大地电磁测深中薄层响应特征与地质目标体拾取的探讨  

Discuss of the response characteristics of magnetotelluric sounding in the thin layer and the picking up of geological target body

作　　者：蒋亚东[1] 雷宛[1] 刘倩[1] 李超[1] 凌飞[1] 

机构地区：[1]成都理工大学地球物理学院,成都610059

出　　处：《物探化探计算技术》2015年第3期292-299,共8页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中国地质调查局地质调查项目(1212011220750)

摘　　要：基于理论模型的正演模拟,探讨了大地电磁测深法中的薄层响应特征,考察不同盖层深度、薄层厚度以及围岩电阻率比等参数对测深曲线的影响,并采用背景值最大归一化建立视电阻率与盖厚比的关系曲线图,总结出高、低薄层的电性响应特征。针对地质目标体的拾取,建立了均匀半空间下的近地表非均匀体与地质目标体理论模型,对比TE、TM极化模式下视电阻率、阻抗相位的单点响应曲线与正演响应拟断面图,总结出区别非均匀体与局部地质目标体异常的重要响应特征。The response characteristics of thin-bed of magnetotelluric sounding is discussed based on theoretical model of forward numerical simulation in former part of the paper.Different depth of cover layer,the thickness of the thin layer and the resistivity ratio of surrounding rock parameters of the impact on sounding curves is investigated.The relationship curve diagram of apparent resistivity and the ratio of the thin layer thickness with cover layer depth is found based on the background value maximum normalized.Sum up the high and low electrical response characteristics of thin layer.The geologic abnormal body is picked up to establishment of uniform half space under the static body and geologic abnormal body theory model in the later part of the paper.Compared the TE and TM polarization mode of apparent resistivity and impedance phase single point response curves and forward response influence,summed up the difference response characteristics between static body and the local geologic abnormal body.

关 键 词：大地电磁测深 薄层响应 地质目标体响应 正演模拟 

分 类 号：P631.325[天文地球—地质矿产勘探]