GEOLOGY & RESOURCES
The Nkana ore bodies occur within the north westerly plunging Nkana Synclinorium, which is part of the Chambishi-Nkana basin located on the southwestern flank of the Kafue Anticline. Copper and cobalt mineralisation occur within the ore shales, which can be structurally complex within the southern and central areas, but moderate to largely planar, shallow to steeply dipping bodies in the northern Mindola mining areas. Copper mineralisation within the property limits changes from mostly chalcopyrite in the South Ore body, to chalcopyrite-bornite in the Central Shaft area and to bornite-chalcopyrite at the Mindola Shafts. Except within the oxide zones near the surface, mineralisation is amenable to treatment by conventional copper flotation techniques while oxide ores are leached. Cobalt occurs as carrollite and cobaltiferous pyrite in approximately equal proportions.
At Mufulira, meta-sandstones, which host economic mineralisation, occur in three closely associated and remarkably uniform ore horizons, found within the Lower Roan Group. The primary sulphides at Mufulira are bornite and chalcopyrite with minor amounts of chalcocite and pyrite. Oxide caps comprising malachite and minor azurite mineralization occur at the eastern and western extremities of the deposit. Both of these are currently being mined via portal access from surface and decline development underground.