Osmium Isotopic Evolution of the Continental Crust

9628195雅各布森这个项目是为了确定大陆地壳物质(主要是河流悬浮物)中的187Os/186Os比率，以限制大陆地壳的Os同位素组成。PI将建立与大陆物质的143ND/144ND变化相关的187Os/186Os变化。这些结果将被用于约束壳幔分异和地壳再循环进入地幔的模型，为块体硅酸盐地球的Os同位素组成提供约束，并对地壳和地幔储集层的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。数据将从表征良好的样品中获得。PIS将开发Re和Os预算的地球化学模型，以及它们与枯竭地幔、大陆地壳和硅酸盐地球其他潜在重要储集层中不相容的亲石元素的关系。最终目的是了解Re和Os在地球壳幔系统中的地球化学行为，以及该系统作为壳幔演化过程示踪剂的作用。

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.