Dynamic and geochemical evolution of the lithospheric mantle beneath the Western Ross Sea Area, Antarctica

智力价值：次大陆岩石圈地幔保存了其构造历史留下的地球化学印记，包括大陆地壳的提取，被年轻的？造山或裂谷期间的软流圈，因俯冲相关的熔体和流体或地幔热柱活动而交代重新富集。现代分析技术使我们有可能通过全岩、矿物或原位痕量元素和锶-钕-氢-铯-氦同位素分析来揭示这种地球化学演化。西部罗斯海地区特别适合进行这种研究，因为它的特点是具有多阶段的构造史。今天，西罗斯海地区是西南极裂谷系统(WARS)的一部分，它代表了地球上最大的裂谷系统之一-S。PI建议使用现代分析技术来限制次大陆岩石圈地幔的动力学和地球化学演化，使用来自山间多个地点的样品。埃里伯斯省和维多利亚州通过与以前探险的调查人员和美国极地岩石储存库合作获得。可利用的地幔包体是新鲜的，范围从尖晶石二辉橄榄岩到交代魏长岩和稀有的网纹岩，而且许多都带有水合相。更广泛的影响：拟议的工作将产生广泛的科学影响，并将启动国家和国际合作。该项目将构成研究生博士论文的基础，博士后将合作进行这项研究。研究结果将在国际会议上提出，并在国际同行评议的期刊上发表，并将在LDEO年度开放参观活动上重点介绍。

Intellectual Merit: The subcontinental lithospheric mantle preserves the geochemical imprint left by its tectonic history, including continental crust extraction, replacement by ?juvenile? asthenosphere during orogeny or rifting, metasomatic re-enrichment by subduction- related melts and fluids or mantle plume activity. Modern analytical techniques make it possible to unravel this geochemical evolution through whole rock, mineral, or in-situ trace element and Sr-Nd-Hf-Os-He isotope analyses. The western Ross Sea area is particularly suited for such a study, as it is characterized by a multi-stage tectonic history. Today the Western Ross Sea area is part of the West Antarctic Rift System (WARS), which represents one of Earth?s largest rift systems. The PIs propose to constrain the dynamic and geochemical evolution of the subcontinental lithospheric mantle using modern analytical techniques using samples from multiple locations between the Mt. Erebus Province and Victoria Land available through collaborations with investigators from previous expeditions and the US Polar Rock Repository. The available mantle xenoliths are fresh and range from spinel lherzolites to metasomatized wehrlites and rare websterites, and many carry hydrous phases. Broader impacts: The proposed work will have broad scientific impacts and will initiate national and international collaborations. The project will form the basis of a Ph.D. thesis for a graduate student and a postdoc will collaborate on the study. Results of the study will be presented at international meetings and published in international peer-reviewed journals and will be highlighted at the LDEO annual Open House.