俯冲带蛇纹岩变质脱水过程中的Mg、Fe同位素分馏行为:进展与展望  

The Fractionation Behavior of Mg and Fe Isotopes during Serpentinite Dehydration in Subduction Zones:Progress and Prospect

作　　者：陈伊翔[1,2] CHEN Yi-xiang(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;CAS Center for Excellence in Comparative Planetology,Hefei 230026,China)

机构地区：[1]中国科学技术大学地球和空间科学学院,合肥230026 [2]中国科学院比较行星学卓越创新中心,合肥230026

出　　处：《矿物岩石地球化学通报》2021年第5期1034-1048,I0002,共16页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(42073029,41773021)。

摘　　要：蛇纹岩在俯冲带地球化学循环中发挥着重要作用。蛇纹岩是俯冲带中极富Mg和Fe的矿物,其变质脱水释放的流体含有显著量的Mg和Fe,对俯冲带中Mg、Fe元素的循环及其同位素的分馏行为起着重要作用。蛇纹岩脱水过程中的Mg、Fe同位素分馏特征与不同温度、压力条件下蛇纹岩体系的矿物组合、释放流体的氧化还原状态、流体中Mg、Fe的价态和种型等密切相关。本文在总结俯冲带蛇纹岩的产出特征、稳定性和主要脱水反应的基础上,系统评述了俯冲带蛇纹岩在变质脱水过程中Mg、Fe同位素分馏行为的研究现状和存在的关键科学问题,并对未来的研究方向进行了展望。Serpentinite plays a key role in the geochemical recycling of subduction zones.It is a mineral with strongly enriched Mg and Fe in subduction zones.The released fluids by the metamorphic dehydration of serpentinite can also contain significant amounts of Mg and Fe.Therefore,serpentinite has a great bearing on the recycling of Mg and Fe elements as well as the fractionation behavior of Mg and Fe isotopes in subduction zones.The fractionation characteristics of Mg and Fe isotopes during the serpentinite dehydration are closely related to the mineral assemblage of serpentinite system at different P-T conditions,the redox state of released fluids,as well as the valence and speciation of Mg and Fe in the fluids.Here I firstly have summarized the occurrence,stability,and main dehydration reactions of the serpentinite system,then have systematically reviewed the recent progresses and remained key questions of previous researches on the fractionation behavior of Mg and Fe isotopes during the metamorphic dehydration of serpentinite in subduction zones,and finally,have proposed prospective directions for future studies.

关 键 词：俯冲带 蛇纹岩 变质脱水 Mg-Fe同位素 壳幔相互作用 

分 类 号：P597.2[天文地球—地球化学]