Airborne conductivity mapping of the Bathurst Mining Camp

Abstract

A multi-parameter helicopter-borne magnetic, electromagnetic (HEM) and radiometric survey completed in 1995 covered the entire Bathurst Mining Camp in Eastern Canada. The five frequency multi-coil HEM system used for this survey covers a wide frequency range and allows detailed conductivity mapping of the ground. In particular the apparent conductivity map generated from the 4433 Hz co-planar EM data shows good correlation with the bedrock geology. Conductive units are accurately delineated and can be used to help supplement detailed geological mapping. Moreover, the conductivity map shows excellent correlation with the calculated first vertical derivative of the total magnetic field, providing a means to distinguish between overburden and bedrock conductivity responses. Many orebodies are associated with discrete, coincident magnetic and conductivity anomalies.