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Adding value in gold exploration. Neil Phillips University of Melbourne & Phillipsgold P/L, Australia. 30 +th SirJulius Wernher Memorial Lecture Institute of Materials, Minerals and Mining. 28 October 2010 London UK. Gold supply shortfall Discoveries Discovery – why it matters
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Adding value in gold exploration Neil Phillips University of Melbourne & Phillipsgold P/L, Australia 30+th SirJulius Wernher Memorial Lecture Institute of Materials, Minerals and Mining 28 October 2010 London UK
Gold supply shortfall • Discoveries • Discovery – why it matters • Exploration in the future • Repeated discoveries – learning from these.
Supply and demand for gold Discover gold Mine gold Sell gold to meet demand
Supply and demand for gold Discover gold Mine gold 2500t pa Sell gold to meet demand 4000t pa
Supply and demand for gold Discover gold Central banks Mine gold Sell gold to meet demand Individuals hoarding
Supply and demand for gold Discover gold Central banks 30000 Mine gold 2500 Sell gold to meet demand 4000 Individuals hoarding ~30000
New Generation Gold Conference • 2009, 2007, 2005, 2003. • Also previously 2001, 1999, 1997, 1995.
Recent discoveries - conclusions • Mature gold provinces • Archaean of Australia, Canada • Established gold regions • Ghana • Less-traditional gold areas (wrt 20th century) • Mali, Peru, China.
Recent discoveries - conclusions • Decreasing dominance of gold-only • Increasing role of gold-plus • Copper-gold • Larger tonnage • Longer life (50-100 years) • Lower gold grade.
Witwatersrand 1886 and 1951 1886: Rand (George Harrison) Klerksdorp 1930s: Carletonville 1940s: Welkom 1951: Evander.
Witwatersrand 1951 to 2010 1951 to 2010: no new goldfields.
Gold production: 1970 - 2010 South Africa World
Future exploration focus Lots of dollars, projects, drilling or Raise discovery rate (σ)
Discovery rate (σ) Adds real value σ Ounces discovered per exploration dollar
Future exploration focus • Country? • Technique? • Idea? • Who? • How to add value.
Which country? Appetite for risk Particular knowledge or expertise Special opportunity geology or commercial deal But not everywhere.
What techniques? Classic success stories Ground magnetics in Witwatersrand EM in Noranda, Canada (Cu, Zn, Au) Regolith methods, Western Australia.
What ideas? – Gold genesis Syngenetic on seafloor Follow horizons, stratigraphy Only for Cu-Pb-Zn-Ag-Au (VMS).
What ideas? – Gold genesis Epigenetic (after rocks have formed) Host rocks – mechanical & chemical Alteration – CO2+K+H2S Orogenic – role of structural geology Hogan 2004
New ideas – Gold genesis Hydrothermal gold deposits do not form at 700oC Continuum model is inappropriate.
Future exploration focus – Who? Discovery is a rare event Within exploration it is atypical
Future exploration focus – Who? Rarely is a discovery so obvious that everyone can ‘see it’, and agrees that it should be drilled.
Future exploration focus – Who? It follows then that .. Harmonious group, consensus Large collaborative team May not correlate with discovery.
Welkom Goldfield 5 km Reproduced from Antrobus (1986)
Wits formation • Since 1900 two ideas • Placer dominates exploration • - no source, no universal sorting mechanism
Welkom Goldfield No gold in source area No special sedimentary sorting 5 km Reproduced from Antrobus (1986)
Witwatersrand gold - ideas A winner was selected Commitment to idea, not to discovery No alternatives. What would Wernher do?
Sir Julius Wernher • Rand goldfields of Johannesburg • Wernher, Beit and Co. • Imperial College
Development of Yandal gold 1894 Alluvial gold 1987 Mt McClure
Yandal Perth
Yandal story – field work • Fe-rich host rocks • Structural style • Carbonate, mica, pyrite alteration • Quartz veining • Anomalous gold • Akin to prospective gold areas. Minsaco Resources 1986
Development of Yandal gold 1894 Alluvial gold 1987 Mt McClure 1992 Bronzewing 1993 Jundee, Nimary 1996 Jundee deeps- Barton, Centenary 1999 Thunderbox
Future exploration focus – Who? Smart, motivated Directed – we are here to make a discovery.
Future exploration focus – Who? Line-of-sight (priorities).
Future exploration focus – Who? Confidentiality
Confidentiality? “Good! I will use your idea in my next talk”.
Don’t worry about someone else stealing your idea; if it is any good you will have to ram it down their throat. (Kerr Wan-Tass, 1997)
Conclusion • Discovery – the magic may lie in the people.