A preliminary resource estimate for the Chocolate Reef structure on the Kahama-Buzwagi property in Tanzania indicates a resource in excess of 1 million oz. gold.
Pangea Goldfields (PGD-T) reports that the calculation is based on 6,500 metres of drilling conducted by joint-venture partner Anglo American.
Currently, the resource stands at 25.3 million tonnes grading 1.74 grams gold per tonne, equivalent to 1.4 million contained ounces, at a cutoff of 0.5 gram. At a cutoff of 1 gram, the figure changes to 12.8 million tonnes grading 2.73 grams gold, equivalent to 1.1 million contained ounces.
Both drill-inferred resource calculations include a high-grade core of 2.06 million tonnes grading 8.16 grams gold, equivalent to 540,000 contained ounces.
The resource was calculated using the sectional method, whereby several rows of fences are drilled perpendicular to the structure’s strike. Mineralized zones that appear to be continuous between fences are then extrapolated to the mid-point of those fences on the basis of geological evidence rather than drill data. This process is designed to give a rough overview of the deposit’s tonnage and grade.
Rows of fences at Chocolate Reef are 100 metres apart, whereas holes along those fences are drilled at intervals ranging from 15 to 50 metres, the average being 25 metres.
Zones between sections were extrapolated 50 metres in both strike directions.
Those zones on individual fences were extrapolated between holes with spacings ranging from 7.5 metres to 25 metres. In addition, the last hole of each of Kahama’s fences would be extended by an additional depth of 25 metres.
“The reason we are using the sectional method is because the zone is fairly wide,” explains Claude Britt, Pangea’s vice-president of exploration. “The longitudinal method does not really apply, so you have either to use this method or a block model-type calculation, while applying different cutoff grades.”
With the exception of section 3500S, the resource occurs within 100 metres of surface. That zone was drill-tested to a depth of 215 metres.
Drilling to date has tested the mineralized zone over a strike length of 1 km and a width of 350 metres. The zone remains open to the north and west, as well as at depth.
The geology at Chocolate Reef is described as simple, with disseminated gold mineralization associated primarily with pyrite and some chalcopyrite, hosted by a felsic intrusive lying near a contact with an ultramafic unit. The mineralized intrusive dips about 70 to the east, strikes north-south and is not folded.
Exploration is being conducted by Anglo, which can earn a 70% interest by spending US$2 million, completing a bankable feasibility study and arranging financing for open-pit mine construction and development. This latest resource calculation has yet to be verified by Anglo.
Anglo is continuing with additional core-splitting, sampling and assaying, following which it will resume infill drilling in the top 100 metres of the deposit. The company will also begin a program of deep drilling to test the deposit at depth.
Anglo also plans to start testing several other geochemical targets near Chocolate Reef.
Be the first to comment on "Chocolate Reef taking shape"