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

Abstract

At request of U.S. Bureau of Land Management, 33,000 acres of South Reveille Wilderness Study Area in southern part of Reveille Range in south-central Nevada were studied. In this report, area studied is referred to as the wilderness study or simply the study Rhyolitic tuff and quartz latite intrusive rocks are dominant rock types. There has been no mining within wilderness study area; however, several mining camps, including Reveille and New Reveille in Reveille mining district, lie close-by to north. Near southern boundary of study area, a 30-ft shaft was sunk in a low-grade goldand silver-bearing quartz vein. No resources were identified in study area. Field work and geochemical sampling revealed one mineralized area that lies astride southern boundary of study area. Most of mineralized area has low mineral resource potential for gold and silver in vein deposits, except for central core, which has moderate resource potential for same metals. Character and Setting The study area includes approximately 33,000 acres in a mountainous part of southern half of Reveille Range in south-central Nevada (fig. 1). The elevation ranges from 8,910 ft at Reveille Peak to about 5,160 ft along eastern boundary of study area. Because climate in 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 Basin and Range physiographic province, is bounded by Reveille Valley graben on west and by Railroad Valley graben on east. Rocks exposed in 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 study area. Thte area is located within southernmost 2 mi of Reveille Range, mostly within 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 Reveille Range has moderate resource potential for gold and silver. The surrounding 6 mi have low resource potential for same metals.