上地幔电导率-温度关系及在大地电磁测深法中应用综述  

A review of the conductivity-temperature relationship of the upper mantle and its application in the magnetotellurics

作　　者：雷璐璐 金胜[1] 魏文博[1] 张乐天[1] 董浩[1] 叶高峰[1] 盛跃 LEI LuLu;JIN Sheng;WEI WenBo;ZHANG LeTian;DONG Hao;YE GaoFeng;SHENG Yue(School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,北京100083

出　　处：《地球物理学报》2023年第5期1771-1795,共25页Chinese Journal of Geophysics

基　　金：国家重点研发计划项目(2016YFC0600301);国家留学基金委项目(202006400054)资助。

摘　　要：上地幔热结构的研究对探索地球内部物质状态和岩石圈形成演化过程,评估自然资源的存储状况,监控火山区岩浆活动从而降低自然灾害风险等有着重要的意义.本文概述了基于不同岩石物理学高温高压实验得到的上地幔矿物电导率-温度关系.通过分析并对比前人的实验结果,讨论了不同实验得到的同一矿物的电导率-温度经验关系中参数差异产生的原因.大地电磁测深法(MT)以其探测深度大,受浅部高阻体影响较小且对低阻体分辨率较高等特点,在研究壳幔电性结构、热状态和地球动力学机制中得到了广泛的应用.以MT得到的上地幔电阻率模型为基础,结合岩石物理学实验标定的矿物电导率-温度经验关系,建立上地幔的温度和熔融百分比模型,这项工作在研究上地幔热状态中起着不可或缺的作用.笔者总结并讨论了前人以MT方法获得电性结构为基础,利用电导率-温度经验关系评价上地幔热状态的应用实例,并对未来的研究工作做了展望,同时对其可行性做了评估.The study of the upper mantle thermal state is very important to understand the interior material state of the earth and evolution of the lithosphere,and to evaluate the storage of natural resources,and to monitor magmatic activities in volcanic zones,which may contribute to the reduction of the risk of natural disasters.This paper summarizes the empirical conductivity-temperature relationships of minerals in the upper mantle based on different petrophysical high-temperature and high-pressure experiments.By comparing the different experimental results of the same minerals,we discuss and analyze the reason why the parameters of the empirical conductivity-temperature relationships obtained from different experiments are different.Magnetotellurics(MT)has the feature of the greater exploration depth,less influence of the large-scale resistors in the shallow area and higher resolution for conductors,which has been widely used in the study of the lithospheric electrical structure,thermal state and geodynamic mechanism.Based on the electrical structure of the upper mantle obtained from the MT,the distribution of the temperature and melt fraction of the upper mantle are estimated,which plays an indispensable role in the study of the upper mantle thermal state.In this study,we summarize the previous conductivity-temperature models based on the electrical resistivity model of the MT method,and prospect the future research of the thermal state of the upper mantle based on the conductivity-temperature relationships,and meanwhile evaluate the feasibility of this work.

关 键 词：上地幔热结构 电导率-温度关系 大地电磁法 上地幔电性结构 熔融百分比 

分 类 号：P313[天文地球—固体地球物理学] P319[天文地球—地球物理学]