Application of heat-flow techniques to geothermal energy exploration, Leach Hot Springs area, Grass Valley, Nevada
A total of 82 holes ranging in depth from 18 to 400 meters were drilled for thermal and hydrologic studies in a 200 km/sup 2/ area of Grass Valley, Nevada, near Leach Hot Springs. Outside the immediate area of Leach Hot Springs, heat flow ranges from 1 to 6.5 hfu with a mean of 2.4 hfu (1 hfu = 10/sup -6/ cal cm/sup 2/ s/sup -1/ = 41.8 mWm/sup -2/). Within 2 km of the springs, conductive heat flow ranges between 1.6 and more than 70 hfu averaging 13.6 hfu. Besides the conspicuous thermal anomaly associated with the hot springs, two additional anomalies were identified. One is associated with faults bounding the western margin of the Tobin Range near Panther Canyon, and the other is near the middle of Grass Valley about 5 km SSW of Leach Hot Springs. The mid-valley anomaly appears to be caused by hydrothermal circulation in a bedrock horst beneath about 375 meters of impermeable valley sediments. If the convective and conductive heat discharge within 2 km of the Leach Hot Springs is averaged over the entire hydrologic system (including areas of recharge), the combined heat flux from this part of Grass Valley is about 3 hfu, consistent with the average regional conductive heat flow in the Battle Mountain High. The hydrothermal system can be interpreted as being in a stationary stable phase sustained by high regional heat flow, and no localized crustal heat sources (other than hydrothermal convection to depths of a few kilometers) need be invoked to explain the existence of Leach Hot Springs.
- Research Organization:
- Geological Survey, Washington, DC (USA); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- OSTI ID:
- 6548788
- Report Number(s):
- USGS-OFR-77-762; LBL-6809
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NEVADA
GEOTHERMAL EXPLORATION
HEAT FLOW
BOREHOLES
DIAGRAMS
DRILL CORES
GEOLOGY
HOT SPRINGS
HYDROLOGY
HYDROTHERMAL SYSTEMS
KGRA
LITHOLOGY
NATURAL CONVECTION
POROSITY
TABLES
TEMPERATURE LOGGING
THERMAL CONDUCTIVITY
CAVITIES
CONVECTION
DATA FORMS
EXPLORATION
GEOTHERMAL SYSTEMS
NORTH AMERICA
PHYSICAL PROPERTIES
THERMAL SPRINGS
THERMODYNAMIC PROPERTIES
USA
WELL LOGGING
WESTERN REGION
Geothermal Legacy
150301* - Geothermal Exploration & Exploration Technology- Geophysical Techniques & Surveys