利用多通道瞬变电磁法识别深部矿体——以内蒙兴安盟铅锌银矿为例  

Identifying deep ore bodies using the Multi-Channel Transient Electromagnetic Method (MTEM):an example of a lead-zinc-silver mine in Inner Mongolia

作　　者：欧阳涛[1,2,3] 底青云 薛国强[4,2,3] 雷达 OUYANG Tao;DI QingYun;XUE GuoQiang;LEI Da(Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;Institutions of Earth Science, Chinese Academy of Sciences,Beijing 100049, China;University of Chinese Academy of Sciences, Beijing 100029, China)

机构地区：[1]中国科学院页岩气与地质工程重点实验室中国科学院地质与地球物理研究所,北京100029 [2]中国科学院大学,北京100049 [3]中国科学院地球科学学院,北京100029 [4]中国科学院矿产资源研究重点实验室中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学报》2019年第5期1981-1990,共10页Chinese Journal of Geophysics

基　　金：国家重大科研装备研制项目"深部资源探测核心装备研发"(ZDYZ2012-1-05)子项目"多通道大功率电法勘探仪"项目资助

摘　　要：多通道瞬变电磁法由于采用伪随机编码发射、最佳匹配相干解码技术,所以相比于传统时间域电磁方法勘探深度大且抗干扰能力强,是目前地面资源勘查领域的研究热点.针对内蒙兴安盟某铅锌银矿埋藏深度大等特点,首先根据矿区资料建立一维以及二维模型,数值计算脉冲响应并分析其特征,说明多通道瞬变电磁对于大埋深低阻异常体有良好的反映,随后通过多通道瞬变电磁技术对矿区进行实例勘查,数据处理过程中利用了反卷积的方法提取大地脉冲响应,根据轴向大地脉冲响应的峰值时刻计算视电阻率,通过对视电阻率进行全波形反演得到解释剖面,与测区钻孔资料对比分析证明,多通道瞬变电磁法是反映深部低阻异常体的有效手段.The Multi-Channel Transient Electromagnetic Method(MTEM)adopts pseudo-random code transmission and best matching coherent decoding technology, thus its exploration depth is larger and the anti-interference ability is stronger than the traditional time domain electromagnetic method, and it becomes a research focus in ground resource exploration. This paper presents the application of the method to a lead-zinc-silver mine in Xing'an League of Inner Mongolia. In view of its large burial depth, firstly, we establish a one-dimensional and a two-dimensional model based on the data of the mining area. Then we calculate the impulse response and analyze its characteristics. Results show that the MTEM can reflect well the resistance anomalies at large depths. This technology is used to carry out an example survey in the mining area. In the data processing process, the deconvolution method is used to extract the earth impulse response, and the apparent resistivity is calculated according to the peak moment of the axial ground impulse response. The full-waveform inversion of the apparent resistivity yields an explanatory profile. The comparison with the borehole data of the survey area proves that the MTEM is an effective method to reveal bodies with low-resistance anomalies in the deep subsurface.

关 键 词：深部矿体 铅锌银矿 多通道瞬变电磁 大地脉冲响应 

分 类 号：P631[天文地球—地质矿产勘探]