Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2486
Geologic transect of the northern Diablo Range, California Geologic transect of the northern Diablo Range, California
No abstract available.
Authors
M. Clark Blake
Geologic setting, petrology, and geochemistry of zoned tungsten-bearing skarns at the Strawberry Mine, central Sierra Nevada, California Geologic setting, petrology, and geochemistry of zoned tungsten-bearing skarns at the Strawberry Mine, central Sierra Nevada, California
The Strawberry mine, 90 km northeast of Fresno, California, occurs on the margin of a small roof pendant of Early Jurassic metasedimentary rocks and middle Cretaceous metaigneous rocks. Middle Cretaceous granitic intrusions surround and intrude the roof pendant. Adjacent to one granodiorite intrusion, several subvertical marble layers are replaced by scheelite-bearing skarns. The skarns...
Authors
Warren J. Nokleberg
Petrographic and chemical characteristics of pyrite-marcasite mineralization in hole 465A, southern Hess Rise Petrographic and chemical characteristics of pyrite-marcasite mineralization in hole 465A, southern Hess Rise
Core recovered from Hess Rise contains concentrations of pyrite, marcasite, and barite in the lowermost meter of limestone (Unit II) and in the brecciated upper part of the underlying volcanic basement (Unit HI). Petrographic and chemical data indicate that the sulfide-barite assemblage in the limestone is mainly a product of low-temperature diagenetic processes. The iron-sulfide phases...
Authors
Randolph A. Koski, James R. Hein
Geologic mapping of Kentucky: A history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978 Geologic mapping of Kentucky: A history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978
In 1960, the U.S. Geological Survey and the Kentucky Geological Survey began a program to map the State geologically at a scale of 1:24,000 and to publish the maps as 707 U.S. Geological Survey Geologic Quadrangle Maps. Fieldwork was completed by the spring of 1977, and all maps were published by December 1978. Geologic mapping of the State was proposed by the Kentucky Society of...
Authors
Earle Rupert Cressman, Martin C. Noger
Magnetic effects of maghemitization of oceanic crust Magnetic effects of maghemitization of oceanic crust
Both theoretical considerations and available experimental results indicate that magnetic effects of maghemitization are strongly dependent on the grain size of the originally unoxidized titanomagnetite. Maghemitization of single‐domain titanomagnetite results in a decrease in coercivity, an increase in susceptibility, and a large decrease in Q ratio. Maghemitization of multidomain...
Authors
M. Prevot, A. Lecaille, Edward A. Mankinen
Physical factors that could restrict mineral supply Physical factors that could restrict mineral supply
Stages in the metal supply process are affected by each of the following physical (geologic) factors: (1) geographic distribution of concentrations of potential ore minerals, (2) depth of these concentrations, (3) mineralogy, (4) grain size of the minerals, and (5) grade and (6) tonnages of the concentrations. For mineral deposits of each type in each geologic and political environment...
Authors
John H. DeYoung, Donald A. Singer
The relation between exploration economics and the characteristics of mineral deposits The relation between exploration economics and the characteristics of mineral deposits
No abstract available.
Authors
Donald A. Singer, D.L. Mosier
Reconnaissance geologic map of the Topaz Lake 15 minute quadrangle, California and Nevada, with Quaternary geology Reconnaissance geologic map of the Topaz Lake 15 minute quadrangle, California and Nevada, with Quaternary geology
No abstract available.
Authors
David A. John, James Giusso, W. J. Moore, R. A. Armin, J. C. Dohrenwend
Two examples of seismic zonation in the San Francisco Bay region Two examples of seismic zonation in the San Francisco Bay region
The science of earthquakes in complex, requiring data and research in seismology, geology, soil mechanics, geophysics, hydrology, and engineering. Nevertheless, if earthquake hazards are to be reduced, earth science information must be translated from scientific and technical language into a form that can be effectively used by planners and decisionmakers. Out of the need to use earth...
Authors
W. J. Kockelman, E. E. Brabb
Regenerate faults of small Cenozoic offset as probable earthquake sources in the southeastern United States Regenerate faults of small Cenozoic offset as probable earthquake sources in the southeastern United States
No abstract available.
Authors
Carl M. Wentworth, Marcia Mergner-Keefer
Research in the Geysers-Clear Lake geothermal area, Northern California Research in the Geysers-Clear Lake geothermal area, Northern California
The Geysers-Clear Lake area is one of two places in the world where major vapor-dominated hydrothermal reservoirs are commercially exploited for electric power production. Because energy can be extracted more efficiently from steam than from hot water, vapor-dominated systems are preferable for electric power generation, although most geothermal electric power facilities tap water...