Publications

This report presents a consistent set of 1:100,000-scale vector topographic contours for all eleven 30x60-minute quadrangles in the San Francisco Bay region for use in visualizing the topography and preparing maps of the region. The contours were prepared by contouring an areally continuous 30-m altitude grid (National Elevation Dataset, Jan., 1999), and differ from USGS hypsographic DLG...

In 2000, the popular press frequently referred to reports that the southwestern United States might experience a shift from relatively wet to dry conditions during the next couple of decades (see http://topex‐www.jpl.nasa.gov/discover/PDO.html). These predictions stemmed from observations that the Pacific Decadal Oscillation (PDO) appeared to abruptly change from a “positive” to a...

This data set maps and describes the geology of the Porcupine Wash 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses parts of the Hexie Mountains, Cottonwood Mountains, northern Eagle Mountains, and south flank of Pinto Basin. It is...

The U.S. Geological Survey conducted a detailed gravity study along part of the Los Angeles Regional Seismic Experiment (LARSE) transect across the San Fernando Basin and Transverse Ranges to help characterize the structure underlying this area. 249 gravity measurements were collected along the transect and to augment regional coverage near the profile. An isostatic gravity low of 50-60...

For many oil and gas fields, estimates of ultimate recovery (the sum of cumulative production plus estimated reserves) tend to increase from one year to the next, and the gain is called reserve growth. Forecasts of reserve growth by the U.S. Geological Survey rely on statistical analyses of historical records of oil and gas production and estimated reserves. The preproposal in this Open...

Oil test wells can provide information on the depth, age, inclination, porosity, permeability, density, faulting, folding, and organic content of geologic formations mapped at the surface, or on units not recognized in surface outcrops. Formation density, as expressed in sonic and density logs commonly obtained when wells are drilled, has become increasingly important in making a crustal...

No abstract available.

The Roseburg 30' x 60' Quadrangle covers the southeastern margin of the Oregon Coast Range and its tectonic boundary with Mesozoic terranes of the Klamath Mountains (see figures 1 and 2 in pamphlet, also shown on map sheet). The geologic framework of the Roseburg area was established by the pioneering work of Diller (1898), Wells and Peck, (1961) and Ewart Baldwin (1974) and his students...

No abstract available.

No abstract available.

Over the past several decades investigators have extensively examined the 238U-234U- 230Th systematics of a variety of geologic materials using alpha spectroscopy. Analytical uncertainty for 230Th by alpha spectroscopy has been limited to about 2% (2σ). The advantage of thermal ionization mass spectroscopy (TIMS), introduced by Edwards and co-workers in the late 1980’s is the increased

The paper geologic map of the east part of the Pullman 1° x 2° degree quadrangle, Idaho (Rember and Bennett, 1979) was scanned and initially attributed by Optronics Specialty Co., Inc. (Northridge, CA) and remitted to the U.S. Geological Survey for further attribution and publication of the geospatial digital files. The resulting digital geologic map GIS can be queried in many ways to...