贵州独山半坡锑矿CSAMT法深部找矿预测

Deep Prospecting Prediction of Banpo Antimony Deposit Based on CSAMT Method in Dushan County,Guizhou Province

贵州独山半坡锑矿处于扬子地块东南缘与华南褶皱带的复合部位,为华南锑矿带具有代表性的大型锑矿床之一。该矿经过30多年开采,工业储量已消耗殆尽,为缓解资源危机,采用可控源音频大地电磁法(Controlled source audio-frequency magnetotelluric method,CSAMT)对该矿区进行深部找矿预测研究。结合相关地质工作成果,在分析矿区地质特征的基础上,首先在半坡锑矿已知矿体上方选择试验坡面进行了CSAMT探测。试验表明,与锑矿化有关的硅化蚀变体与解译异常套合较好,可见采用该法寻找深部蚀变地质体实现间接寻找深部隐伏锑矿床具有可行性。然后在半坡锑矿边深部系统开展了CSAMT法探测工作,对探测数据采用曲线平移法进行静校正后进行了二维地形反演,并结合矿区成矿地质特征进行了综合解译。研究表明:1矿区L112~L122线深部存在一向上隐伏隆起构造,半坡断层与半坡隆起构造顶部交切和隆起顶部的剥离空间为有利的成矿区域;2CSAMT解译的高阻体附近相对低阻区为重点找矿区域,成矿断层+CSAMT解译的封闭高阻体为该区重要的找矿标志;3L118线117.2#点位深部存在隐伏锑矿体的可能性较大。结合上述分析,在L118线117.2#点位附近布设了WZK118-1钻孔进行验证,结果表明:在695.39~697.33 m深部见到新隐伏富锑矿体,其赋存位置与CSAMT断面解译的可能存在隐伏锑矿(化)体的位置基本吻合,可见采用CSAMT法在该矿区进行锑矿深部找矿具有一定的成效,可供类似矿山深部找矿参考。

The Banpo antimony deposit is located in the composite position of the southeast margin of Yangtze massif and South China fold belt,it is one of the representative of the large antimony deposits in the South China antimony belt.At present,after mining for more than 30 years,the industrial reverses of the deposit has been depleted.In order to alleviate the resources crisis of the deposit,the controlled source audio-frequency magnetotelluric method（ CSAMT） is adopted to conducted the deep prospecting prediction work in the mining area.Combing with some related geological results of the mining area,based on analyzing the geological characteristics of the mining area,firstly,the test profile is selected in the mining area to conduct CSAMT detection,the test results show that the superposition effect of the silicide erosion variation body related to antimony mineralization and interpretation anomaly is good,it is feasible to conduct the prospecting of deep alteration geological body by using CSAMT method to find the deep concealed antimony deposit; secondly,the CSAMT method is used to conduct deep prospecting prediction work in the edge and deep of the mining area,the detection data is conducted static correction by using curve translation method,and the static correction results is conducted 2D terrain inversion,the comprehensive interpretation is done based on the metallogenic geological characteristics of the mining area.The study results show that： 1a upper concealed uplift structure is existed in the deep area below the L112 L122 line in the mining area,the stripping space of the top of Banpo arched structure and the intersection area of Banpo fault and top of Banpo arched structure are the favorable metallogenic areas; 2theprospecting area is the relative low resistance area near the high resistance body by CSAMT interpretation,the key prospecting indicators of the metallogenic fault and the closed high resistance body by CSAMT interpretation;（3）the concealed antimony deposit is more likely existed the deep of 117.2# point of L118 line.The WZK118- 1 dirll is set in the 117.2 point of L118 line to verify the above analysis results,the results show that the new concealed rich antimony ore-body is found in the deep of 695.39 697. 33 m,its location is basically consistence with the location of the concealed antimony（ mineralizaiton） ore-body by CSAMT interpretation,it is further indicated that the good effect of the deep prospecting prediction of antimony deposit by using CSAMT method is obtained,it can provide some reference for the deep prospecting work of similar mines.