DIAMOND PAGE — More kimberlite at Marsfontein — Exploration program tests geophysical and geochemical targets

Drilling at the Marsfontein property in South Africa’s Northern Province has intersected kimberlite along two fissure systems that lead from the currently producing M1 pipe.

The 6,000-metre percussion drilling program was mounted by property holders De Beers Consolidated Mines (DBRS-Q), which holds a 60% interest, and SouthernEra Resources (SUF-T), which holds 40%. The campaign tested 11 of 14 exploration targets previously outlined by geophysical and geochemical surveys on the property. Of those targets tested, eight proved to be underlain by kimberlite.

The targets were strung along two fracture corridors, the southwesterly striking M-8 trend and the northwesterly striking M-3. Both had been defined partly by earlier soil surveys, which had found zones with kimberlite indicator minerals in residual soils.

Along M-8, the drilling program tested a 1.9-km strike length southwest of the M-1 pit. The drilling pattern included tests of four indicator mineral zones: M-9, M-10, M-16 and M-17.

Along this line, what SouthernEra describes as “consistent intersections” of kimberlite occur at depths of 50 to 100 metres below surface. The intersections were between 0.4 and 2 metres in true width.

Infill percussion drilling, to test the continuity of the kimberlite body between drill intersections, is now going on, and the partners plan to bring a diamond core drill on to the targets to provide intact samples. Early testing of the percussion cuttings indicates that the chemistry of the kimberlite minerals is similar to that seen at M-1 and also at the Leopard fissure at Klipspringer, farther west on the SouthernEra land package.

On the M-3 trend, three holes sunk along a 500-metre strike length northwest of an earlier test pit encountered zones of kimberlite between 1 and 2 metres in width. A fourth hole was drilled about 2 km northwest of the M-3 test pit on an indicator mineral zone known as M-14 and intersected kimberlite as well; this material, however, did not resemble the kimberlite in the M-1 or M-3 pits, or in the M-8 drill intersections.

The partners are also assessing a diamond-bearing gravel zone south of the M-1 pipe, using geophysical surveys. They plan to begin a sampling program after the surveys have established the shape and size of the gravel deposit.