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

南极洲西罗斯海区岩石圈地幔的动力学和地球化学演化

• 批准号: 1043540
• 负责人: Cornelia Class
• 金额: $ 29.94万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-15 至 2015-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1043540&HistoricalAwards=false
• 关键词: Dynamic; geochemical; evolution; lithospheric; mantle

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.

学术价值：次大陆岩石圈地幔保留了其构造历史留下的地球化学印记，包括大陆地壳的提取、“幼年期”的替代。造山运动或裂谷期间的软流圈，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。现代分析技术使得通过整个岩石、矿物或原位微量元素和 Sr-Nd-Hf-Os-He 同位素分析来阐明这种地球化学演化成为可能。罗斯海西部地区特别适合进行此类研究，因为它具有多阶段构造历史的特点。如今，西罗斯海地区是西南极裂谷系统 (WARS) 的一部分，该系统是地球上最大的裂谷系统之一。 PI 提议利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，该技术使用来自埃里伯斯山省和维多利亚地之间多个地点的样本，这些样本是通过与之前的探险和美国极地岩石储存库的研究人员合作获得的。可用的地幔捕虏体是新鲜的，范围从尖晶石二辉橄榄岩到交代的韦尔沸石和稀有的网沸石，并且许多带有水相。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。该项目将构成博士学位的基础。研究生和博士后的论文将合作进行这项研究。研究结果将在国际会议上展示并在国际同行评审期刊上发表，并将在 LDEO 年度开放日上重点展示。