Geophysical investigations of ground water flow associated with the Saratoga warm springs and the Tecopa hot springs near Death Valley California.

摘要

Electrical and ground magnetic surveys at Saratoga Springs in southern Death Valley, California and Tecopa hot springs in the vicinity of Death Valley reveal faults that may control the ground water flow. Magnetic and conductivity data reveal intersecting east and north striking faults at Saratoga Springs. Similarly northwest and northeast trending intersecting faults in the Precambrian basement have been identified at Isolated Spring (Tecopa hot springs). High conductivity and low resistivity values along the inferred faults at Saratoga Springs indicate that these faults provide conduits for ground water flow. A high conductivity anomaly along the northwest trend at Tecopa hot springs suggests a near surface flow of water from the hot springs along the bedrock. This water is cooled by mixing with the shallow aquifer. A deep groundwater flow along faults allows water to be heated as it traverses high temperature rock and accounts for the water temperature of about 41°C at Tecopa hot springs at the bath and lower temperatures in springs nearby. The ground water path suggested in a model by Mifflin (1988) requires Saratoga Springs water temperature to be above 41°C due to the longer flow path from the Spring Mountains. However Saratoga Springs and Isolated Spring water temperatures are about 30°C and 36°C, respectively. It is likely that cold water from the Amargosa River percolates downward and flows along the east trending fault south of Saratoga hills. This cold water mixes with hot water rising at the fault intersection and this accounts for the lower water temperature at Saratoga as compared to Tecopa. A similar scenario occurs at the Isolated Springs at Tecopa hot springs.