Geological studies shed light on Kidd Creek mine

Studies have enabled Falconbridge to increase reserves at its Kidd Creek copper-zinc mine, north of Timmins, Ont.

Moreover, the research has resulted in a new mine model which could lead to additional discoveries in this and other regions of the Canadian Shield.

In 1992, the Geological Survey of Canada, the Ontario

Geological Survey and Falconbridge began a multidisciplinary study of the orebody in order to assist base metal exploration in the region. The program was concerned with stratigraphy and structure, alteration and mineralogy, and geochemistry and volcanology.

The findings, only recently released, reveal how the Kidd Creek deposit differs from other volcanogenic massive sulphide (VMS) deposits.

Classic VMS models commonly feature a subvolcanic intrusion (generally a large sill buried 2 to 4 km below the surface) as the heat source that mobilizes the ore-forming, hydrothermal fluids. This leads to the formation of several closely spaced deposits, giving rise to mineral districts. (The Noranda massive sulphide camp is one such district.)

The Kidd Creek deposit is now understood to be singular, as opposed to belonging to a mineral district, and the implication is that other parts of the Canadian Shield that are rich in ultramafic rocks have potential for similarly large and singular VMS deposits.

As a result of these findings, a new geological research project is under way in the southern Abitibi region. The participants (including five major mining companies, the Geological Survey of Canada, and the Ontario and Quebec provincial surveys) are attempting to determine the potential for VMS and nickel-copper-platinum deposits.