The great majority of gold deposits in Zambia are mesothermal lode deposits (veins and more dispersed occurrences in brittle and brittle-ductile shear zones). Most are localized within structures related to the Mwembeshi Shear Zone in central Zambia. This major inter-cratonic shear zone was undoubtedly trans-crustal in vertical extent and clearly acted as an important conduit for fluid flow and magma emplacement. It also exhibits a history of multiple reactivation throughout the Lomamian and Lufilian (Pan-African) Orogenies (c.950-450Ma) and was even reactivated during Karoo rifting. Consequently there was considerable potential for the genesis of substantial lode deposits, particularly where dilational zones (releasing bends, dilational jogs, etc.) facilitated maximum fluid flow, and where the shear zone traversed the carbonate rocks, carbonaceous siltstones and ironstones of the lower Katanga sequence which would have proved highly efficient chemical traps for hydrothermal gold.

Significant skarn and breccia deposits were probably developed adjacent to syntectonic granitoidal and even syenitic intrusions associated with the shear zone, although to date only relatively small occurrences have been identified in the Mumbwa area around the Hook Granite Complex and satellitic intrusions. A similar prospectivity can be assigned to the poorly known Kapiri Mposhi - Kipushi Shear Zone and adjacent NNE-trending zones of deformation.

In eastern Zambia, key targets related to the Mwembeshi Shear Zone include areas where it traverses the restricted occurrences of volcanosedimentary rocks (eg. Sasare area) and also the offset zones related to the West Mvuvye and Chindeni Dislocations, the former appearing to have been a focus for fluid flow (and wallrock alteration) and the latter as it also traverses mafic volcanic rocks.

Within the Zambezi Belt south of the Mwembeshi Shear Zone, thrusting and faulting of the complex Basement-Muva-Katanga terrain was accompanied by widespread de-watering, resulting in the genesis of a considerable number of gold prospects, screening of which could pinpoint optimum potential in terms of host structure and country rocks. Similar and probably more substantial fluid flow occurred within the early Lufilian thrust zones of the Domes Region of north-western Zambia to generate complex copper ± gold ± uranium lodes within the lower Katanga sequences and these represent important exploration targets.

In north-eastern Zambia a similar lode-gold potential, not yet investigated, exists within the Luongo Fold and Thrust Zone, the Chambeshi Fold and Thrust Zone, and the Shiwa Ngandu Fold Zone, where leaching of Basement rocks and de-watering, quite possibly on a massive scale during the Irumide-age crustal shortening, could have created conditions favorable for gold metallogenesis. The minor occurrences of palaeoplacer gold within the lower Mporokoso Group littoral sediments of the Bangweulu Block have some similarities to Witwatersrand-type mineralization and merit a basin-wide evaluation.

Combined reserves and resources of copper-cobalt ore in operating mines of the Copperbelt exceed two billion tonnes and these have mostly been delineated for exploitation after privatization of the industry has been completed. Some what similar styles of copper mineralization, variously containing gold, uranium and cobalt, are evident in the Domes Region to the west of the Copperbelt and are attractive exploration targets. Recognition that a number of these deposits are hosted by thrust zones, however, offers greater opportunities for locating deposits at higher elevations within the Katanga sequence than normally anticipated.

Precious metal enrichment is also more probable in such zones, and manto-type copper-gold deposits may be developed in adjacent carbonate and shale units. Recognition of thrust-hosted copper mineralization also encourages critical evaluation of the established synsedimentary or syndiagenetic model for the Copperbelt mineralization in the search for new deposits. Widespread scapolitization of the Katanga sequence in the Domes Region attests to another phase of hydrothermal activity, involving NaCl-brines probably derived by dissolution of evaporites, and the occurrence of copper enrichment (0.8%) in scapoliteschists in the Mujimbeji prospects of the Kabompo Dome indicates yet another potential type of exploration target.

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Other Base Metals and Rare Metals

Zinc and lead deposits discovered to date are hosted entirely by carbonate rocks occurring stratigraphically at the Lower Roan - Upper Roan transition. Considerable potential remains in the Kabwe area, and the Katanga-age carbonate sequences northwest of Mumbwa offer a similar potential. The migration of NaCl-rich brines, indicated by the distribution of scapolite in northwestern Zambia, could have led to extensive mobilization of Pb and Zn and the subsequent genesis of vein and replacement deposits in lower-Katanga carbonate rocks and even in overlying Kundelungu carbonate units. The common occurrence of vein and replacement deposits of barite within the early Proterozoic sequences of the Bangweulu Block, where caught up in the Luongo Fold and Thrust Zone, also suggest the activity of NaCl-enriched brines and thus imply that conditions here too may have been favorable for the transport and precipitation of Pb and Zn.

Substantial resources of iron have been identified, mostly in lower Katanga successions, and the requirement here is for thorough evaluation of known deposits within the context of potential demand from burgeoning Zambian industrial and manufacturing sectors and a wider demand throughout central Africa.

80km east of Lusaka, would be a priority for tungsten exploration. Syntectonic and posttectonic granitic magmatism associated with the Irumide Orogeny in north-eastern Zambia may have led to tin and tungsten enrichment in the Chambeshi Fold and Thrust Zone and Shiwa Ngandu Fold Zone.

The occurrence of diamonds and indicator minerals in Zambia highlights the considerable exploration potential. The most favorable terrains are the stable cratonic Bangweulu Block and possibly the Kabompo area of western Zambia where alluvial diamonds are particularly abundant. The rift-related kimberlites and associated rocks of eastern Zambia have limited potential as they were probably derived from thermally eroded, and hence diamond-depleted, mantle.

Systematic exploration of the Ndola Rural area utilizing a combination of radiometric surveys and soil geochemistry, supported by detailed mapping, offers considerable potential for the discovery of additional deposits of the high-quality gemstones.