Cominco plans more deep drilling at Tulsequah Chief

Tulsequah Chief is a former producer some 35 miles northeast of Juneau, Alaska. It was operated by Cominco at about 500 tons per day until 1957 when low metal prices forced a mine closure.

At that time the mine had proven and probable reserves of 780,000 tons grading 1.3% copper, 1.6% lead, 8.0% zinc, 0.07 oz gold per ton and 2.9 oz silver in several massive sulphide lenses.

The project is now a joint venture between Cominco (60%) and Redfern (40%). By the end of the 1988 work program, reserves in all categories had been increased to 2.38 million tons grading 2.03% copper, 1.25% lead, 6.25% zinc, 0.075 oz gold and 2.68 oz silver.

According to John Greig, Redfern president, the system is expanding with depth and the individual mineral zones in the upper levels appear to be merging at depth into a larger zone.

As a result, Greig estimates the potential for a sizeable deposit (10-15 million tons) is much greater than before the start of this year’s dril ling.

Bill Wolfe, exploration manager for Cominco, said he was not prepared to comment on the tonnage implications because the holes drilled to date are spaced too far apart to know if the intersections can be joined up.

“But the holes do demonstrate that there is mineralization at a depth of about 1,100 ft below the old workings,” he said. “Therefore we are encouraged to think there is potential to find something down there, which is all we were hoping for with these holes.”

Assays are expected shortly for holes 16 and 18, the deepest to date. Both are reported to have intersected the mineral horizon at about the 3675 level which is 1,650 ft down dip from the lowest mine level.

According to Redfern, drill hole 16 intersected 7.9 ft of high grade mineralization, and hole 18 intersected 34.7 ft of better than average grade mineralization based on visual estimates.

Hole 17 intersected and stayed in a post-mineral dyke through the mineralized area, and holes 19 and 20 are drilling.

The phase-one budget is being extended by at least $500,000 to accomplish further deep drilling and a phase-two program involving further deep drilling and infill drilling will be considered after the first- phase program is completed.

The latest results from holes staggered over a strike length of about 750 ft are: interceptwidthcopperleadzincgoldsilver Holeft.ft.%%%oz/toz/t 12923.5-935.512 2.250.483.840.0351.36 131230-127949 1.031.396.240.0682.90 141109-1110 1 0.450.987.800.0040.16 1172.5-1174 1.52.171.082.190.0020.32 (Note: drill hole 14 encountered mainly massive pyrite): 151294.5-1299.6 5.11.080.6724.500.0483.01 1359-1375.616.60.931.739.400.0611.14

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