1 / 6

WHAT IS REALLY SPECIAL ABOUT SOUTHERN AFRICA ?

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,

banyan
Download Presentation

WHAT IS REALLY SPECIAL ABOUT SOUTHERN AFRICA ?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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 1990’s) • Potential for giant deposits of deposit styles that have not been historically major producers • a) Nickel-PGE deposits of Noril’sk type • b) Magnetite-Cu-Au-REE-U deposits of Olympic Dam type • c) Anomalous deposits related to “b”

  4. WHY NORIL’SK TYPE TARGETS IN SOUTHERN AFRICA ? • 1. Norli’sk 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 Noril’sk

  5. WHY NORIL’SK TYPE TARGETS IN SOUTHERN AFRICA ? (Cont’d) • 4. Mineralization at Insizwa, Transkei, similar to Noril’sk • 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 Noril’sk. 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

More Related