USING LAKE SEDIMENTS TO INFER LATE-GLACIAL HYDROLOGIC CONDITIONS OF PLUVIAL LAKE MOJAVE, CALIFORNIA

Silver Lake is an intermittent playa located in the Mojave Desert of Southern California (Figure 1). Silver Lake’s predecessor is Lake Mojave, a pluvial lake that occupied the basin during the late Pleistocene (ca. 25 ka) through the Early Holocene (ca. 8 ka). The hydrologic setting and depositional history of Lake Mojave makes it well suited to record the past winter precipitation in the San Bernardino Mountains and possibly the late summer/early fall North American Monsoon in the Mojave Desert. The Mojave River is the primary source of inflow for Silver Lake, its headwaters draining the San Bernardino Mountains and surrounding desert drainage basin. The hydrologic and climatic conditions necessary to sustain Lake Mojave are significantly different than the prevailing modern climatic conditions. Lacustrine sediments deposited in the basin present an opportunity to reconstruct the variable states (e.g., deep vs. shallow) of Lake Mojave and their relationship to climatic forcings such as insolation and Atlantic Meridional Overturning Circulation. A newly acquired 23 m sediment core from the lake’s depocenter will serve as the basis for a paleohydrologic investigation of this region. This thesis will focus on 4.2 m section of mud spanning ca. 21 to 14 ka. A multi-proxy approach will be used to infer past lake dynamics. Age control will be determined on AMS C-14 dated ostracods.