Cominco/Redfern deposit has production potential

Redfern Resources (VSE) will also participate in the $1.5 million work program which could be extended depending on results. A minimum 10,000 ft of drilling is planned along with 500 ft of drifting. The unit value of existing reserves at Tulsequah appears ample enough to justify production, The Northern Miner gathers, so it’s now just a matter of finding enough tonnage.

W. J. (Bill) Wolfe, Cominco’s exploration manager for Western Canada, said that a threshold reserve of at least five million tons would be required to resume production; the grade would have to be similar to that mined before, he added. Mining operations ceased in 1957 because of poor metal prices leaving in situ reserves of 780,000 tons grading 0.07 oz gold per ton, 2.9 oz silver, 1.3% copper, 1.6% lead and 8% zinc.

The program should easily expand those reserves because, as Dr Wolfe pointed out, the mine has never been explored below the old workings. It’s totally open down dip and he said there appears to be a trend to increased tonnage per vertical foot at depth.

Redfern has spent almost $2.8 million on the property since 1987 and will be vested with a 40% interest after expending another $150,000. The company has sufficient funds on hand to participate in the forthcoming program on a pro rata basis. But Redfern is seeking alternate financing so it won’t have to dip into its cash reserves.

Recognizing the importance of the property, Cominco has held onto the Tulsequah Chief since it closed. But the property has been dormant for years and Cominco produced the first geological map of its surface geology about two years ago “in terms of a modern volcanogenic concept,” Wolfe said. In the past, there was a shear zone interpretation of the geology and earlier work did not appreciate the stratigraphic nature of the deposits, he emphasized.

Since exploration resumed on the property, the 5400 level adit has been rehabilitated and they have been drilling the known deposit from this horizon. The whole mine was developed by adits and most of the higher portion of the mountain has been explored. Mike Casselman, senior geologist, said the stratigraphy seems to pinch out up the mountain but there is still potential laterally.

One intriguing scenario the company is pursuing is whether the various zones coalesce at depth. Two deep holes have been put down into the E zone and they both averaged about 5% copper, 3% zinc, and 0.08 oz gold over lengths of 57.5 ft and 11.5 ft respectively; and this lens has been extended down dip “with no sign that it’s stopping,” said Wolfe. “We are seeing evidence of the biggest lens of all time being developed in the E zone,” he added.

Michael Kenyon, a Redfern director, said “the mineral system is getting thicker and more altered with depth which could mean we are getting closer to the actual vent area.

“The thing that’s most interesting,” he said “is that those two drill holes in the E lens had almost exactly the same grade. It’s phenomenal that those two holes are 300 ft apart and you can just about lay one right over the top of the other.”

So far the E lens has been traced some 730 ft beneath the lowest mine level. The G lens was mined previously and was thought to have been cut off by a dyke. But the lens has been picked up at depth and mineralization has now been outlined along 1,000 ft of strike length. Five long surface holes were drilled beneath the old workings which led to the discovery of the G lens but it was too costly to drill from surface. So they re-opened the 5400 level which is no longer useful for drilling purposes.

The zinc content in the G lens is somewhat higher as is the gold. One 1987 drill hole returned 20.5 ft of 8% zinc and 0.185 oz gold and last year another hole returned 5.7 ft of 0.17 oz gold and 14% zinc. The new exploration drift will enable Cominco to test known zones 1,000 ft down dip from present levels of testing, said Casselman. “By this time next year we should have a good idea of what we have. This is one of the highest profile zinc deposits in Canada. But we have to figure out the stratigraphy and the volcanogenic model it fits,” he said.

The Tulsequah Chief is similar geologically to Westmin Resources’ Buttle Lake mine on Vancouver Island, a 5-metal polymetallic mineral deposit with excellent gold values.

Access is good and concentrate would be barged down the Tulsequah river to the Taku which flows into the ocean. All concentrate would be shipped to Juneau, Alaska. Although no recent metallurgical test work has been done, there were no problems in the past and recoveries would probably rise with new technology.

Historically, the sulphide lenses at Tulsequah ranged from 50,000- 100,000 tons. The largest lens ever mined occurred on the Big Bull property several miles away which is 100%-owned by Cominco. Only routine mapping has been done on the Big Bull and the mineral horizon there is chopped up by a northerly trending fault.

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