The Great Dyke is a layered complex similar to that of the Bushveld Complex. It extends for 550 kilometres and has a maximum width of 11 kilometres. Within the Great Dyke four geological complexes are known to contain PGM and base metal deposits. These are the WedzaComplex (Mimosa – Aquarius and Implats), the Selukwe Complex (Unki – Anglo Platinum), the Hartley Geological Complex (Hartley and Ngezi Platinum Mines – Zimplats) and the Musengezi Complex.
The stratigraphy is broadly divided between a lower ultramafic and an overlying mafic sequence. The ultramafic sequence hosts the P1 pyroxenite, which in turn hosts the economic PGM-bearing Main Sulphide Zone (MSZ). The MSZ is generally 2 to 3 metres thick. Optimal mineralisation varies and, in contrast to the Bushveld Complex, is often difficult to follow visually. Peak values for the PGM and base metals are vertically offset, with palladium peaking at the base, platinum in the centre and nickel towards the top.
MINERAL RESOURCES AND MINERAL RESERVES
Mimosa Mineral Resources and Mineral Reserve Statement 2014