Experimental partitioning of osmium between pyrite and fluid: Constraints on the mid-ocean ridge hydrothermal flux of osmium to seawater
Experimental partitioning of osmium between pyrite and fluid: Constraints on the mid-ocean ridge hydrothermal flux of osmium to seawater
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DOI：
10.1016/j.gca.2020.10.029
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发表时间：
2021
影响因子：
5
通讯作者：
D. Syverson;Joachim A. R. Katchinoff;Laurel R. Yohe;B. Tutolo;W. Seyfried;A. Rooney
中科院分区：
文献类型：
--
作者：
D. Syverson;Joachim A. R. Katchinoff;Laurel R. Yohe;B. Tutolo;W. Seyfried;A. Rooney
本研究提出了实验，地球化学建模和现场数据，重点是在大洋中脊热液环境的条件下，在沉淀后的黄铁矿和流体之间的锇（Os）的分配。溶解的Os在350° C和50 MPa的实验条件下沉淀时强烈地分配到黄铁矿中，具有代表性的相对Os/Fe分配系数，D黄铁矿-F luid Os/Fe在10和15之间。将实验确定的D黄铁矿-F luid Os/Fe整合到地球化学模型中表明，由于导电加热的海水与富含溶解金属（如Os和Fe）的原始高温热液流体混合引起的硫化物沉淀，大量的Os保留在海底下。与现有的Os浓度和同位素数据的热液流体和硫化物矿物从广泛的热液系统的实验和建模的限制比较表明，现代高温热液系统是一个次要来源的非放射性的Os现代全球海洋溶解的Os预算由于大部分的Os被隔离到硫化物矿物内形成的海底。
This study presents experimental, geochemical modeling, and field data focusing on the partitioning of osmium (Os) between pyrite and fluid upon precipitation at conditions representative of mid-ocean ridge hydrothermal environments. Dissolved Os partitions strongly into pyrite upon precipitation at experimental conditions, 350° C and 50 MPa, with a representative relative Os/Fe partition coefficient, D Pyrite-F l u i d Os/F e, between 10 and 15. Integrating the experimentally determined D Pyrite-F l u i d Os/F e into a geochemical model indicates that a significant amount of Os is retained within the subseafloor due to sulfide precipitation induced by mixing of conductively heated seawater with pristine high temperature hydrothermal fluids that are enriched in dissolved metals, such as Os and Fe. Comparison with existing Os concentration and isotopic data of hydrothermal fluids and sulfide minerals from a wide range of hydrothermal systems with the experimental and modeling constraints suggest that modern high temperature hydrothermal systems are a minor source of unradiogenic Os to the modern global ocean dissolved Os budget due to the majority of Os being sequestered into sulfide minerals formed within and on the seafloor.