South African manganese deposits are currently confined to the Early Proterozoic Transvaal Supergroup, Northern Cape Province. They can be grouped into two major categories:
1. Syngenetic carbonate-rich manganese deposits interbedded with the banded iron formations (BIF) of the Hotazel Formation, colloquially called the Kalahari Manganese Field.
2. Karst-fill type manganiferous material from residual Fe-rich manganese developed in dolomites of the Campbell Rand Subgroup in the Postmasburg Fe-Mn Fields.
The Kalahari Manganese Field is situated within a structural basin, known as the Dimoten Synclinorium, plunging at an angle of 3° to 8° to the north and northwest. It extends from Mamatwan Mine in the south for approximately 40 km to Wessels Mine in the north, with an east-west extent varying between 5 and 15 km.
Local Geology
The manganese mineralisation at Mamatwan is hosted by the Hotazel Formation of the Postmasburg Group (Transvaal Supergroup) and occurs as stratiform bodies interbedded with banded ironstone formation. This Formation is characterized by three manganese-rich horizons, called the Lower, Middle and Upper Bodies respectively, separated by BIF.
The lowermost of the three units, the Lower Body (LB), is the only unit exposed and currently mined at Mamatwan Open Pit Mine. The Middle Body is poorly developed, often ferruginized, and carries no economic value. The Upper Body (UB) is considered to be potentially eco ........
