While the indicated and inferred resource increased to 933,300oz gold, from 847,500oz reported in 2019, the indicated portion rose 77% from 450,400oz to 762,500oz, reflecting an extensive amount of infill drilling completed since the last resource estimate.
Notably, the grade of the updated resource remained high at 13 grams per tonne.
The main component of the updated resource is the newly discovered Deep A zones where the tenor of mineralisation is said to be "very good" at circa 16.3g/t, and the total resource size is 840,400oz.
The Deep A Zones remains open to depth.
The updated resource is expected to underpin a pre-feasibility study due by June next year, at which time a formal production decision is anticipated.
However, the mill at Kiena has been restarted and is expected to process about 6,000t of development ore by year-end to help verify metallurgy.
Laurentian Bank Securities expects the Kiena mill to process ore intermittently as underground development is completed, ahead of a formal production decision.
The past-producing Kiena mine is fully permitted and has existing mining and milling infrastructure, including a 930m production shaft and a 2,000t/d mill.
From 1981 to 2013, the mine produced 1.75Moz gold from 12.5Mt ore at a head grade of 4.5g/t gold. The bulk of this production came from the S-50 Zone between depths of 100m-1,000m. Operations were suspended in 2013.
A March preliminary economic assessment outlined, on an after-tax basis, a net present value at 5% discount of C$416.1 million and an internal rate of return of 102%. The $34.8 million project has a capex payback period of 1.7 years.
The project can add about 86,000ozpa to Wesdome's current 200,000oz-plus production from its Eagle River Complex in Wawa, Ontario.
Wesdome shares (TSX:WDO) last traded at $10.71 in Toronto, capitalising the company at $1.5 billion.