Publications

Seismic reflection profiles near Sites 994, 995, and 997 were collected with seismic sources that provide maximum resolution with adequate power to image the zone of gas hydrate stability and the region direction beneath it. The overall structure of the sediment drift deposit that constitutes the Blake Ridge consists of southwestward-dipping strata. These strata are approximately...

The Chester County observation-well network was established in 1973 through a cooperative agreement between the Chester County Water Resources Authority (CCWRA) and the U.S. Geological Survey. The network was established to monitor local ground-water levels, to determine drought conditions, and to monitor ground-water-level trends. Drought-warning and drought-emergency water-level...

The U.S. Geological Survey investigated ground-water resources of northeastern St. Joseph County, Indiana, during 1990-93. The investigation included field measurements of water levels and numerical models of ground-water flow. This report documents results of that work and includes descriptions of (1) hydrogeologic framework, (2) water levels, (3) model sensitivity to variations in...

A map showing ground-water levels in the carbonate rocks in part of East Whiteland and Charlestown Townships, Chester County, Pennsylvania, was constructed from water levels measured in 64 wells on December 6, 1994. Observed water-level altitudes range from 226 feet above sea level near Morehall Road to 400 feet above sea level near State Route 401 in East Whiteland Township.

A map showing ground-water levels in crystalline and metasedimentary rocks in Valley and West Brandywine Townships, Chester County, Pennsylvania, was constructed from water levels measured in wells from May 1992 through August 1993. Pre-1992 measurements were incorporated on the map to provide control in areas where more recent data were not available. Because little ground-water...

No abstract available

About 43 million gallons per day of ground water was used in 1985 by the 150,000 people living in the 10 valleys of central Pennsylvania that are underlain by Cambrian and Ordovician carbonate rocks. Noticeable effects on water levels from withdrawals occur in the vicinity of the Borough of State College where an average of 8.1 million gallons per day is pumped. The carbonate aquifer...

Pesticides (herbicides and insecticides) are used extensively in the White River Basin. Application of herbicides to corn and soybeans accounts for most of the use. The U.S. Geological Survey collected samples from four networks of monitoring wells in the White River Basin during 1994-95. The most frequently detected compounds in ground water were desethyl atrazine (a breakdown product...

Ground-water samples collected from 267 wells were analyzed for radon as part of a water-quality reconnaissance of subunits of the Lower Susquehanna and Potomac River Basins conducted by the United States Geological Survey (USGS) as part of the National Water-Quality Assessment (NAWQA) program. Radon is a product of the radioactive decay of uranium. Airborne radon has been cited by the...

Physical and chemical data were collected from May 1991 through April 1993 at a 4.5 hectare field site in Cumberland County, Pa., about 5 kilometers southeast of Newville. These data were used to define the hydrogeologic setting of a field site representative of the intensively farmed carbonate valleys of southeastern and south-central Pennsylvania. The environmental processing of...

Some aggregates of rutile, classically considered to be "elbow" twinned, instead are topotactic replacements of ilmenite or other hexagonal titaniferous precursors. Twinned rutile can be differentiated from the reticulated rutile of topotactic replacements by the angle of prism intersections, junction morphology, and the overall form of the aggregate. In a special case of topotactic...

Massachusetts and Cape Cod Bays form a semienclosed coastal basin that opens onto the much larger Gulf of Maine. Subtidal circulation in the bay is driven by local winds and remotely driven flows from the gulf. The local-wind forced flow is estimated with a regional shallow water model driven by wind measurements. The model uses a gravity wave radiation condition along the open-ocean...