Darroughs Hot Springs are located in Sec. 7 and 8 T11N, R43E in Big Smoky Valley about 97 km north of Tonopah, where the hot spring waters are used for a spa. The hot springs discharge several hundred liters per minute of water that is near the boiling point for that elevation. A 247.5-m-deep well drilled in 1962 (and redrilled in 1963) by Magma Power Co. and associates encountered temperatures up to 129.4°C with a very large flow of water and minor steam (Koenig, 1970). Ranch wells have also hit boiling water at shallow depths; water from one well at the hot springs was reportedly used to heat a ranch house in the 1970s. Anomalous radioactivity (75 µR/hr) is reported from near the edge of a fenced pool (Wollenberg, 1974b). Travertine and a trace of siliceous sinter are reported (Mariner and others, 1974).
The springs issue from valley fill on an alluvial fan. The mountain front, about 2.4 km to the west, is a fault scarp of a major basin-and-range fault along the east side of the Toiyabe Range. The amount of displacement on this fault is unknown. Fiero (1968) has suggested that the hot springs are along a fault parallel to this major fault, whereas Trexler and others (1980) suggest that the geothermal area is located along the northerly extension of a range-front fault segment. Best estimates for thermal aquifer temperatures at Darroughs Hot Springs from several chemical geothermometers are in the 93-135°C range. The upper limit of the range was nearly attained in the Magma well. Geophysical data for Darroughs Hot Springs are reported in Kaufmann (1976), Long and others (1976), O'Donnel (1976), and Peterson and Dansereau (1976a).
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