Analysis of a Lake Superior coastal food web with stable isotope techniques
Janet R. Keough, Michael E. Sierszen, Cynthia Hagley
1996, Limnology and Oceanography (41) 136-146
Food-web components of a Lake Superior coastal wetland and adjacent offshore waters were examined with stable isotope ratio techniques for carbon and nitrogen. We found distinct carbon isotope ratio signatures for organisms collected in the wetland and from offshore. Both food-web groups seemed to be based on carbon fixed by phytoplankton. Compared to...
The roles of organic matter in the formation of uranium deposits in sedimentary rocks
Charles S. Spirakis
1996, Ore Geology Reviews (11) 53-69
Because reduced uranium species have a much smaller solubility than oxidized uranium species and because of the strong association of organic matter (a powerful reductant) with many uranium ores, reduction has long been considered to be the precipitation mechanism for many types of uranium deposits. Organic matter may also be...
Magma transport and metasomatism in the mantle; a critical review of current geochemical models; reply
Jane E. Nielson, Howard G. Wilshire
1996, American Mineralogist (81) 760-765
Navon et al. (1996) demonstrated that the Navon and Stolper (1987) model can be formulated to reproduce a pattern of light-ion lithophile trace element (LIL) enrichments produced by a single, small-scale metasomatic process recorded in a composite xenolith from Dish Hill, California (Nielson et al. 1993). The Navon and Stolper...
Continental-margin seismic stratigraphy: Assessing the preservation potential of heterogeneous geological processes operating on continental shelves and slopes
James A. Austin Jr., Craig S. Fulthorpe, Gregory S. Mountain, Daniel L. Orange, Michael E. Field
1996, Oceanography (9) 173-177
No abstract available....
Procedures for estimating unit hydrographs for large floods at ungaged sites in Montana
Stephen R. Holnbeck, Charles Parrett
1996, Water Supply Paper 2420
Flood hydrographs for 26 gaging stations and rainfall data were used together with a rainfall-runoff simulation model to derive unit hydrographs and important unit-hydrograph variables. Methods were developed for estimating unit hydrographs at ungaged sites using either the Clark or dimensionless unit-hydrograph methods. The 26 derived unit hydrographs were compared...
Geologic map of the Savannah River Site, Aiken, Allendale, and Barnwell counties, South Carolina
D.C. Prowell
1996, Miscellaneous Field Studies Map 2300
Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States
R. L. Hosman
1996, Professional Paper 1416-G
The Gulf Coast Regional Aquifer-System Analysis study includes all major Cenozoic aquifer systems in the Gulf Coastal Plain of Alabama, Arkansas, westernmost Florida, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas. Although Cenozoic deposits are not uniformly differentiated, interstate correlations of major Paleocene and Eocene units are generally established, and...
Geologic map of the Bracey 7.5-minute Quadrangle, Mecklenburg County, Virginia, and Warren County, North Carolina
P. E. Sacks
1996, Miscellaneous Field Studies Map 2285
Relation of land use to nitrate in the surficial aquifer along the Straight River, north-central Minnesota, 1992-93
J. F. Ruhl
1996, Fact Sheet 099-96
The U.S. Geological Survey studied the relation of land use to nitrate concentrations in the surficial aquifer along the Straight River near Park Rapids in north-central Minnesota (see adjacent map) during 1992 to 1993. Concern about health hazards to humans and livestock from use of ground water contaminated by nitrate...
Statewide Floods in Pennsylvania, January 1996
R.E. Thompson
1996, Fact Sheet 103-96
Rivers and streams throughout Pennsylvania (fig. 1) experienced major flooding during January 1996. Flood stages (water-surface heights) and discharges (flows) in many of the Commonwealth's waterways were measured by the U.S. Geological Survey (USGS) and approached or exceeded record levels established during previous floods. Setting the stage for the flooding...
National Water-Quality Assessment Program; nitrate and pesticides in ground water, Blaine, Cassia, Lincoln, and Minidoka Counties, south-central Idaho
Michael G. Rupert, M.A. Stone, Douglas S. Ott
1996, Fact Sheet 246-95
40Ar/39Ar ages of some Challis Volcanic Group rocks and the initiation of Tertiary sedimentary basins in southwestern Montana
John W. M’Gonigle, G. Brent Dalrymple
1996, Bulletin 2132
Occurrence of polycyclic aromatic hydrocarbons in urban streams as assessed using semipermeable membrane devices, Dallas-Fort Worth metropolitan area, Texas
J. Bruce Moring
1996, Fact Sheet 081-96
One of the primary goals of the U.S. Geological Survey's National Water Quality Assessment (NAWQA) Program is to determine the occurrence and distribution of contaminants in stream sediments and tissues of aquatic organisms (Crawford and Luoma, 1993). Metals and persistent organic contaminants are of principal concern. Polycyclic aromatic hydrocarbons (PAHs) are...
