大地电磁法磁反射系数在深埋含锰地层调查中的应用--以贵州松桃杨立掌锰矿床毗邻区的次级成锰槽盆为例  

Application of the Magnetic Reflection Coefficient in AMT to Survey of Deep Manganese-Bearing Strata:An Example of the Manganese-Bearing Sub-Basin Near Yanglizhang Manganese Deposit in Songtao of Guizhou Province

作　　者：闵刚[1] 张予杰[2] 张解成 孔凡涛 蔡盼盼 王品丰 MIN Gang;ZHANG Yujie;ZHANG Xiecheng;KONG Fantao;CAI Panpan;WANG Pinfeng(Key Laboratory of Earth Exploration and Information Technology of MOE,Chengdu University of Technology,Chengdu,Sichuan 610059;Chengdu Geological Survey Center of China Geological Survey,Chengdu,Sichuan 610081;Shenzhen Investigation&Research Institute Co.,Ltd,Shenzhen,Guangdong 518000)

机构地区：[1]成都理工大学地球勘探与信息技术教育部重点实验室,四川成都610059 [2]中国地质调查局成都地质调查中心,四川成都610081 [3]深圳市勘察研究院有限公司,广东深圳518000

出　　处：《地质与勘探》2020年第5期1005-1018,共14页Geology and Exploration

基　　金：中国地质调查局项目“武陵山成矿带酉阳-天柱地区矿产地质调查”(编号:121201010000160904);国家自然科学基金项目(编号:41274078)联合资助。

摘　　要：音频大地电磁法是深埋金属矿勘探中一种常用的物探方法,研究音频大地电磁对深埋、薄层锰矿的勘探效果具有重要的理论意义及实践价值。论文首先通过建立典型地电模型,完成了大地电磁正演模拟、反演计算及大地电磁的磁反射系数成像,从理论上提出磁反射系数可以提高大地电磁法的深部分辨率;然后以贵州松桃杨立掌锰矿床毗邻区的次级成锰槽盆为勘探对象,完成了横跨成锰槽盆的音频大地电磁勘探及资料处理,获得了沿测线方向的二维电阻率模型和磁反射系数成像等值线图;最后参考研究区物性资料及钻井柱状图,进行了电阻率模型与磁反射系数成像结果的地质地球物理综合解释。研究发现,磁反射系数能够有效提高大地电磁法对深部电性层的划分能力,合理运用磁反射系数开展大地电磁多参数解释有利于提高大地电磁法的解释分辨率。The audio magnetotelluric(AMT)is a common geophysical method in surveys of deep metal deposits.Study on the effect of this method has important theoretical practical significance.In this work,a typical geo-electric model was established firstly based on geological and physical property data,on which AMT forward modeling,inversion calculation and imaging of the magnetic coefficient were carried out.Thus it was suggested that magnetic reflection coefficient can enchance deep resolution of the MT method.Then in a manganese-bearing sub-basin adjacent to the Yanglizhang manganese deposit in Songtao of Guizhou Province,AMT profiling,data processing and inversion were performed,yielding a 2 D resistivity model and contour diagrams of the magnetic reflection coefficient.At last,referring to the previous studies of physical property data and drilling data,the resistivity model and magnetic reflection coefficient were comprehensively interpreted.The research results of this work show that the magnetic reflection coefficient can,when appropriately used,effectively improve the ability of AMT in classifying deep electrical layers and enhance the interpretation resolution of the AMT method.

关 键 词：音频大地电磁法 电阻率 磁反射系数 锰矿床 线性边界 次级成锰槽盆 杨立掌锰矿区 松桃 贵州 

分 类 号：P631[天文地球—地质矿产勘探]