Volcanic centers of southwestern Nevada: Evolution of understanding, 1960--1988

Journal Article · Wed May 10 04:00:00 EDT 1989 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB094iB05p05908· OSTI ID:6395221

Carr, W J; Orkild, P P

Since about 1960, geologists of the U.S. Geological Survey and, morerecently, those of Los Alamos and Lawrence Livermore national laboratories,supported largely by the U.S. Department of Energy (DOE) and its predecessors,have been unraveling a complex series of ash flow sheets, lavas, and relatedcalderas in the southwestern Nevada volcanic field in and near the Nevada TestSite (NTS). Extensive detailed geologic mapping aided in delineation offour major calderas: Silent Canyon (/similar to/14 Ma), Timber Mountain--OasisValley (/similar to/11.5 Ma), Black Mountain (/similar to/7.5 Ma), and Stonewall Mountain(/similar to/6 Ma). In the 1960s, key concepts that contributed to the understandingof volcanology were the recognition of vertical compositional zonation withinash flow sheets, the significance of caldera rim and moat lavas, therelation between caldera collapse and intracaldera breccias and ash flow facies,and the correlation of intracaldera and outflow-sheet facies. Deep drill holeswithin Silent canyon and Timber Mountain caldera provided vital informationon caldera geometry and intracaldera facies. Radiometric dating has producednearly 100 dates that define the age of the field between about 16 and 6 Ma.

• Research Organization: Los Alamos National Laboratory, New Mexico(US); Golden, Colorado; U.S. Geological Survey, Denver, Colorado
• OSTI ID: 6395221
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 94:B5; ISSN JGREA
• Country of Publication: United States
• Language: English

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58 GEOSCIENCES
580202* -- Geophysics-- Volcanology-- (1980-1989)
AGE ESTIMATION
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GEOLOGIC SURVEYS
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GEOTHERMAL SYSTEMS
HYDROTHERMAL ALTERATION
IGNEOUS ROCKS
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