Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah

Technical Report · Thu May 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/5285736· OSTI ID:5285736

Rohrs, D T; Bowman, J R

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

Related Subjects

15 GEOTHERMAL ENERGY
ALKALINE EARTH METAL COMPOUNDS
AMPHIBOLE
BIOTITE
CALCITE
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBON ISOTOPES
CARBONATES
CHALCOGENIDES
CHEMISTRY
CLAYS
FELDSPARS
GEOCHEMICAL SURVEYS
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GEOLOGY
GEOTHERMOMETRY
GRANITES
Geothermal Legacy
HYDROGEN ISOTOPES
HYDROTHERMAL ALTERATION
IGNEOUS ROCKS
ISOTOPE RATIO
KGRA
MICA
MINERALS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PLUTONIC ROCKS
QUARTZ
ROCKS
ROCKY MOUNTAIN REGION
ROOSEVELT HOT SPRINGS
SAMPLING
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SURVEYS
THERMAL WATERS
USA
UTAH
WATER SPRINGS