MERN - Québec Mines - Abitibi - James Bay Triennial Plan 2003-2006












février 2003
 

Ni–Cu–PGE Deposits in the Cape Smith Belt

Abdelali Moukhsil and Serge Perreault
Géologie Québec

EXPLORATION FOR Ni, Cu AND PGEs

Over the years, several showings of Ni–Cu mineralization have been discovered in the Cape Smith Belt (Ungava Trough). The earliest work that mentions such occurrences dates back to the end of the 19th century. The first copper–nickel showings in the Cape Smith–Wakeham Bay area were discovered by Murray Watts in 1937. These showings were developed by various companies in subsequent decades.

The Cape Smith Belt has unique mineral potential that is still largely undeveloped in Québec. During the 1950s, several companies became interested in this area, in conjunction with geological mapping undertaken by the gouvernement du Québec. Numerous showings and deposits were discovered at the time, including the Delta and Expo-Ungava deposits, as well as most of the Raglan mining camp deposits (Figure 1). Toward the mid-1980s, the belt was confirmed as a target area for platinum exploration.

In 1997, High North Resources, under Ungava Minerals Corporation's option, carried out a drilling program (1,038 m), mapping and airborne/ground-based geophysical surveys on the Expo-Ungava property. The program revealed that the Expo-Ungava deposit was formed of massive sulfide lenses at the base of ultramafic sills injected into the Povungnituk Group. The geochemical signature of these ultramafic sills is similar to ultramafic suites and cogenetic flows forming the Chukotat Group (Picard et al. 1995, MB 94-30). The geological model suggests that sulfides accumulated in troughs at the base of an ultramafic lava flow or sill that opens towards the west. The trough is truncated to the west by a thrust fault that juxtaposes sedimentary and volcanic rocks. A number of remobilized massive sulfide lenses occur within the sediment in the fault walls.

In 2001, Canadian Royalties Inc., under Ungava Minerals Corporation's option (Figure 1), discovered significant amounts of platinum and palladium as a result of new analyses of core samples taken during the 1997 drilling program conducted by High North Resources. During the initial program, drill cores were assayed for nickel, copper and cobalt but not for the platinum group elements (platinum, palladium, and rhodium). Other work carried out by the company in the summer of 2001 revealed mineralization along a length of 732 m in the east–west axis, with an average width of 107 m along the north–south axis.

During the same period, Canadian Royalties Inc. discovered significant amounts of platinum, palladium, nickel, and copper as the result of work done on a new showing (Phoenix), located on the TK property, 20 km south of the Raglan mining camp and 7 km northeast of Expo–Ungava. The mineralization comprises massive sulfides near the base of an ultramafic sill (TK sill) similar to the Raglan sill.

Prospects

The most recent results of the work carried out by Canadian Royalties reveals an outstanding potential for PGEs associated with ultramafic sills cogenetic to the Chukotat Group that are injected into the Povungnituk Group. The Povungnituk is currently one of the most promising sectors for mineral exploration in Québec due to the significant quantities of lava flows and mafic and ultramafic sills it contains. The task at hand is to find sufficient volume to make mining of these elements economically feasible. The prospects in this regard are excellent.

See also:

Geological overview
Ni-Cu dominant magmatic deposits
PGE dominant magmatic deposits

















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