Troilus Mining’s optimization drilling at its namesake gold and copper project in north-central Quebec keeps finding metal where the mine plan assumes there is none. The fifth batch of results from the Z87 program, released on November 11, covers eight holes totalling 3,195 metres. Hole 87-26-524 intersected 1.33 grams a tonne gold equivalent over 34 metres from 207 metres downhole in the Z87 hangingwall, including 3.08 grams a tonne gold equivalent over 12 metres. The gold grade alone was 1.29 grams a tonne over the full interval and 3.04 grams over the included section.
The same hole returned a second, broader interval lower down: 0.78 grams a tonne gold equivalent over 131 metres from 435 metres, including 1.41 grams over 42.4 metres, from inferred material inside the reserve pit. Hole 87-26-536 cut 1.09 grams a tonne gold equivalent over 59.5 metres about 50 metres below the pit, and an extended historical hole returned 0.79 grams over 71 metres at the pit base. Reported grades are uncut, and true thicknesses are about 75 to 90 percent of drilled lengths.
The results exist because the historical record is incomplete. Z87 was mined by open pit in the former Troilus operation, but many historical holes were never continuously sampled, leaving core intervals of several hundred metres without assays. For resource estimation those gaps are assigned half the laboratory detection limit, which writes the hangingwall down as waste in the block model. Troilus is now assaying that material and drilling inferred blocks in and around the pit to test conversion to indicated resources.
None of the 2026 drilling is in the current numbers. The resource and reserve estimates have an effective date of December 31, 2025 and underpin the technical report published on September 9, 2026. To date Troilus has released 47 holes totalling 17,716 metres of a completed program of about 22,800 metres. Chief executive Justin Reid said the results will feed future modelling to assess converting waste to ore, reducing the strip ratio and adding flexibility to the mine plan.
The development case around the drilling is a 26-year open-pit operation on the site of the former mine, with construction anticipated in 2027, first ore in September 2029 and commercial production in March 2030, per the September update reported by Mining.com. Every tonne of hangingwall material that converts from waste to ore improves that plan’s early economics, which is why a drill program aimed at old, unsampled core carries weight beyond its grades.