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The Idaho statewide surface-water-quality monitoring network consists of 56 sites that have been monitored from 1989 through 2002 to provide data to document status and changes in the quality of Idaho streams. Sampling at 33 sites has covered a wide range of flows and seasons that describe water-quality variations representing...

The Oquirrh Mountains are located in north central Utah, in the easternmost part of the Basin and Range physiographic province, immediately south of the Great Salt Lake. The range consists of a northerly trending alignment of peaks 56 km long. Tooele and Rush Valleys flank the Oquirrh Mountains on the western...

This report contains major- and trace-element concentration data for soil samples collected from 265 sites along two continental-scale transects in North America. One of the transects extends from northern Manitoba to the United States-Mexico border near El Paso, Tex. and consists of 105 sites. The other transect approximately follows the...

Mineral deposit models are important in exploration planning and quantitative resource assessments for two reasons: (1) grades and tonnages among deposit types are significantly different, and (2) many types occur in different geologic settings that can be identified from geologic maps. Mineral deposit models are the keystone in combining the...

Drainage from abandoned and inactive mines and from naturally mineralized areas in the San Juan Mountains of southern Colorado contributes metals to the upper Animas River near Silverton, Colorado. Tracer-injection studies and associated synoptic sampling were performed along two reaches of the upper Animas River to develop detailed profiles of...

The Fort Chaffee Maneuver Training Center is a facility used to train as many as 50,000 Arkansas National Guardsmen each year. Due to the nature of ongoing training and also to a poor understanding of environmental procedures that were practiced in the World War II era, areas within Fort Chaffee...

 The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site but proximal analog. The Straight...

Red Mountain Creek, an acid mine drainage stream in southwestern Colorado, was the subject of a synoptic study conducted in August 2002. During the synoptic study, a solution containing lithium chloride was injected continuously to allow for the calculation of streamflow using the tracer-dilution method. Synoptic water-quality samples were collected...

This work evaluates the use of the biotic ligand model (BLM), an aquatic toxicity model, to predict toxic effects of metals on aquatic biota in areas underlain by different rock types. The chemical composition of water, soil, and sediment is largely derived from the composition of the underlying rock. Geologic...

This report presents the results of one aspect of an integrated watershed-characterization study that was undertaken to assess the impacts of historical mining and milling of silver-lead-zinc ores on water and sediment composition and on aquatic biota in streams draining the northern part of the Coeur d'Alene Mining District in...

Overview -- Germanium is a hard, brittle semimetal that first came into use a half-century ago as a semiconductor material in radar units and as the material from which the first transistor was made. Today it is used principally as a component of the glass in telecommunications fiber optics; as...

Overview -- Silver is one of the eight precious, or noble, metals; the others are gold and the six platinum-group metals (PGM). World mine production in 2001 was 18,700 metric tons (t) and came from mines in 60 countries; the 10 leading producing countries accounted for 86 percent of the...

In 1999, the U.S. Geological Survey (USGS) initiated studies of mercury and methylmercury occurrence, transformation, and transport in the Bear River and Yuba River watersheds of the northwestern Sierra Nevada. Because these watersheds were affected by large-scale, historical gold extraction using mercury amalgamation beginning in the 1850s, they were selected...

The Vienna mineralized area of south-central Idaho was an important silver-lead-producing district in the late 1800s and has intermittently produced lead, silver, zinc, copper, and gold since that time. The district is underlain by biotite granodiorite of the Cretaceous Idaho batholith, and all mineral deposits are hosted by the biotite...

Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles,...

Mechanisms of copper toxicity and consequences of exposure vary due to uptake route and ionoregulatory status. The goal of this research was to develop a model fish system to assess the influence of different Cu exposure routes (waterborne or dietary) on bioavailability, uptake, and effects in hybrid striped bass (Morone...

The East Tianshan is a remote Gobi area located in eastern Xinjiang, northwestern China. In the past several years, a number of gold, porphyry copper, and Fe(-Cu) and Cu-Ag-Pb-Zn skarn deposits have been discovered there and are attracting exploration interest. The East Tianshan is located between the Junggar block to...

Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub...

Early life-stage toxicity tests with copper and pentachlorophenol (PCP) were conducted with two species listed under the United States Endangered Species Act (the endangered fountain darter, Etheostoma fonticola, and the threatened spotfin chub, Cyprinella monacha) and two commonly tested species (fathead minnow, Pimephales promelas, and rainbow trout, Oncorhynchus mykiss). Results...

Acute (24-h) toxicity tests were used in this study to compare lethality responses in early life stages (glochidia) of six freshwater mussel species, Leptodea fragilis, U. imbecillis, Lampsilis cardium, Lampsilis siliquoidea, Megalonaias nervosa, and Ligumia subrostrata, and two standard test organisms, Ceriodaphnia dubia and Daphnia magna. Concentrations of carbaryl, copper,...

Weathering of metal-sulfide minerals produces suites of variably soluble efflorescent sulfate salts at a number of localities in the eastern United States. The salts, which are present on mine wastes, tailings piles, and outcrops, include minerals that incorporate heavy metals in solid solution, primarily the highly soluble members of the...

Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation....

New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to < 1.1 ka....

Delineation of metal uptake routes in aquatic invertebrates is critical for characterizing bioaccumulation dynamics and assessing risks associated with metal exposure. Here we demonstrate that Cu stable isotopic ratios can be manipulated in both exposure media and algae to determine the efflux rate constant (ke) and...

The rate at which ore deposits form is one of the least well established parameters in all of economic geology. However, increased detail in sampling, improved technology of dating, and sophistication in modeling are reducing the uncertainties and establishing that ore formation, at least for the porphyry copper-skarn-epithermal base and...