High Resolution Paleomagnetic Secular Variation and SedimentHistory in Sediments from the Gulf of California: DSDP Site 480 and Atlantis II Cores

缺氧的各种沉积物正以特别高的速度在加利福尼亚州海湾的边缘堆积。这些沉积物的时间和空间分布仍有待确定，因此，对其来源的充分了解也是不确定的。卡林博士在dsdp 480站点研究了这些物质的地球化学和古地磁特征。目前的奖励是对这一地点进行重新采样，并参加90年6月的取心巡航，以扩大这一数据集。他有五个目标：1)改进480站点的古地磁时间尺度，校准到将在WHOI测量的增量O18记录，并与A.Soutar(Scripps)将于6月收集的盒子岩芯的类似工作合作，校准到自动波峰计数技术；2)根据480站的XRF和LECO地球化学分析，重建了过去250年的生产力、海洋环流和大陆气候：3)检验了即将到来的活塞芯记录的古地磁长期变化的最后20年，用AMS C14、增量O18和VOLE计数进行了测年；4)结合岩石磁学、沉积学和地球化学研究，评估成岩作用对快速沉积沉积物中记录的古地磁信号保真度的影响；以及5)使用类似的岩石磁学和地球化学分析，表征过去20年来生产力和对加利福尼亚州海湾的陆源输入的时空变化。

Anoxic, varved sediments are accumulating along the margins of the Gulf of California at especially high rates. The temporal and spatial distribution of these sediments remains to be determined, and consequently a full understanding of their origin is uncertain. Dr. Karlin has studied the geochemical and paleomagnetic character of these materials at DSDP Site 480. The present award is to resample this Site and to participate on a coring cruise in June '90 to augment this data set. He has five objectives: 1) refine the paleomagnetic time scale at Site 480, calibrating to a delta O18 record that will be measured at WHOI, and to an automated varve-counting technique in collaboration with similar work by A. Soutar (Scripps) on box cores to be collected in June; 2) reconstruct the last 250 Kyrs of productivity, ocean circulation , and continental climate from XRF and LECO geochemical analyses from Site 480; 3) examine the last 20Kyrs of paleomagnetic secular variation recorded in the upcoming piston cores, dating with AMS C14, delta O18 and varve counting; 4) combine rock magnetic, sedimentological and geochemical studies to evaluate the effects of diagenesis upon the fidelity of paleomagnetic signals recorded in rapidly deposited sediments; and 5) use similar rock magnetic and geochemical analyses to characterize the last 20Kyrs of spatial and temporal variations in productivity and terrigenous input to the Gulf of California.