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洋中脊热液系统是将相对富集在深部的Os运移到海底表面的重要媒介,同时该过程也是全球Os循环的重要组成部分.在归纳总结洋中脊热液系统各物源组分和产物中Os的化学形态、含量及其同位素组成特征的基础上,探讨了Os在洋中脊热液活动各阶段中的分布演化规律及物源贡献特征.在缺乏沉积物覆盖的洋中脊区域,热液系统中的Os及其同位素组成特征主要受控于海水和不同构造环境下洋壳组分特征的差异以及这两种物源组分混合比例的不同.经历了海底之下的水岩反应后,围岩会将下渗海水中的部分放射性成因Os固定,而将自身富集的非放射性成因Os释放进入热液流体中.堆积在海底之上的各种热液产物中的Os大多来自海水,而海底之下的热液产物则因为海水下渗深度以及海水与热液流体混合程度的差异而体现出宽泛的Os含量和~(187)Os/~(188)Os比值变化范围.
The mid-oceanic ridge hydrothermal system is an important medium for transporting relatively rich Os in the deep to the surface of the seafloor, and is also an important part of the global Os cycle.In summary, And the chemical composition and content of Os in their products and their isotopic compositions, the distribution and evolution of Os in hydrothermal activities of the mid-oceanic ridges and the contribution of their provenance were discussed.In the absence of sediments-covered mid-ocean ridge The characteristics of Os and its isotopic composition in the regional and hydrothermal systems are mainly controlled by the differences in the characteristics of the oceanic crust and seawater in different tectonic settings and the mixing ratio of these two provenances. After the rock reaction, the surrounding rock will fix some radiogenic Os in the infiltration seawater and release the self-enriched non-radiogenic Os into the hydrothermal fluid. Os in various hydrothermal products deposited on the seafloor Most of them come from seawater, while the hydrothermal products under seafloor show broad Os content and range of change of ~ (187) Os / ~ (188) Os ratio because of the depth of seawater infiltration and the degree of mixing of seawater and hydrothermal fluids .