Multiphase origin of polymetallic Zn-Pb-Cu (Au-Ag-Fe-V) ore deposits in the Bamba-Kilenda, in the foreland of the West Congo Belt (WCB), Kongo Central (Democratic Republic of Congo)

The Bamba-Kilenda deposit, once exploited, will come to a standstill shortly before the independence events of 1958. However, archival data present usable economic reserves. Recent scientific studies on this deposit and other deposits raise many questions about the genesis of these minerals. Our field observations enriched by those of our predecessors, given the time allotted for our stay in Bamba-Kilenda, allowed us to present the staging of the vein deposits observed in the survey FK2 /4, which corroborates a multiphase emplacement of the deposit of Bamba-Kilenda: - Phase 1: Installation by-basinal hydrothermal fluids having drained feldspar layers of schisto-sandstone enriching with potassium; - Phase 2: Placement by ascending Orogenic fluids and iron having particularly collected potassium from the schisto-sandstone roof and ores of the first phase; - Phase 3: Infiltration of sedimentary fluids in the brecciated zone enlarged by the dissolution of the wall limestone along the Masungu fault. This mode of penetration accompanied by dissolution of carbonates is attributed to the last phase of mineralization at Bamba-Kilenda which is the richest in iron. The supergene weathering has finally reshaped the deposit at great depth, since the vertical discharge of the fault is estimated after to nearly 600 m. The superficial alteration of the sulphide primary mineralization is responsible for the formation of copper oxides, hydroxides, silicates and carbonates in the superficial oxidation zones and supergene secondary enrichment observed in the deposit. The vanadates of Pb, Zn and Cu (Vanadinite and Descloïzite - Mottramite series) that we observe in the Bamba-Kilenda deposit come from the oxidation of mineral base metal concentrations