Osisko drills more high grades across Windfall deposit

Core from the Windfall deposit frequently shows visible gold. Credit: Osisko Mining.

Osisko Mining (TSX: OSK) is finding more high grades at its 100%-owned Windfall gold project in Eeyou Istchee James Bay, Que. The company says the results demonstrate the continuity of the mineralization, and that several zones are at least partly open, meaning there is still potential for expansion. Osisko is working on a feasibility study for Windfall, with an expected release in the first half of 2022.

In the meantime, the company offered these selected high grade intercepts from ongoing drilling:

  • 388 g/t gold over 2.2 metres in WST-21-0823;
  • 135 g/t gold over 6.3 metres and 24.3 g/t gold over 5.2 metres in WST-21-0828;
  • 187 g/t gold over 2.5 metres in WST-21- 0763A;
  • 113 g/t gold over 3.7 metres in OSK-W-21-2479-W5;
  • 130 g/t gold over 2.9 metres and 38.8 g/t gold over 3.2 metres in OSK-W-21-2287-W3;
  • 61.5 g/t gold over 3 metres in OSK-W-21-2544; and
  • 41.5 g/t gold over 4.4 metres in OSK-W-21-2520.

The Windfall resource estimate was updated in February. Using a 3.5-g/t gold cut-off, the deposit has 6 million measured and indicated tonnes grading 9.6 g/t gold (1.9 million oz. contained gold) and 5.9 g/t silver (1.1 million oz. contained silver), There area also 16.4 million inferred tonnes grading 8 g/t gold (for 4.2 million oz.) and 2.7 g/t silver (for 1.4 million oz.).

Osisko is planning an underground mine with a pair of access ramps and a mill on site. The preliminary economic assessment was updated when the new resource numbers were tabulated. It says the project would have a net present value (after taxes and mining duties) of $1.5 billion and an internal rate of return of 39.4%.

After pre-production capital expenses, the mine will have an 18-year life during which time approximately 4.2 million oz. of gold will be recovered. Mine start-up is expected in 2024 and full production in 2025. All-in sustaining costs net of by-product credits over the life of mine are estimated at US$610.10 per ounce.

Read the updated Windfall PEA at www.OsiskoMining.com.

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