Search Results

Estimating numbers of undiscovered mineral deposits has been a source of unease among economic geologists yet is a fundamental task in considering future supplies of resources. Estimates can be based on frequencies of deposits per unit of permissive area in control areas around the world in the same way that...

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...

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...

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....

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...

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,...

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....

We conducted a study with cadmium (Cd) and copper (Cu) in the delta of San Francisco Bay, using nitrogen and carbon stable isotopes to identify trophic position and food web structure. Cadmium is progressively enriched among trophic levels in discrete epiphyte‐based food webs composed of macrophyte‐dwelling invertebrates...

Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. The magnetic susceptibility measurements, chemical analyses, and alteration class provided a database for study of magnetic susceptibility in these altered rocks....

Copper production through smelting generates large volumes of material flows. As copper contained in ore becomes copper contained in concentrate to be fed into the smelting process, it leaves behind an altered landscape, sometimes mine waste, and always mill tailings. Copper concentrate, fluxing materials, fuels, oxygen, recyclables, scrap and water...

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...

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...

Ground water historically has been the sole source of water supply for the community of Joshua Tree in the Joshua Tree ground-water subbasin of the Morongo ground-water basin in the southern Mojave Desert. The Joshua Basin Water District (JBWD) supplies water to the community from the underlying Joshua Tree ground-water...

After my visit to the adobe-walled archaeological site of Chan Chan, near Trujillo in northern Peru in the summer of 2000 (Geotimes, August 2003), my guide asked if I would like to see the metallurgical furnaces used by the Chimú, ancient residents and master metalsmiths of the region. Chan Chan...

Stormwater wetlands are created to retain water from storms and snow melt to reduce sediment, nutrient, and contaminant pollution of natural waterways in metropolitan areas. However, they are often a source of attractive habitat to wetland-associated wildlife. In this study of 12 stormwater wetlands and a larger, older reference site,...

The U.S. Geological Survey, in cooperation with the National Park Service conducted an intensive assessment of selected springs along the Colorado River Corridor in Arches National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park in 1997 and 1998, for the purpose of measuring and...

This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the Mahanoy Creek Basin in east-central Pennsylvania. The Mahanoy Creek Basin encompasses an area of 157 square miles (407 square kilometers) including approximately 42 square miles (109 square kilometers) underlain...

In 2001, the National Guard Bureau and the U.S. Geological Survey began a project to compile hydrogeologic data and determine presence or absence of soil, surface-water, and ground-water contamination at the Idaho Army National Guard Orchard Training Area in southwestern Idaho. Between June 2002 and April 2003, a total of...

Many municipalities in Kansas rely on small reservoirs as a source of drinking water and for recreational activities. Because of their significance to the community, management of the reservoirs and the associated basins is important to protect the reservoirs from degradation. Effective reservoir management requires information about water quality, sedimentation,...

The Humboldt River Basin is an arid to semiarid, internally drained basin that covers approximately 43,000 km2 in northern Nevada. The basin contains a wide variety of metallic and nonmetallic mineral deposits and occurrences, and, at various times, the area has been one of the Nation's leading or important producers...

In January 1999, the U.S. Geological Survey began an expanded monitoring program near Deer Trail, Colorado, in cooperation with the Metro Wastewater Reclamation District and the North Kiowa Bijou Groundwater Management District. Monitoring components were biosolids, soils, crops, ground water, and streambed sediments. The monitoring program addresses concerns from the...

In January 1999, the U.S. Geological Survey (USGS) began an expanded monitoring program near Deer Trail, Colorado, in cooperation with the Metro Wastewater Reclamation District and the North Kiowa Bijou Groundwater Management District. Monitoring components were biosolids, soils, crops, ground water, and streambed sediment. The monitoring program addresses concerns from...

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...

The three most important arsenical pesticides and herbicides that were extensively used on apple, blueberry, and potato crops in New England from mid-1800s to recent times are lead arsenate, calcium arsenate, and sodium arsenate. Lead arsenate was probably the most heavily used of the arsenical pesticides until it was banned...

The Indian River Basin, located near Sitka Alaska, drains an area of 12.3 square miles. This watershed is an important natural resource of Sitka National Historic Park. At the present time, the watershed faces possible development on large tracts of private land upstream of the park that could affect the...