Mineral resources of the Palen-McCoy Wilderness Study Area, Riverside County, California

The Palen-McCoy Wilderness Study Area (CDCA3Z5) is an area of about 81,000 acres located 20 mi west-northwest of Blythe and 15 mi east of Desert Center in the Mojave Desert of southeastern California. Geologic, geochemical, geophysical, and mineral surveys of the wilderness study area were conducted by the U.S. Geological Survey and the U.S. Bureau of Mines between 1981 and 1984 in order to appraise the identified mineral resources and to assess the mineral resource potential of the area. These surveys indicate that the Palen-McCoy Wilderness Study Area has identified resources of iron and pyrophyllite, that a small part of the area has high resource potential for iron, and that a small part of the area has moderate resource potential for pyrophyllite. The entire wilderness study area has low potential for copper, uranium, manganese, and clay, and unknown potential for oil, gas, and geothermal energy. Character and Setting The Palen-McCoy Wilderness Study Area includes the southern part of the Palen Mountains and the broad valley that lies between that range and the McCoy Mountains to the east (fig. 1). The southern Palen Mountains are composed of Jurassic(?) and Cretaceous metasedimentary and minor metavolcanic rocks (McCoy Mountains Formation of Miller, 1944) and a structurally overlying andesite-diorite complex. The remainder of the study area is covered by Quaternary alluvium that is underlain locally by Tertiary sedimentary rocks.