Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
New aeromagnetic data reveal large strike-slip (?) faults in the Northern Willamette Valley, Oregon
High-resolution aeromagnetic data from the northern Willamette Valley, Oregon, reveal large, northwest-striking faults buried beneath Quaternary basin sediments. Several faults known from geologic mapping are well defined by the data and appear to extend far beyond their mapped surface traces. The Mount Angel fault, the likely source of the Richter magnitude (M1) 5.6 earthquake in 1993, is at leas
Authors
Richard J. Blakely, Ray Wells, T.L. Tolan, M.H. Beeson, A.M. Trehu, L.M. Liberty
Forest clearing and regional landsliding
The influence of forest clearing on landsliding is central to long-standing concern over the effects of timber harvesting on slope stability. Here we document a strong topographic control on shallow landsliding by combining unique ground-based landslide surveys in an intensively monitored study area with digital terrain modeling using high-resolution laser altimetry and a coarser resolution region
Authors
D. R. Montgomery, K. M. Schmidt, H. M. Greenberg, W. E. Dietrich
Geologic datasets for weights of evidence analysis in northeast Washington: 1. Geologic raster data
This dataset contains the combination of geology data (geologic units, faults, folds, and dikes) from 6 1:100,000 scale digital coverages in eastern Washington (Chewelah, Colville, Omak, Oroville, Nespelem, Republic). The data was converted to an Arc grid in ArcView using the Spatial Analyst extension.
Authors
David E. Boleneus, J. Douglas Causey
Geophysical constraints on the Virgin River Depression, Nevada, Utah, and Arizona
Gravity and aeromagnetic data provide insights into the subsurface lithology and structure of the Virgin River Depression (VRD) of Nevada, Utah, and Arizona. The gravity data indicate that the Quaternary and Tertiary sedimentary deposits hide a complex pre-Cenozoic surface. A north-northwest-trending basement ridge separates the Mesquite and Mormon basins, as evidenced by seismic-reflection, gravi
Authors
Victoria E. Langenheim, J. M. Glen, R.C. Jachens, G. L. Dixon, T.C. Katzer, R. L. Morin
Age and paleoenvironmental significance of mega-invertebrates from the "San Pedro" Formation in the Coyote Hills, Fullerton and Buena Park, Orange County, Southern California
The "San Pedro" Formation in the Coyote Hills contains an invertebrate fossil as-semblage of 184 taxa from 158 localities. The fauna consists of two annelids, 174 mollusks (80 bivalves, 94 gastropods, and three scaphopods), five arthropods, and three echinoids, along with other minor constituents recognized by not specifically identified during the present study. These fossils are divided into thr
Authors
Charles L. Powell, Dave Stevens
Book review: Geomagnetism. (Research: Past and Present)
Book information: Geomagnetism. (Research: Past and Present)" Wilfried Schröder, editor, 2000. Science Edition /IDCH-IAGA, Darmstadt Germany. 248 p.
Authors
Edward A. Mankinen
Sulfur-, oxygen-, and carbon-isotope studies of Ag-Pb-Zn vein-breccia occurrences, sulfide-bearing concretions, and barite deposits in the north-central Brooks Range, with comparisons to shale-hosted stratiform massive sulfide deposits: A section in Ge
Stratiform shale-hosted massive sulfide deposits, sulfidebearing concretions and vein breccias, and barite deposits are widespread in sedimentary rocks of Late Devonian to Permian age in the northern Brooks Range. All of the sulfide-bearing concretions and vein breccias are hosted in mixed continental-marine clastic rocks of the Upper Devonian to Lower Mississippian Endicott Group. The clastic roc
Authors
Karen D. Kelley, David L. Leach, Craig A. Johnson
Bedrock assemblages of the Bering Strait region: Implications for offshore metal sources in the marine environment: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998
The Bering Strait region is important habitat for Pacific walrus (Odobenus rosmarus divergens). Elevated metal levels in tissues of some walrus have raised concerns about the sources of these metals. This study synthesizes and integrates onshore geology, regional gravity and magnetic data, and information about mineral deposits and the natural processes that weather, erode, and disperse metals in
Authors
Travis L. Hudson, Richard W. Saltus
Regional baseline geochemistry and environmental effects of gold placer mining operations on the Fortymile River, eastern Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998
A systematic water-quality study of the Fortymile River and many of its major tributaries in eastern Alaska was conducted in June of 1997 and 1998. Surface-water samples were collected for chemical analyses to establish regional baseline geochemistry values and to evaluate the possible environmental effects of suction-dredge placer gold mining and bulldozer-operated placer gold mining (commonly re
Authors
Richard B. Wanty, Bronwen Wang, Jim Vohden, Paul H. Briggs, Allen L. Meier
Geologic setting of the Fortymile River area - Polyphase deformational history within part of the eastern Yukon-Tanana uplands of Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998
The Fortymile River area lies within the Yukon-Tanana lithotectonic terrane of east-central Alaska. This terrane is a mosaic of several lithotectonic assemblages, each with a coherent lithologic, metamorphic, and deformational history. Previous workers have shown that the Fortymile River area is underlain by rocks of the Seventymile, Taylor Mountain, and Nisutlin assemblages. The Taylor Mountain t
Authors
Warren C. Day, Bruce M. Gamble, Mitchell W. Henning, Bruce D. Smith
Digital geologic map of Arizona: A digital database derived from the 1983 printing of the Wilson, Moore, and Cooper 1:500,000-scale map
This report describes a digital geologic GIS database in an Arc/Info format for the “Geologic Map of Arizona” by Wilson and others (1983 edition).
Authors
Douglas M. Hirschberg, G. Stephen Pitts
Preliminary maps of Quaternary deposits and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database
This report presents a preliminary map and database of
Quaternary deposits and liquefaction susceptibility for the nine-county San
Francisco Bay region, together with a digital compendium of ground effects
associated with past earthquakes in the region. The report consists of (1) a
spatial database of fivedata layers (Quaternary deposits, quadrangle index, and
three ground effects layers
Authors
Keith L. Knudsen, Janet M. Sowers, Robert C. Witter, Carl M. Wentworth, Edward J. Helley, Robert S. Nicholson, Heather M. Wright, Katherine H. Brown