Publications

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

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

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.

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

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

Book information: Geomagnetism. (Research: Past and Present)" Wilfried Schröder, editor, 2000. Science Edition /IDCH-IAGA, Darmstadt Germany. 248 p.

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

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

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

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

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).

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