Imaging an Ag-Au rich epithermal system in British Columbia, Canada, with airborne ZTEM and ground magnetotelluric data

Abstract

We present initial results from a study combining airborne Zaxis tipper electromagnetic (ZTEM) and ground-based magnetotelluric (MT) data to image an epithermal system in British Columbia. The collocated employment of both methods allows a direct comparison of both data sets in the overlapping frequency band and shows solid consistency. Stand-alone inversion of ZTEM data suffers from the lack of electric amplitude information, which can be provided by the MT data. The results of three-dimensional (3-D) inversion modeling of the two data sets are presented. Models of electrical conductivity derived from both data sets are consistent and depict the geologic structure of the intrusion, with the volcanic rocks imaged as more resistive units, and parts of the mafic intrusion and the Quaternary cover appear as conductive features.