EXPLORATION 1998 — Platexco calculates platinum resource at Winnaarshoek

Toronto-based Platexco (PGMI-T) is encouraged by the resource estimate received for its Winnaarshoek property, a platinum group metals (PGM) prospect on the eastern limb of the Bushveld igneous complex in northeastern South Africa.

The company hired the South African consulting firm Micon International to calculate the estimate based on 38 holes — WH1 through WH28 and WHU1 through WHU10. These were collared during Platexco’s ongoing drilling campaign (T.N.M., Dec. 29/97).

Within the Merensky Reef at Winnaarshoek, Micon calculated: 6.2 million tonnes grading 6.61 grams PGM per tonne in the measured category (PGM here refers to platinum, palladium, rhodium and gold concentrations); 6.2 million tonnes of 6.61 grams PGM in the indicated category; and 23.6 million tonnes of 6.61 grams PGM in the inferred category.

The calculations are based on Merensky-reef thicknesses for the measured, indicated and inferred categories of 0.98, 0.85 and 0.91 metre, respectively.

Within the UG-2 reef at Winnaarshoek, Micon caluculated: 3.7 million tonnes grading 6.44 grams PGM (measured); 9.1 million tonnes of 7.06 grams (indicated); and 38.1 million tonnes of 6.88 grams (inferred).

The UG-2 thickness is 0.87 metre in all three categories.

Based on a limited set of assays for the individual platinum group elements in the measured and indicated categories, the Merensky reef values broke down into 3.8 grams platinum per tonne; 2.1 grams palladium; 0.5 gram gold; 0.2 gram rhodium; 0.4 gram ruthenium; and 0.1 gram iridium.

The UG-2 broke down into: 2.9 grams platinum per tonne; 3.2 grams palladium; 0.1 gram gold; 0.6 gram rhodium; 0.9 gram ruthenium; and 0.1 gram iridium.

Micon notes that the thicknesses and platinum-metals content of the mineralized layers are similar to layers currently being mined in the Bushveld. For example, at Amplats’ Atok operation, the only fully operating platinum mine on the eastern limb of the Bushveld, proven and probable reserves in the Merensky stand at about 68 million tonnes grading 6.06 grams PGM per tonne.

The nickel and copper sulphide contents of the 0.8-metre mining width in the Merensky reef for holes WH1 through WH22 graded, on average, 0.2% nickel and 0.11% copper — typical values for the Merensky.

Holes WH29 through WH32, which post-dated the resource estimate, returned a width greater than 0.8 metre grading between 5.76 and 12.89 grams PGM per tonne.

Assay results are pending from several more holes, including WH39 through WH42, which were drilled at 800-metre spacings to intersect the Merensky at depths of between 400 and 600 metres.

To round out the current campaign of Merensky reef exploration, another six holes are being drilled into the reef at depths between 400 and 800 metres.

Drilling of the UG-2 is continuing. Of note, hole WH40 intersected the UG-2 at a depth of 800 metres.

As well, Micon carried out a limited program of duplicate sampling and assaying — a check that confirmed the PGM content of the Merensky and UG-2 Reefs.

A program of further work, comprising some 8,400 metres of drilling, has been proposed by Micon at an estimated cost of $955,000.

Warren Newfield, Platexco’s vice-president of corporate development, says that discussions have been ongoing with a number of suitors regarding the Winnaarshoek property, and that progress is being made with applications at Platexco’s Mokopane platinum project on the Potgietersrus limb of the Bushveld.

He adds that the company hopes to be listed on the Toronto Stock Exchange in several months.