Program planned for Yukon copper deposit

The Williams Creek copper deposit will be further worked during the 1991 season by Western Copper Holdings, a junior owned about 36% by Teck (TSE) and its partner Thermal Exploration of California. Western Copper and Thermal have an option to each earn a 50% interest in the property from vendor Archer, Cathro & Associates which retains either a 2.5% net smelter royalty interest (up to $2.5 million) or a 15% net profits interest.

The Williams Creek copper deposit is situated 22 miles by road northwest of Carmacks, Yukon. Total oxide and sulphide geological reserves are reported to be 16.3 million tons grading 1.15% copper and 0.02 oz. gold per ton. The deposit is contained within a 70 degrees east- dipping tabular zone of porous and fractured rock within a competent granitic intrusive.

The upper 800 ft. of the deposit is reported to be almost totally oxidized, with most of the copper in the form of malachite. Sulphide mineralization intersected below the oxidized material consists of chalcopyrite, bornite and minor molybdenite.

A recent evaluation by an independent engineering firm indicates that the oxide portion of this deposit can be open pit mined and heap leached, with the cathode copper produced by solvent extraction and electrowinning. Capital costs for this type of operation would be an estimated $30-40 million.

For the proposed heap leach operation, a preliminary open pit reserve of seven million tons grading 1.13% copper has been calculated to a depth of 500 ft., with a 2-to-1 strip ratio.

During the 1991 work season, the companies intend to carry out further drilling to increase confidence in the estimated reserves and to further investigate the metallurgical characteristics of the deposit.

Robert Quartermain, president of Western Copper, said preliminary metallurgical testing in the fall of 1989 was encouraging; the test work indicated copper recoveries in excess of 80% can be expected for mineralized material crushed to one inch.

Additional testing is planned to further determine copper recoveries, particularly of subsurface material, and to further ensure the deposit’s amenability to the proposed processing methods.

Western Copper recently applied for a listing on the Vancouver Stock Exchange.