Conference Papers
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Field and modelling studies of immiscible fluid flow above a contaminated water-table aquifer
A method was developed for measuring the spatial distribution of immiscible liquid contaminants in the subsurface. Fluid saturation distributions measured at a crude-oil spill site were used to test a numerical multiphase flow model.
Authors
W.N. Herkelrath, H.I. Essaid, K.M. Hess
Geochemical mass-balance in a small forested watershed in southwestern Pennsylvania
An intensive hydrologic investigation of the North Fork Bens Creek Watershed on Laurel Hill in southwestern Pennsylvania was made during 1984-85. Precipitation was sampled weekly, and stream water was sampled monthly and during selected storms for discharge and chemical composition. The watershed is underlain by sandstone and sandy shale consisting of quartz, feldspar, muscovite, chlorite, calcite
Authors
Emitt C. Witt, Michael Bikerman
Geologic controls on the formation and evolution of quaternary coastal deposits of the northern Gulf of Mexico
A study of the barrier islands and wetlands in the deltaic plain of Louisiana is presented. Its purpose was to document rapid changes and to learn more about the processes responsible and the geologic framework within which they operate. It included systematic collection and analysis of precision nearshore hydrographic data, high resolution seismic profiles, surface sediment samples, continuous vi
Authors
S.J. Williams, S. Penland, A. H. Sallenger, R.A. McBride, J.L. Kindlinger
Geology and mineralization of the Wyoming Province
The Wyoming Province is an Archean craton which underlies portions of Idaho, Montana, Nevada, Utah, and much of Wyoming. The cratonic block consists of Archean age granite-gneiss with interspersed greenstone belts and related supracrustal terranes exposed in the cores of several Laramide uplifts. Resources found in the Province and in the adjacent accreted Proterozoic terrane include banded iron f
Authors
W.D. Hausel, B.R. Edwards, P. J. Graff
Geology of the Bayan Obo iron-rare-earth-niobium deposits, Inner Mongolia, China
The plate tectonic setting, regional geology, and certain aspects of the economic geology of the iron-rare-earth-niobium ore bodies at Bayan Obo, Inner Mongolia, China, were studied by a team of geologists from the Tianjin Geologic Research Academy and the U.S. Geological Survey between 1987 and 1989. These ore bodies were formed by hydrothermal replacement of Middle Proterozoic dolomite in an int
Authors
L. J. Drew, M. Qingrun, S. Weijun
Geophysical borehole logging in the unsaturated zone, Yucca Mountain, Nevada
Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given
Authors
Ulrich Schimschal, Philip H. Nelson
Gravitational circulation in a tidal strait
Eight months of continuous measurements of tidal current profiles with an acoustic Doppler current profiler (ADCP) were made in Carquinez Strait, California, during 1988 for the purpose of estimating long-term variations in vertical profiles of Eulerian residual currents. Salinity stratification near the ADCP deployment site also was analyzed. The strength of density-driven gravitational circulati
Authors
P. E. Smith, R. T. Cheng, J.R. Burau, M.R. Simpson
Ground-water recharge from streamflow data, NW Florida
Annual base flows of streams draining Okaloosa County and adjacent areas in northwest Florida were determined through hydrograph separation and correlation techniques for purposes of evaluating variations in ground-water recharge rates. Base flows were least in the northern part of the county and greatest in the southern part. Topographic and soils data were then superimposed on the distribution o
Authors
John Vecchioli, W. C. Bridges, Roger P. Rumenik, J. W. Grubbs
Herbicides in streams. Midwestern United States
Results from a 2-year study of 149 streams geographically distributed across the corn-producing region of 10 midwestern States show that detectable concentrations of herbicides persist year round in most streams. Some herbicides exceeded proposed maximum contaminant levels for drinking water for periods of several weeks to several months following application. Atrazine was the most frequently dete
Authors
Donald A. Goolsby, E. Michael Thurman, Dana W. Kolpin
How do foraging seabirds sample their environment?
No abstract available.
Authors
G.L. Hunt, John F. Piatt, Kjell Einar Erikstad
Hydrologic and geochemical approaches for determining ground-water flow components
Lyman Lake is an irrigation-storage reservoir on the Little Colorado River near St. Johns, Arizona. The main sources of water for the lake are streamflow in the Little Colorado River and ground-water inflow from the underlying Coconino aquifer. Two approaches, a hydrologic analysis and a geochemical analysis, were used to compute the quantity of ground-water flow to and from Lyman Lake. Hydrologic
Authors
H. W. Hjalmarson, F. N. Robertson
Hydrologic monitoring for effects of geothermal and ground-water development, Long Valley caldera, California
No abstract available.
Authors
C. D. Farrar, D. L. Lyster