Paleomagnetism of Glacial Diamictons and Subglacially Deformed Sediment

冰川磨粒的剩余磁化方向尚未根据沉积时间和地点的既定地磁场记录进行检验，磨粒作为地磁场记录者的准确性也尚未确定。来自纽约州莫霍克山谷西部变异沉积物的DRM的晚期威斯康辛地磁偏角的已确定记录将用于测试来自同时期的沉积物，沉积物流动沉积物，上层雨蚀区和冰川下变形湖床的残留物的保真度。除剩磁外，还将测量磁化率的各向异性（AMS）和非滞后磁化率的各向异性（AAS）。AMS将用于确定以带有粘性剩余物的粗颗粒为主的织物，而原子吸收光谱法应记录以带有稳定剩余物的细颗粒为主的织物。微组构的岩石学分析、AMS和AAS将用于确定各种类型的金刚石中的残余方向和颗粒排列是否与地磁场方向、质量运动、冰下剪切、脱水或压实有关。与以往的工作不同，本研究将：1)根据已建立的地磁场记录测试剩余物方向，2)区分成因直径类型，以及3)使用原子吸收光谱和岩石组构分析来研究颗粒排列。

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.