Re-Os Isotopic Studies of Crust-Mantle Evolution on the Earth

研究人员将分析太古代的Re-Os同位素系统 科马提岩和英云闪长岩-花岗闪长岩; 地幔捕虏体;以及来自大洋中脊、大洋 岛屿和岛弧。 这些研究的具体目标是 确定Os同位素地幔生长曲线 岩石的来源;了解岩石的行为 火成体系中的Re和Os;研究 研究大洋地幔再循环 地壳在上地幔中的作用以及大洋地壳在 岛弧火山作用 Re-Os同位素体系具有独特的潜力， 地球的地球化学研究 该系统提供了新的 对从Rb-Sr、SM-Nd 和U-Th-Pb系统的几个原因：Re和Os都是 亲铁元素Os在地幔中是相容的，Re 一般是不相容的，Os在 地幔与地壳的对比， 形成玄武质岩石，从Re中强烈破碎。 使用 Re-Os同位素系统将提供对 对流地幔的贫化和富集储层， 岩石圈，古代大陆地壳的创造， 它的岩石圈根源和俯冲板片成分的作用 在收敛的边缘。

The PIs will analyze the Re-Os isotopic systematics of Archean komatiites and tonalites-granodiorites; mafic layered intrusions; mantle xenoliths; and recent basalts from mid-ocean ridges, ocean islands and island arcs. The specific goals of these studies are to determine the Os isotopic mantle growth curve; to determine the source of cratonic core rocks; to understand the behavior of Re and Os in igneous systems; to study the formation of the subcontinental mantle and to investigate recycling of oceanic crust within the upper mantle and the role of oceanic crust in island arc volcanism. The Re-Os isotopic system has unique potential to contribute to geochemical studies of the Earth. This system provides new information complementary to that available from the Rb-Sr, SM-Nd and U-Th-Pb systems for several reasons: both Re and Os are siderophile elements, Os is compatible in the mantle while Re generally is incompatible, Os has a relatively high abundance in the mantle compared to the crust and the melting events that form basaltic rocks strongly fractionate Os from Re. The use of the Re-Os isotopic system will provide a greater understanding of the depleted and enriched reservoirs of the convecting mantle and the lithosphere, the creation of ancient continental crust with its lithospheric roots and the role of subducted slab components at convergent margins.