从探测深度看时域航电的找矿效果

THE EVALUATION OF TIME-DOMAIN AEM PROSPECTING FOR CONDUCTING ORES BY DEPTH PENETRATION ANALYSIS

从时域航电的探测深度出发,分析其找矿效果不佳的原因.首先给出了时域航电探测深度的定义,然后通过理论计算和模型实验给出了对几种常用模型的探测深度,并对导电覆盖和围岩对探测深度的影响做出初步估计.最后结合探测深度对测区飞行高度进行分析,得出测量飞行高度太高是找矿效果不佳的主要原因之一的结论,为第二代航空物探引以为鉴戒.

In this paper, the cause of ineffective exploration result was evaluated by depth penetration of time-domain airborne electromagnetic methods, in which the definition of depth penetration of time-domain airborn electromagnetic methods was given. And then the penetration depth of time-domain AEM is estimated by computer and scale modelling for several kinds of models. The effects of conductive overburden and host rock on the penetration depth are discussed. Finally, the flying height in time-domain survey in China was analysed according to the penetration depth. It is pointed out that one of the major problems in prospecting for conductive deposits is that the flying height is too high to get reliable anomalies.