Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology

该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金。南极东部基岩地质年代学的大部分资料及其侵蚀历史的记录都保存在其边缘周围的新生代沉积物中。该项目旨在利用这些沉积物，通过测量单个碎屑晶体和碎屑碎屑中多个晶体上的多个地质和温度计的年龄（锆石和磷灰石的 U/Pb、裂变径迹和 (U-Th)/He 测年，以及角闪石、云母和长石的 40Ar/39Ar 测年）来了解其冰下来源和盾构的侵蚀历史。单个颗粒和碎屑的多计时器年龄的结合提供了基岩来源的强大指纹，使我们能够通过边缘周围的第四纪混晶追踪始新世河流砂岩的来源。相同颗粒和碎屑的多个热计时（冷却）年龄也使我们能够解释这些基岩来源的侵蚀时间和速率。描绘基岩年龄单元的分布、沉积物迁移联系以及新生代的侵蚀历史，将使我们能够测试与以下相关的构造模型：（1）甘布尔采夫冰下山脉的起源，（2）河流和地形演化，以及（3）冰川生长和侵蚀的历史。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Much of the inventory of East Antarctic bedrock geochronology, as well as a record of its erosional history, is preserved in Cenozoic sediments around its margin. This project is to use these sediments to understand their sub-ice provenance and the erosional history of the shield by measuring ages of multiple geo- and thermochronometers on single detrital crystals and on multiple crystals in detrital clasts (U/Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar). The combination of multi-chronometer ages in single grains and clasts provides a powerful fingerprint of bedrock sources, allowing us to trace provenance in Eocene fluvial sandstones through Quaternary diamicts around the margin. Multiple thermochronometric (cooling) ages in the same grains and clasts also allows us to interpret the timing and rates of erosion from these bedrock sources. Delineating a distribution of bedrock age units, their sediment transport connections, and their erosional histories over the Cenozoic, will in turn allow us to test tectonic models bearing on: (1) the origin of the Gamburtsev Subglacial Mountains, (2) fluvial and topographic evolution, and (3) the history of glacial growth and erosion.