可控源音频大地电磁法深部找矿实验效果

THE TEST RESULT OF THE CONTROLLED SOURCE AUDIO-FREQUECY MAGNETOTELLURIC METHOD IN THE PROSPECTING FOR DEEP ORE DEPOSITS

为了考查电磁法在探测深部金属矿及地质构造方面的实际效果,用可控源音频大地电磁法分别在埋深为500 m和1 100 m的两个已知隐伏铁、铜矿体上进行了实验工作。实验结果表明地电异常显示了矿体、断层以及岩层接触带的分布。在矿体埋藏深度小于500 m、矿层较厚时,地电异常十分明显;若矿体埋藏深度大于1 000 m,地电异常主要反应了控矿、容矿构造。

To examine the actual result of the electric-magnetic method in detecting deep metallic ore deposits and structures, the au- thors conducted two tests in two known buried iron and copper ore deposits by using Controlled Source Audio-frequency Magnetotelluric Method （CSAMT）. The two known ore bodies have the buried depths of about 500 m and 1 100 m, respectively. The results of the tests show that the geoelectrical anomalies can indicate the distribution of ore bodies, faults and lithologic contact zones. When the buried depth of the ore body is less than 500 m and the ore bed is relatively thick, the geoelectrieal anomaly is very obvious. When the buried depth of the ore body is more than 1 000 m, the geoelectrical anomaly mainly reflects the ore-controlling and ore-hosting structure.