Geothermal resource analysis in Twin Falls County, Idaho

Technical Report · Mon Oct 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6159385· OSTI ID:6159385

Baker, S J; Castelin, P M

Thermal water is prevalent throughout central Twin Falls County. Most wells and springs that occur in the area produce thermal water from fractures in the Idavada Volcanics. However, in an area east of Hollister, thermal water issues from fractures in the Paleozoic rocks. In an attempt to explain the hydrothermal relationship between these two reservoir rocks, one composite model for the entire geothermal system in the area is proposed. As with other conceptual models of the system, available geologic, hydrologic, and geochemical data were used to develop the model. The chemistry of the thermal water appears to be strongly governed by the chemical composition of the rocks that it comes in contact with and the length of time that it is exposed to them. The shorter flow paths to the south appear to occur entirely within the Paleozoic rocks, according to the calcium bicarbonate chemistry of the thermal water. As the flow paths become progressively longer toward the north, the thermal waters apparently encounter the silicic volcanics during their ascent. The chemistries of the thermal waters gradually equilibrate to the new host rock conditions and lose their Paleozoic signatures as exposure time increases. Ultimately, the chemistry of the thermal water changes to a sodium bicarbonate type.

• Research Organization: Idaho Dept. of Water Resources, Boise, ID (USA)
• Sponsoring Organization: DOE/CE
• DOE Contract Number: FC07-88ID12748
• OSTI ID: 6159385
• Report Number(s): DOE/ID/12748-2; ON: DE91005105
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
GEOCHEMICAL SURVEYS
GEOTHERMAL RESOURCES
IDAHO
THERMAL WATERS
GEOCHEMISTRY
GEOLOGIC FORMATIONS
GEOTHERMAL GRADIENTS
TEMPERATURE GRADIENTS
CHEMISTRY
FEDERAL REGION X
NORTH AMERICA
RESOURCES
SURVEYS
USA
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