The city of Gabbs is located on the eastern edge of Gabbs Valley where it abuts the Paradise Range, which is host to a complex assortment of mineral deposits, the most important being magnesite. Both North and South Gabbs, and municipal wells, are situated within the low Quaternary alluvium within one-half mile of the range front. Gabbs was originally settled during World War II when emergency mining and milling operations were undertaken by the Federal Government to extract magnesium, and Basic, Inc. (later C.E. Basic) took over the facilities in 1948 (Geothermal Development Associates, 1981). Extensive information on the mineralogy and geology of Gabbs and the Paradise Range is available in Cleveland (1963, 1964), Dockery (1982), Humphrey and others (1958), John and others (1988), Lee (1962), Martin and Willard (1956), Meinwald (1982), Mitchell (1991), Oldow and Lallement (1993, 1994), Ridgley and Hardyman (1993), Schilling (1967), Stewart and others (1999), Thomason (1986), Vitaliano (1947, 1963, 1966, 1970, 1971) and Weaver (1982).
Many water wells drilled for a water supply for the magnesite-brucite mine and mill of Basic, Inc. near the town site of Gabbs have abnormally high water temperatures, 21-68.3°C (Eakin, 1962b), although Pillsbury measured the well temperatures as ranging between 47-68ºC with Na-K-Ca geothermometer estimates of 76-85ºC (Geothermal Development Associates, 1981). Mariner estimated the mean reservoir temperature to be 53ºC (Mariner and others, 1982, p. 47). Well depths range from 51-175 m. Geothermal fluids were collected from well no. 10, which was completed to a depth of 60 m. The water temperature at the time of collection was 60ºC (Trexler and others, 1987, p. 16). The northern most well is the city’s current water source and it was sampled in April 2006. Its temperature upon sampling was 20°C (12N 36E Sec. 22).
Some water must be cooled in cooling towers before use. As the water is reportedly high in fluoride, bottled water is supplied by the local water company for drinking (Nevada State Journal, July 20, 1977). The thermal wells are located in Sec. 28, T13N, R36E, and Secs. 22, 27, 28, 33, Tl2N, R36E, in a north-trending zone at least 8 km long. This zone coincides in part with a north-trending fault along the west edge of the Paradise Range.
In 1981, the Nevada Department of Energy contracted with Geothermal Development Associates to prepare a plan for geothermal utilization in Gabbs. In 1986, C.E. Basic was using the wells not only for their water, but also as a source of process heat for the magnesite mill (Geothermal Resources Council Bulletin, 1986). More recently, the water has been cooled before use at the mill.
Photos
Gabbs cooling tower, cooling tower for mill water supply.