Multiple episodes of hydrothermal activity and epithermal mineralization in the southwestern Nevada volcanic field and their relations to magmatic activity, volcanism and regional extension

Technical Report · Sat Dec 31 04:00:00 EST 1994

DOI:https://doi.org/10.2172/240930· OSTI ID:240930

Weiss, S. I.; Noble, D. C.; Jackson, M. C. ^[1]

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1. Univ. of Nevada, Reno, NV (United States); and others

Volcanic rocks of middle Miocene age and underlying pre-Mesozoic sedimentary rocks host widely distributed zones of hydrothermal alteration and epithermal precious metal, fluorite and mercury deposits within and peripheral to major volcanic and intrusive centers of the southwestern Nevada volcanic field (SWNVF) in southern Nevada, near the southwestern margin of the Great Basin of the western United States. Radiometric ages indicate that episodes of hydrothermal activity mainly coincided with and closely followed major magmatic pulses during the development of the field and together spanned more than 4.5 m.y. Rocks of the SWNVF consist largely of rhyolitic ash-flow sheets and intercalated silicic lava domes, flows and near-vent pyroclastic deposits erupted between 15.2 and 10 Ma from vent areas in the vicinity of the Timber Mountain calderas, and between about 9.5 and 7 Ma from the outlying Black Mountain and Stonewall Mountain centers. Three magmatic stages can be recognized: the main magmatic stage, Mountain magmatic stage (11.7 to 10.0 Ma), and the late magmatic stage (9.4 to 7.5 Ma).

• Research Organization: Nevada Univ., Reno, NV (United States). Center for Neotectonic Studies
• OSTI ID: 240930
• Report Number(s): DOE/NV/10461--T46; ON: DE96006638
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
CALDERAS
FLUORITE
GEOLOGIC FAULTS
HIGH-LEVEL RADIOACTIVE WASTES
HYDROTHERMAL ALTERATION
ISOTOPE DATING
LAVA
MINERALIZATION
MINERALS
NEVADA
PROGRESS REPORT
SEDIMENTARY ROCKS
SITE CHARACTERIZATION
TUFF
UNDERGROUND DISPOSAL
VOLCANIC ROCKS
VOLCANISM
YUCCA MOUNTAIN