A core hole into the hydrothermal system of the Long Valley caldera

Conference · Sun Mar 01 00:00:00 EST 1987

OSTI ID:5319546

Wollenberg, H; White, A; Flexser, S; Sorey, M; Farrar, C

To investigate the present-day hydrothermal system, the ''Shady Rest'' hole was continuously cored 715m into the southwestern moat of the Long Valley caldera. The hole intersected 100m of glacial till and 300m of postcaldera rhyolite before entering the welded Bishop Tuff and bottoming in that unit. A sharp temperature rise over the upper 350m, and near-isothermal conditions below reflect the presence of approx.200/sup 0/C water moving through open, calcite-lined fractures in silicified Early Rhyolite and Bishop Tuff. The depth to the Bishop is the shallowest encountered in holes in the caldera, and the temperatures measured are among the hottest observed in wells drilled within the caldera.

• Research Organization: Lawrence Berkeley Lab., CA (USA); Geological Survey, Menlo Park, CA (USA); Geological Survey, Santa Rosa, CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5319546
• Report Number(s): LBL-24569; CONF-8703199-1; ON: DE88006335
• Resource Relation: Conference: Symposium on the Long Valley caldera: pre-drilling data review, Berkeley, CA, USA, 17 Mar 1987
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
GROUND WATER
CHEMICAL COMPOSITION
HYDROTHERMAL SYSTEMS
TEMPERATURE SURVEYS
LONG VALLEY
HYDROLOGY
CALDERAS
DRILL CORES
SITE CHARACTERIZATION
TEMPERATURE GRADIENTS
CALIFORNIA
ENERGY SYSTEMS
FEDERAL REGION IX
GEOPHYSICAL SURVEYS
GEOTHERMAL SYSTEMS
HYDROGEN COMPOUNDS
NORTH AMERICA
OXYGEN COMPOUNDS
SURVEYS
USA
WATER
Geothermal Legacy