WHAT IS REALLY SPECIAL ABOUT

1
WHAT IS REALLY SPECIAL ABOUT SOUTHERN AFRICA ?

• Contains rocks of many of the productive time
  periods on Earth controlled by two major ancient
  (Archaean) cratons
• Contains two of the most productive giant
  layered intrusions on Earth
• a) Bushveld Complex - Pt, Tl, Cr, Ni, Sn,
  magnestite,
• refractory minerals
• b) Great Dyke Cr, Pt, Ni
• Contains the unique Witwatersrand Basin (Au, U)
• Contains a variety of alkaline intrusions
• a) Kimberlites diamonds
• b) Carbonatites Cu, Fe, P, phosphate,
  vermiculite at
• Phalabowra

2
WHY IS SOUTHERN AFRICA SO RICHLY ENDOWED ?

• Geology records a very long history
• a) Some of the oldest basement rocks on Earth
  (ca 3800 Ma)
• b) Some of the oldest greenstone belts on Earth
  (ca 3500 Ma)
• c) Some of the oldest well-preserved sedimentary
  basins on
• Earth e.g. Witwatersrand Basin at ca 2800 Ma
• d) Most continuous Archaean-Early Proterozoic
  sedimentary
• record on Earth
• e) Some of the oldest Archaean-style
  subcontinental mantle
• lithosphere on Earth
• 2. Late tectonic uplift and erosion
• a) Exposes deeply buried mineral deposits
• b) Causes dispersions of metals in streams and
  rivers
• c) Creates diversity of mineral deposits at
  different levels of
• Earths crust

3
PROSPECTIVITY OF SOUTHERN AFRICA

• Exceptionally well-endowed terranes
• Very mature exploration terranes in general,
  particularly Bushveld and Witwatersrand provinces
• World-class technology to explore and mine at
  deep levels
• Previous history of virtual restriction to major
  mining companies
• Opportunities for smaller to medium size vigorous
  exploration companies (cf Australian and Canadian
  companies in 1990s)
• Potential for giant deposits of deposit styles
  that have not been historically major producers
• a) Nickel-PGE deposits of Norilsk type
• b) Magnetite-Cu-Au-REE-U deposits of Olympic
  Dam type
• c) Anomalous deposits related to b

4
WHY NORILSK TYPE TARGETS IN SOUTHERN AFRICA ?

• 1. Norlisk described by some as the most
  economic ore body on Earth
• a) 900 Mt at 2.7 Ni
• b) PGE/Ni ratios 5 times greater than Sudbury
• c) Copper more enriched than Sudbury
• 2. Correct tectonic environment in the Mesozoic
  in eastern South Africa large rift basalt
  province with subvolcanic sills
• 3. Basalts include high-MgO varieties similar to
  Norilsk

5
WHY NORILSK TYPE TARGETS IN SOUTHERN AFRICA
? (Contd)

• 4. Mineralization at Insizwa, Transkei, similar
  to Norilsk
• Ni-Cu-Pd rich sulphide ore
• Similar PGE minerals
• Similar ilmenites and ferrochromites in the ore
• 5. Basaltic and gabbroic rocks show major Ni
  depletion as at Norilsk. Potentially giant
  Ni-sulphide ore bodies in region
• 6. Insizwa is small main ore bodies not yet
  discovered

6
WHY OLYMPIC DAM TYPE DEPOSITS IN SOUTHERN AFRICA ?
1. Typically related to craton edges around
Archaean subcontinental mantle lithosphere
abundant in region 2. Probably related to
alkaline intrusions abundant in region 3.
Phalabowra (Cu, Au, PGE) may be an example of a
proximal deposit 4. Vergenoeg (F, REE) may
be an associated deposit style 5. Messina (Cu)
and occurrences of mineralized breccias (Cu) at
Groothoek Zebadita may be related styles 6.
Normally discovered after detailed multi-client
aeromagnetic and gravity surveys Africa
has many gaps in such information