Exploring through cover ? the integrated interpretation of high resolution aeromagnetic, airborne electromagnetic and ground gravity data from the Grant's Patch area, Eastern Goldfields Province, Archaean Yilgarn Craton Part A: Mapping geology using airbo

Abstract

Conductivity values derived from TEMPEST AEM data were compared with conductivity values derived from ground EM data and borehole induction logs. The high degree of correlation at scales of around 100 m laterally and less than 10 m vertically allow the conductivity data derived from AEM data to be interpreted with confidence. An extensive drilling database was used to interpret the conductivity distribution. This showed that the conductivity variations at Grant's Patch are principally associated with the regolith, specifically with in situ saprolite. The fresh bedrock in this area is uniformly resistive in comparison with the regolith, which attains a maximum conductance of around 50 S. The regolith conductivity variations can be used to infer basement lithology because the regolith is largely in-situ and the thickness and conductivity of the regolith materials are demonstrably litho-dependent. Information derived from the AEM data has lead to a significantly improved understanding of the geology (lithology, structure, alteration and weathering) in the Grant's Patch Area.