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

学术价值：次大陆岩石圈地幔保留了其构造史留下的地球化学印记，包括大陆地壳的提取，被“幼年”地壳取代。造山运动或裂谷运动期间的软流圈，由俯冲相关的熔体和流体或地幔柱活动引起的交代再富集。现代分析技术可以通过整个岩石、矿物或原位微量元素和Sr-Nd-Hf-Os-He同位素分析来揭示这种地球化学演化。罗斯海西部地区具有多阶段构造史的特点，特别适合进行此类研究。今天，西罗斯海地区是西南极裂谷系统（WARS）的一部分，它代表了地球的一个板块。美国最大的裂谷系。PIs建议使用现代分析技术来限制次大陆岩石圈地幔的动态和地球化学演化，这些分析技术使用的样本来自埃里伯斯山省和维多利亚地之间的多个地点，这些样本是通过与以前探险的研究人员和美国极地岩石库的合作获得的。可用的地幔捕虏体是新鲜的，从尖晶石橄榄岩到交代的韦氏岩和罕见的韦氏岩，许多都带有含水相。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。该项目将成为一名研究生和一名博士后合作研究的博士论文的基础。这项研究的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年度开放日上重点介绍。

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.