astrophysics Data System (ADS)

    Sames, Benjamin; Cifelli, Richard L.; Schudack, Michael E.

    2010-08-01

    The timespan represented by the hiatus between nonmarine Upper Jurassic (Early Berriasian?) and unconformably overlying Lower Cretaceous deposits throughout the North American Western Interior foreland basin has been under discussion for the entire 20th century and remains controversial to date. Ongoing research in revision of Early Cretaceous nonmarine ostracods of some respective North American formations leads to a breakthrough concerning the verification of their biostratigraphic utility as well as their subsequent application. These ostracods are not as endemic as hitherto believed and can be used for supraregional and