地壳岩石矿物电导率实验研究进展

Review of experimental studies on electrical conductivity of crustal rocks and minerals

矿物和岩石电导率的实验研究一直都是国内外专家学者所关注的重点内容,目前电导率的实验测量主要采用交流阻抗谱的方法.从实验结果来看,地壳矿物和岩石电导率的影响因素主要分为外部环境和内部性质两部分,包括矿物和岩石所受到的温度和压力大小、内部赋存的流体和熔体、岩石颗粒边缘的碳膜、岩石的颗粒大小和面理方向以及矿物晶格赋存的结构水与晶格方向等.结合地球物理探测结果,前人对下地壳高导层成因提出了各自不同的看法,同时电导率的实验数据对于解释地下岩层结构、动力学特征也带来了一定的帮助.通过总结可以发现对于断层带的电导率性质目前仍然知之甚少,在今后的实验研究中则需要重点关注.

The electrical conductivity of minerals and rocks is a research hotspot for the petrophysicists. AC impedance spectroscopy is the primary method applied in electrical conductivity measurement.For the experimental results,the influential factors of the electrical conductivity of minerals and rocks in the crust are divided into two parts： the factors of external environment and the factors of interior properties. These factors contain temperature, pressure, saline fluid,partial melting,grain boundary carbon films,grain size,the direction of foliation,water contents of minerals,orientation-related anisotropy of minerals and so on. Combining with the data of Magnetotelluric（ MT）,scientists have proposed many conclusions to interpret the presence of highly conductive layers,the structure of stratum and geodynamical features of the earth. Finally,we can find that the electrical conductivity of the fault zones in the upper crust is still unclear so far. In the future,we need to pay more attention to study this area.