Collaborative Research: Millennial-Scale Carbonate Deposition Events Along the California Margin and Their Links to Paleoceanography and Paleoclimate

本项目将检验这一假设，即加州海岸更新世晚期生物碳酸盐积累的千年尺度增加是由于地表水生产的变化，而不是由于差异保存。 生产反过来被假定为已导致不同的沿海上升流，与强风和上升流对应的时间干燥的大陆性气候。 在过去的50万年里，将以500年的间隔对一套ODP岩心进行取样，以确定方解石、蛋白石和有机碳的积累速率。 将分析两个150，000持续时间的时间切片，以确定上涌程度的南极有孔虫的分类和同位素组成，并对花粉进行分析，以评估同时发生的大陆性气候。

SUMMARYThis 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.