The Kokoseb Gold Project is held in a joint venture, with Wia Gold Limited owning 80% and Epangelo Mining Company, Namibia’s state-owned mining company, holding the remaining 20%.
- subscription is required.
Summary:
The Kokoseb Gold Project lies withing the Northern Central Zone of the Pan-African Damaran Orogenic Belt. The project area is underlain by neo-Proterozoic metasediments, including the Kuiseb schist formation, host of Kokoseb, Twin Hills and Ondundu gold deposits in Namibia. Known gold deposits, including Kokoseb, are orogenic type deposits by nature.
Kokoseb gold mineralisation is hosted by the Kuiseb schist formation, biotite-schists (metasediments) which have been intruded by several granitic phases. The gold mineralised zone appears as a contact like aureole around a central granitic pluton, with a diameter of approximately 3km in each direction.
Gold mineralisation is present as native gold grains and lesser silver bearing gold grains that are spatially associated with sulphides dominated by pyrrhotite, löllingite and arsenopyrite. Gold grains have developed at the contact between löllingite and arsenopyrite following a retrograde reaction.
Gold mineralisation is found in the Kuiseb Formation metasediments which are extensively intruded by both late syn-tectonic and post tectonic granites, and minor N-S to NNE-SSW trending mafic dykes.
Within the Kokoseb area, the Kuiseb schist forms a domal feature cored by a post tectonic leucogranite, the “Central Granite Pluton”, which consists predominantly of medium grained quartz, K-feldspar and plagioclase, with accessory biotite, muscovite, magnetite, garnet and tourmaline.
Granite dykes, granitic veinlets and pegmatites cross cutting the Kuiseb schist represent the same granite phase or later granitic phases. Gold mineralisation wraps around this pluton in a roughly arcuate form but seems best developed along the western and northern margins of the Central Pluton.
The schist units consist of poorly foliated, dark grey, quartz/plagioclase/Kfeldspar rich, biotite bearing, schist and black, better foliated biotite schists.
Gold mineralisation, present as native gold grains and lesser silver bearing gold grains, is spatially associated with sulphides dominated by pyrrhotite, löllingite and arsenopyrite in order of abundance.
Sulphides manifest as foliation-controlled blebs, stringers and disseminations and löllingite is always spatially associated with arsenopyrite and pyrrhotite where a retrograde reaction rim of arsenopyrite is always developed at the contact between pyrrhotite and löllingite.
This contact zone between löllingite and arsenopyrite is typically where gold grains are developed, though they can also occur as partial inclusions within löllingite and rarely within pyrrhotite. Gold is commonly associated with bismuthinite and native Bi mineralisation. Pyrite is the most common sulphide but does not show any direct association with gold mineralisation.
Mineralisation generally outcrops, with locally a maximum of 1 to 2 m of barren superficial material. Weathering extends to an average of around 32 m depth.
Mineralisation remains open along strike and at depth where there is clear potential for the MRE to continue to grow via extension drilling.
Dimensions
The MIK modelling utilised a set of mineralised domains interpreted by Matrix which capture composites with gold grades of generally greater than 0.1 g/t and delineate zones within which the tenor of mineralisation is similar. The mineralised domains have a combined strike length of around 6.8 km, with average widths of around 70 m, 100 m, 70 m, and 45 m for the south, northwest, north and east domains respectively. Mineral Resources are reported within an optimal pit shell generated at a gold price of $US2,300/oz. The pit shell extends over around 5.8 km of strike and reaches a maximum depth of around 480 m.
Mineral Resources extend from surfaced to 480 m depth with around 75% from depths of less than 230m and 90% from shallower than 300 m.