Molybdenum mineralization in an active geothermal system, Valles caldera, New Mexico
Shallow, sub-ore-grade molybdenite mineralization has been discovered in the active, high-temperature geothermal system penetrated by Continental Scientific Drilling Program corehole VC-2A at Sulfur Springs, in the western ring-fracture zone of the Valles caldera, New Mexico. This mineralization is hosted by fractured, quartz-sericitized, intracaldera ash-flow tuffs younger than 1.12 Ma. The molybdenite is an unusual, poorly crystalline variety that occurs in vuggy veinlets and breccia cements also containing quartz, sericite (illite), pyrite, and fluorite, as well as local sphalerite, rhodochrosite, and chalcopyrite. Fluid-inclusion data suggest that this assemblage was deposited from very dilute solutions at temperatures near 200/sup 0/C. Geochemical modeling indicates that under restricted pH and fO/sub 2/ conditions at 200/sup 0/C, the molybdenite and associated phases would be in equilibrium with hydrothermal fluids now circulating in the deep subsurface. The shallow molybdenite zone intersected in VC-2A may be the near-surface expression of deep, Climax-type stockwork molybdenum mineralization.
- Research Organization:
- Univ. of Utah Research Institute, Salt Lake City (USA)
- OSTI ID:
- 5360698
- Journal Information:
- Geology; (United States), Vol. 15:8
- Country of Publication:
- United States
- Language:
- English
Similar Records
Initial results from VC-1, first Continental Scientific Drilling Program core hole in Valles caldera, New Mexico
Scientific core hole Valles caldera No. 2b (VC-2b), New Mexico
Related Subjects
GEOTHERMAL RESOURCES
GEOCHEMISTRY
MOLYBDENUM
MINERALIZATION
NEW MEXICO
DRILL CORES
GEOLOGIC MODELS
HYDROTHERMAL SYSTEMS
MINERALOGY
MINERALS
RESERVOIR FLUIDS
RESERVOIR TEMPERATURE
WELL DRILLING
CHEMISTRY
DRILLING
ELEMENTS
ENERGY SYSTEMS
FEDERAL REGION VI
FLUIDS
GEOTHERMAL SYSTEMS
METALS
NORTH AMERICA
RESOURCES
TRANSITION ELEMENTS
USA
150201* - Geology & Hydrology of Geothermal Systems- USA- (-1989)