Recent studies have suggested that the Triassic to middle Jurassic arc of the southwest Cordilleran United States occupied an extensional graben from the Klamaths to the Sonoran Desert. Preliminary work indicates that the arc may also have been the site for large-scale sinestral rifting in the Mojave Desert to Sonoran Desert portion, with continued transpression in the northern portion. This project will conduct detailed sedimentologic and geochronlogical studies aimed at testing these working hypothesis. Results may demonstrated the importance and timing of both transtension and transpression along the Menozoic arc of the southwestern United States.
