Osmium Isotopic Compositions and Osmium Distribution in the Mid-Ocean Ridge Hydrothermal System
Huang Wei
Tao Chunhui
Li jun
Sun Zhilei
Deng Xiguang
Cui Ruyong
Abstract：The hydrothermal fluids occur along the mid-ocean ridges are capable of transporting a great amount Os from deep in-terior of the earth where it is relatively enriched to the ocean floor,this process plays a significant role in the global cycling of Os.The geochemical behavior of Os during the various stages of the hydrothermal circulation,its distribution and evolution features and source contributions are estimated basing on the chemical speciation,concentrations and isotopic compositions of Os in the sources for the hydrothermal systems and the hydrothermal deposits.The Os data from the sediment-free mid-ocean ridge systems indicated that there is a nearly complete Os isotope exchange between the interacting seawater and the oceanic crust during the hydrothermal circulation,the behavior of Os appears to be controlled by the relative proportions of seawater and crustal composition in the different tectonic areas.Reactions of seawater with surrounding rock result in the radiogenic Os removing from seawater to the altered host rock,and the nonradiogenic Os lost from the wall rock to the hydrothermal fluid. The hydrothermal deposits accumulated above the seafloor carry Os which is predominately seawater-derived,the Os of the hy-drothermal products beneath the the seafloor reflecting mixing of seawater-derived and ocean crust-derived Os.
Keywords：Mid-ocean ridgeHydrothermal systemOsmiumisotopics
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 441-451 )