Southern Big Smoky Valley (Alum) (updated 2005)

Three widely separated wells in the southern part of Big Smoky Valley are reported to have slightly anomalous water temperatures. The Emigrant well (NW¼ Sec. 6, T1N, R38E) had a reported temperature of 25ºC (Trexler and others, 1979, Table 1) or 26.7ºC (Rush and Schroder, 1970). It is reportedly 98.7 m deep and first encountered water at 93.9 m. An unnamed 166.4-m-deep well (NW¼ Sec. 14, T1N, R37E) had a reported temperature of 21.7 ºC. The Fishlake Livestock Co. well (SE¼ SE¼ Sec. 5, T1S, R39E) was reported to have a 0.63 L/min flow of hot water at 50.3 m; it was reported destroyed (Rush and Schroder, 1970). It appears that this well is in the vicinity of a geothermal anomaly defined by gradient-hole drilling (See GeothermEx, 2004, Alum-Silver Peak prospect). The maximum temperature encountered in drill holes was 118.3ºC at 453.8 m Geothermometry suggests a higher temperature geothermal system at depth (GeothermEx, 2004). The geothermal anomaly is centered on the Alum Mine (SE¼ SW¼ Sec. 29, T1N, R38½E, protracted on the Goldfield 30´x60´ topographic map), where native sulfur was mined in the 1920s. Native sulfur at the Alum Mine is found as crystals coating fractures in an altered rhyolite dike; potassium alum is also present as veins (Spurr, 1904; Branner, 1959). The deposit is apparently latest Pleistocene, as alunite associated with the sulfur has been dated by K-Ar methods at 0.29±0.01 Ma (Vikre, 2000, p. 751).

Chemistry