Geologic map of the Granite Peak and Sapphire Mountain Area, U.S. Army Dugway Proving Ground, Tooele County, Utah (M-238)

By: D. L. Clark, R. F. Biek, G. C. Willis, K. D. Brown, P. A. Kuehne, J. B. Ehler, and C. L. Ege

Granite Peak and Sapphire Mountain are range blocks composed of igneous and metamorphic rocks located on the southeast margin of the Great Salt Lake Desert in the northeastern Great Basin. These mountains are unique, in part because they have undergone relatively little detailed geologic study as a result of their location within the U.S. Army Dugway Proving Ground since 1942. Exploration and mining activities for base metals and other commodities occurred on Granite Peak in the late 1800s and early 1900s.

At the request of the U.S. Army Dugway Proving Ground, Special Programs Division, the Utah Geological Survey conducted geologic mapping of the Granite Peak and Sapphire Mountain area. This mapping was performed in August 2005 using standard field mapping methods and aerial photographs provided by Dugway Proving Ground personnel. The geologic map data were placed on a composite topographic base map at 1:24,000 scale that we prepared by combining parts of four U.S. Geological Survey 7.5' topographic maps. This map is based on limited field mapping and aerial photograph interpretation. Because the mapping was conducted under a shortened schedule, the geology depicted does not everywhere meet 1:24,000-scale geologic map standards. Much of this geologic mapping data has been incorporated into smaller-scale geologic maps of Dugway Proving Ground and adjacent areas.

Other Information:
Published: 2009
Plates: 2 pl.
Scale: 1:24,000
Location: Tooele County
Media Type: Paper Map