Windy Mountain outlines `huge’ porphyry copper deposit

A preliminary reserve estimate of more than 30 million tons grading 0.48% copper marks the end of a successful 35-hole grassroots drilling program on Windy Mountain Explorations’ (COATS) MacLeod Lake copper project, north of Chibougamau, Que. The large, low-grade find has been identified as a porphyry copper deposit stretching for one kilometre along strike and over 200 metres downdip with an average thickness of 60 metres. The zone is open along strike and at depth.

“This has all the makings of a very exciting new discovery,” said Steve Vaughn, lawyer-geologist for Windy Mountain. “The deposit is unique in its mineralization — a copper-molybdenum-gold-silver deposit has never been mined on the Canadian Shield to my knowledge.”

Most Canadian porphyry copper deposits are centred around distinctive calc-alkaline intrusive bodies in central British Columbia. In the past, the Canadian Shield has never been considered favorable geological environment for these large, low-grade orebodies.

Estimates of 30.1 million tonnes grading 0.48% copper, 0.07% molybdenum, 0.05 grams gold per tonne gold and 4.31 grams silver are based on a cutoff grade of 0.25% copper. Within the mineralized zone, a higher-grade core contains 9.9 million tonnes grading 0.71% copper and 0.13% molybdenum. Windy President Stanley Mourin said he was surprised to find such substantial reserves after drilling only 35 holes. Almost all of the holes contained copper, however, over widths of up to 90 metres.

Since the Main zone mineralization occurs above 150 metres, it is likely that an open pit operation would be feasible should the deposit ever be mined. Preliminary estimates indicate a stripping ratio of 1-to-1 (one tonne of waste for every one tonne of ore).

To protect their wholly owned find, the directors of Windy have adopted a “poison pill” plan, subject to shareholder approval. According to Windy President Stanley Mourin, the plan is designed to prevent “inappropriate takeover bid tactics.” Mourin added that he was unaware of any current plans for a hostile takeover.

On news of the discovery, Windy’s shares jumped 75 cents to a high of $3.25 before dropping back to below $3. Gorden-Daly Grenadier Securities, which is not a member of any stock exchange, acts as underwriter for the stock.

MacLeod Lake is an isolated property in northern Quebec, 400 km east of James Bay. Recently, Indian bands in the area filed a lawsuit against the Quebec government, demanding that ownership of a large tract of land, including MacLeod Lake, be returned to them. Copper mineralization on the property was discovered accidentally by a company exploring for uranium in 1982. In 1988, Windy outlined two main copper-molybdenum showings. The first consists of a zone of silica bounded by a granite dyke and the other of granitic gneisses intruded by narrow quartz veins. Both are rich in molybdenum and chalcopyrite — a copper sulphide.

Windy’s 5,000-metre drill program focused on proving reserves around the showings. Drilling was angled perpendicular to the strike of the mineralization and confined to sections spaced 100 metres apart. Drill spacing within the sections ranged from 30 to 100 metres, and grade values were projected halfway between drill holes or for 50 metres, whichever was the lesser distance.

Windy is planning a major program of geological mapping, prospecting, geochemical sampling and ground geophysics to be followed by diamond drilling to further delineate the known zone of mineralization. The company will also explore for additional mineralization in the 935-sq. km area surrounding the MacLeod Lake property.