Westmin looks bullish on Silbak, Big Missouri

There appears to be little doubt that Westmin Resources w ill have a viable mining operation at Stewart, B.C., when it completes this year’s work program at its British Silbak and Big Missouri gold properties.

A new reserve estimate should be available by year-end at which time the company will begin a formal feasibility study, says Arthur E. Soregaroli, vice-president exploration.

Westmin now is testing the Glory Hole area where some highly encouraging gold and silver assays have been returned (N.M., Oct. 27/86). These results were expected, he confirms, because residual ore had been noted in previously-worked stoping areas.

This high grade ore occurs in the hangingwall and footwall of these stopes and also in sloughed material that has fallen into the stopes. Many of these stopes have been filled with good grade material that was simply below the cut-off grade mined by previous operators.

Dr Soregaroli says the high grade sections “seem to have some continuity” which should help in meeting his prediction that “the strip ratio will go down and the grades go up.” Before this year’s program, the company reported reserves of approximately 6.4 million tons grading 0.06 oz gold and 2.5 oz silver at a 5.5-to-1 strip ratio. Exploration activity this year has largely been directed towards upgrading the confidence level of those reserves for the feasibility study.

That study will determine the economics of installing a 1,500- 2,000-ton-per-day milling operation on the British Silbak property where the bulk of the reserves exist. The Big Missouri property some five miles to the north will likely be a seasonal mining operation where its output would be stockpiled and blended as required by the Silbak mill.

There are four main gold zones at the Big Missouri, all of which were drilled this summer to define more accurately the higher grade sections and the lateral extent of the deposits. Those zones have been pretty well defined but there is still considerable potential in the Martha Ellen zone which will be tested at a later date. One of the proposed open pits is the surface expression of the Big Missouri underground mine, he notes. Drilling from underground

Westmin is drilling the bottom of the proposed Silbak open pit from the No 2 underground level. They were unable to drill this area from surface because of open stopes. Drillers have successfully traversed some of the narrow, empty stopes from underground drill stations, which meant they had to re-collar their holes blind in either the hangingwall or footwall of the stope.

The previous operators selectively mined high grade portions of the Silbak ore zone and Dr Soregaroli emphasizes these stoped-out areas have been taken into account when calculating reserves. He also points out that the company has been very conservative in establishing reserve grade and tonnage.

There is still considerable underground potential between the open pit and the No 6 level and also below that horizon. Work there has defined a geological reserve of 320,000 tons grading 0.12 oz gold and 1.1 oz silver and there is “still potential for a lot more,” he says.

Canacord Resources is providing $2 million towards the 1986 exploration program in return for 13.35% of Westmin’s interest in the Silbak and Big Missouri projects. For another $1 million before Feb 28, 1987, Canacord can increase its equity to 18.75%. British Silbak Premier Mines has the option to earn 50% working interest in the Silbak property and under certain condition be reduced to a 20% net carried interest in the Big Missouri, but Westmin can buy that down to 22.5% for $1 million. Westmin will probably be able to generate its own power at the mine because there is an old hydroelectric plant on the property which was used by the Big Missouri. This would represent considerable saving when compared to diesel-generated electricity.