Wed 18th March @ noon, Rm 312.222

Abstract:

Ore forming processes involve the redistribution of heat, mass and momentum by a wide range of processes operating at different time and length scales. The fastest process at any given length scale tends to be the dominant control. Applying this principle to the array of physical processes that operate within magma flow pathways – e.g. thermal aureole formation, country rock assimilation, sulfide liquid equilibration – leads to some key insights into the origins of magmatic Ni-Cu-PGE sulfide ore deposits. This talk explains the approach, and considers how it applies to the understanding of the most recent major nickel sulfide discovery in Australia, the Nova-Bollinger system in the Albany-Fraser Orogen. Processes operating on timescales from days to millions of years can be identified in the ores and host rocks at length scales from kilometres to hundreds of metres.

Short bio:

Dr Steve Barnes is an economic geologist with particular interests in magmatic ore deposits, layered intrusions and Archean volcanism. He has been with CSIRO in Perth since 1985, with a brief interlude in the exploration industry, and leads the Ore Deposit Petrology team in CSIRO Mineral Resources. He has published over 180 journal papers and book chapters covering ore deposits and host rocks on six continents. He was the recipient in 2011 of the Gibb-Maitland Medal of the Geological Society of Australia WA Division for services to Western Australian geology.