地球深部电导率的实验室约束  

Laboratory Derived Constraints on Electrical Conductivity in the Earth's Interior

作　　者：王多君[1] 于英杰[1] 郭颖星[1] 刘在洋[1] 李丹阳[1] 

机构地区：[1]中国科学院研究生院地球科学学院,北京100049

出　　处：《矿物岩石地球化学通报》2011年第1期40-45,共6页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中国科学院知识创新工程重要方向项目(XMXX280728;KZCX2-YW-Q08-3-4);国家自然科学基金资助项目(40774036;41074063)

摘　　要：矿物岩石电导率实验研究对于认识地球内部的电导率分布和地球动力学具有重要的意义。本文于实验室中研究了一些典型地壳和地幔矿物、岩石的电导率,并将实验结果与野外电磁结果进行了对比。研究结果表明,含水矿物的脱水和存储于名义无水矿物中的水会显著提高岩石的电导率。含水矿物的脱水可能是导致地壳出现高导层的主要原因,而地幔的高导层则可能是由名义无水矿物中赋存的水所引起。实验室矿物、岩石电导率模型与野外大地电磁结果的对比,为研究地球内部的热状态和水含量的分布提供了重要依据。Experimental studies on electrical conductivities of minerals and rocks are critical to understanding the distributions of electrical conductivities of the Earth＇s interior and geodynamics processes.We investigated several minerals and rocks in the crust and the upper mantle and compared the experiments results with those derived from MT.The results indicate that both dehydration of hydrous minerals and water stored in the nominally anhydrous minerals can significantly enhance the electrical conductivity of minerals and rocks.The high conductivity layers（HCLs） in the crust were attributed to the dehydration of hydrous minerals.In contrast,the high conductivity layers（HCLs） in the upper mantel were caused by the water dissolved in the nominally anhydrous minerals such as olivine and pyroxene.Comparisons of experimental electrical conductivity determined with those from field geophysical models provide a clue to study the thermal states and distribution of water in the earth＇s interior.

关 键 词：矿物岩石 电导率 地温梯度 高导层 

分 类 号：P631.325[天文地球—地质矿产勘探]