Geoffrey Phelps, MSc
Phelps works in the GMEG Science Center. He received a BA in geology from UC Berkeley and an MSc from the University of London, Birkbeck in geographic information science. He specializes in geologic mapping, gravity and magnetics, and spatial analysis. Presently his research is focused on using data science tools in 2D and 3D geologic mapping, and gravity and magnetic forward and inverse modeling.
Science and Products
Filter Total Items: 28
Principal facts for gravity stations in the vicinity of Coyote Spring Valley, Nevada, with initial gravity modeling results Principal facts for gravity stations in the vicinity of Coyote Spring Valley, Nevada, with initial gravity modeling results
Gravity measurements were made along 5 profiles across parts of the Coyote Spring Valley and vicinity in order to aid in modeling the depth and shapes of the underlying basins and to locate faults concealed beneath the basin fill. Measurements were taken at 200 m (660 ft) spacing along the profiles. Models based on these and existing regional data reveal two north-south-trending basins...
Authors
Geoffrey A. Phelps, E. B. Jewel, V.E. Langenheim, R.C. Jachens
High-angle faults in the basement of Yucca Flat, Nevada Test Site, Nevada, based on analysis of a constrained gravity inversion surface High-angle faults in the basement of Yucca Flat, Nevada Test Site, Nevada, based on analysis of a constrained gravity inversion surface
Using a model of the topographic subsurface derived from drill hole and gravity inversion analysis of the basement rocks in Yucca Flat, Nevada Test Site (NTS), Nevada, a fault map and digital fault dataset were constructed based on offsets of the basement surface. Because these faults are, in large part, not present at the surface, they are interpreted to be inactive faults, older than...
Authors
Geoffrey A. Phelps, Edwin H. McKee
Preliminary geologic map of the Little Piute Mountains, California: A digital database Preliminary geologic map of the Little Piute Mountains, California: A digital database
The Little Piute Mountains Digital database contains digital geologic and geographic information for the study area. The geology was mapped at a scale of 1:8,000, and the topographic information was input from the Little Piute Mountains, CA 1:24,000 quadrangle. The accuracy of the spatial information is limited to the input scale. Postscript files, originally published in paper format as...
Authors
Keith A. Howard, Michael L. Dennis, Karl Karlstrom, Geoffrey A. Phelps
Preliminary geologic map of the Little Piute Mountains, San Bernardino County, California Preliminary geologic map of the Little Piute Mountains, San Bernardino County, California
Introduction The Little Piute Mountains in the eastern Mojave Desert expose a series of folds and thrust faults involving metamorphosed Paleozoic strata (Miller and others, 1982; Stone and others, 1983). Detailed mapping of these structures was undertaken to help elucidate regional Mesozoic structural evolution. Earlier geologic maps were prepared by Cooksley (1960a,b,c,d, generalized by...
Authors
Keith A. Howard, Michael L. Dennis, Karl E. Karlstrom, Geoffrey A. Phelps
Science and Products
Filter Total Items: 28
Principal facts for gravity stations in the vicinity of Coyote Spring Valley, Nevada, with initial gravity modeling results Principal facts for gravity stations in the vicinity of Coyote Spring Valley, Nevada, with initial gravity modeling results
Gravity measurements were made along 5 profiles across parts of the Coyote Spring Valley and vicinity in order to aid in modeling the depth and shapes of the underlying basins and to locate faults concealed beneath the basin fill. Measurements were taken at 200 m (660 ft) spacing along the profiles. Models based on these and existing regional data reveal two north-south-trending basins...
Authors
Geoffrey A. Phelps, E. B. Jewel, V.E. Langenheim, R.C. Jachens
High-angle faults in the basement of Yucca Flat, Nevada Test Site, Nevada, based on analysis of a constrained gravity inversion surface High-angle faults in the basement of Yucca Flat, Nevada Test Site, Nevada, based on analysis of a constrained gravity inversion surface
Using a model of the topographic subsurface derived from drill hole and gravity inversion analysis of the basement rocks in Yucca Flat, Nevada Test Site (NTS), Nevada, a fault map and digital fault dataset were constructed based on offsets of the basement surface. Because these faults are, in large part, not present at the surface, they are interpreted to be inactive faults, older than...
Authors
Geoffrey A. Phelps, Edwin H. McKee
Preliminary geologic map of the Little Piute Mountains, California: A digital database Preliminary geologic map of the Little Piute Mountains, California: A digital database
The Little Piute Mountains Digital database contains digital geologic and geographic information for the study area. The geology was mapped at a scale of 1:8,000, and the topographic information was input from the Little Piute Mountains, CA 1:24,000 quadrangle. The accuracy of the spatial information is limited to the input scale. Postscript files, originally published in paper format as...
Authors
Keith A. Howard, Michael L. Dennis, Karl Karlstrom, Geoffrey A. Phelps
Preliminary geologic map of the Little Piute Mountains, San Bernardino County, California Preliminary geologic map of the Little Piute Mountains, San Bernardino County, California
Introduction The Little Piute Mountains in the eastern Mojave Desert expose a series of folds and thrust faults involving metamorphosed Paleozoic strata (Miller and others, 1982; Stone and others, 1983). Detailed mapping of these structures was undertaken to help elucidate regional Mesozoic structural evolution. Earlier geologic maps were prepared by Cooksley (1960a,b,c,d, generalized by...
Authors
Keith A. Howard, Michael L. Dennis, Karl E. Karlstrom, Geoffrey A. Phelps