New Geologic Map—Black Warrior Geothermal Area, Washoe and Churchill Counties
Preliminary Geologic Map of the Truckee Range, Black Warrior Geothermal Area, Washoe and Churchill Counties, Nevada
Authors: Andrew J. Sadowski and James E. Faulds
Series: Open-File Report 2016-07
Version: first edition, July 2017
Format: map: 40 x 30 inches, color, cross sections; text: 12 pages, color
The Black Warrior geothermal system lies 20 km east of the southern end of Pyramid Lake in the Truckee Range of northwestern Nevada. It is an amagmatic blind geothermal system, lacking hydrothermal surface manifestations (no fumaroles, hot springs, sinter deposits, or high temperature alteration) and also lacks recent (<5 Ma) volcanism. The system was discovered through temperature gradient drilling (100–600 m depth) by Phillips Petroleum Company in the 1980s (Sass et al., 1999). The Black Warrior area, synonymous with the North Valley prospect, exhibits a maximum observed temperature of ~128°C at 552 m surrounded by elevated temperature gradients (figure 2). Also, a weak shallow anomaly was observed with a 2-m temperature survey circa 2009 (Kratt, personal communication).
The 1:24,000-scale geologic map of the Black Warrior geothermal area showcases the results of detailed stratigraphic and structural analyses. The map focuses on the Truckee Range in northwestern Nevada and covers portions of four adjoining 7.5-minute quadrangles: Black Warrior Peak, Russell Peak, Nixon, and Juniper Peak. The detailed map was produced to evaluate the structural controls of the Black Warrior geothermal system and overall geothermal potential of the area (Sadowski and Faulds, 2015; Sadowski, 2016).
Ultimately, the structural relationships at Black Warrior may help to guide exploration efforts for other blind geothermal systems in the Great Basin region and other extensional settings.
This map was prepared with support from the Great Basin Center for Geothermal Energy, the U.S. Department of Energy, Nevada Petroleum and Geothermal Society, American Association of Petroleum Geologists, and Geological Society of America.