Great Lakes hits high-grade zones at Michigan copper bet

The first two holes of Great Lakes Minerals’ (TSE) 8,000-ft. drilling program on the Keweenaw project in northern Michigan have intersected high-grade copper mineralization over strong widths. Hole 593-90-1, designed to infill between several widely spaced holes completed by Homestake Mining (NYSE) and Inco (TSE) during the mid-1970s, intersected 10 ft. grading 5.7% copper and 34.5 ft. grading 3.1% copper. Both of the mineralized lenses are contained within an 80- to 100-ft.-wide zone averaging 1.5-2% copper.

The second hole, 200 ft. along strike to the east, intersected 33 ft. grading 2.3% copper, including a 13-ft. section grading 4.5% copper.

Great Lakes can earn a 50% interest in the Keweenaw property from Michigan Mining and Manufacturing by spending $1.5 million on exploration. Over the next few months, the Toronto-based company will spend almost $400,000 to confirm the continuity of mineralization in the 543-S deposit, which hosts probable reserves of 3.1 million tons grading 2.95% copper, mostly within 500 ft. of surface. Contained within the 543-S is a higher-grade reserve of 1.3 million tons grading 4% copper.

With the submittal of a water discharge permit, Great Lakes has already started the site permitting procedure required for future production. Previous metallurgical testing by Inco, during its extensive exploration drive on the property, yielded a recovery of 93% to produce a concentrate grading more than 40% copper.

Great Lakes will also test the St. Louis deposit 20 km to the west of 543-S. According to Homestake, the deposit hosts open pit reserves of 8 million tons grading 0.8% copper and has the potential to host a large-tonnage, low-grade native copper deposit.