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说，即加利福尼亚海岸晚更新世期间生物成因碳酸盐堆积的千年级增加是地表水产量变化的结果，而不是差异保存的结果。反过来，生产被认为是由不同的沿海上升流造成的，与大陆气候较干燥的时期相对应的是更强的风和上升流。在过去的500,000年中，将每隔500年对一套ODP型岩芯进行采样，以确定方解石、蛋白石和有机碳的累积速率。将对两个持续时间为150,000的时间片进行浮游有孔虫的分类和同位素组成分析，以确定上升流的程度，并对花粉进行分析，以评估发生的大陆性气候。

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.