The Gwillim property totals 486 ha and is located 8 km by road northwest of Chibougamau. The western part of the property (385 ha) is under a 50/50 joint venture between Dore Copper and Argonaut Gold Inc. (through its wholly owned subsidiary Prodigy Gold Inc.) with Dore Copper being the operator. The eastern part of the property (102 ha) is 100% owned by Dore Copper. Located on the joint venture land, the Gwillim mine operated between 1974 and 1976 and again from 1980 to 1984. In total 245,066 short tons were mined at a grade of 4.79 g/t Au1. Most of the production came from the Main zone, which extended along strike for 122 m with an average width of 2.6 m and up to a depth of 114 m.
In 1987, two high-grade intercepts of 7.6 m at 38.0 g/t Au and 7.9 m at 17.9 g/t Au were drilled by Greenstone Resources at moderate depths of 200 to 300 m at the KOD zone (300 m south of the mined Gwillim Main zone)2. A further 25 holes were drilled from the surface before a ramp was developed and the zone was further explored from underground in 1988 but not mined (some development through ore). In 1989, three more surface holes were drilled to depths of 400 m with one hole confirming the extension of the high-grade mineralization beyond 300 m vertical depth. No other significant exploration activities are reported after this work.
In 2021, the JV drilled two holes with hole KOD-21-02 intercepting 3.33 g/t Au over 13.3 m and 10.14 g/t Au over 4.0 m, and hole KOD 21-03 intercepting 3.03 g/t over 4 m and 4.64 g/t Au over 6 m, including 11.69 g/t Au over 2 m (refer to news release dated April 21, 2022).
In December 2022, the JV drilled two holes totaling 1,320 m on the KOD zone. Hole KOD-22-04 intersected two main mineralized zones: 9.67 g/t Au over 5.3 m, including 19.46 g/t Au over 2.1 m, starting at a vertical depth of approximately 580 meters and 11.10 g/t Au over 3.0 m, which are interpreted as zones B and C of the KOD mineralized structure. These gold intercepts in zones B and C are located approximately 190 and 215 m, respectively, below hole KOD-21-03. In addition, a wide zone of low-grade mineralization, 0.86 g/t Au over 42.3 m, was intersected from 460 to 502.3 m. Assays are pending for hole KOD-22-05 from 130 to 323.5 m in hole KOD-22-04. Refer to news release dated May 29, 2023.
Gwillim is hosted within the Bruneau Formation in pillowed basalts and gabbroic sill. Mineralization is hosted predominantly within east-west, steeply dipping structures containing quartz-carbonate veins with limited amounts of massive sulphides. At KOD, there are two parallel east-west vein zones, approximately 50 m apart, with the mineralization predominantly occurring in the northernmost vein. The thickness of the mineralization varies between 0.3 m and 5.0 m. The KOD zone is open along strike and below 600 meters.
Following a compilation of all data available, Doré Copper now has a solid database for 3D modeling of the various mineralized zones (e.g. preliminary modeling of B and C zones at the KOD zone.
In January 2023, a 146 line-kilometre airborne VTEM™ survey was completed over the joint venture property. The flight lines were flown at a 75 meter spacing. A number of anomalies have been identified in this survey and are expected to be followed up in the field starting in the summer of 2023. A significant, large anomaly is located on the KOD zone starting at a depth of 150 meters, just west of holes KOD-22-04 and 05 (shown on the long sections).
1 Structural and Stratigraphic Control on Magmatic, Volcanogenic, and Shear Zone-Hosted Mineralization in the Chapais-Chibougamau Mining Camp, Northeastern Abitibi, Canada – Leclerc et al., 1992 Society of economic geologist inc. V 107, pp. 963-989.
2 Diamond Drilling Report on the Gwillim Lake KOD Zone, Greenstone Resources (internal report) – Robert McIntosh, Project Geologist, Flanagan McAdam and Company, December 1989.