VANCOUVER (miningweekly.com) – Mine developer Osisko Mining has published the first resource estimate for its fully-owned Windfall Lake project, in Quebec’s Abitibi greenstone belt, outlining about 2.8-million gold ounces in the inferred category above the 3 g/t cutoff.
Toronto-headquartered Osisko advised in a press release after market close on Monday that the resource estimate was the culmination of 1 453 drill holes for 596 733 m in the resource area, completed by previous operators on the project since 1997, and includes 812 new drill holes for 413 692 m completed by Osisko from October 2015, to March 5.
Drilling continues at the Windfall gold deposit, and results disclosed by Osisko since March 5, representing 131 drill holes and about 40 000 m of infill and extension holes, mainly in the Lynx and Underdog zones, are not incorporated in this mineral resource estimate.
According to Osisko, Windfall now holds 2.38-million tonnes in the indicated category, grading on average 7.85 g/t gold for 601 000 oz of gold. The inferred category holds 10.6-million tonnes grading 6.7 g/t gold, for 2.28-million ounces of yellow metal.
“Today's mineral resource estimate is a great start to defining the larger Windfall system, and it is complemented by our recently announced Osborne-Bell mineral resource estimate. Our plan is to incorporate Windfall gold deposit and Osborne-Bell into a single [preliminary economic assessment], scheduled for early in the third quarter of 2018, which will model a blended mining scenario with processing at a central Lebel-sur-Quévillon mill site,” president and CEO John Burzynski said in a statement.
The Windfall mineral resource estimate is distinct from the Osborne-Bell mineral resource estimate, which the company reported last month. The Osborne-Bell deposit is located on the Quévillon property, 17 km West of Lebel-sur-Quévillon, Quebec, and could potentially be mined and processed at the same proposed mill complex that would process Windfall ore. Osborne-Bell has a total inferred mineral resource estimate of 2.59-million tonnes grading 6.13 g/t gold, for 510 000 oz of gold, using a similar 3 g/t lower cutoff grade.
Burzynski noted that the Lynx and Underdog zones, in particular, have “excellent” down plunge potential for additional mineral resources. The company is continuing its 800 000 m drill programme to expand and explore the deposit. He pointed out that the infill drilling to convert inferred resource to indicated resource has produced higher average grades and is a focus of its ongoing programme.