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

这项研究考察了海洋岩石中稀有气体的同位素变化，并产生了对地幔化学结构、岩浆部分熔融过程以及海洋地壳演化和变质作用中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。数据将用于检查上地幔化学和同位素非均质性的长度尺度。样本来自三个区域：大西洋中脊（ODP Leg 209），凯恩海洋核复核，以及北冰洋超缓慢扩展的Gakkel脊。所有样品都已对其他重要的地球化学参数进行了很好的分析表征。这项工作的更广泛影响包括通过支持美国国家科学基金会资助的俄勒冈州立大学新的惰性气体设施，为科学建设基础设施。研究生和本科生将参与研究，项目成果将纳入研究生地球化学课程的教学计划。结果将在网上公布。

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.