可控源音频大地电磁测量(CSAMT)方法在寨上金矿区的应用

Application of Controlled Source Audio-frequency Magnetotelluric(CSAMT)Measurement Method in Zhaishang Gold Mine

寨上金矿地表第三系和第四系地层覆盖厚,因而地表找矿和深部矿体定位较难。针对勘查现状,开展可控源音频大地电磁测量（CSAMT）工作。在贯穿寨上矿区南北矿带的16线开展CSAMT测量工作,结果显示南北矿区的电阻率存在显著差异。通过16线电阻率二维反演,扎麻树背斜呈北陡南缓,核部较陡立的形态。破碎蚀变带（矿体）位于高、低阻异常的梯度带上,揭示出10条破碎蚀变带（南、北矿带各5条破碎蚀变带）与已知构造带和矿脉分布套合较好。对寨上矿区南矿带测区范围勘探线进行了电阻率测量工作,43~95线CSAMT测量联合剖面显示,各矿脉深部存在较大的找矿空间,扎麻树背斜核部的35号脉总体北倾,异常下延深度较大,深部具有找矿潜力。可控源音频大地电磁测量工作解决了寨上金矿构造展布问题,探索其南、北矿带深部矿脉分布规律,为该矿区深部勘探提供了理论依据。

Due to the tertiary and quaternary strata overlay thickness on the surface of Zhaishang gold mine,it is difficult to position the deep orebody and surface prospecting.According to current situation of exploration,a good deal of work Controlled Source Audio-frequency Magnetotelluric measurements were carried out.In addition,through CSAMT survey work at 16 lines in north and south ore belt,the results showed that there were significant differences between the north and the south mining area in resistivity.Through analyzing resistivity two-dimensional inversion of the 16 lines,it was found that Zhaimashu anticline displayed north step south slow,and a vertical form at karyomere.Broken alteration zone（orebody）was located in the high and low resistivity anomaly gradient belt,suggesting that there were 10 broken alteration zone,south and north ore belt each has 5 broken alteration zones,and the known structural belt and vein distribution sets was better.We completed the resistivity measurement at south ore belt area of the gold mine,43~95 line CSAMT joint profile measurement showed that the deep veins were larger prospecting space.The 35 series in Zhamashu arch core overall exhibited north dipping with abnormal current larger depth,and the deep prospecting was potential.In general,controlled source audio-frequency magnetotelluric measurements can solve the problem of structure distribution,explore the south and north ore zone of deep vein distribution at the gold mine,which provides a theoretical basis for deep exploration.