Geology & Mineralization
The Rainy River district comprises multiple volcanogenic-style gold deposits situated within the Late Archean Wabigoon Subprovince of Ontario. Local stratigraphy comprises a series of tholeiitic mafic volcanic rocks structurally overlain by calc-alkalic dacitic metavolcanic rocks that host the bulk of gold mineralization in the district.
Regional Geologic Setting
District Geologic Setting
Deposit Geology & Alteration – Plan View
Mineralized zones generally follow the regional northwesterly strike and southerly dip of stratigraphy. The largest of these, the ODM/17 Zone, extends 1,600 metres along strike, 975 metres down dip (open at depth), and has a true width of 200 metres. Three principal styles of gold mineralization have been identified at Rainy River: gold-bearing sulphide ± quartz stringers and veins in felsic quartz-phyric rocks, (ODM/17, Beaver Pond, 433 and HS Zones), quartz-ankerite-pyrite shear veins in mafic volcanic rocks (CAP/South Zone), and sulphide-bearing silver-enriched quartz veinlets in dacitic tuffs and breccias (Intrepid Zone). Most of the gold mineralization identified to date occurs in the sulphide bearing stringers and veins within the felsic quartz-phyric rocks. A fourth style of mineralization characterized by copper-nickel-platinum minerals occurs within a small, younger mafic-ultramafic intrusion (34 Zone) situated within the main cluster of gold and silver deposits. All deposits show some degree of deformation, excepting the copper-nickel-platinum-bearing type.
Open Pit Mineral Resource – Plan View
Deposit Geology – N-S Cross Section
Deposit Geology – E-W Long Section
The Rainy River project represents one of Canada’s newest emerging gold districts. The Rainy River district was first explored for nickel sulphide style mineralization in the mid-1960s. The eventual recognition of the district’s gold potential in 1988 led to the discovery of gold mineralization in what has become a large system of stratiform gold-rich volcanogenic style sulphide deposits. To date, exploration efforts have delineated 3.8 million ounces of gold reserves plus an additional 2.7 million ounces of measured and indicated resources. As the project advances toward its mid-2017 target for the start of commercial production, New Gold continues to focus on the discovery of additional gold resources with the potential to enhance and extend the commercial life of the project.
Geology and Mineralization of the Rainy River Gold Deposit, Ontario