Cominco, Redfern planning more deep drilling at Tulsequah Chief

The details have yet to be finalized, but Cominco (TSE) and junior partner Redfern Resources (TSE) are planning a 1991 drilling program for the Tulsequah Chief massive sulphide project in coastal northwestern British Columbia. Tulsequah Chief is a former producer operated by Cominco from 1951 to 1957 when low metal prices forced a closure. Today the base metal giant holds a 60% interest, while Redfern owns 40% of the property.

This year’s drilling program will be aimed at further testing the reserve potential of the deposit to depth, with the key target being the H lens discovered during the 1990 deep drilling program. This lens was intersected by two holes — 22 and 23 — while drilling to test the down-dip extension of the A-B lens last year.

Hole 22 returned 164 ft. (130 ft. true width) grading 2.9% copper, 1.6% lead, 9.1% zinc, 0.11 oz. gold and 5.0 oz. silver per ton, while hole 23 returned 89.5 ft. (62 ft. true width) of 1.2% copper, 1.2% lead, 5.4% zinc, 0.11 oz. gold and 4.2 oz. silver per ton. These holes showed precious metal values somewhat higher than those typically encountered in the past.

Several holes drilled subsequent to 22 and 23 encountered post-mineral dyking and a clay-rich fault zone and returned little or no mineralization. However, one of the holes did encounter a new mineralized lens, the I zone, higher stratigraphically than the H lens. This area will also be further tested in the coming program.

Before the 1990 program began, Tulsequah Chief was reported to contain preliminary geologic reserves totalling 5.8 million tons grading 1.6% copper, 1.31% lead, 7.02% zinc, 0.08 oz. gold and 2.94 oz. silver per ton. These reserves were initially thought to be contained within the A-B lens, however a better understanding of the deposit’s multiple horizons gained during last year’s program is expected to result in a portion of the reserves being re-assigned to the deeper H lens.

Redfern expects to release an updated preliminary reserve calculation which will incorporate all results from last year’s wide-spaced drilling program. “Last year’s drilling certainly increased reserves over those announced at the end of 1989,” said Redfern President John Greig. “And we’re very optimistic about this year’s program.”

Greig said the dip of deposit is flattening to about 55 degrees in the H lens with depth, compared with about 70 degrees in the A-B lens.

“It’s still an ideal attitude,” he said. “But the average thickness of the H lens is substantially greater than the 20-ft. average in the A-B lens, probably two to three times as thick.”

The Tulsequah Chief property is well located. Transportation of concentrates could be accomplished by barge or road to deep water port facilities.