瞬变电磁法工作电流的设置与找矿效果分析

在地表覆盖有碎石流或接地条件较差的工区,用接地类激电方法难以达到较好的勘探效果。而在这类地区采用不接地回线的瞬变电磁方法具有其他方法所不可替代的优势,其无需接地,且横向分辨率较高,可利用的参数较多,适用于各种地理环境,并且受地形影响较小,可以获得良好的找矿效果。但在工作中要注意发射电流的合理设置,不同大小的发射电流取得的勘探结果也不一样,大的发射电流未必就能发现低阻体引起的异常,并相应提高曲线的异常幅度,若发射电流设置不合理,将影响最终的找矿效果。通过在东莫扎抓、纳日贡玛等矿区的应用实例,说明了合理设置发射电流的重要性。

Analysis on Prospecting Effect and the Setting of Operating Current in Transient Electromagnetics Method

It is hard to achieve favorable prospecting effect by using IP technology of grounding mode in the working areas with the surface covered by gravels or areas with worse grounding conditions.However,Transient Electromagnetics Method of using phrase to phrase loops has advantages that can not be replaced by other methods as no grounding need,high diastropic resolution,and the parameter that can make use of is more,being applicable to various geography environment work,and be subjected to the topographic influence smaller,and favorable effect of mineral prospecting.Rational setting of the emission current is particularly supposed to be noticed,otherwise to be different exploration results.Powerful emission current does not necessarily help to find the abnormality caused by low resistive anomaly and improve abnormal curve amplitude accordingly,which will impact on the final exploration.The importance of setting emission current properly is exemplified by the mineral areas in Dongmozhazhua and Narigongma.