Deep hole to probe Geco potential

In what is probably the deepest hole ever commissioned by Noranda (TSE), a diamond drill will probe the Manitouwadge Synform to a depth of 8,000 ft. in a long-shot bid to extend the productive life of the Geco complex in Manitouwadge, Ont.

The proposed $400,000 hole (Hole 93-2) will be collared about 1.5 miles northwest of Gecos No. 4 shaft.

In essence, its a wildcat hole, Gecos Chief Geologist Hugh Lockwood told The Northern Miner. It will test one of the last areas unexplored here that can hold a Geco-size orebody.

Lockwood said the hole has been positioned at the plunge projection of the Willroy orebody, a 4-million-tonne producer depleted years ago. The Geco mine itself has enough ore (roughly 3.4 million tonnes) to last until 1996. To date, mined tonnage has reached 52 million tonnes.

The Manitouwadge Synform is an easterly plunging (about 30), folded sequence of highly metamorphosed Archean volcanics and sediments. The Geco orebody, as well as Willroy and smaller such deposits, occur on the south limb of the Synform.

In years gone by, an 8,000-ft. hole seemed futile. An orebody discovered at that depth, in Canada at least, was considered uneconomic. But with the success of fairly rich mineralization which Inco has found with the deep Victor deposit near Sudbury, Ont., depth targets have been extended. The successes in the Sudbury camp have shown that, with the right grade and tonnage and a little bit of luck, orebodies at that depth can make it, Lockwood said.

A minimum of 25 million tonnes of high-grade massive ore is the threshold target for an economically minable deposit.

Should the long-shot hole hit, the entire camp might once again liven up. Hucamp Mines (CDN) holds ground optioned to Noranda to the east of Geco. Other known players in the area have been Minnova (now a subsidiary of Toronto-listed Metall Mining) and Granges (TSE).

This single deep hole, however, is not the last effort to be expended near Geco. Lockwood said exploration will continue within a 50-mile radius of the mine for the next two years.

As well, the Geological Survey of Canada has four geologists in the area re-interpreting the Manitouwadge Synform and field-mapping.

The 8,000-ft. hole will be completed by early 1994.