This project is a collaborative multidisciplinary tectonic investigation of the Mojave Desert region of southern California that will be conducted by workers at the University of Utah (EAR89-16838, The University of Kansas (EAR89-16802) and the University of North Carolina (EAR89-17291). The study will assess the continuity of a late Jurassic fold-thrust belt found in the Cronese Hills that may continue to the southwest and will determine how much Cretaceous and younger overprint there may be on this tectonic belt. The magnitude and spatial distribution of Tertiary extension in the Central Mojave will be studied. The work will focus on field mapping, geochronology and metamorphic petrology of pre-Tertiary rocks in the western Mojave and mapping, geochronology and basin analysis of mid-Tertiary syntectonic deposits in the central Mojave. Results will contribute to regional tectonic syntheses of southwestern North America and to characterization of processses governing the tectonic evolution of continental-margin orogens and the large- scale superimposed extension of the crust.