OMITIOMIRE, NAMIBIA – A NEW STYLE OF LARGE “STRATIFORM” COPPER DEPOSIT

Karl Hartmann* and Ken Maiden**

* Exploration Manager, Craton Mining and Exploration (Pty) Ltd, Windhoek, Namibia

** Executive Director, International Base Metals Limited, Sydney

Omitiomire is an unusual large low grade copper deposit in central Namibia. Craton Mining and Exploration (Pty) Ltd, a subsidiary of Sydney-based International Base Metals Limited, has drilled 250 holes to define a resource of 98 million tonnes at 0.51% Cu (500,000 tonnes contained copper) over an area of 2200 x 700 metres. Banded mafic rocks, which host the disseminated chalcocite, consist mainly of quartz, plagioclase, biotite and amphibole with minor chlorite, epidote, sphene, K-feldspar and magnetite. Low levels of gold and platinoids are associated with copper. Metallurgical testwork has shown excellent recoveries.

Known extensions indicate that a target of + 1 million tonnes contained copper is achievable. Extensive geochemical anomalies suggest that Omitiomire could be part of a significant new copper district.

In seeking analogies, there are similarities with the Lumwana copper-cobalt deposits (700 Mt at 0.7% Cu) in northwestern Zambia and perhaps with copper deposits in the Carajas district of northern Brazil.