Sulfi de ore prospecting in carbon-containing stratum using comprehensive time-domain induced polarization and controlled-source audio-frequency magnetotellurics  

综合时间域激电和可控源音频大地电磁方法实现含炭地层硫化矿找矿应用

作　　者：Sun Ren-Bin Chu Li-Xia Zhang Gui-Bin Cheng Qiu-Ming Xiang Yun-Chuan Hu Bin Zhang Chang-Rong Li Jian-Fu Zhao Yi-Jun 孙仁斌;楚丽霞;张贵宾;成秋明;向运川;胡斌;张昌榕;李建伏;赵绎钧(中国地质调查局发展研究中心,北京100037;中国地质大学(北京),北京100083;中国地质大学地质过程与矿产资源国家重点实验室,北京100083;萨尔茨堡大学,奥地利萨尔茨堡5020;内蒙古自治区地质矿产勘查开发局,呼和浩特010011)

机构地区：[1]Development and Research Center,China Geological Survey,Beijing 100037,China [2]China University of Geosciences,Beijing,100083,China [3]University of Salzburg,Salzburg,5020,[e-mail] [4]Inner Mongolia Geology Mineral,Hohhot,010010,China.

出　　处：《Applied Geophysics》2020年第5期809-822,903,共15页应用地球物理（英文版）

基　　金：The Research is funded by Comprehensive Intelligent Mapping System and Application of Geological Survey(DD20190415);Exploration and Development Tracking and Result Integration of Energy and Important Mineral Resources(DD20190457);Resource Assessment and Prediction for Main Tectonic Metallogenetic Domains in the World(DD20190459).

摘　　要：Carbon-bearing stratum normally features low resistance and high polarization.If the lithostratigraphy of the exploration area contains large amounts of carbon,the induced polarization anomaly caused by metal sulfide ore bodies will be inundated by the high polarization of carbon-containing wall rock.In this work,we adopted time-domain induced polarization(TDIP)and controlled-source audio-frequency magnetotellurics(CSAMT)on deep prospecting of the carbon-bearing stratum of the Ar Horqin Banner,Inner Mongolia.The underground medium is divided into target geologic bodies according to the geological information within the known exploration line borehole,and the physical properties of various target geologic bodies are calculated using weighted averages to build a geologic-geophysical model that can fit the observation data.Consequently,we can determine the range and morphological characteristics of the electrical properties of the ore-bearing geologic bodies in the inversion results in the study area.Then we can use the characteristics summarized from the known exploration line to interpret unknown exploration line.Results indicated that,when the diff erence in physical properties between the ore body and interference wall rock is not clear,the geologic body can be classifi ed via the paragenetic(associated)assemblage relations of the underground medium.Geological interpretation is guided by the comprehensive physical properties of ore-bearing geologic bodies to avoid interferences.含炭质地层普遍具有低阻高极化电性特征,如果勘查区岩石地层含大量炭质,金属硫化物矿体引起的激电异常将被含炭围岩的高极化特征淹没。本文选择在内蒙古阿鲁科尔沁旗某含炭质地层研究区内,利用时间域激电(TDIP)和可控源音频大地电磁(CSAMT)开展深部找矿研究工作,根据已知勘探线钻孔内的地质信息将地下介质划分为若干目标地质体,采用标本物性加权平均统计方式计算各类目标地质体的物性参数,构建可以拟合实际观测数据的地质-地球物理模型,进而确定含矿地质体在反演结果中电性范围及电性形态特征,并应用于未知勘探线解释。取得以下主要认识:矿体与干扰围岩物性特征差异不明显时,可通过地下介质的共(伴)生组合关系进行地质体分类,以地质体综合物性指导地质解释工作,实现含矿地质体与干扰地质体的剥离。

关 键 词：TDIP CSAMT carbon-containing stratum sulfur containing lead-zinc-silver deposit weighted average of physical property 

分 类 号：P631.325[天文地球—地质矿产勘探]