From abstract: Pegmatite occurs widely in Nevada and northwestern Arizona, but little mining has been done for such pegmatite minerals as mica, feldspar, beryl, and lepidolite. Reconnaissance for beryl-bearing pegmatite in Nevada and in part of Mohave County, Ariz., and detailed studies in the Dawley Canyon area, Elko County, Nev., have shown that beryl occurs in at least 11 districts in the region. Muscovite has been prospected or mined in the Ruby and Virgin Mountains, Nev., and in Mohave County, Ariz. Feldspar has been mined in the southern part of the region near Kingman, Ariz., and in Clark County, Nev.

This is a preliminary geologic map of a section of the Nevada Test Site.

The Topopah Spring and Timber Mountain 15-minute quadrangles comprising about 500 square miles in southern Nye County, Nev., are bounded by longitudes 116°15' W. and 116°30' W. and by latitudes 36°45' N. and 37°15' N. (fig. 1) The quadrangles are mostly within the Nevada Test Site and are approximately 90 miles northwest of Las Vegas (fig. 1). Lathrop Wells, the nearest town, is about 10 miles south of the southern boundary of the Topopah Spring quadrangle.

From introduction: The maps and tables comprising this report are being transmitted at this time to provide interested users with a summary of the geology of the Ul2e tunnel system. The system was constructed to provide access to underground test sites. This report contains part of the geologic information obtained from investigations conducted by the U. S. Geological Survey to determine the geologic environment of the underground test sites. Results of geophysical and radiometric surveys, and physical properties are being studied. This work was done on behalf of the U. S. Atomic Energy Commission.