Geophysical Responses over the Cannington Ag-Zn-Pb Deposit-Queensland

Abstract

The Cannington deposit is a high grade Ag-Zn-Pb deposit found in 1990 by BHP Minerals drilling an isolated 1,000 nT aeromagnetic feature. Following the discovery of Cannington, numerous airborne, ground and borehole surveys have been carried out which overall, provided some assistance at better defining the ore system but did not lead to the discovery of new major deposit in the area. While Cannington possessed a clear magnetic response, the presence of a thick conductive cover made the use of EM and electrical techniques challenging. BHP used Cannington as a test ground for a variety of new techniques including a ground SQUID EM sensor, modified airborne EM technology (higher power and lower base frequency) and over 10 years after discovery, the first ever Falcon airborne gravity gradiometer survey in Australia.