高密度电阻率法中负电位差的产生原因及其可利用性

The reason for the generation of negative potential difference in high-density electrical method and its utility

在高密度电法勘探的实践过程中,人们大多数时候仅使用电阻率参数的异常情况来进行解释推断工作,而在合适的地电条件下,往往能够测到有规律的、幅值较大的负电位差。作者通过对倾斜岩土界面及溶洞等两种常见边界条件下自然电场分布的理论分析,来阐明自然电场存在的原因及其在外加人工电场作用下可能发生的偏转,并认为高密度电阻率法中负电位差的产生是由于人工电场与山地电场、溶洞过滤电场综合作用所致。文中所列的几个工程实例表明,负电位差可以辅助判断倾斜基岩面的深度、区分"低阻圈闭高阻"异常是否岩溶空洞。

In the practice of high-density electrical prospecting, geologists usually only use the parameters of resistivity anomalies to perform interpretation and deduction. However, under suitable geoelectric conditions, regular large amplitude negative potential differ- ence can be observed. Based on theoretical analysis in combination with several engineering examples, the authors explain the high- density electrical potential difference of negative exploration process to determine the role of adjuvant.