为推动电磁剖面(EMAP)技术向找矿勘探领域发展,本文针对密集阵列剖面(DEMAP)测量方式,利用三维积分方程法对层状介质中赋存三维地质异常体的电性结构进行了数值模拟,并在青海野马泉铁锌矿集区西部进行了大地电磁(MT)与DEMAP的野外对比观测实验.数值模拟结果显示,DEMAP观测方式获得的结果受偏移距影响,造成的视电阻率和相位误差与偏移距大小和地下电性结构的复杂性密切相关,但在整体上,统计误差≤10%.通过对野马泉矿集区的实验结果分析可得,DEMAP与MT的视电阻率断面和相位断面具有较好的一致性.本文从理论和实验上都表明DEMAP观测技术是一种有潜力的、经济、快速、有效的找矿手段.
In order better to develop the electromagnetic array profiling(EMAP)method for prospecting metallic ores,we studied the dense EMAP measurement by theoretical simulation and field experiments.We carried out numerical simulation for the models of 3Dbodies embedded in layered-earth on a dense EMAP way and conventional 5-component measuring way using the method of integral equations to compare the anomalis of phase and apparent resistivity,and conducted on DEMAP as well as MT field observations in the western Yemaquan mine of Qinghai Province.We also applied a statistic method to analyze the anomalies.Simulation results indicate that distortion of impedance is related to offset and underground electrical structures,and is less than 10%.The observation results show DEMAP resistivity cross-sections or DEMAP phase cross-sections are in good agreement with those of MT.Numerical simulation and field observations indicate that DEMAP is a potential,economical,fast and effective tool for exploration of metallic ores.