蛇纹石化橄榄岩的氧化-还原特征  

Oxidation-Reduction Characteristics of the Serpentinized Peridotite

作　　者：王先彬[1] 卓胜广[2] 张明峰[1] 迟洪兴[2] 杨辉[1] 马向贤[1] 郑国东[1] 范桥辉[1] 孙则朋 

机构地区：[1]甘肃省油气资源研究重点实验室中国科学院油气资源研究重点实验室,兰州730000 [2]东北大学秦皇岛分校,河北秦皇岛066004

出　　处：《矿物岩石地球化学通报》2016年第2期231-238,共8页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金项目(41103022;41272146;41272146)

摘　　要：蛇纹石化橄榄岩是温都尔庙蛇绿岩套中最为重要的岩石类型,主要矿物组合为蛇纹石+碳酸盐矿物+磁铁矿+滑石。富SiO_2流体的加入,促使岩石进一步发生蛇纹石化作用而缺失水镁石。穆斯堡尔谱测量揭示了铁元素化学种的分布特征,蛇纹石化程度与氧化-还原特征的相关性。蛇纹石化橄榄岩含铁总量和Fe^(3+)的分布与磁铁矿和蛇纹石密切相关,Fe^(3+)以分布于蛇纹石中占优势。这对正确估算蛇纹石化过程中H_2的生成量有十分重要的意义,对估算俯冲带Fe^(3+)输入和评估原生地幔岩的蛇纹石化作用有重要参考价值。Serpentinized peridotite is one of the most important rocks in the Wenduermiao ophiolitesuite, which are mainly composed of serpentine, carbonates, magnetite, and talc. The input of the SiO2-rich fluid will result in the lack of brueite due to the further serpentinization of peridotite. Mossbauer spectra analysis has revealed distribution features ofchemical species of Fe and the relationship between serpentinization degrees and oxidization-reduetion properties in this study. The results suggested that the total amount of Fe and the distribution of Fe3＋ in serpentinized peridotite were closely related to magnetite and serpentine, especially Fe3＋ was dominantly distributed in serpentine. These have very important significances for properly evaluating the amount of H2 produced in the serpentinization process, and have important reference values for evaluating the input of Fe3＋ in subduction zone as well as the serpentinization of the primary mantle rock.

关 键 词：蛇纹石化橄榄岩 穆斯堡尔谱 蛇纹石化程度 铁元素化学种 氧化-还原条件 

分 类 号：P588.125[天文地球—岩石学]