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CopperCo’s tenement package (Figure 1) covers approximately 2,500km2 of highly prospective ground within the Western Succussion of the Mount Isa Block, a priority target region for base metal deposits.  The Mount Isa Block is Australia’s premier base metals province - the Proterozoic rock sequence contains a range of copper (e.g. Mount Isa, Mount Gordon Operations), copper-gold (e.g. Ernest Henry, Osborne) and zinc-lead-silver (e.g. George Fisher, Century, Cannington) deposits.

Oxide copper deposits are formed from primary sulphide copper deposits as a result of weathering processes.  The Proterozoic rocks of northwest Queensland and their contained base metal deposits have been subjected to weathering processes for an extended time period, resulting in a weathering profile which extends to depths of 60m or more. 

Within the weathered zone, copper has been leached from the primary ore zones and re-precipitated as zones of “oxide copper”, consisting of the minerals malachite, azurite, chrysocolla, cuprite, tenorite, native copper and others.  The oxide copper zone may form a “blanket,” extending laterally beyond the limits of the primary copper zone. 

Typically, an enriched “supergene zone” is developed below the base of complete oxidation.  In this zone, secondary chalcocite overprints and replaces primary chalcopyrite.

Although a number of oxide copper bodies are known in the Western Mount Isa Block, these deposits have not been the target for the major mining companies which have previously explored the region.  They have been considered too small and too difficult for copper recovery.  However, the availability, over the past 20 years or so, of solvent extraction – electrowinning (“SX-EW”) technology allows the commercial extraction of copper from such ores.