Water Sampling At Long Valley Caldera Geothermal Area (McKenzie & Truesdell, 1977)

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Exploration Activity: Water Sampling At Long Valley Caldera Geothermal Area (McKenzie & Truesdell, 1977)

Exploration Activity Details
Location Long Valley Caldera Geothermal Area
Exploration Technique Water Sampling
Activity Date 1976 - 1976

Usefulness useful
DOE-funding Unknown

Exploration Basis
The study investigated corrections that could be applied to the sulfate geothermometer (Fournier, 1976) to account for the effects of subsurface boiling and dilution, in order to increase the effective temperature range of the geothermometer from 100-200°C to 140-350°C. This range encompasses the temperature range of greatest interest in geothermal exploration/production. Analysis and geothermometry are described as applied to the Yellowstone, WY, Long Valley, CA, and Raft River, ID geothermal systems.
Spring and well water samples were collected by Lawrence M. Willey during a geochemical sampling survey published in 1976 (Mariner and Willey, 1976). Details of sampling practices and field treatment are detailed in the text. Waters analyzed from the Long Valley Caldera include samples taken from the Casa Diablo Magma-Ritchie No. 5 geothermal well, Hot Creek spring, and unnamed hot spring GT 31. All of these waters were apparently of mixed composition between thermal water and dilute near-surface meteoric water, and so application of the sulfate isotope geothermometer yielded minimum reservoir temperature estimates from 184° to 246°C, with the highest temperature estimate obtained from the Magma-Ritchie No. 5 well.

Additional References