高温高压下不同压力、氧逸度、水含量、铁含量和碳含量的人工合成榴辉岩电导率的实验研究及地球物理学意义

In conjunction with the AC impedance spectroscopy technique of electrochemistry and multi-anvil high-pressure apparatus (e.g. YJ-3000t and Kawai-1000t type of second class anvil), we select the synthetic pyrope-almandine eclogite with different chemical compositions as starting materials. Another hot-press were adopted in order to obtain our experimental sample with different water content and carbon content. Electrical conductivities for the synthetic pyrope-almandine eclogite will be performed under conditions of temperature range from 673 K to 1273 K, pressure range from 1.0 GPa to 6.0 GPa and controlled oxygen fugacities (e.g. Re+ReO2、Cu+CuO、Ni+NiO、Mo+MoO2、Fe+FeO、Fe+Fe3O4、Fe2O3+Fe3O4、Co+CoO and Cr+Cr2O3). A quantitative functional relationship between electrical conductivity and six dominant influential factors (temperature, pressure, oxygen fugacity, water content, iron content and carbon content) will be thoroughly established. A series of characteristic parameters on the pyrope-almandine eclogite conduction mechanism that are expressed in the Arrhenius relation will be obtained such as the activation enthalpy, pre-exponential factor, activation energy, activation volume, etc. In combination with previous field magnetotelluric results, some preliminary scientific Earth dynamics issues for the Dabie-Sulu ultra-high metamorphic belt as a typical tectonic unit will be explored for hot-subduction, cold-subduction, mantle convection, etc. And furthermore, we can apply our results to provide one reasonable explanation of high conductivity anomaly for Dabie-Sulu region from the data of magnetotelluric observation.

将交流阻抗谱测量技术与YJ-3000t、Kawai-1000t高压设备相结合，以人工合成的不同成分的镁铝榴石-铁铝榴石榴辉岩为初始样品，通过热压合成不同水含量和碳含量的实验样品，在高温、高压和不同氧逸度条件下原位测量镁铝榴石-铁铝榴石榴辉岩电导率，系统综合地建立起样品电导率与温度、压力、氧逸度、水含量、铁含量、石墨含量等六大影响因素之间的函数关系式；建立起表征人工合成的镁铝榴石-铁铝榴石榴辉岩各种导电机制的活化焓、指前因子、活化能、活化体积等物性参数与影响因素变化的定量函数关系；结合野外大地电磁测深结果，初步探究大别-苏鲁典型构造单元超高压变质带的热俯冲、冷俯冲、地幔对流等地球动力学问题，进而对大地电磁观测的大别-苏鲁地区高导异常成因提供合理的解释。

将交流阻抗谱测量技术与YJ-3000t、Kawai-1000t高压设备相结合，以人工合成的不同成分的镁铝榴石-铁铝榴石榴辉岩为初始样品，通过热压合成不同水含量和碳含量的实验样品，在高温、高压和不同氧逸度条件下原位测量镁铝榴石-铁铝榴石榴辉岩电导率，系统综合地建立起样品电导率与温度、压力、氧逸度、水含量、铁含量、石墨含量等六大影响因素之间的函数关系式；建立起表征人工合成的镁铝榴石-铁铝榴石榴辉岩各种导电机制的活化焓、指前因子、活化能、活化体积等物性参数与影响因素变化的定量函数关系；结合野外大地电磁测深结果，初步探究大别-苏鲁典型构造单元超高压变质带的热俯冲、冷俯冲、地幔对流等地球动力学问题，进而对大地电磁观测的大别-苏鲁地区高导异常成因提供合理的解释。