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Thakadu
Technical Report
RSG Global, Thakadu Copper Project, July 24, 2007 (PDF 15.20MB)
The Thakadu deposits are sediment-hosted strataform disseminated sulphide zones in a poly-deformed and metamorphosed sequence of volcanic, volcaniclastic and clasticsedimentary units. The primary sulphide minerals are chalcopyrite (85-90%) and bornite (10-15%) with minor pyrite adjacent to the copper bearing material. The upper approximately 50 m of the deposits are characterized by secondary zones of oxidation, in which the primary sulphides are replaced by chalcocite, malachite and cuprite-tenorite together with traces of native copper and marcasite.
The primary ore-forming minerals at the Thakadu deposit are chalcopyrite (85-90%) and bornite (10-15%), both as fine to medium grained disseminations throughout the host rocks. Minor pyrite occurs adjacent to the copper-bearing zone, but only rarely inside it. A mineralogical zonation is apparent with a chalcopyrite-bornite assemblage in the centre, ranging outward to chalcopyrite, and then pyrite on the outside margins.
Chalcocite and covellite are present in trace quantities. The oxide zone at the Thakadu deposit consists of chalcocite, malachite, cuprite-tenorite, chrysocolla and traces of native copper and marcasite. The Makala deposit exhibits the same general characteristics as the Thakadu deposit in terms of host rock lithologies, primary sulphide mineralogy and sulphide mineral zonation.
Structural mapping in the vicinity of Thakadu and Makala has shown that a major ESE-WNW shear zone exists just to the north of the Makala deposits. Initial drilling has indicated that the degree of shearing and flattening of the ore zones around Makala has been intense. Furthermore, Thakadu has been shown to exist within a parasitic z-fold on the north limb of a regional fold structure. The fold structure closes to the SE, well away from the trace of the northerly shear. No exploration work has ever been focused on the fold closure, or on the southern limb of the fold.
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