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

加利福尼亚湾沉积物的高分辨率古地磁长期变化和沉积物历史：DSDP Site 480 和 Atlantis II 岩心

• 批准号: 9012586
• 负责人: Robert Karlin
• 金额: $ 9万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-09-01 至 1993-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9012586&HistoricalAwards=false
• 关键词: Resolution; Paleomagnetic; Secular; Variation; SedimentHistory

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.

缺氧、变化的沉积物正在加利福尼亚湾边缘以特别高的速度积累。 这些沉积物的时间和空间分布仍有待确定，因此对其起源的充分了解尚不确定。 Karlin 博士在 DSDP 480 号站点研究了这些材料的地球化学和古磁特征。目前的奖励是对该站点重新采样并参加 90 年 6 月的取芯巡航，以扩充该数据集。 他有五个目标：1) 完善 480 号站点的古地磁时间尺度，校准到将在 WHOI 测量的 delta O18 记录，并与 A. Soutar (Scripps) 合作对 6 月份收集的盒状岩芯进行类似工作，校准自动瓦夫计数技术； 2) 根据 Site 480 的 XRF 和 LECO 地球化学分析重建最近 250 凯尔的生产力、海洋环流和大陆气候； 3) 检查即将到来的活塞核心中记录的最后 20Kyr 的古地磁长期变化，使用 AMS C14、Delta O18 和 varve 计数进行测年； 4）结合岩石磁性、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； 5) 使用类似的岩石磁力和地球化学分析来表征过去 20Kyr 的生产力和对加利福尼亚湾的陆源输入的空间和时间变化。