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 StatusAdvanced exploration
Mineral Resources (2021)Indicated: 2.66 Mt @ 2.68% Cu and 0.26 g/t Au, containing 157 M lbs of copper and 22,000 oz of gold
Inferred: 4.54 Mt @ 3.20% Cu and 0.27 g/t Au, containing 320 M lbs of copper and 39,000 oz of gold

OVERVIEW

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.

The Company, while operating as a private company, completed a drilling program of 14,047 meters in 14 holes (including wedges) in 2017-18 and reported a NI 43-101 mineral resource estimate in 2019. Subsequent drilling programs by the Corporation in 2020 and 2021 have successfully expanded the deposit along strike and down plunge.  

Dore Copper updated the mineral resource estimate (“MRE”) in October 2021 (see October 6, 2021 news release). This MRE will form the basis of the mine plan to be outlined in a preliminary economic assessment (“PEA”) anticipated to be completed by January 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 (2,700 tpd), 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 totalling 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 a 14-hole (including wedges) drilling program totalling 14,047 meters in 2017-18. The positive results from the program expanded two areas of mineralization: Main Vein below the dyke and the Lower Deep Vein. Following this program, the Company reported a mineral resource estimate of 1.35 Mt averaging 3.01% Cu and 0.29 g/t Au, containing 89.8 M lbs of copper and 13,000 oz of gold in the Indicated category; and 1.66 Mt averaging 3.84% Cu and 0.27 g/t Au, containing 140.3 M lbs of copper and 15,000 oz of gold in the Inferred category.

Dore Copper completed 10,237 meters of drilling at Corner Bay in 2020. The program successfully extended the Main Vein below the dyke 200 meters along strike to the south and over 500 meters vertically. 

Following positive results from the ongoing 30,000 meter drilling program, which further expanded the Corner Bay deposit, Dore Copper reported in October 2021 a significant increase in the mineral resource estimate (“MRE”) from the 2019 MRE: an Indicated Resource of 2.66 Mt averaging 2.68% Cu and 0.26 g/t Au, containing 157 M lbs of copper and 22,000 oz of gold and an Inferred Resource of 4.54 Mt averaging 3.20% Cu and 0.27 g/t Au, containing 320 M lbs of copper and 39,000 oz of gold (details in October 6, 2021 news release). Approximately 19,000 metres of the 2021 drilling program was included in the October 2021 MRE. 

Although the Main Vein (above and below the dyke) at the Corner Bay deposit has limited strike extension, it remains open down plunge and the current drilling program is successfully demonstrating continuity between the Main Vein below the dyke and the Lower Deep Vein (assays are pending). Both the West and East Veins are open along strike and at depth. In addition, a number of parallel zones remain to be tested.

The next step is to commence infill drilling in 2022.

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 1,000 meters along strike. Mineralization consists mostly of pyrite and chalcopyrite 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 four main mineralized veins (subparallel Main Vein 1 and Main Vein 2 above the dyke, Main Vein below the dyke, and Lower Deep Vein) 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 Lower Deep Vein is a deeper lens in the same shear, with the same general orientation as the other veins, dipping 65° west. The current drilling program is successfully demonstrating continuity between the Main Vein below the dyke and the Lower Deep Vein (assays are pending). This part of 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.

In general, the mineralization ranges in thickness from 0.4 meter to over 20 meters (all eight veins have been modelled with a two meter minimum true thickness). 

MAPS & SECTIONS

Isometric View Showing the Mineral Resources and Potential for Expansion
Cross Section Showing the Mineralized Structures
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.