BCGS December Technical Talk – Wednesday December 10, 2014
SPEAKER: Ken Witherly, Condor Consulting
TITLE: Application of Airborne Magnetics, EM and Gravity to the Ring of Fire Intrusive Complex, Ontario
DATE/TIME: Wednesday December 10th, 2014 at 4:30pm. LOCATION: Room 451, 409 Granville St (UK Building at Granville and Hastings), Vancouver
Abstract:
The Ring of Fire is an intrusive complex composed of mafic and ultramafic rocks hosted in the Archean age McFaulds greenstone belt located in James Bay lowlands of northern Ontario. Due to low topographic relief and an extensive cover of Paleozoic platform carbonate rocks, the area remained largely under explored until kimberlites were found in 1988. This lead to the development of the Victor diamond mine in 2006. Subsequent exploration for kimberlites resulted in the serendipitous discovery of the McFaulds VMS deposits in 2002 (ref Mugall 2010). With this discovery came the recognition that there was a greenstone belt present in the area and it could host economic deposits. A semi-regional Geotem survey was flown in 2003. Exploration in the area was complicated as a number of junior companies had positions in the area and while they would share the costs of expensive surveys, they were competing for what was deemed the best land positions. Ground surveys were conducted based on the Geotem results, with the targeting model being either kimberlite or VMS. This work eventuated in the discovery of a major deposit of chromite and a number of significant nickel sulfide deposits in 2007-2008. During this time, numerous airborne and ground surveys were carried out including a regional Falcon AGG and mag survey in early 2011. While various technical and commercial presentations have been made on the Ring of Fire geophysical work, due to the complicated claim ownership most of these have tended to focus on the results controlled by one group. This review is intended to look at the overall area which hosts at three significant deposit styles; VMS, magmatic nickel and chromite.
