Geochemistry, age and strontium isotope composition of late tertiary and quaternary basalts and andesites in western Nevada and their relation to geothermal potential. Final report, October 1, 1982-December 31, 1983

Technical Report · Sun Jan 01 00:00:00 EST 1984

DOI:https://doi.org/10.2172/6838221· OSTI ID:6838221

Fultz, L A; Bell, E J; Trexler, D T

This research was undertaken to characterize the late Cenozoic volcanic rocks associated with active geothermal systems in west-central Nevada. Petrographic and microprobe, geochemical and isotopic analysis and age dating techniques were used to characterize these young volcanic rocks. These data were combined with the limited data previously reported in the literature on these same volcanic areas to interpret their petrogenesis. The overall characterization resulted from integrating the petrogenesis with a structural-tectonic model of the region. Potassium-argon isotopic ages ranging up to 14 million years were determined for eight localities within the Reno 1 x 2/sup 0/ study region. These ages are consistent with the morphology of the volcanic landforms, the active geothermal systems associated with them, and with other isotopic ages reported in the literature for these and similar rocks within the study region. Petrographic analysis of hand specimens and thin-sections indicated mineralogic assemblages of the respective rock types and specific mineral textures and phenocryst compositions and characteristics. These identifications were further substantiated by microprobe analysis of selected phenocrysts and groundmass phases. Classification of the respective rock types was also based on chemical composition and normative calculations using the program PETCAL. Basaltic andesites are identified and described for Steamboat Hills, Table Mountain, Silver Springs, Churchill Butte, Cleaver Peak, Desert Peak and Carson City sites.

• Research Organization: Nevada Univ., Reno (USA). Div. of Earth Sciences
• DOE Contract Number: FC03-80RA50075
• OSTI ID: 6838221
• Report Number(s): DOE/RA/50075-1; ON: DE84012404
• Resource Relation: Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
NEVADA
AGE ESTIMATION
GEOCHEMICAL SURVEYS
GEOTHERMAL SYSTEMS
ANDESITES
BASALT
CHEMICAL COMPOSITION
CLASSIFICATION
RESOURCE POTENTIAL
STRONTIUM ISOTOPES
TECTONICS
VOLCANIC ROCKS
ALKALINE EARTH ISOTOPES
FEDERAL REGION IX
IGNEOUS ROCKS
ISOTOPES
NORTH AMERICA
ROCKS
SURVEYS
USA
Geothermal Legacy