Alamos Island Gold shaft delay: ground support, capex and output lens for engineers
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
Alamos Gold has delayed commissioning of the Island Gold stage 3+ shaft to mid‑2027 and lifted its capex estimate about 5% above the original US$835 million budget after encountering a dyke in the underground ore and waste bin area that requires extra ground support and reinforcement of the loading pocket. Underground mining rates at Island Gold are still expected to exceed 2,000 t/d in H1 2027, rising to 2,400 t/d in H2, but slower development at Puerto Del Aire and seismic‑related rehabilitation at Young‑Davidson are set to weigh on 2027 production and costs. The Island Gold–Magino district expansion, including doubling Magino mill capacity to 20,000 t/d and targeting 534,000 oz/y at US$1,025/oz AISC from 2028, remains on schedule for Q1 2028 completion.
Technical Brief
- Encountered dyke intersecting ore and waste bin excavations is driving redesign of ground support and loading pocket reinforcement.
- Additional support in the dyke zone implies higher-density reinforcement, likely closer bolt spacing and heavier sets.
- Young-Davidson rehabilitation after June seismic events includes rebuilding access drives and installing stronger ground support systems.
- Seismic-related works at Young-Davidson suggest enhanced dynamic support design, with reassessed rock mass behaviour and support demand.
- Failure investigation focus will be characterising dyke geomechanical properties, mapping discontinuities and reassessing bin and pocket stability.
- Ongoing monitoring should include convergence measurements, support load monitoring and seismic event tracking around the shaft and bins.
Our Take
With all‑in sustaining costs up 42% year‑on‑year and group production down 16%, the delay at Island Gold increases near‑term reliance on Young‑Davidson and Magino; our June 2026 note on seismic‑related output losses at Young‑Davidson underlines how operational disruptions at one Canadian asset can quickly tighten the group’s cost and volume profile.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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