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，静脉曲张的沉积物以尤其高的速度沿加利福尼亚湾的边缘积聚。 这些沉积物的时间和空间分布仍有待确定，因此对它们的起源有充分的理解是不确定的。 Karlin博士在DSDP站点480上研究了这些材料的地球化学和古磁特征。目前的奖项是为了重新置换该站点并参加了90年6月的Coring Cruise，以增强此数据集。 他有五个目标：1）在480站点上完善古磁时间尺度，校准将在WHOI上测量的Delta O18记录，以及与A. Soutar（Scripps）在同类工作中合作的自动化Varve-counting技术。盒子将于6月收集； 2）从XRF和LECO地球化学分析中，重建了最后250台生产率，海洋循环和大陆气候的统计； 3）检查即将到来的活塞芯中记录的古磁性世俗变异的最后20公里，与AMS C14，Delta O18和Varve计数约会； 4）结合岩石磁性，沉积学和地球化学研究，以评估成岩作用对迅速沉积沉积物中记录的古磁信号的保真度的影响； 和5）使用类似的岩石磁和地球化学分析来表征加利福尼亚湾生产率和陆源输入的空间和时间变化的最后20公里。