Steve Beresford presents 'Putting the poly in polymetallic Ni-Cu-PGE deposits' as part of the SGEG Facets of Exploration webinar series.
Abstract:
The largest and most valuable deposit style of any commodity is a subset of mafic hosted Nickel deposits where Ni is not the most valuable metal. The mineral system we have developed over the last twenty years includes the major contribution of lithospheric architecture and intrusive geometry that are now common use in industry. In addition, this construct asks and attempts to answer the key question. What controls the polymetallic nature of these special deposits? The answer includes everything from mantle source, intra LIP timing, oxidation state, to halogens, features that are absent from most Nickel deposits. Unlike most Nickel deposits, these systems have a hydrothermal/metasomatic footprint that defines the equivalent of the potassic zone in porphyry deposits and defines the tip of the iceberg. This footprint is a suite of mineral, hydrogeochemical and hyperspectral characteristics that transform the explorer's toolbox. How we form a polymetallic deposit is the end result of a concentration of processes that avoids the most common and easiest genetic paths but leads to a causally emergent perfect storm for massive sulfide concentration and fractionation (putting the poly in polymetallic). We propose that the common perception that these deposits are rare and remote is because our current exploration techniques overlook them. Thus, we are avoiding our industry’s greatest prize.
Biography:
Steve has worked across industry and academia. In his past life, he was a Professor at UWA, Lecturer at Monash University, and has been Chief Geologist of three mining companies IGO, First Quantum, and MMG. Steve is the co-host of the Exploration Radio podcast and co-author of UNCOVER and is presently the Chair of CET. Steve has worked in 64 countries in most of the world's Ni belts and deposits and what he really does is explore for the next Nickel and Copper supergiant.
