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

这项工作将确定南极洲威尔克斯地沿海地区冰川海洋沉积物的年龄和来源。这些沉积物可以提供对东南极地盾（EAS）历史的深入了解，这是地球上最古老的大陆地壳部分之一，但由于几乎完全的冰盖覆盖而无法直接研究。这项研究将使用澳大利亚国立大学的SHRIMP离子微探针来测定沉积物中发现的锆石和独居石的年代。感兴趣的样品包括从冰碛物的疏浚物中获得的复晶卵石和卵石碎屑，以及来自大陆边缘冰川杂岩岩心的砂基质部分。将选择来自冰碛物的火成岩和变质岩的单个碎屑进行锆石和/或独居石年龄测定，而将分析来自分层和非分层杂岩的碎屑锆石，以进行复合锆石来源分析。此外，将确定Beacon超群砂岩的碎屑锆石年龄，以评价中生代盆地中锆石的再循环。从这两个来源获得的年龄的整合将提供一个很好的代表性的EAS地形下的威尔克斯地冰盖。该项目将使我们能够更多地了解遥远的大陆内部，并提高我们解释过去冰流模式的能力，而不会对南极洲造成进一步的环境影响。这些结果将提高我们对前寒武纪构造和地壳演化的理解，并有助于确定未来冰上地球物理调查和目前正在考虑的基底钻探项目的目标。就更广泛的影响而言，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.