Transient electromagnetic studies over a Cu-Zn-Au mineral prospect Gairloch, Scotland

Abstract

Comparative studies of different transient electromagnetic loop configurations have been made in a controlled mineral environment. The operational and interpretational advantages of the common, separated inline, and fixed transmitter loop profiling techniques are analyzed with respect to their response characteristics and detection capabilities. Laboratory and computer-aided theoretical simulations show that peak amplitude, response minima, and cross-over points are all important interpretative clues for estimating the location, attitude, and physical extent of the target mineralization. However such features are non-unique and profiling with more than one target-loop geometry is advisable to minimize interpretational ambiguities. It is shown that improved signal-to-noise ratios and detection limits are achievable with the fixed central transmitter loop system but in resistive terrains large loops and earlier channel information are needed for the detection of poor conductors at depth.