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Inflows of metal-rich, acidic water that drain from mine dumps and tailings piles in the Leadville, Colorado, area enter the non-acidic water in the upper Arkansas River. Hydrous iron oxides precipitate as colloids and move downstream in suspension, particularly downstream from California Gulch, which has been the major source of...

No abstract available....

In 1971, the near-failure of a dam during a magnitude 6.7 earthquake forced 80,000 people to evacuate their residences. In 1994, the replacement dam survived an almost identical earthquake with little damage. Underlying this progress in designing critical structures are years of research on the powerful shaking during large earthquakes....

The estimated total quantity of freshwater withdrawn on the island of Kauai, Hawaii, in 1990 was 370.84 million gallons per day of which 46.29 million gallons per day (12 percent) was from ground-water sources, and 324.55 million gallons per day (88 percent) was from surface-water sources. An additional estimated 40.94...

Most states have adopted some form of instream-flow–protection program. These programs are of three types: instream-flow water rights; reservations of water for instream purposes; and conditions on consumptive water rights. No matter which type of protection program is adapted, the same question remains: How can we tell if it works?...

The White River Narrows area of Southeast Nevada contains 18 regionally distributed middle Tertiary dacite to rhyolite ash-flow tuffs. Geochemical data provide an excellent opportunity to study stratigraphic and petrologic relations of these tuffs. Chemical data for each of the tuffs are distinctive and provide a significant addition to other...

Combined use of seismic-refraction, direct-current resistivity, very-low-frequency terrain-resistivity, and inductive terrain-conductivity methods were demonstrated at sites in Connecticut, New York, and Maine. Although no single method can define both the hydrogeologic boundaries and general grain-size characteristics of sand and gravel aquifers, a combination of these methods can. Comparisons of measured...

This factsheet briefly summarizes and clarifies the application of aerial infrared surveys in geophysical exploration for geothermal energy sources and environmental monitoring for potential volcanic hazards....

The Midcontinent Industrial Minerals Workshop, in St. Louis, Missouri, September 16-17, 1991, was the fourth U.S. Geological Survey-sponsored meeting on the essential role of industrial rocks and minerals in the Nation's social and economic framework. The meeting was organized, supported, and the agenda was determined by a group from the...

The Trinity River Basin National Water Quality Assessment (NAWQA) study-unit staff began assessment activities in 1991, and in 1992, undertook a retrospective review of existing data on pesticides. The main purpose of this review was to aid in the design of a pesticide-sampling network for the study unit. The review...

No abstract available....

No abstract available....

The High Plains aquifer underlying the semiarid Southern High Plains of Texas and New Mexico, USA was used to illustrate solute and isotopic methods for evaluating recharge fluxes, runoff, and spatial and temporal distribution of recharge. The chloride mass-balance method can provide, under certain conditions, a time-integrated technique for evaluation...

No abstract available....

No abstract available....

A statistical analysis of the age composition of striped bass Morone saxatilis harvested in Albemarle Sound and the Roanoke River, North Carolina. indicated that in 1988–1992 the population experienced a relatively high rate of total mortality. Age‐3 and older fish were estimated to have been fully vulnerable to fishing mortality and to...

This study was undertaken to evaluate the relationship between mammalian and piscine 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalency factors (TEFs) for PCBs, based on induction of CYP1A enzyme activity, catalytic protein, and mRNA. Rainbow trout administered a single i.p. injection of TCDD had an average (±SD) ED50 of 0.91 ± 0.14 μg...

The National Water-Quality Assessment Program assesses the status of and trends in the quality of the Nation's ground- and surface-water resources. The occurrence and distribution assessment component characterizes broad-scale water-quality conditions in relation to major contaminant sources and background conditions in each study area. The surface-water design focuses on streams....