POST PLIOCENE DETACHMENT ON THE EASTERN SIDE OF THE COYOTE MOUNTAINS, SALTON TROUGH, SOUTHERN CALIFORNIA

On-going mapping in the Coyote Mountains on the western side of the Salton Trough indicates that a post-Pliocene Imperial Group aged detachment formed during the continuing opening and deepening of the Salton Trough. In the area mapped, the first unit above the detachment surface is a marine mudstone of the Pliocene Imperial Group. Rocks below and cut by the detachment surface are; a basal conglomerate of the Pliocene Imperial Group, the Miocene Alverson Volcanics, and, possibly. the metamorphic rocks that make up the core of the Coyote Mountains. The detachment was then cut and folded by movement along northwest, primarily right-lateral faults that are associated with the Elsinore Fault. Uplift of the Coyote Mountains along these right-lateral faults preserves the detachment in graben valleys on the eastern side of the Coyote Mountains.