First Quantum cuts more copper oxides in Congo (November 17, 2003)

First Quantum Minerals (FM-T) has pulled more long intersections of copper-bearing oxides and sulphides from its newly discovered Lufua zone in the Democratic Republic of Congo’s Katanga province.

The company announced the discovery of Lufua in mid-September and is now in the midst of a 5,000-metre program of reverse-circulation drilling. Recent highlights include:

— hole 42, which intersected 81 metres grading 1.79% copper;

— hole 45, which intersected 59 metres grading 1.98% copper and 15 metres grading 0.51% copper;

— hole 44, which cut 33 metres grading 1.9% copper; and

— hole 19, which returned 19 metres of 1.25% copper.

Holes 44 and 45 had to be abandoned in mineralization because of rig difficulties, though the problem was fixed after the completion of hole 49.

Results are still pending for the bottom 12 metres of a 78-metre interval that was cut by hole 41. The upper 26 metres ran 0.8% copper, and the hole was abandoned in mineralization.

Holes 46-48 also returned long sections of copper mineralization, though, in the case of the first two, in both oxides and fresh material. Hole 46 averaged 1.75% copper over 94 metres, of which the first 50 metres ran 2.01% and the final 44 metres, 1.46% copper.

Results for hole 47, also bottomed and abandoned in mineralization, include 0.71% copper over 11 metres of oxides and 2.1% copper over 84 metres of sulphides. The sulphide section began 39 metres down-hole of the oxide section, which, like the others, is close to surface.

Hole 48 assayed 1.25% copper over 13 metres starting at 61 metres down-hole, and 1% copper over 81 metres starting at 116 metres. Both sections are primary in nature.

Primary mineralization occurs in quartz-dolomite veinlets that carry chalcopyrite, and in later quartz-dolomite-chalcopyrite-bornite veins. There is also disseminated chalcopyrite accompanied by potassic and albitic alteration in the host rocks — Katangan metapelites.

Oxidation extends to various depths and is strongly influenced by post-mineral faulting.

To date, 29 core and reverse-circulation holes have been sunk since drilling began in July.

Lufua is 45 km from the company’s Bwana Mkubwa solvent extraction-electrowinning plant, on the Zambian side of the border. The plant currently treats ore from the company’s Lonshi deposit, also in the Congo, though south of Lufua.