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The USGS has undertaken a first order evaluation of sand & gravel resources in the Lower Boise River Valley in response to rapid urban expansion in the Boise-Nampa-Caldwell corridor in southwest Idaho. The study is intended to provide land-use planners and managers, particularly in the Bureau of Land Management, with...

Heavy rainfall from the storm of December 14-16, 1999 triggered thousands of landslides on steep slopes of the Sierra de Avila north of Caracas, Venezuela. In addition to landslides, heavy rainfall caused flooding and massive debris flows that damaged coastal communities in the State of Vargas along the Caribbean Sea....

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This publication consists of the online version of a CD-ROM publication, U.S. Geological Survey Open-File Report 01-146. The data for this publication total 557 MB on the CD-ROM. For speed of transfer, the main PDF document has been compressed (with a subsequent loss of image quality) from 145 to 18.1...

This Open-File Report contains a digital geologic map and map database of the Lakeview 7.5' quadrangle, Riverside County, California, that includes: 1. ARC/INFO (Environmental Systems Research Institute) version 7.2.1 double-precision coverages of the various elements of the geologic map 2. A Postscript file to plot the geologic map on a topographic base,...

This preliminary experimental lithogeochemical map shows the distribution of rock types in the Virginia and Maryland parts of the Chesapeake Bay watershed. The map was produced digitally by classifying geologic-map units according to composition, mineralogy, and texture; rather than by age and stratigraphic relationships as shown on traditional geologic maps....

Determining the economic viability of mineral deposits of various sizes and grades is a critical task in all phases of mineral supply, from land-use management to mine development. This study evaluates two simple tools for estimating the economic viability of porphyry copper deposits mined by open-pit, heap-leach methods when only...

The Variable-Recharge Package is a computerized method designed for use with the U.S. Geological Survey three-dimensional finitedifference ground-water flow model (MODFLOW-88) to simulate areal recharge to an aquifer. It is suitable for simulations of aquifers in which the relation between ground-water levels and land surface can affect the amount and distribution of recharge. The method is based on the...

This materials flow study includes a description of lead supply and demand factors for the United States to illustrate the extent of lead recycling and to identify recycling trends. Understanding the system of materials flow from source to ultimate disposition can assist in improving the management of the use of natural resources...

This trip will cross the northern Sangre de Cristo Range, from Westcliffe to Crestone, Colorado, by way of the Hermit Pass Road and the Rito Alto pack trail (Fig. 1 below; road and trail shown on Fig. 2). The traverse is designed to give the geologist a sample of the...

Two framework-supported, poorly bedded conglomerate units of the middle Upper Pennsylvanian and middle Lower Permian Strathearn Formation belonging to the overlap assemblage of the Antler orogen are prominent in the northern Carlin trend. These horizons stratigraphically and temporally bracket thrust emplacement of a major allochthonous thrust plate of mainly quartzarenite...

In the mid 1980s, the National Acid Precipitation Assessment Program (NAPAP), in cooperation with the National Park Service (NPS) and the U.S. Geological Survey (USGS), initiated a Materials Research Program (MRP) that included a series of field and laboratory studies with the broad objective of providing scientific information on acid...

In response to the 1992 creation of the Monterey Bay National Marine Sanctuary (MBNMS), the United States Geological Survey (USGS) initiated a multiyear investigation of the Sanctuary continental margin. As part of the investigative effort, this report summarizes the shipboard procedures, subsequent laboratory analyses, and data results from three seafloor...

A marine K-T boundary interval has been identified throughout the Badlands National Park region of South Dakota. Data from marine sediments suggest that deposits from two asteroid impacts (one close, one far away) may be preserved in the Badlands. These impact-generated deposits may represent late Maestrichtian events or possibly the...

A method of analysis and quality-assurance practices were developed for the determination of four mosquito insecticides (malathion, metho-prene, phenothrin, and resmethrin) and one synergist (piperonyl butoxide) in water. The analytical method uses liquid-liquid extraction (LLE) and gas chromatography/mass spectrometry (GC/MS). Good precision and accuracy were demonstrated in reagent water, urban...

The former George Air Force Base (GAFB), now known as the Southern California Logistics Airport (SCLA), is located in the town of Adelanto, approximately 100 km northeast of Los Angeles, California (Fig. 1). In this report, we present acquisition parameters, data, and interpretations of seismic images that were acquired in...

The U.S. Army Corps of Engineers, Baltimore District, has been conducting biological surveys of the inflow and outflow streams of East Sidney Lake since the early 1980's. These surveys are made to identify possible detrimental effects as well as benefits of the lake and to better understand the aquatic communities...

Suspended-sediment concentration data were collected in San Francisco Bay during water year 1999 (October 1, 1998-September 30, 1999). Optical backscatterance sensors and water samples were used to monitor suspended sediment at one site in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and...