Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah
The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.
- Research Organization:
- Utah Univ., Salt Lake City (USA). Dept. of Geology and Geophysics
- DOE Contract Number:
- AC07-78ET28392
- OSTI ID:
- 5285736
- Report Number(s):
- DOE/ET/28392-46
- Country of Publication:
- United States
- Language:
- English
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Part I - Geology and Geochemistry of the Roosevelt Hot Springs - A Summary. Part II - Geophysics of the Roosevelt Hot Springs Thermal Area, Utah. Part III - Roosevelt Hot Springs Area Field Trip
Related Subjects
CALCITE
ISOTOPE RATIO
CARBONATES
ROOSEVELT HOT SPRINGS
GEOCHEMICAL SURVEYS
SILICATES
THERMAL WATERS
GEOTHERMOMETRY
WATER SPRINGS
AMPHIBOLE
BIOTITE
CARBON ISOTOPES
CLAYS
FELDSPARS
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GEOLOGY
GRANITES
HYDROGEN ISOTOPES
HYDROTHERMAL ALTERATION
MINERALS
OXYGEN ISOTOPES
QUARTZ
ROCKS
SAMPLING
UTAH
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CHALCOGENIDES
CHEMISTRY
IGNEOUS ROCKS
KGRA
MICA
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
PLUTONIC ROCKS
ROCKY MOUNTAIN REGION
SILICON COMPOUNDS
SILICON OXIDES
SURVEYS
USA
Geothermal Legacy