多种电磁法在某金矿的野外勘探应用

刘春明^{1, 2, 3}，佟铁钢^{1, 2, 3}，何继善^{1, 2, 3}

(1. 中南大学 有色资源与地质灾害探测湖南省重点实验室，长沙 410083；
2. 中南大学 地球科学与信息物理学院，长沙 410083；
3. 中南大学 地质调查研究院，长沙 410083)

摘 要：为了对比分析广域电磁法、音频大地电磁法(AMT)与可控源音频大地电磁法(CSAMT)的勘探效果，在山东某金矿的已知地质剖面开展了多种电磁法实验勘探，通过对比分析在相同剖面上的实验结果发现，相对于AMT而言，广域电磁法具有浅层分辨能力高、抗干扰能力强、工作效率高等优点；相对于CSAMT而言，则具有勘探深度大、抗干扰能力强、工作效率高等优点。关于广域电磁法的高频段广域电阻率与卡尼亚电阻率不重合现象、场源效应和阴影效应、电磁场多分量综合利用等问题上还值得探讨和研究。

关键词：广域电磁法；音频大地电磁法；可控源音频大地电磁法；勘探深度；抗干扰能力

Exploration of various electromagnetic method in some gold mine

LIU Chun-ming^{1, 2, 3}, TONG Tie-gang^{1, 2, 3}, HE Ji-shan^{1, 2, 3}

(1. Key Laboratory of Non-ferrous Resources and Geological Hazard Detection, Central South University,
Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. Institute of Geological Survey, Central South University, Changsha 410083, China)

Abstract:A variety of electromagnetic exploration methods, involving the wide field electromagnetic method, the audio magnetotelluric method (AMT) and the controlled source audio frequency magnetotelluric method (CSAMT), were carried out on a known geologic profile of a gold mine in Shandong Province, with the purpose of comparison in the real exploration effects. Through the comparison of the exploration results, from the same section, it is found that the wide field electromagnetic method has advantages of shallow high resolution capability, strong anti-interference ability and high survey efficiency compared with AMT, and it is better than CSAMT in the exploration depth, anti-interference ability and working efficiency. However, the study and research should be moved further including the inconsistency phenomenon between the wide field electromagnetic resistivity and the Cagniard resistivity at high frequency, source effect and static effect, and the utilization of electromagnetic multi-components.

Key words:wide field electromagnetic method; AMT; CSAMT; exploration depth; anti-interference ability