Osmium Isotopes in Seawater

迄今为止关于锇的海洋地球化学的工作表明， 需要限制海洋的锇同位素组成， 为了得到宇宙和地球的Os通量从更多的 对沉积物和锰结核进行的测量。 的 海洋的锇同位素组成无法得到适当评估 如果没有对海洋学的初步了解， 元素的行为。 这项研究将阐明海洋 通过测定Os的分布， 海水中的同位素组成 与一个单独的，但 海洋固相相容性研究，该项目将 大大提高了我们对海洋的整体理解 元素的地球化学循环。 这样的基础工作是 利用这种同位素系统的潜力来探测 海洋地球化学过程 是否存在锇同位素体系 海水是否均匀将决定其沉积特征 记录了地壳、地幔和 全球范围内的宇宙起源，或者如果它追踪更多的地方来源， 影响其积累的过程。 这反过来又决定了 无论是古宇宙物质流还是古氧化还原状态 海洋的沉积记录可以重建 在一个更直接的时间尺度上， 在水柱中的Os行为将为使用 在受影响沿海地区和围隔地区人为锇作为示踪剂 盆。

The work to date on the marine geochemistry of osmium points to the need to constrain the Os-isotopic composition of the oceans in order to derive cosmic and terrestrial Os fluxes from the more readily conducted measurements on sediments and Mn-nodules. The Os-isotopic composition of the oceans cannot be properly assessed without at least a first order understanding of the oceanographic behavior of the element. This research will elucidate the marine chemistry of Os through determination of its distribution and isotopic composition in seawater. Together with a separate but compatible study of marine solid phases, the project will significantly increase our overall comprehension of the marine geochemical cycle of this element. Such groundwork is prerequisite to exploiting the potential of this isotopic system for probing marine geochemical processes. Whether the Os-isotopic system in seawater is homogeneous will determine if its sedimentary signature records the relative magnitudes of its crustal, mantle and cosmogenic sources on the global scale or if it traces more local processes affecting its accumulation. This in turn determines whether the paleo cosmogenic material flux or the paleo-redox state of the oceans might be reconstructed from sedimentary records of Os. On a more immediate timescale, an understanding of the behavior of Os in the water column will provide the basis for using anthropogenic Os as a tracer in affected coastal areas and enclosed basins.