高温高压下不同成分斜长石电导率的实验研究及地球物理意义

项目名称： 高温高压下不同成分斜长石电导率的实验研究及地球物理意义

项目编号： No.41304068

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 胡海英

作者单位： 中国科学院地球化学研究所

项目金额： 25万元

中文摘要： 矿物岩石电导率的实验数据可以约束野外电磁观测数据的反演结果。大地电磁测深结果显示大陆中、下地壳普遍存在着异常高导层。目前对高导层的起源一直没有统一的认识，其原因是影响岩石电导率变化的因素有很多，比如温度、压力、矿物组成、矿物化学成分等，具体哪些影响因素对岩石的电性起主导作用，一直都存有争议。因此，建立地壳主要造岩矿物的电导率与各影响因素之间的函数关系是最基础也是最重要的一步。斜长石作为长石矿物的一个类质同象系列，广泛地存在于地壳各类岩石中，它的电导率在很大程度上影响着地壳岩石的电学性质。本项目拟借助交流阻抗谱测量技术和高温高压设备，首次系统地开展斜长石电导率与温度、压力和化学成分之间定量关系的研究，并结合其他矿物电导率数据建立含斜长石地壳岩石的电导率，最终构建地壳电导率-深度剖面并探究矿物组分与矿物化学成分对其影响，从而可能为中、下地壳高导层的起因提供一个新的解释。

中文关键词： 电导率；斜长石；高温；高压；高导层

英文摘要： Laboratory electrical conductivity data of minerals and rocks can provide important constraints on the inversion results obtained from the field magnetotelluric data. Magnetotelluric surveys have revealed that a high conductivity zone (HCZ) exists in many places worldwide in the middle to lower continental crust, whereas there is still no generally accepted explanation for the origin of HCZ until now. The reason is that many factors such as temperature, pressure, mineralogical constituents and mineralogical composition, can affect the electrical conductivity of rocks, however, it is still controversial that which of these factors mainly control the electrical properties of rocks under the conditions of the middle to lower continental crust. Consequently, it is the first most important step to establish the relationship between the electrical conductivity of the major rock-forming minerals and these factors. Plagioclase, which is a solid solution series in feldspar family, is widespread and common in the different categories of crustal rocks in the Earth's crust. To some extent, the electrical conductivity of plagioclase has an important influence on the electrical properties of rocks in the Earth's crust. Therefore, in this project it will be the first time to systematically study on the quantitative relationshi

英文关键词： electrical conductivity；plagioclase；high temperature；high pressure；high-conductivity zones