This project will test the hypothesis that millenial-scale increases in biogenic carbonate accumulation during the Late Pleistocene off the coast of California resulted from changes in surface water production, rather than from differential preservation. The production in turn is postulated to have resulted from varying coastal upwelling, with stronger winds and upwelling corresponding to times of drier continential climate. A suite of ODP cores will be sampled at 500-year intervals over the last 500,000 years to determine accumulation rates of calcite, opal and organic carbon. Two time slices of 150,000 duration will be anlayzed for taxonomic and isotopic composition of planktic foraminifera to determine degree of upwelling, and for pollen to assess cor-occurring continental climate.
