Publications
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Mineralogical characterization of weathered and less weathered strata of the Meade Peak phosphatic shale member of the Permian Phosphoria Formation: Measured sections E and F, Rasmussen Ridge, and measured sections G and H, Sage Creek area of the Webster
The Permian Phosphoria Formation of the western U.S. includes one of the largest
phosphate deposits in the world. Despite the economic significance of this formation, its
fine-grained nature has discouraged detailed mineralogical characterization and
quantitative studies. Recently, selenium and other potentially hazardous trace elements
in mine wastes have drawn increased attention to these rocks
Authors
A. C. Knudsen, M. E. Gunter, J. R. Herring, R. I. Grauch
Preliminary gravity inversion model of Frenchman Flat Basin, Nevada Test Site, Nevada
The depth of the basin beneath Frenchman Flat is estimated using a gravity inversion method. Gamma-gamma density logs from two wells in Frenchman Flat constrained the density profiles used to create the gravity inversion model. Three initial models were considered using data from one well, then a final model is proposed based on new information from the second well. The preferred model indicates t
Authors
Geoffrey A. Phelps, Scott E. Graham
Evaluation of airborne thermal-infrared image data for monitoring aquatic habitats and cultural resources within the Grand Canyon
This study examined thermal-infrared (TIR) image data acquired using the airborne Advanced Thematic Mapper (ATM) sensor in the afternoon of July 25th, 2000 over a portion of the Colorado River corridor to determine the capability of these 100-cm resolution data to address some biologic and cultural resource requirements for GCMRC. The requirements investigated included the mapping of warm backwate
Authors
Philip A. Davis
Gravity map and data of the eastern half of the Big Bear Lake, 100,000 scale quadrangle, California and analysis of the depths of several basins
Gravity surveys are useful tools for helping to understand the 3-dimensional geology of an area. Many gravity measurements were made in the 1960s and 1970s by various groups in order to produce gravity maps covering California at a scale of 1:250,000 for the California Division of Mines and Geology. (For this area see Biehler et. al. 1988.) More recent surveys have focused on specific areas and pr
Authors
Carter Roberts, Robert Jachens, Allan Katzenstein, Gregory Smith, Russell Johnson
Results of weekly chemical and isotopic monitoring of selected springs in Norris Geyser Basin, Yellowstone National Park during June-September, 1995
Each year at Norris Geyser Basin, generally in August or September, a widespread hydrothermal 'disturbance' occurs that is characterized by simultaneous changes in the discharge characteristics of many springs, particularly in the Back Basin. During the summer season of 1995, water samples from eight widely distributed hot springs and geysers at Norris were collected each week and analyzed to dete
Authors
R.O. Fournier, U. Weltman, D. Counce, L. D. White, C. J. Janik
Isostatic gravity map of Yukon Flats, east-central Alaska
The gravity data used to make this map were collected between 1959 and 1984. The data were collected by automobile, aircraft, and watercraft. Most of the data were collected as part of a U.S. Geological Survey (USGS) regional gravity data collection project. Some of the data were collected as part of other USGS local projects. One data set was collected by the NGS (National Geodetic Survey). This
Authors
Robert L. Morin
Preliminary report on geophysical data in Yavapai County, Arizona
Recently acquired geophysical data provide information on the geologic framework and its effect of groundwater flow and on stream/aquifer interaction in Yavapai County, Arizona. High-resolution aeromagnetic data reflect diverse rock types at and below the topographic surface and have permitted a preliminary interpretation of faults and underlying rock types (in particular, volcanic) that will prov
Authors
V. E. Langenheim, J.P. Hoffmann, K.W. Blasch, Ed DeWitt, Laurie Wirt
Field-trip guide to the geology of the Lexington Reservoir and Loma Prieta areas in the Santa Cruz Mountains, Santa Clara and Santa Cruz Counties, California
This guide contains a road log and five stop descriptions for a field trip in the southern Santa Cruz Mountains. The trip officially begins at the boat dock parking area on Alma Bridge Road near the dam of Lexington Reservoir. Stop 1 involves a walk up the Limekiln Trail to examine a large landslide in serpentinite that frequently takes out the trail. Stop 2 is at Miller Point picnic area along th
Authors
Philip W. Stoffer, Paula Messina
Composition of the Rex Chert and associated rocks of the Permian Phosphoria Formation: Soda Springs area, SE Idaho
This study, one in a series, reports bulk chemical and mineralogical compositions, as well as petrographic and outcrop descriptions of rocks collected from three measured outcrop sections of the Rex Chert member of the Phosphoria Formation in SE Idaho. The three measured sections were chosen from ten outcrops of Rex Chert that were described in the field. The Rex Chert overlies the Meade Peak Phos
Authors
James R. Hein, Brandie McIntyre, Robert B. Perkins, David Z. Piper, James Evans
Interpreting the earthquake source of the Wabash Valley seismic zone (Illinois, Indiana, and Kentucky) from seismic-reflection, gravity, and magnetic-intensity data
Reprocessing of seismic-reflection data reveals new images of upper- to middle-crustal structures beneath the Wabash Valley seismic zone, located north of the New Madrid seismic zone within the seismically active southern Illinois basin. Four intersecting deep seismic profiles (243 km total) indicate an anomalous, 5–10-km-wide zone of dipping reflections and diffractions below the western flank of
Authors
John H. McBride, Thomas G. Hildenbrand, William J. Stephenson, Christopher J. Potter
Publications of Western Earth Surface Processes Team 2001
The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping and related topical earth-science studies in the Western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues, such as ground-water quality, landslides and other potential geo
Authors
II Powell, R. W. Graymer
Digital version of "Open-File Report 92-179: Geologic map of the Cow Cove Quadrangle, San Bernardino County, California"
This is a digital map database version of a previous printed geologic map, U.S. Geological Survey Open-File Report 92–179. The original paper map has been faithfully reproduced as a geologic map database for use in a GIS, and thus does not contain updated geologic information for the map area. This publication consists of three parts:
1. Documentation in the form of a this publication's Open File
Authors
Howard G. Wilshire, David R. Bedford, Teresa Coleman