Glacial proxies of East Antarctic shield basement in Wilkes Land, Antarctica

这项工作将确定南极威尔克斯岛沿海地区冰川形成的海洋沉积物的年龄和来源。这些沉积物可能有助于洞察东南极地盾(EAS)的历史，东南极地盾是地球上最古老的陆壳部分之一，但由于几乎完全覆盖了冰盖，因此无法直接进行研究。这项研究将使用澳大利亚国立大学的SHRIMP离子微探测器来测定沉积物中发现的锆石和独居石的年龄。感兴趣的样品包括从挖泥船拖运的耕作中获得的多晶鹅卵石和鹅卵石碎屑，以及大陆边缘冰川直径岩芯的砂基馏分。来自岩屑的单个火成岩和变质岩碎屑将被选择用于锆石和/或独居石的年龄测定，而来自层状和非层状直径的碎屑锆石将被用于复合锆石来源的分析。此外，还将确定Beacon Supergroup砂岩的碎屑锆石年龄，以评价显生界盆地中的锆石回收。从这两个来源获得的年龄的综合将很好地代表威尔克斯陆地冰盖下的EAS地形。该项目将使我们能够更多地了解遥远的大陆内陆，并提高我们在不进一步影响南极洲环境的情况下解释过去冰流模式的能力。这些结果将提高我们对前寒武纪构造和地壳演化的理解，并有助于针对未来的冰上地球物理调查和目前正在考虑的地下室钻探项目。在更广泛的影响方面，该项目将为地球科学本科生提供教育和培训机会。

This work will determine the age and provenance of glacially derived marine sediments from the coastal regions of Wilkes Land, Antarctica. These deposits may offer insight into the history of the East Antarctic Shield (EAS), which is amongst the oldest sections of continental crust on Earth, but cannot be studied directly because of nearly complete ice sheet coverage. The study will use Australian National University's SHRIMP ion microprobe to date zircon and monazite found in the sediments. Samples of interest include polymictic pebble and cobble clasts obtained from dredge hauls of tills, as well as sand-matrix fractions from cores of glacial diamicts on the continental margin. Individual clasts of igneous and metamorphic rocks from tills will be selected for zircon and/or monazite age dating, whereas detrital zircons from stratified and non-stratified diamictons will be analyzed for composite zircon provenance analysis. In addition, detrital zircon ages will be determined for Beacon Supergroup sandstones to evaluate recycling of zircon in Phanerozoic basins. Integration of ages obtained from both sources will provide a good representation of the EAS terrains underlying the Wilkes Land ice sheet. This project will allow us to learn more about the remote continental interior and improve our ability to interpret past ice-flow patterns without further environmental impact on Antarctica. The results will improve our understanding of Precambrian tectonics and crustal evolution, and help target future over-ice geophysical surveys and basement drilling projects currently under consideration. In terms of broader impacts, the project will provide educational and training opportunities for undergraduate students in Earth science.