断层构造的大地电磁响应曲线变化特征的研究  

RESEARCH ON THE CHANGE CHARACTERISTICS OF MT RESPONSE CURVES OF FAULT STRUCTURE

作　　者：李学民[1] 曹俊兴[1] 贺桃娥[2] 

机构地区：[1]"油气藏地质及开发工程"国家重点实验室 [2]西南石油学院

出　　处：《天然气工业》2004年第7期42-44,57,共4页Natural Gas Industry

基　　金：国家自然科学重大基金项目 (4 9894 190 );国家自然科学基金项目 (4 0 2 74 0 19)资助

摘　　要：在大地电磁测深法中 ,分析大地电磁响应曲线的变化特征是其资料处理和解释工作中相当重要的一个环节。文章以断层构造为例 ,利用有限差分法分别计算出TE、TM模式的视电阻率值和相位 ,并且绘制了大量的视电阻率曲线和相位曲线 ;通过对TE、TM曲线变化情况的综合分析 ,得到了TE、TM视电阻率曲线形成的“喇叭”形状以及“放大器”和“均衡器”特征等认识 ,根据曲线的这些表现特征 ,可以初步判断该测区可能存在断层构造。文章还建议将该方法应用于地垒、地堑、背斜等其它地质构造。In magnetotelluric (MT) sounding.it is a very important link in the data processing and interpretation to analyze the change characteristics of MT response curves. By taking the fault structure as an example, the apparent resistivity and phase values of the TE and TM modes were calculated by use of finite difference method and a large number of the apparent resistivity and phase curves were drawn up by the authors. The reasons why the 'Bugle'-like, 'Amplifier'-like and 'Equalizer'- like shapes were formed on the TE and TM apparent resistivity curves were understood through analyzing comprehensively the changes of the TE and TM curves. According to these characteristics of the curves, it can be initially identified that the fault structure may be able to exist in the research area. In the paper, it is suggested that such a method may be used for the other geological structures as horsts, grabens and anticlines, etc.

关 键 词：断层 大地电磁响应 视电阻率 相位曲线 测井曲线 天然电磁场 

分 类 号：P631.4[天文地球—地质矿产勘探]