Investigating Upper Mantle Heterogeneity and Partial Melting Beneath Mid-Ocean Ridges Using Helium and Argon Isotopes in Abyssal Peridotite, Gabbro and Basalt

利用深渊橄榄岩、辉长岩和玄武岩中的氦和氩同位素研究大洋中脊下的上地幔异质性和部分熔融

• 批准号: 0850666
• 负责人: David Graham
• 金额: $ 32.39万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-15 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0850666&HistoricalAwards=false
• 关键词: Investigating; Upper; Mantle; Heterogeneity; Partial

This research examines the isotopic variations of noble gases in oceanic rocks and produces data that bear significantly on debates about the chemical structure of Earth's mantle, partial melting processes of magmas, and the origin of fluids involved in ocean crust evolution and metamorphism. Analyses of noble gases (He, Ar) and CO2 will be some of the first made for seafloor peridotites and gabbros. Data will be used to examine the length scales of chemical and isotopic heterogeneity in the upper mantle. Samples come from three areas: the Mid-Atlantic Ridge (ODP Leg 209), the Kane oceanic core complex, and the ultra-slow spreading Gakkel Ridge in the Arctic Ocean. All samples have already been well characterized analytically for other important geochemical parameters. Broader impacts of the work include building infrastructure for science through support of the new NSF-funded Noble Gas Facility at Oregon State University. Graduate and undergraduate students will be engaged in research and project results will be incorporated into instructional programs of graduate level classes in geochemistry. Results will be posted on the web.

这项研究探讨了稀有气体在大洋岩石中的同位素变化，并产生了对有关地幔化学结构、岩浆部分熔融过程以及洋壳演化和变质作用所涉及的流体起源的争论具有重要意义的数据。 稀有气体（He，Ar）和CO2的分析将是对海底橄榄岩和辉长岩的首次分析。 这些数据将用于研究上地幔化学和同位素不均匀性的长度尺度。 样本来自三个领域：大西洋中脊（ODP 209航次）、凯恩海洋核心复合体和北冰洋超慢速扩张的加克尔脊。所有样品都已经很好地分析了其他重要的地球化学参数。 这项工作的更广泛影响包括通过支持俄勒冈州州立大学新的NSF资助的惰性气体设施来建设科学基础设施。 研究生和本科生将从事研究，项目成果将纳入地球化学研究生水平课程的教学计划。 结果将在网上公布。