Osmium Isotopic Evolution of the Continental Crust

该项目旨在确定大陆地壳物质（主要是河流悬浮载荷）中的187Os/186Os比值，以约束大陆地壳的Os同位素组成。PI将根据大陆物质中的143Nd/144Nd变化来确定1870年代/ 1860年代的变化。研究结果将用于约束壳幔分异和地壳再循环到地幔的模型，为块状硅酸盐土的Os同位素组成提供约束条件，并对壳幔储层的Os同位素变化进行质量平衡考虑。测量将通过N-TIMS同位素稀释法进行。数据将获得良好的表征样品。pi将开发稀土和稀土的地球化学模型，以及它们与枯竭地幔、大陆地壳和硅酸盐地球中其他潜在重要储层中不相容的亲石元素的关系。最终目的是了解Re和Os在地壳-地幔系统中的地球化学行为，并利用该系统作为地壳-地幔演化过程的示踪剂。

9628195 Jacobsen This project is to determine the 187Os/186Os ratios in continental crust materials (primarily river suspended loads) to constrain the Os isotopic composition of the continental crust. The PI's will establish the 187Os/186Os variations in relation to the 143Nd/144Nd variations in continental materials. The results will be used to constrain models of crust-mantle differentiation and crustal recycling into the mantel, to provide constraints on the Os isotopic composition of the bulk silicate Earth, and to conduct mass balance considerations for the Os isotopic variations in crust and mantle reservoirs. Measurements will be carried out by N-TIMS isotope dilution methods. Data will be obtained on well characterized samples. The PIs will develop geochemical models for the budgets of Re and Os and their relation to the incompatible, lithophile elements in the depleted mantle, continental crust, and other potentially significant reservoirs in the silicate Earth. The ultimate goal is to understand the geochemical behavior of Re and Os in the Earth's crust-mantle system and the utility of this system as a tracer for crust-mantle evolution processes.