Neil Phillips University of Melbourne & Phillipsgold P/L, Australia
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Neil Phillips University of Melbourne & Phillipsgold P/L, Australia Adding value in gold exploration 28 October 2010 London UK 30 +th SirJulius Wernher Memorial Lecture Institute of Materials, Minerals and Mining
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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 - PowerPoint PPT Presentation
Transcript of Neil Phillips University of Melbourne & Phillipsgold P/L, Australia
Neil PhillipsUniversity of Melbourne &Phillipsgold P/L, Australia
Adding value in gold exploration
28 October 2010
London UK
30+th SirJulius Wernher Memorial LectureInstitute of Materials, Minerals and Mining
• 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
Sell gold to meet demand
4000t pa
2500t pa
Supply and demand for gold
Discover gold
Mine gold
Sell gold to meet demand
Central banks
Individuals hoarding
Supply and demand for gold
Discover gold
Mine gold 2500
Sell gold to meet demand 4000
Central banks 30000
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: Carletonville1940s: Welkom1951: Evander.
Witwatersrand 1951 to 2010
1951 to 2010: no new goldfields.
Gold production: 1970 - 2010
South Africa World
Future exploration focus
Future exploration focus
Lots of dollars, projects, drilling
or
Raise discovery rate (σ)
Discovery rate (σ) Adds real value
σOunces discovered per exploration dollar
Future exploration focus
• Country?• Technique?• Idea?• Who?
• How to add value.
Which country?
Appetite for riskParticular knowledge or expertiseSpecial 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 eventWithin 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.
Reproduced from Antrobus (1986)
5 km
Welkom Goldfield
Hydrothermal model
Wits formation
• Since 1900 two ideas• Placer dominates exploration• - no source, no universal sorting mechanism
Reproduced from Antrobus (1986)
5 km
Welkom Goldfield
No gold in source area
No special sedimentary sorting
Witwatersrand gold - ideas
A winner was selectedCommitment to idea, not to discoveryNo 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 Bronzewing1993 Jundee, Nimary1996 Jundee deeps- Barton, Centenary1999 Thunderbox
Future exploration focus – Who?
Smart, motivatedDirected – 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.
