|Paleoproterozoic manganese and base metals deposits at Kisenge-Kamata (Katanga, DR Congo)|
In: Ore Geology Reviews. Elsevier: Amsterdam. ISSN 0169-1368; e-ISSN 1872-7360
Katanga; Mn carbonate ore; Orosirian; Kasai block; Intracontinentalgraben basin
|Auteurs|| || Top |
- De Putter, T.
- Liégeois, J.-P.
- Dewaele, S.
- Cailteux, J.
- Boyce, A.
- Mees, F.
The Kisenge-Kamata manganese deposit (Katanga, D.R. Congo) belongs to a group of Paleoproterozoic sedimentary manganese ore occurrences that have been recognized for various parts of Africa. It is a relatively small deposit with total estimated reserves of ∼12 Mt ore, but it is of major importance for understanding key aspects of the geology of the Kasai Block of the Congo Craton. The available constraints indicate that the deposit formed in the 2.0–1.9 Ga time interval, in the Orosirian period. The manganese-rich facies of the Kisenge-Kamata deposits range in composition from manganese carbonate rocks to non-calcareous deposits dominated by manganese-rich garnet. Associated rocks are mainly grey graphitic shales. The Kisenge-Kamata sediments are significantly enriched in Cu, Co, Ni, Zn and other accessory metals (V, Mo, Ga). Field constraints and geochemical data suggest that the Kisenge-Kamata sediments were probably deposited in a relatively small intracratonic basin (graben) within the Kasai Block, with an inlet allowing periodical access for ocean water influx carrying Mn, REE and other metals. Primary carbonate ore has relatively low δ13C (−3 to −6‰) and high δ18O (+13 to +20‰) values, confirming their derivation from marine fluids.