Selkirk Copper Mines (TSXV: SCMI) has published an updated mineral resource estimate for its Minto copper-gold-silver project in the Yukon, lifting measured and indicated tonnage by 280% over the 2025 estimate.
The 2026 figures put 47.8 million tonnes into the measured and indicated categories at 0.89% copper, 0.34 g/t gold and 3.2 g/t silver. Contained metal comes to 940 million pounds of copper, 530,000 ounces of gold and 4.97 million ounces of silver, up 182%, 184% and 188% respectively.
The estimate breaks down at cut-offs of CAD$30 per tonne net smelter return for open pit material and CAD$80 for underground.
- Measured:
- Underground: 348,000 tonnes grading 0.92% copper, 0.39 g/t gold and 3.3 g/t silver
- Containing 7 million pounds of copper, 4,400 ounces of gold and 36,500 ounces of silver
- Underground: 348,000 tonnes grading 0.92% copper, 0.39 g/t gold and 3.3 g/t silver
- Indicated:
- Underground: 25.7 million tonnes grading 1.15% copper, 0.49 g/t gold and 4.4 g/t silver
- Containing 650 million pounds of copper, 403,700 ounces of gold and 3.64 million ounces of silver
- Open pit: 21.8 million tonnes grading 0.59% copper, 0.17 g/t gold and 1.8 g/t silver
- Containing 283 million pounds of copper, 121,700 ounces of gold and 1.29 million ounces of silver
- Underground: 25.7 million tonnes grading 1.15% copper, 0.49 g/t gold and 4.4 g/t silver
- Inferred:
- Underground: 9.8 million tonnes grading 0.91% copper, 0.36 g/t gold and 3.5 g/t silver
- Containing 196 million pounds of copper, 112,200 ounces of gold and 1.11 million ounces of silver
- Open pit: 7.1 million tonnes grading 0.55% copper, 0.13 g/t gold and 1.6 g/t silver
- Containing 85 million pounds of copper, 30,100 ounces of gold and 353,800 ounces of silver
- Underground: 9.8 million tonnes grading 0.91% copper, 0.36 g/t gold and 3.5 g/t silver
Roughly half of the indicated expansion came from higher metal price assumptions and revised design basis inputs pulling lower grade material above the cut-off, with the balance attributable to drilling. Average grade fell as a result.
Mineralization at Minto sits in 69 modelled lenses of foliated granodiorite and migmatite, typically four to 30 metres thick and running 100 to 1,000 metres along strike. The lenses are stacked and gently dipping across a three by three kilometre area, extending at least 650 metres below surface, with chalcopyrite and bornite the dominant sulphides and precious metals occurring as inclusions within them.
RELATED: Selkirk Copper Extends High Grade Copper Zones at Minto in First Phase 2 Assays
President and chief executive Colin Joudrie said the added material gives the mine planning team more to build against a targeted 12 to 15 year mine life at 4,100 tonnes per day of mill feed, and described the resource growth as evidence of scope to add mineable tonnes “in a cost-effective and timely manner.”
None of the ongoing 50,000 metre Phase 2 program is reflected in the update. That campaign is 75% complete at roughly 37,000 metres, and early assays released this month included 2.33% copper, 1.98 g/t gold and 22.3 g/t silver over 5.9 metres from a depth of 142 metres at Minto East.
An updated preliminary economic assessment is being built on the new estimate. A feasibility study is slated to begin in the third quarter, with the supporting technical report due within 45 days.
Selkirk Copper last traded at $1.94 on the TSX Venture.
