Cu-Ore Vein
The copper mineralisation in study area is primarily an IOCG type, characterised by the presence of iron oxide-Copper-Gold (IOCG) deposits. It is hydrothermal origin where veins disseminations are genetically asssociated with I type magmatism. The deposit is characterised by more than 20% iron hydroxide. The copper mineralisation in the area, occurs mainly as carbonate and oxide ore on the surface showing malachite, chalcocite Cu2S (copper glance, redruthite), cuprite Cu2O (chalcontrichite), chrysocolla (CuSiO23.2H2O or (CuAl)2H2Si2O5(OH)4) and azurite (Cu3(CO3)2(OH)2) with minor amounts of chalcopyrite (CuFeS2), bornite (CuFeS2), arsenopyrite (FeAsS) and iron oxide. Limonite (FeO(OH)•nH2O) is present in major mount. The Copper chrome (local name) is mainly chalcocite (Cu2S) and is observed in Pit No. 1 and 2 within the mineralised zone as rich segregations and veins within the carbonate rock and adjoining the phyllitic rock which has a strike (mainly limonite) length of 50 m, average width extending below up to 30 m depth (as intersected in Drill Hole 3, and 13). It is generally found associated with malachite/azurite and chalcocite. From field observations it is seen that the copper mineralization area, is of three types - 1) as encrustations of malachite/azurite (Cu3(CO3)2(OH)2), 2) hydroxidized ferruginized cuprite ore in the top soil and 3) High grade copper chrome ore (chalcocite, and iron occurring as limonite). The malachite/chrysocolla/chalcocite/azurite ore occurs as distinct bands on the surface associated with metasiltstone/carbonate sequence while the oxidized ferruginized cuprite ore occurs as lumps, rarely as rich segregations and impersistent bands. The grey copper chrome ore is generally found as rich segregations associated with carbonate/quartz veins and also carries malachite encrustations. It is normally associated with malachite azurite zone and rarely seen as boulders in the Pit 2 and Pit 1. The copper ore in the area occur in three forms viz; 1. Lumpy ore 2. Fragile ore and 3. Dusty ore.
Primary Sulphide Mineralisation
The primary sulphides mainly comprise chalcopyrite (CuFeS2 - copper sulphide) chalcocite (Cu2S), pyrite (Fe2S), pyrrhotite (Fe1-xS or Fe7S8-FeS or Fe9S10), arsenopyrite (FeAsS) with minor specks of bornite CuFeS2 noticed within the sulphide assemblage. The sulphides have been intersected in three of the bore hole viz: BH-5, 10 and 13 drilled. At times unaltered primary sulphide grains are also noticed within the highly oxidised chalcocite ore. The zone of mineralisation is highly sheared and brecciated and sulphides occurs mainly as fracture fillings and sometimes as fine disseminations along foliation planes and segregations within the quartz-carbonate-limonite host rock. Two deeper bore holes BH-5, and 10 ich zone of primary sulphide mineralisation at a depth of around 65.00 to 70. 00 m. From this intersection, it is inferred that below the oxide copper ore, we are likely to encounter sulphide zone comprising mainly chalcopyrite, covellite CuS, pyrite and pyrhottite.
Regional Geology
The geological complexities and multiple tectono-thermal events as seen in the Zambia is largely due to the country’s unique position between three major cratons viz; the massive Kasai Craton to the west, and the Zimbabwe-Kaapvaal (‘Kalahari’) and Tanzania craton to the south and north respectively (Duane and Saggerson 1993). The copper and the associated cobalt mineralisation in Zambia occurs within the Neoproterozoic Katanga Supergroup sediments adjacent to their contact with underlying older basement rocks.
