Corner Bay - Doré Copper Mining Corp

Corner Bay

Location55 km by road south of Chibougamau, QC
Ownership100% Dore Copper
HistoryDevelopment: ramp to 115 m; bulk sample of ~36k tonnes averaging 2.48% Cu and 0.44 g/t Au
CommoditiesCopper and gold
Current StatusStarting Feasibility Study
Mineral Resources (2022)Indicated: 2.68 Mt @ 2.66% Cu and 0.26 g/t Au, containing 157 M lbs of copper and 22,000 oz of gold
Inferred: 5.86 Mt @ 3.43% Cu and 0.27 g/t Au, containing 443 M lbs of copper and 51,000 oz of gold


Dore Copper, through its wholly-owned subsidiary CBAY Minerals Inc., holds a 100% interest in the Corner Bay Project located in the vicinity of Chibougamau, Québec, approximately 55 km by road from its Copper Rand mill. 

Corner Bay is a significant high-grade copper-gold deposit located on the south flank of the Lac Dore Complex. Its was discovered in the early 1980s and accessed by a ramp to 115 meters in 2008. No past production is reported although an underground bulk development sample of approximately 36,000 tonnes was mined and processed at the Copper Rand mill in 2008. Mill recoveries were 94.4% for copper and 81.5% for gold.

Drilling programs by the Corporation from 2017 to 2022 have successfully expanded the deposit along strike and down plunge. The Corner Bay deposit remains open at depth.

Dore Copper completed a preliminary economic assessment (“PEA”) in May 2022. The PEA contemplates the re-development plan of a hub-and-spoke operation model with Corner Bay as the main feed to the Corporation’s centralized Copper Rand mill, supplemented by the Devlin and Joe Mann deposits.

The Corner Bay deposit was discovered in 1982 by a joint venture between Corner Bay Exploration Ltd. and Rio Algom Inc. In 1995, the property was acquired by Ressources MSV Inc. which subsequently merged with Campbell Resources Inc. and carried out several exploration drilling programs up to 2008. An initial mineral resource estimate was prepared in 2006. In 2008, Campbell initiated an underground bulk sampling program by driving a ramp down to 115 meters and establishing three levels (-55 m, -75 m, and -105 m). Development muck totaling approximately 36,000 tonnes averaging 2.48% Cu and 0.44 g/t Au was processed at the Copper Rand mill with recoveries of 94.4% for copper and 81.5% for gold. At the end of 2008, Campbell suspended the bulk sample exploration program at Corner Bay.

Following the acquisition of Corner Bay,  Dore Copper (while private) completed several drilling program from 2017 to 2021, which have successfully expanded deposit along strike and down plunge The results from these programs were incorporated in an updated Mineral Resource estimate of the Corner Bay deposit for the PEA: an Indicated Resource of 2.68 Mt averaging 2.66% Cu and 0.26 g/t Au, containing 157 M lbs of copper and 22,000 oz of gold; and an Inferred Resource of 5.86 Mt averaging 3.43% Cu and 0.27 g/t Au, containing 443 M lbs of copper and 51,000 oz of gold.

In 2022, Doré Copper completed 44 holes totaling 38,405 meters, mainly to upgrade the Inferred Resource to the Indicated category for the Feasibility Study. The drilling program which started in early 2022 was designed to infill the Corner Bay deposit at a 50 to 60 meter spacing from surface to a depth of 1,000 meters.

The Corner Bay property is located on the southern flank of the Lac Dore Complex. It is in contact with an intrusive breccia, a transition zone between the Chibougamau Pluton and the Lac Dore Complex. A wide zone (300-450 m) of pyroxenites, gabbros, and magnetite rich mafics, associated with the Layered Zones, separates this breccia from the gabbroic anorthositic sequence which represents the most important lithology on the Corner Bay property. 

The anorthositic sequence hosts the copper mineralized shear (approximately N-S, dipping 70° west) which extends from surface down to 1,300 meters vertically (open) and over 1,000 meters along strike. Mineralization consists mostly of chalcopyrite and pyrite with sporadic pyrrhotite. The alteration is characterized by sericitization and intense chloritization in proximity to the mineralization and within the shear in general. The ore body is bisected by the regional Gabbro Isle dyke, a large north-south striking diorite dyke dipping sub-vertical. There are numerous conjugate and parallel mineralized structures beyond the main shear that remain to be drill tested.

The deposit consists of three main mineralized veins (subparallel Main Vein 1 and Main Vein 2 above the dyke, and Main Vein below the dyke) that make up the bulk of the deposit, and four other parallel smaller veins (West Veins and East Vein). The Main Vein below the dyke is the continuation of the mineralization above in Main Vein 1 and 2, but as the name implies, it is located below the Gabbro Isle dyke and dips 80° towards the west. The mineralized zones vary from 15 cm to 8.0 metres in thickness (averaging 2.2 metres) and are located within a shear zone ranging from 2.0 to 25.0 metres in thickness. The deposit has limited strike extension and remains open down plunge. 

Identified and drilled in 2020 and 2021, the West Veins are three parallel veins located 60 meters to 100 meters below surface and located approximately 400 meters west of the Main Vein 1 and 2. They are sub-vertical and range in thickness from 0.5 meter to 3.0 meters. The mineralized structure hosting these veins extends for hundreds of meters along strike and still remains sparsely drilled. A new parallel vein (East Vein) was identified 200 meters to the east of the Main Vein above the dyke. Both the West and East Veins are open along strike and at depth.


Long Section of Corner Bay – Looking West
Surface Geology
Location map
Surface Infrastructure
CB-21-32_5.5m at 3.46% Cu
CB-21-32W1_6.8 meters at 3.67% Cu.