Overview
PLEX is a 21,000-hectare district-scale land package situated along the contact of the La Grande and Opinaca geological subprovinces in the Eeyou Istchee James Bay region of Québec – the same geological boundary that hosts the Éléonore mine and the Cheechoo gold deposit. The property hosts the Orfée Zone, a structurally controlled, high-grade gold occurrence defined by multiple sub-parallel corridors with expansion potential both at depth and along strike. A 2003 historical, non-compliant estimate outlined 125,000 ounces at 14.5 g/t gold. This estimate is considered historical and is not compliant with NI 43-101; it should not be relied upon as a current mineral resource.
Geology
PLEX straddles the La Grande–Opinaca subprovinces contact, a regional-scale structural and metamorphic boundary that represents the principal gold metallotect of the Eeyou Istchee James Bay territory. The La Grande Subprovince to the north is characterized by volcano-plutonic rocks, while the Opinaca Subprovince to the south is dominated by higher-grade metasedimentary assemblages and migmatites. This subprovince contact has acted as a long-lived conduit for hydrothermal fluids, and the clustering of significant gold deposits along it — including Éléonore, Cheechoo, La Pointe, and Orfée — speaks to its enduring metallogenic significance.
The Orfée Zone is interpreted as an orogenic gold occurrence controlled by major structural corridors at this subprovince boundary. The high grade of the historical estimate (14.5 g/t) relative to typical bulk-tonnage deposits in the region points to structurally focused, vein-hosted mineralization — a style that commonly hosts additional parallel zones along strike and at depth, and one that has historically proven responsive to systematic structural reinterpretation.
Historical Work
Virginia Mines conducted an extensive exploration campaign at PLEX, accumulating approximately 38,000 m of historical drilling across the property. This dataset forms the foundation for Sirios’ current targeting work and provides a robust basis for reassessing the Orfée Zone geometry and identifying new corridors.
Infrastructure
PLEX benefits from the same regional infrastructure advantages as the broader James Bay gold belt, including established road networks, access to hydroelectric power, and a mature permitting and community engagement framework. Its location along the La Grande–Opinaca contact places it within one of Québec’s most active and well-serviced exploration corridors.
Next Steps
Sirios is focused on comprehensive data reinterpretation and structural targeting at PLEX, with the objective of defining high-priority drill targets across the Orfée Zone and identifying new structural corridors. Given the size of the land package, the quality of the historical data, and the demonstrated high-grade potential of the Orfée Zone, PLEX has the potential to emerge as a cornerstone asset within Sirios’ James Bay portfolio.