An assessment of ZTEM and time domain EM results over three mineral deposits

Abstract

The ZTEM airborne EM system was introduced by Geotech Ltd. into commercial service in 2008. Based on measuring the tipper ratios of AFMAG frequencies, ZTEM provides conductivity information about the earth's near surface that can assist in the exploration for a variety of mineral deposit styles. The results of a surveys over three deposits will be examined; a skarn-style or carbonate replacement deposit in Mexico, a porphyry copper deposit in British Columbia and an epithermal precious-base metals deposit in the Yukon. For each survey, an helicopter time domain EM (HTEM) data set is available to compare with the ZTEM results. Overall, while similarities were noted between the ZTEM and HTEM results, there were also some significant differences that are not totally understood based on available geological information.