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Dacite tephras produced by the 1991 pre-climactic eruptive sequence at Mt. Pinatubo display extreme heterogeneity in vesicularity, ranging in clast density from 700 to 2580 kg m-3. Observations of the 13 surge-producing blasts that preceded the climactic plinian event include radar-defined estimates of column heights and seismically defined eruptive and...

Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina....

Water samples collected for the determination of volatile organic compounds (VOCs) are often preserved with hydrochloric acid (HCl) to inhibit the biotransformation of the analytes of interest until the chemical analyses can he performed. However, it is theoretically possible that residual free chlorine in the HCl can react with dissolved...

The present lead (Pb)-isotopic database of over 200 analyses from nearly 90 samples of non-mare basalt, lunar highland rocks (>3.9 Ga) delineate at least three isotopically distinct signatures that in some combination can be interpreted to characterize the systematics of the entire database. Two are fairly new sets of lunar...

Among the solar wind-implanted volatiles present in the lunar regolith, ³He is possibly the most valuable resource because of its potential as a fusion fuel. The abundance of ³He in the lunar regolith at a given location depends on surface maturity, the amount of solar wind...

The oxidation of ammonia (NH3) and methane (CH4) was investigated in an alkaline saline lake, Mono Lake, California (U.S.A.). Ammonia oxidation was examined in April and July 1995 by comparing dark 14CO2 fixation rates in the presence or absence of methyl fluoride (MeF), an inhibitor of NH3 oxidation. Ammonia oxidizer‐mediated dark 14CO2fixation rates were...

Phytoremediation uses the natural ability of plants to degrade contaminants in ground water. A field demonstration designed to remediate aerobic shallow ground water that contains trichloroethene began in April 1996 with the planting of cottonwood trees over an approximately 0.2-hectare area at the Naval Air Station, Fort Worth, Tx. Ground...

18O values establish that waters are predominantly of meteoric origin. The chemical compositions of water and gases are controlled mainly by the ambient rock types, and chemical geothermometry gives reservoir temperatures of 80-150 degrees C indicating shallow to moderate circulation depths of up to 6 km. However, compositions and isotope...

Selenium stable isotope ratio measurements should serve as indicators of sources and biogeochemical transformations of Se. We report measurements of Se isotope fractionation during selenate reduction, selenite sorption, oxidation of reduced Se in soils, and Se volatilization by algae and soil samples. These results, combined with previous work with Se...

As part of the National Water-Quality Assessment (NAWQA) Program, the U.S. Geological Survey (USGS) oversaw the installation of 30 shallow monitoring wells in the Columbia, South Carolina metropolitan area. The ground water sampled from these wells was used to study the recent effects of human activities on shallow ground water...

The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation and the city of Columbia, Missouri, collected hydrologic data from September 1993 through October 1996 as part of a hydrologic characterization of the Columbia/Eagle Bluffs Wetland Complex. The wetland complex was constructed in the Missouri River alluvial plain...

The water-table aquifer in Vega Alta, Puerto Rico, has been contaminated with volatile organic compounds. A three-dimensional ground-waterflow and solute-transport model was developed and calibrated to evaluate the effects of remedial alternatives designed to reduce the magnitude and extent of a trichloroethylene plume in the water-table aquifer. The development of...

This report describes the ground-water systems in the unconsolidated sand and gravel aquifers of the Coastal Plain of New Jersey and Long Island and in the fractured bedrock and valley-fill aquifers of northern New Jersey; summarizes current knowledge about the occurrence and distribution of nitrate, volatile organic compounds (VOCs), and...

Residential and commercial development of about 80 square miles that primarily replaced undeveloped and agricultural areas occurred in Salt Lake Valley, Utah, from 1963 to 1994. The effects of human activities on the quality of shallow ground water in the recently developed areas were studied by the U.S. Geological Survey...

The Prairie du Chien-Jordan (PDCJ) aquifer (Prairie du Chien-Trempealeau aquifer in Wisconsin), composed of dolomite and sandstone of Cambrian to Ordovician age, is the principal bedrock aquifer in the Upper Mississippi River study unit of the National Water-Quality Assessment (NAWQA) Program. The aquifer supplies approximately 75 percent of the ground...

The quality of urban stormwater is characterized with respect to 188 properties and constituents. Event-mean concentrations and loads for three land uses (residential, industrial, commercial), and annual loads for 12 selected properties and constituents for 26 gaged basins in the DallasFort Worth study area are presented. During February 1992–June 1993,...

In 1997 synoptic streamflow, water-quality, and biological investi- gations in the Big Black Creek Basin were conducted by the U.S. Geological Survey in cooperation with the City of Moody, St. Clair County, and the Birmingham Water Works Board. Data obtained during these synoptic investigations provide a one-time look at the...

Ground-water contamination of the surficial terrace alluvial aquifer has occurred at U.S. Air Force Plant 4, a government-owned, contractor-operated facility, northwest of Fort Worth, Texas. A poorly constructed monitoring well, P–22M, open to the underlying middle zone of the Paluxy aquifer was installed at landfill 3, October 1987, allowing leakage...

Between February 1998 and April 1998, geophysical logs were collected in nine boreholes adjacent to the Berkley Products Superfund Site, West Cocalico Township, Lancaster County, Pa. Video surveys were conducted on four of the nine boreholes. The boreholes range in depth from 320 to 508 feet below land surface, are...

A study of the effects of storm runoff from urban areas on water quality at Fort Leavenworth, Kansas, was conducted from May 1994 through September 1996. The purpose of this report is to present information to assess the current (1994-96) conditions and possible methods for anticipating future water-quality effects from...

Continuous-record water-level gages were established at three sites on Mountain Island Lake and one site downstream from Mountain Island Dam. The water level of Mountain Island Lake is controlled by Duke Power Company releases at Cowans Ford Dam (upstream) and Mountain Island Dam (downstream). Water levels on Mountain Island Lake...

Water samples were collected from four lakes in Byram Township, Sussex County, N.J., in the summer of 1998 as part of an investigation of the occurrence of volatile organic compounds (VOCs) in domestic wells of lakeside communities. Cranberry Lake and Lake Lackawanna are surrounded by densely populated communities where the...

This report presents selected geologic, hydrologic, and water-quality data collected in and near Belvidere, Ill., during 1989-96. The data were collected primarily by the U.S. Geological Survey and U.S. Environmental Protection Agency in support of an ongoing ground-water study of the glacial drift aquifer and bedrock aquifers of Ordovician and...