Mineral resources of the South Reveille Wilderness Study Area, Nye County, Nevada

At the request of the U.S. Bureau of Land Management, 33,000 acres of the South Reveille Wilderness Study Area in the southern part of the Reveille Range in south-central Nevada were studied. In this report, the area studied is referred to as "the wilderness study area", or simply "the study area." Rhyolitic tuff and quartz latite intrusive rocks are the dominant rock types. There has been no mining within the wilderness study area; however, several mining camps, including Reveille and New Reveille in the Reveille mining district, lie close-by to the north. Near the southern boundary of the study area, a 30-ft shaft was sunk in a low-grade goldand silver-bearing quartz vein. No resources were identified in the study area. Field work and geochemical sampling revealed one mineralized area that lies astride the southern boundary of the study area. Most of the mineralized area has low mineral resource potential for gold and silver in vein deposits, except for the central core, which has moderate resource potential for the same metals. Character and Setting The study area includes approximately 33,000 acres in a mountainous part of the southern half of the Reveille Range in south-central Nevada (fig. 1). The elevation ranges from 8,910 ft at Reveille Peak to about 5,160 ft along the eastern boundary of the study area. Because the climate in the region is semiarid, stream channels are characteristically dry and littered with unconsolidated siltto boulder-sized material. The Reveille Range, a north-northwest-trending uplifted fault block within the Basin and Range physiographic province, is bounded by the Reveille Valley graben on the west and by the Railroad Valley graben on the east. Rocks exposed in the range consist of Paleozoic (505 to 245 million years before present (Ma)) sedimentary strata and Tertiary (26.1 to 3.8 Ma) tuff and basalts (see Geologic Time Chart, last page of report). The study area contains only Tertiary rocks. Identified Mineral Resources and Mineral Resource Potential A single mineralized area was identified in the study area. Thte area is located within the southernmost 2 mi of the Reveille Range, mostly within the study area. It is defined by a goldand silver-bearing quartz vein, highly fractured and bleached rhyolite, and a 3,000-ft-long by 1,800-ft-wide area of iron-stained rhyolite containing low concentrations of arsenic, an element commonly associated with gold in this geologic environment. The southern 2 mi of the Reveille Range has moderate resource potential for gold and silver. The surrounding 6 mi have low resource potential for the same metals.