Naturally occurring and mining-affected dissolved metals in two subbasins of the Upper Animas River Basin, southwestern Colorado
Winfield G. Wright, Cathy J. Janik
1996, Fact Sheet 243-95
No abstract available....
Agricultural pesticides found in ground water of the Quincy and Pasco basins
Lonna M. Roberts, Joseph L. Jones
1996, Fact Sheet 240-95
No abstract available....
Nutrients in the Nation's Waters--Too Much of a Good Thing?
David K. Mueller, Dennis R. Helsel
1996, Circular 1136
Historical data on nutrients (nitrogen and phosphorus) from about 12,000 ground-water and more than 22,000 stream samples have been compiled and related to possible sources. This existing information was collected by many agencies for a variety of purposes. Therefore, though it can be used to determine where concentrations differ, the...
Hydrogeology and potential effects of changes in water use, Carson Desert agricultural area, Churchill County, Nevada
Douglas K. Maurer, Ann K. Johnson, Alan H. Welch
1996, Water Supply Paper 2436
Operating Criteria and Procedures for Newlands Project irrigation and Public Law 101-618 could result in reductions in surface water used for agriculture in the Carson Desert, potentially affecting ground-water supplies from shallow, intermediate, and basalt aquifers. A near-surface zone could exist at the top of the shallow aquifer near the...
Are agricultural pesticides in surface waters of the central Columbia plateau?
R. J. Wagner, J.C. Ebbert, L.M. Roberts
1996, Fact Sheet 241-95
Lithostratigraphy, microlithofacies, and conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), eastern Sadlerochit Mountains, Northeast Brooks Range, Alaska
A.P. Krumhardt, A. G. Harris, K.F. Watts
1996, Professional Paper 1568
The lithostratigraphy, microlithofacies, and conodonts are described in a key section of the Wahoo Limestone (Middle Carboniferous); this unit forms a hydrocarbon reservoir at Prudhoe Bay. The Wahoo was deposited in a range of environments on the inner part of a high-energy carbonate ramp. Microfacies and conodont biofacies used together...
Geochemical and hydrologic controls on phosphorus transport in a sewage-contaminated sand and gravel aquifer near Ashumet Pond, Cape Cod, Massachusetts
Donald A. Walter, Brigid A. Rea, Kenneth G. Stollenwerk, Jennifer G. Savoie
1996, Water Supply Paper 2463
Currently (1993), about 170 kg/yr of phosphorus discharges into Ashumet Pond on Cape Cod from a plume of sewage-contaminated ground water. Phosphorus in the plume is mobile in two distinct geochemical environments--an anoxic zone containing dissolved iron and a suboxic zone containing dissolved oxygen. Phosphorus mobility in the suboxic zone...
Patterns of late Cenozoic volcanic and tectonic activity in the West Antarctic rift system revealed by aeromagnetic surveys
John C. Behrendt, R. Saltus, D. Damaske, A. McCafferty, C. A. Finn, D. Blankenship, R.E. Bell
1996, Tectonics (15) 660-676
Aeromagnetic surveys, spaced ≤5 km, over widely separated areas of the largely ice- and sea-covered West Antarctic rift system, reveal similar patterns of 100- to 1700-nT, shallow-source magnetic anomalies interpreted as evidence of extensive late Cenozoic volcanism. We use the aeromagnetic data to extend the volcanic rift interpretation over West...
Pesticides in ground water: Current understanding of distribution and major influences
Water Resources Division, U.S. Geological Survey
1996, Fact Sheet 244-95
This report summarizes a comprehensive analysis of existing information on national and regional patterns of pesticides in the atmosphere and major influences on their sources and transport. It is one of a four-part series that synthesizes current knowledge and understanding of pesticides in water resources of the nation as part...
Simulation of selected reservoir operations in the upper Truckee River Basin, California
Steven N. Berris, G. W. Hess, K. D. Cartier
1996, Fact Sheet 082-96
Hydrology of the Mississippi River valley alluvial aquifer, south-central United States
D. J. Ackerman
1996, Professional Paper 1416-D
Ground-water flow simulation indicates that pumpage from the aquifer since the early 1900's has caused a decrease in ground-water outflow to rivers, an increase in flow from rivers into the aquifer, and an increase in flow to the aquifer through the overlying confining unit. By the mid-1970's, rivers became a...
Stream water and sediment quality in the Old Lead Belt, Missouri
Water Resources Division, U.S. Geological Survey
1996, Fact Sheet 214-95