EFFECTIVENESS OF TRANSIENT ELECTROMAGNETICS IN MINERAL DEPOSIT EXPLORATION: A CASE STUDY OF THE KERRY ROAD Cu-Zn-Au SULPHIDE DEPOSIT, NORTHWEST SCOTLAND

Abstract

It is well known that mineral deposits with surface showing have long been discovered and only ‘blind’ and deeply buried deposits are yet to be discovered. It is equally well known that the global economic growth is dependent upon non-renewable resources, particularly minerals, and will continue doing so for sometime to come. The global population is projected to grow by about 1.6 billion from 6.1 to 7.7 billion people by the year 2020, with most of this growth taking place in developing nations. The demand for minerals in developing nations will equally increase. Finding new deposits to satisfy this demand is therefore a challenge and requires not only the use of more effective exploration techniques but also combining a number of methods to increase the chances of discovery. This paper discusses the Transient Electromagnetics (TEM) method and its effectiveness in mineral exploration using the stratiform volcanogenic massive Cu-Zn-Au sulphide deposit at Kerry Road in northwest Scotland as a case study. This deposit is hosted in the Proterozoic Loch Maree Group (LMG) composed of metagreywackes and metabasalts. The ore occurs in a quartz-carbonate horizon composed of 15-20% pyrite, pyrrhotite plus chalcopyrite, sphalerite, marcasite and galena. Earlier geophysical studies and drilling of the deposit had detected mineralisation at a depth of about 9 m. Exploration with TEM detected the same mineralization at a depth of about 8 m with a dip of 88-90o thereby demonstrating the effectiveness of the technique.