Recent geoscientific work and future perspectives for the James Bay region
Daniel Bandyayera, Sylvain Lacroix and Jean Goutier (MRNF)

From a historical perspective, geological surveys by the Québec government in the James Bay region can be divided into three important periods. The first period (1950-1960) covers mapping at 1:63,360 scale of the area between Lac Troilus and the Monts Otish. The second period (1970) concerns mapping coverage at 1:63,360 scale or 1:100,000 scale of extensive areas, prior to the creation of major hydroelectric reservoirs. In the 1980s, detailed work focused on the Troilus and Upper Eastmain areas. The third period began in the mid-1990s with the Near North project. During this time, the Frotet-Evans, Eastmain and La Grande volcanic belts were mapped at 1:50,000 scale, whereas the central part of the James Bay region (33B) and areas to the west of Caniapiscau (23E and 23L) were mapped at 1:250,000 scale.

Recently, the discovery in 2003 by Virginia Gold Mines of the Roberto gold deposit on the Eleonore property, northeast of Opinaca Reservoir, triggered a staking rush throughout the Eastmain Belt. Since the summer of 2006, Géologie Québec has launched a three-year mapping program at 1:50,000 scale of the Opinaca area, covering the transition zone between the Opinaca and La Grande subprovinces. Preliminary results indicate that metasomatized turbiditic sediments similar to those hosting the Roberto deposit extend for a significant distance to the west (bordering the Opinaca Reservoir Pluton). The discovery of new felsic centres and of mineralized hydrothermal breccias, and correlations of Algoma-type iron formations of regional extent are among the new mineral potential targets delineated as a result of these recent efforts.

Over the next few years, the Géologie Québec plans to intensify its geoscientific efforts in this emerging mining region of Québec, in order to support and further stimulate ongoing exploration work. The Opinaca mapping project should continue for another year, with the area located to the east of Eleonore targeted for 2008-2009. The Géologie Québec also plans to cover extensive portions of the James Bay region with aeromagnetic surveys to provide a regional coverage approaching what is available in the Abitibi. Finally, the Géologie Québec wants to support geoscientific activities that can lead to increased knowledge and better understanding of Quaternary deposits, namely by collaborating on projects proposed by regional stakeholders and universities. The Géologie Québec’s definitive programming of future geoscience projects will be established following annual consultations with industry and regional stakeholders.