长导线源瞬变电磁响应衰减曲线多个“符号反转”现象特征分析  

Study on characteristics of multiple"symbol reversal"phenomena of grounded-wire source transient electromagnetic decay response curve

作　　者：李论 王鹏 LI Lun;WANG Peng(Xi’an Research Insitiute,China Coal Technology and Engineering Group Crop.,Xi’an 710077, China)

机构地区：[1]中国煤炭科工集团西安研究院有限公司,西安710077

出　　处：《物探化探计算技术》2020年第6期773-781,共9页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家重点研发计划项目(2017YFC06061806)。

摘　　要：在四川某石墨矿区进行长导线源瞬变电磁勘探时,经常发现瞬变电磁响应衰减曲线出现“符号反转”现象,甚至有些测点的响应衰减曲线出现多次“符号反转”,在可能造成该现象出现的众多原因中,激电效应的影响是不可忽略的。因此,在对分析实测长导线源瞬变电磁响应特征的基础上,利用含激电效应的长导线源瞬变电磁一维正演,探讨瞬变电磁响应衰减曲线中多次“符号反转”现象特征,说明激电效应也是引起瞬变电磁响应衰减曲线出现多次“符号反转”现象的原因。When conducting grounded-wire source transient electromagnetic exploration in a graphite mining area in Sichuan,it is often found that the transient electromagnetic response decay curve has a"symbol reversal"phenomenon,and even some response of the measurement station appear multiple"symbol reversal",possibly among the many causes of this phenomenon,and the effects of the induced polarization(IP)effects are not negligible.Therefore,based on the analysis of the characteristics of the measured grounded-wire source transient electromagnetic response,the grounded-wire source transient electromagnetic one-dimensional forward modeling is used to discuss the phenomenon of multiple"symbol reversal"in the transient electromagnetic response decay curve in this study.This indicates that the IP effects is also the cause of multiple"symbol reversal"phenomena that may cause the transient electromagnetic response decay curve.

关 键 词：长导线源瞬变电磁实测数据 正演响应 多次“符号反转”现象 激电效应 

分 类 号：P631.3[天文地球—地质矿产勘探]