Paleomagnetism of Glacial Diamictons and Subglacially Deformed Sediment

冰川多聚体和冰下变形沉积物的古地磁学

• 批准号: 8816097
• 负责人: John Ridge
• 金额: $ 5万
• 依托单位: Tufts University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-01 至 1991-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816097&HistoricalAwards=false
• 关键词: Paleomagnetism; Glacial; Diamictons; Subglacially; Deformed

Remanent magnetization directions in glacial diamictons have not been tested against established records of the geomagnetic field at the time and place of deposition and the accuracies of diamictons as geomagnetic field recorders have not been determined. An established record of Late Wisconsinan geomagnetic declination, from DRM in varved sediment in the western Mohawk Valley, New York, will be used to test the fidelity of remanence from contemporaneous till, sediment flow deposits, pelagic rainout diamicton, and subglacially deformed lacustrine beds. In addition to remanence, anisotropy of magnetic susceptibility (AMS) and anisotropy of anhysteretic susceptibility (AAS) will be measured. AMS will be used to determine fabrics dominated by coarse particles that carry a viscous remanence, while AAS should record fabrics dominated by fine particles that carry a stable remanence. Petrographic analysis of microfabrics, AMS, and AAS will be used to determine whether remanence directions and particle alignment in various types of diamictons are related to geomagnetic field orientation, mass movement, subglacial shearing, dewatering or compaction. Unlike previous works, this study will: 1) test remanence direction against an established geomagnetic field record, 2) distinguish between genetic diamicton types, and 3) use AAS and petrofabric analysis to study grain alignment.

Remanent magnetization directions in glacial diamictons have not been tested against established records of the geomagnetic field at the time and place of deposition and the accuracies of diamictons as geomagnetic field recorders have not been determined. 纽约西部莫霍克山谷的DRM中，威斯康星州已故的地磁偏差的既定记录将用于测试同时耕种，层状loaut diamicton和seplagic Rainout Diamicton和宽宽宽片果皮果皮的遗产的延迟。 除了再延误外，还将测量磁敏感性（AMS）的各向异性（AMS）和无脑易感性（AAS）的各向异性。 AMS将用于确定由携带粘性的粗粒颗粒主导的织物，而AAS应记录以携带稳定透明度的细颗粒主导的织物。 微生物，AMS和AA的质学分析将用于确定各种二氧化酮中的延迟方向和粒子对齐是否与地磁磁场方向，质量运动，冰山下剪切，脱水，脱水或压实有关。 与以前的作品不同，这项研究将：1）针对已建立的地磁野外记录的测试避孕方向，2）区分遗传性透析类型，3）使用AAS和Petrofabric分析来研究谷物对齐。