1. School of Earth & Environmental Sciences, University of St Andrews, Bute Building, Queen's Terrace, St Andrews KY16 9TS, UK
2. Ralph J. Roberts Center for Research in Economic Geology, Department of Geological Sciences and Engineering, University of Nevada, Reno, USA
3. Business School and Centre for Exploration Targeting, School of Earth Sciences, The University of Western Australia, Crawley, Perth, Australia