Diamond Fields confirms strike extensions of Voisey

As a result of recent drilling at the Voisey Bay copper-nickel-cobalt project in Labrador, Diamond Fields Resources (TSE) concludes that two other zones of sulphide mineralization exist, one east and one west of the main deposit.

The Eastern Deeps zone, 1,300 metres east-southeast of the main ovoid zone, occurs in a wedge of layered, troctolite (olivine-plagioclase gabbro) that features sulphides disseminated throughout. The troctolite body is about 100 metres thick near the deposit but is open to the southeast, where vertical drill hole VB95-194 intersected a mineralized thickness of 661 metres, including 138 metres of semi-massive sulphides which, in turn, contain several lenses of massive sulphides measuring up to 8.7 metres thick.

The style of mineralization in the Eastern Deeps is similar to that of the main deposit, and Diamond Fields President Cliff Carson has speculated that “it may be that the ovoid is the edge, and that a larger body is what we’re looking at now.”

Diamond Fields now believes that drill hole VB95-166/166A, which intersected 287 vertical metres of disseminated sulphides (including 32 metres of semi-massive to massive sulphides last summer), penetrated the new zone. The 32-metre intersection had an average grade of 1.47% nickel, 0.67% copper and 0.07% cobalt; the surrounding 287-metre intersection averaged 0.44% nickel, 0.22% copper and 0.02% cobalt. The company says visual estimates of metal content in drill cores from the new hole are “significantly higher” than these earlier results.

Drill investigation also continues west of the main ovoid. Four holes have been drilled on line 1+00 W, 1,300 metres west of the deposit, and all were found to contain what Diamond Fields calls “significant intercepts of sulphide mineralization.”

The best results were from hole VB95-172, which intersected lenses of massive sulphide mineralization through the entire troctolite body. A 56.4-metre intersection had average grades of 1.14% nickel, 0.61% copper and 0.06% cobalt, and contained a 21.4-metre interval grading 1.75% nickel, 0.85% copper and 0.09% cobalt.

This mineralized zone, now named the West discovery, had been detected by an airborne electromagnetic (EM) survey and ground follow-up geophysics using horizontal loop EM. The horizontal loop anomaly was found to weaken to the west, but subsequent transient-EM surveys, featuring greater depth penetration, indicated that the conductor deepens to the west, rather than disappearing. One possible explanation of the transient-EM picture is that the conductor may flatten at depth.

Near the main deposit, drilling on the western extension of the ovoid body has confirmed that the host troctolite contains mineralization from the surface to depths of at least 400 metres. Pit delineation holes are being drilled and will ultimately provide 50-metre spacing for pit planning.

The mineralization delinated on the western extension will eventually be added to the preliminary, minable reserves for the Voisey Bay pit, but no date has yet been set for the reserves to be recalculated. Mineralized intersections on the western extension, published by Diamond Fields, have ranged from 22 to 106 metres, and grades have ranged from 0.71% to 1.49% nickel, 0.53% to 1.17% copper and 0.03% to 0.06% cobalt. Current minable reserves in the open pit stand at 31.7 million tonnes grading 2.83% nickel, 1.68% copper and 0.12% cobalt.

Nuts-and-bolts work on the design and approval of mine facilities continues, including hydrogeological and geotechnical investigations. A program of drilling in the main mineralized body to provide a 35-tonne bulk sample for metallurgical testing is almost finished, and this will free some drills for delineation drilling on the Eastern Deeps zone.

Exploration drilling on the Sarah prospect, 6 km north of the deposit, contained disseminated to semi-massive sulphides near the base of a troctolite unit. Other geophysical targets have been selected and will be tested over the next three months.

Diamond Fields has also acquired claim licences for 2,541 sq. km on the southern and western coasts of Greenland, in areas believed to have been joined to the Labrador coast before the Labrador Sea was opened. Airborne EM surveys and ground follow-up are almost complete, and some targets may be drilled in 1996.