Geological mapping in the Côte-Nord (North Shore) area
Department survey creates interest among mining companies

André Gobeil
Géologie Québec

During the summer of 2004, the Department carried out geological mapping in the watersheds of the Outardes and Manicouagan Rivers north of Baie-Comeau (NTS 22F/10 – lac Varin). The project is part of a wide program of geological mapping aimed at improving knowledge of the mineral potential of the Côte-Nord area, thereby favoring the diversification of its economy.

The area is underlain mainly by anorthosites and related rocks belonging to the Grenville geological province, which covers most of the Côte-Nord region. The Grenville is well known for its titanium and iron potential, which is best demonstrated by the Lac Tio deposit located north of Havre-Saint-Pierre. The Grenville also has excellent potential for base metals, such as copper, nickel, and cobalt, and for dimension stone, which is currently experiencing strong growth in Québec.

During this survey, several mineral occurrences were discovered in rocks belonging to the Vallant Anorthositic Suite. A dozen new iron and titanium (ilmenite) showings have been added to those already known in the area; half of them are enriched in phosphorus (apatite).

Massive magnetite–ilmenite (Fe–Ti) showing hosted in leuconorite.	Magnetite–ilmenite–apatite (Fe–Ti–P) showing located on an island in the Outardes River.

Two new copper-nickel showings in anorthosite of the Vallant Suite are unusual in that they do not appear to be associated with mafic or ultramafic rocks, which are the typical hosts for these metals. These discoveries thus open up a new exploration approach for such deposits.

Several occurrences of granitic dimension stone have been found in the Vallant Anorthositic Suite and in the Varin Plutonic Suite. The quality and size of the resource in these sites remain to be determined. It should be noted that Autoroute 389, secondary roads, and numerous forest roads provide easy access to the area.

Uses:

Titanium: In oxide form, it is used as a pigment in paint and as an additive in plastics, paper, and medicines. It is used in alloys for planes and missiles. It is found in golf clubs, bicycles, portable computers, and prostheses. It is often used as a catalyzer, for example, in the polymerization process.

Phosphorus: It is an ingredient in chemical fertilizers (phosphates), fireworks, matches, toothpaste, and cleaning agents. It is used as a nutritional additive in cheese and as an additive in lubricants. It can be found, among other places, in delicatessen products, soft drinks, yeast, and condensed milk.