This project is requested for a two-year investigation of the geochemical, geochronological, and isotopic characteristics of Mesozoic plutonic rocks from the central and western Mojave Desert of southern California. The main purpose of this study is to gather data that can be used to test models for the tectonic, magmatic, and paleogeographic evolution of southern California. For example, several major strike-slip and thrust faults are proposed to pass through the Mojave Desert. These faults, if present, should produce noticeable discontinuities in the age and isotopic character of Mesozoic plutonism. At present there are virtually no data that can be used to test these hypotheses. All major plutonic phases will be studied in a transect running from the western tip of the Mojave Desert to the north-central Mojave Desert northeast of Barstow, California. Sample collection will be based on (1) ongoing detailed mapping by coworkers in the central Mojave Desert, and (2) detailed mapping by the P.I. and his students. The results of this study will be useful to workers in several major ongoing projects in areas bordering the Mojave Desert, including the southern Sierra Nevada, the eastern Mojave Desert, and the Transverse and Peninsular Ranges.
