Falconbridge’s deep hole will test Sudbury’s `twin’

A 1,500-metre hole designed to test the Wanapitei anomaly northeast of Sudbury, Ont., recently got under way.

As operator of the “Mirage project,” Falconbridge has collared the deep hole in Sheppard Twp., just north of the western peak of the magnetic anomaly. “The location is based on geophysical targets — both airborne magnetic and ground seismic,” said Paul Severin, manager of exploration for Falconbridge’s Sudbury office. “We’re seeing some seismic reflections down to about 1,000 metres.”

Severin said the reflections may represent the contact between the sedimentary package outcropping at surface and the potentially mineral-rich basement rocks at depth. But he stressed that, until the hole has reached its target depth at the end of October, his exploration team will be groping in the dark.

The Mirage project is based on the theory that the Wanapitei anomaly, similar in size and shape to the nearby Sudbury anomaly, could be associated with Sudbury-like mineralization. Although geophysical studies have confirmed that the Sudbury anomaly is too strong to be caused by the complex itself, the possibility of a genetic relationship between the Wanapitei and Sudbury anomalies has geologists excited.

The 14 underground mines within the Sudbury igneous complex produce more than $1-billion worth of copper, nickel and platinum annually.

But until 1990, when the Ontario government lifted a land caution over the prospective ground, Sudbury’s neighboring “twin” had never been explored. Shortly after the ground was reopened, Falconbridge staff staked 1,500 claims in Sheppard, Mackelcan and Aylmer twps., close to the western peak of the anomaly. Last spring, they added 358 claims to the package.

Other landholders in the area include Flag Resources (ASE), with about 600 claims at the heart of Falconbridge’s land package and Teck (TSE). Flag says it holds the western peak of the anomaly.

More cautioned ground may be reopened when the Ontario government negotiates a new treaty with the Teme-Augama Anishnabai band, which recently lost its claim to the Temagami area (T.N.M., Aug. 26/91). The eastern third of the Wanapitei anomaly is currently under caution.