Date of Award
Master of Science
Geological and Environmental Sciences
Dr. Christopher J. Schmidt
Dr. W. Thomas Straw
Masters Thesis-Open Access
Sevier thrusting in the White Sulphur Springs area was associated with left-lateral movement along the Lewis and Clark line . During Middle Miocene time, the Lewis and Clark line exhibited right-lateral movement, forming extensional features that either truncated Sevier structures or followed preexisting Sevier zones of weakness.
The Smith River Valley is a pull-apart basin that is filled with Tertiary volcanic ash and clay-rich sediments that are thermally nonconductive relative to surrounding rocks.
Hydrothermal activity in the area is associated with a structurally controlled circulation system accompanied by a high thermal gradient. Thermal discharge is constrained along the north-trending White Sulphur Springs normal fault. Calculated reservoir temperatures ranging from 52° C (Na-K-Ca-Mg) to 99° C (Quartz) indicates that variable degrees of mixing occur. The estimated reservoir temperature (72° C ± 10° C) limits thermal development in the area to space heating and recreational use.
Gierke, "Structural Geology and Geothermal Investigation of the White Sulphur Springs Area, Montana" (1987). Master's Theses. 1217.