2017 Richard W. Hutchinson Lecture

Structural controls on nickel sulfide deposits: examples from China and Russia inform models for Voisey’s Bay

Abstract
The global distribution of magmatic Ni-Cu-Co-platinum group element (PGE) sulfide deposits and mineralization in mafic-ultramafic intrusions is controlled by the geometry and structural setting of the magma chamber. The recognition that the Ovoid Deposit and the Eastern Deeps Deposit at Voisey’s Bay are localized where a dyke-like conduit connects to a larger intrusive body has been a key observation that has underpinned much of the exploration activity. Likewise the geological relationships in the Noril’sk Type intrusions indicate a localization of mineralization within the thicker axial parts of magma conduits that follow and are modified by major structures like the Noril’sk-Kharaelakh Fault. These structural relationships are repeated at Jinchuan in Gansu Province and other deposits in China; where the configuration of the intrusion is controlled by regional structures that create space for the emplacement of a small intrusion. All of these examples share common features including the space created within and adjacent to fault zones by the local structures that link into mantle-penetrating fractures that localize magmatism in the roots of large igneous provinces at cratonic margins. These primary controls likely provided the setting in which many of the Thompson ultramafic chonoliths were originally formed, and the model can be applied to the vast majority of global magmatic sulfide mineral systems as an exploration guide.

About Peter Lightfoot
Peter received his B.A. from Oxford University, M.Sc. from the University of Toronto and Ph.D. from the Open University. Following post-doctoral studies at the Geological Survey, he worked extensively on Sudbury whilst undertaking research on Noril’sk. Peter started work as a Senior Geologist with Inco before Voisey’s Bay was acquired

A reception with a tribute to Dick Hutchinson will be held in the Materials Science Atrium following the presentation. An RSVP to Paula.Luchak@uwo.ca would be appreciated.