Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains

Abstract: This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica's largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow.摘要：本探索性研究小额资助项目旨在探究冈布茨冰下山脉（Gamburtsev Subglacial Mountains, GSM）的成因与演化历史。该山脉被认为是南极最大冰盖的成核点，但其年代未明，有可能晚于冰盖的形成过程。此外，其形成或可反映冈瓦纳大陆裂解时期的构造事件。本项目将分析由大洋钻探计划（Ocean Drilling Program）从普里兹湾获取的、源自GSM的碎屑锆石与磷灰石晶体。分析工作涵盖采用铀-铅（U/Pb）、裂变径迹、（铀-钍）/氦（(U/Th)/He）三种方法开展的三重测年热年代学研究。该联合技术可同时揭示高温与低温地质过程，且对造山事件以及后续因侵蚀作用引发的冷却与剥露过程均具有潜在敏感性。就拓展性影响而言，本项目将为一名博士后研究员的研究工作提供支持。