LATE-GLACIAL TO HOLOCENE HYDROLOGIC RECONSTRUCTION USING LAKE SEDIMENTS FROM ABBOTT LAKE, CALIFORNIA

This study reconstructs the late-Glacial to Holocene hydrologic variability of central coastal California using sediment cores extracted from Abbott Lake in Monterey County, California. Since Abbott Lake is one of only a few natural, permanent lakes between coastal southern and central California, it serves as an important location for extending the knowledge of past hydrologic variability along the coast of western United States. To reconstruct past hydrologic variability for this region, two sediment cores were collected from Abbott Lake. These cores reveal a complex sedimentological history indicative of large amplitude hydrologic change. A multi-proxy methodology was used including surface mapping, differential GPS, magnetic susceptibility, organic and carbonate content, and grain size. In addition, freshwater gastropods within the sediment cores were analyzed for δ¹⁸O_(calcite) to infer past evaporative conditions. Age control for the study is based on multiple AMS ¹⁴C dates on discrete terrestrial organic matter. The results of this study are compared to regional records of hydrologic variability. Specifically, this comparison will assess the spatial and temporal relationship of hydrologic change across coastal southern and central California as well as Wise’s (2010) proposed western United States hydrologic latitudinal dipole.