Core Holes At Long Valley Caldera Geothermal Area (Eichelberger, Et Al., 1988)
Exploration Activity: Core Holes At Long Valley Caldera Geothermal Area (Eichelberger, Et Al., 1988)
|Exploration Activity Details|
|Location||Long Valley Caldera Geothermal Area|
|Exploration Technique||Core Holes|
|Activity Date||1987 - 1988|
Three additional core holes were drilled in the caldera's west moat in 1987-1988, including the INYO-4 (a.k.a. RDO-10) well 216 m southwest of the Inyo Craters and the MLGRAP-1 and -2 temperature gradient holes near the town of Mammoth Lakes. These wells were drilled as part of scientific investigations (in the case of INYO-4) and to investigate the feasibility of using thermal waters beneath Mammoth Lakes for direct use (MLGRAP-1 and -2).
INYO-4 was a 22° slant hole drilled to 854 m depth (610 m vertical depth) in July 1987, with a maximum temperature of 80°C measured in a thick early rhyolite flow at 490 m (vertical) depth (Eichelberger et al., 1988). MLGRAP-1 and -2 were drilled between November 1987 and January 1988 to depths of about 468 and 491 m, respectively, with maximum temperatures of 75°C encountered in the bottom of each hole (Sorey et al., 1991). Data from these wells have been used to constrain the extent of hydrothermal circulation beneath the caldera's west moat presented in more recent conceptual models of the larger hydrothermal system (Sorey et al., 1991).
- John C. Eichelberger, Thomas A. Vogel, Leland W. Younker, C. Dan Miller, Grant H. Heiken, Kenneth H. Wohletz (1988) Structure and Stratigraphy Beneath a Young Phreatic Vent: South Inyo Crater, Long Valley Caldera, California
- Michael L. Sorey, Gene A. Suemnicht, Neil C. Sturchio, Gregg A. Nordquist (December 1991) New Evidence On The Hydrothermal System In Long Valley Caldera, California, From Wells, Fluid Sampling, Electrical Geophysics, And Age Determinations Of Hot-Spring Deposits