The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin

智力优势：该项目将调查东南极冰盖在始新世-渐新世过渡期间的冰川进退情况，这是冰增长的一个主要阶段。在南极洲东部的Preniz湾，在大洋钻探计划的739、742和1166号站点的钻孔中，取芯了130-170米厚的始新世-渐新世冰川海洋沉积物过渡层。最近，通过测井和多道地震解释，确定了Preniz Bay钻孔之间的相关性。最近在南极洲东部威尔克斯陆缘的钻探在两个钻孔中恢复了覆盖在主要区域不整合面上的最早渐新世沉积物。PI将研究五个钻孔中岩心的岩石地层学和风化历史，以建立南极大陆边缘沉积物中独特的始新世-渐新世过渡记录，包括冰川前进和后退周期、物理风化的开始、冰川等渗和自引力过程，以及对边缘结构、沉积物路线和离岸沉积物分散的影响。将使用更新的分类方案通过详细的岩心描述重新检查五个钻孔的岩心，以便可以比较钻孔之间的岩相。将收集样品，通过ICP-AES进行详细的激光粒度和大量主要元素地球化学分析，以确定沉积物的化学蚀变程度。主要冰增长的阶段将被视为物理侵蚀沉积物的标志床，并将与记录南大洋近海南极冰增长的同位素记录相关联。更广泛的影响：该项目将通过提供多达两个带薪实验室实习，课堂练习以及该奖项支持的研究设备的可用性，使大量少数民族本科生受益。该项目还允许支持和培训一名研究生。

Intellectual Merit: This project will investigate glacial advance and retreat of the East Antarctic Ice Sheet through the Eocene-Oligocene transition, a major episode of ice growth. In Prydz Bay, East Antarctica, a 130-170 m thick Eocene-Oligocene transition interval of glaciomarine sediments was cored in drillholes of the Ocean Drilling Program at Sites 739, 742 and 1166. Correlations between the Prydz Bay drillholes have recently been made through well-log and multichannel seismic interpretations. Recent drilling on the Wilkes Land margin of East Antarctica recovered earliest Oligocene sediments overlying a major regional unconformity in two drillholes. The PI will study the lithostratigraphy and weathering history of cores in the five drillholes, to establish a unique Eocene-Oligocene transition record within Antarctic continental margin sediments of glacial advance and retreat cycles, the onset of physical weathering, and glacio-isostasy and self-gravitation processes with implications for the margin architecture, sediment routing, and off-shore sediment dispersal. Cores from the five drillholes will be re-examined through detailed core description using an updated classification scheme, so that lithofacies can be compared between drillholes. Samples will be collected for detailed laser particle size and bulk major element geochemistry via ICP-AES to determine the degree of chemical alteration of the sediments. Phases of major ice growth will be recognized as marker beds of physically eroded sediment and will be correlated to isotopic records documenting Antarctic ice growth offshore in the Southern Ocean. Broader impacts: This project will benefit a large minority undergraduate student population through the availability of up to two paid laboratory internships, a classroom exercise, and the availability of research equipment supported by this award. The project also allows support and training of a graduate student.