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, William G., "Structural Geology and Geothermal Investigation of the White Sulphur Springs Area, Montana" (1987). Masters Theses. 1217.