An alternative tool to controlled-source audio-frequency magnetotellurics method for prospecting deeply buried ore deposits  

一种大尺度固定源深部资源电磁探测新方法

作　　者：Qingyun Di Guoqiang Xue Changmin Fu Ruo Wang 底青云;薛国强;付长民;王若(Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Frontier Technology and Equipment Development Center for Deep Resources Exploration,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Innovation Academy for Earth Science,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Frontier Technology and Equipment Development Center for Deep Resources Exploration,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [3]Innovation Academy for Earth Science,Chinese Academy of Sciences,Beijing 100029,China [4]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [5]Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China

出　　处：《Science Bulletin》2020年第8期611-615,M0003,共6页科学通报（英文版）

基　　金：supported by Deep Resources Exploration and Mining Project(2018YFC0603200);National Natural Science Foundation of China(41874088);Project of National Deep Exploration Technology and Experimental Research(Sino Probe-09-02(201011079));the Key Project of Knowledge Innovation of Chinese Academy of Sciences(KZCX2-YW-121)。

摘　　要：Due to the rapid development of China's economy,most nearsurface resources have been mined[1].It is an urgent task to detect deep-seated oil and gas and mineral deposits.Electromagnetic methods have proven to be effective tools in the exploration of deeply buried resources and targets[2,3]-The controlled-source audio-frequency magnetotellurics method(CSAMT)and the magnetotelluric method(MT)are commonly used electromagnetic approaches[4-6].被动源电磁法虽探测深度大(>10 km),但信噪比低.传统的主动源电磁法(如可控源音频大地电磁法,CSAMT)采用接地发射源形式,发射线长2 km,发射功率30 kW,是国际上矿产普查、水文与工程环境等领域主流方法.但由于发电机较重,不利于山区工作.另外,受发射功率的限制,收发距一般小于10 km,观测范围有限、探测深度小.为了实现深部资源兼顾大探深、高分辨探测,本文提出一种新的深部资源探测方法(WEM),即利用长度大于100 km、功率达到兆瓦级的国家级大尺度固定发射天线,收发距由常规的10 km拓展到3000 km以上,可实现全国领土和邻海范围内的电磁探测.经过数值模拟和实际资料反演,发现这种固定源形式的观测方法深度大、精度高.这种全新的地球物理探测方法,将会在深部资源探测中具有较大的推广应用潜力.

关 键 词：CSAMT 大尺度 电磁探测 WEM 深部资源 固定源 

分 类 号：P631.325[天文地球—地质矿产勘探]