煤田地质与勘探2025，Vol.53Issue(11)：12-22,11.DOI:10.12363/issn.1001-1986.25.06.0422
考虑激发极化效应的脉状矿体地-井瞬变电磁响应研究
Investigating surface-borehole transient electromagnetic responses from veined orebodies considering induced polarization effects
摘要
Abstract
[Objective]The observational data derived using the surface-borehole transient electromagnetic(TEM)meth-od tend to feature complex curve morphologies,a problem posing significant challenges to data processing and interpret-ation.This study aims to ascertain the mechanisms behind the generation of such complex responses using forward mod-eling.[Methods]Using the vector finite element-based spectral method and the Cole-Cole model,this study developed a 3D forward modeling technique incorporating the induced polarization(IP)effect.By constructing a typical theoretical model of low-resistivity veined orebodies,it systematically analyzed the electromotive force(EMF)responses excited by transmitter loops at different orientations.[Results and Conclusions]The results indicate that the induced EMF curves from surface-borehole TEM responses were characterized by complex morphologies,with multiple sign reversals com-monly observed.These characteristics were jointly controlled by the relative locations between transmitter loops and sur-vey points,the resistivity contrast between veined orebodies and surrounding rocks,and the IP effect.The sign reversals in the late delay stage arose primarily from the individual or combined effects of the IP effect and the resistivity contrast between veined orebodies and surrounding rocks,representing a significant indicator for identifying concealed veined orebodies.The results of this study provide a theoretical basis for the mechanistic analysis and geological interpretation of complex TEM responses.关键词
瞬变电磁法/地-井装置/三维正演/激发极化效应/脉状矿体Key words
transient electromagnetic(TEM)method/surface-borehole configuration/3D forward modeling/induced polarization(IP)effect/veined orebody分类
天文与地球科学引用本文复制引用
李建慧,王垚,王文闯,谢劭健,祝思维..考虑激发极化效应的脉状矿体地-井瞬变电磁响应研究[J].煤田地质与勘探,2025,53(11):12-22,11.基金项目
地球深部探测与矿产资源勘查国家科技重大专项项目(2024ZD1003000) （2024ZD1003000）
