Latest quaternary volcanism in the St. George Basin, southwestern Utah

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6013196

Millings, III, V T; Green, J D; Nusbaum, R L ^[1]

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1. Coll. of Charleston, SC (United States). Dept. of Geology

The St. George Basin was the site of mafic volcanism from about 6 Ma to 1 ka. The nature of latest Quaternary volcanism is of interest because the Basin is recognized as a low temperature (< 90C) geothermal resource area and it is part of the transition zone between the Basin and Range Province and the Colorado Plateau. The authors have studied the geochemistry, mineralogy, and aerial distribution of two of the youngest eruptions centers: (1) Veyo Volcano; and (2) the Diamond Valley scoria cones (DVSC). Veyo Volcano erupted basaltic andesite, beginning with an explosive stage marked by a 0.5 m basal Plinian layer. Later eruptions alternated between quiescent and Strombolian-styles. Phenocrysts include clear plagioclase, sieve-texture plagioclase, olivine and rare augite. The DVSC and associated Santa Clara lava flow are tholeiitic basalt, consisting of olivine phenocrysts, and rare plagioclase phenocrysts. Based on preliminary geochemical data, Diamond Valley rocks exhibit lower incompatible element ratios compared to mafic rocks on the Markagunt Plateau and transition zone rocks. In contrast, Veyo Volcano rocks are similar to transition zone mafic rocks with regard to incompatible element abundances.

• OSTI ID: 6013196
• Report Number(s): CONF-9304188--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:4
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150200* -- Geology &amp; Hydrology of Geothermal Systems
58 GEOSCIENCES
580000 -- Geosciences
CENOZOIC ERA
CHEMISTRY
DEVELOPED COUNTRIES
GEOCHEMISTRY
GEOLOGIC AGES
GEOTHERMAL RESOURCES
IGNEOUS ROCKS
MINERALOGY
NORTH AMERICA
QUATERNARY PERIOD
RESOURCES
ROCKS
USA
UTAH
VOLCANIC ROCKS
VOLCANISM