Petra Diamonds said it has received and analysed samples taken from delineation /evaluation drill core at its kimberlite KX36, part of the Kukama East project in central Botswana. The initial drilling and microdiamond analysis results indicate that the kimberlite has significant potential.
The company said the next move will be to start a large diameter drilling programme in the next couple of weeks in order to obtain a bulk sampling.
Petra Chief Executive Officer, Johan Dippenaar, said these initial drilling and microdiamond analysis results indicate that kimberlite KX36 has significant potential, in terms of its possible size, diamond grade and potential coarse diamond size frequency distribution.
“The next step is a large diameter bulk sampling drilling programme, commencing in April 2012, in order to obtain further information with regards to grade and an indication of diamond value,” Dippenaar said.
The company has now received results from work undertaken on KX36 last year, when a total of 1,373 metres was drilled in five holes and 250 diamonds, collectively weighing 0.756 carats, were recovered from 403.88 kilogrammes of kimberlite.
The largest diamond recovered was transparent white, weighing 0.393 carats.
An initial model puts the diamond grade for the kimberlite between 75 carats per hundred tonne (cpht) and 180 cpht.
Incorporation of drilling results into the existing 3D geological model indicates a potential kimberlite tonnage of between 28 million tonnes and 34 Mt to a vertical depth of 516 metres. The deposit remains open at depth.
Technical director Jim Davidson said: “Our exploration programme in Botswana has led to the discovery of five new kimberlites so far, and the strong micro diamond results and the favourable coarser diamond size indications for kimberlite KX36 are most encouraging.
“We have now launched the next phase of our evaluation of this exciting discovery, with the bulk sampling work programme scheduled to commence shortly. KX36 is approximately 60 kilometres from the nearest known kimberlite, meaning there is the potential for KX36 to be part of a new kimberlite field,” he added.
A drilling and microdiamond sampling campaign was carried out at KX36 in 2011 and microdiamond results from samples taken from delineation/evaluation drill core have now been received and analysed. A total of 1,373m was drilled in five holes; the deepest borehole was drilled to a vertical depth of 516m below surface, with the borehole ending in kimberlite at that depth.
A total of 250 diamonds, collectively weighing 0.756 carats, was recovered from 403.88kg of kimberlite; the largest diamond recovered was a white, transparent dodecahedron, weighing 0.393 carats.
Patra said delineation drilling and geophysics indicate a surface area of approximately five hectares under circa 78m of Kalahari overburden.
Petra’s exploration activity is focused on Botswana, which is considered to be one of the best addresses in the world for diamond exploration, given its stable fiscal regime and its superb geological prospectivity.
Sekaka Diamonds (Pty) Limited (Sekaka) is Petra’s wholly owned operating subsidiary in Botswana.
Sekaka holds diamond prospecting licences in Botswana covering approximately 22,250km2, all of which are “on craton” (areas underlain by ancient, thickened continental crust, known to host economic primary diamond deposits) and Petra/Sekaka operate a highly focused and cost effective exploration programme in country.
The kimberlite KX36 is situated in the Kukama East project area, in the south east extremity of the Central Kalahari Game Reserve.