SouthernEra tests Camafuca pipe in Angola

Results from a 1998 drill campaign at the Camafuca diamond property in Angola’s Lunda Norte province suggest that the kimberlite may be richer than previously thought.

SouthernEra Resources (SUF-T), which owns a 51% interest in the project, treated 8 tonnes of core at its Klipspringer mine in neighbouring South Africa. The core represents 23 holes that were drilled to confirm and infill selected areas of the 160-ha pipe.

The best grades came from the epiclastic grit (EKG) unit, with 4,789 kg yielding 2.18 carats for an average grade of 45.2 carats per 100 tonnes. Similar grades were obtained for each of the epiclastic sandstone and volcaniclastic breccia units, with the former yielding 0.07 carat from 1,766 kg and the latter, 0.1 carat from 1,344 kg.

Individual samples were separated into the three rock types and found to contain between 181 kg and 750 kg of core. The samples yielded stones ranging from 0.01 to 0.39 carat in weight, or 0.06 carat on average. Owing to the plant’s design, only stones greater than 1 millimetre were recovered, leaving material of between 0.425 and 1 mm for separate treatment by caustic dissolution methods.

SouthernEra notes that the results for the EKG unit are significantly higher than those obtained by previous operators (13 carats per 100 tonnes) and that those operators may have underestimated the pipe’s overall resource at 88 million cubic metres averaging 0.15 carat per cubic metre.

The company is processing 25,000 tonnes of trenched material on site, and soon will treat core from 17 additional holes completed last April. Some of that core is being independently analzed to see if the higher-grading weathered material can be selectively mined by a cutting-wheel dredge.

For 1999, SouthernEra has budgeted US$3 million for the Camafuca project. Once further sampling results are availabe, the resource will be recalculated.

In addition to its own interest, SouthernEra holds a 14% stake on behalf of two companies. The remaining interest is divided among a state-owned mining company, with 20%, and a private Angolan mining company, with 15%.

Meanwhile, combined production at SouthernEra’s wholly owned Klipspringer and adjacent 40%-owned Marsfontein properties (60%-held by De Beers Consoldiated Mines [DBRS-Q] and its partners) has surpassed the 1-million-carat mark. Mining began on the former in April 1998, and on the latter, in August of that year.

Marsfontein has provided the bulk of the production, having pulled 960,403 carats from 300,278 tonnes treated. The open pit currently extends to 50 metres below surface but eventually will be deepened to 150 metres. A second waste cut allowing for this extension is under way.

SouthernEra’s main processing plant, which is on one of the several farms that make up its Klipspringer property, is treating all material mined by the joint venture, is now producing more than 5,000 carats per day.

Ongoing exploration at Marsfontein has led to the discovery of six soil anomalies, bringing to 18 the number discovered to date. Reverse-circulation drilling will begin shortly, as will additional ground geophysical surveys.

Bulk-sampling of the M3 kimberlite and overlying gravels continues. The former has averaged 13.9 carats per 100 tonnes; the latter, 4.9 carats. The largest stone recovered so far weighed 4.5 carats.