Reposta Eletromagnética de um Corpo Tabular Vertical sob Manto de Intemperismo em Multifreqüência, Multi-separação obtidas no Laboratório, com Diferentes Sistemas de Bobinas

Abstract

Overburden effects on EM response of a vertical tabular conductor are studied through model experiments by varying: a) frequencies between 25O Hz to 35 kHz; b) coil separation and c) coil systems i.e., horizontal coplanar, vertical coplanar and vertical coaxial systems. The results demonstrate that EM responses are affected varyingly in different coil systems by the overburden At low frequencies the response of overburden-orebody approximates the response of the orebody alone while at high frequencies it corresponds to that of the overburden alone. Increase in separation moves the response to lower frequencies. This study shows that it is possible to know in advance the band of frequencies where the EM response of the target is least affected by the overburden. This will help in planning an EM survey in a region of known overburden parameters.