Critical Resources Ltd (ASX:CRR, FRA:9S70) has outlined a 2026 exploration program aimed at unlocking resource growth across the Northern Prospects at its 100%-owned Mavis Lake Lithium Project in Ontario, Canada.
The program will target district-scale lithium potential outside the current Mavis Lake Main Zone, with work designed to refine priority targets and support the next phase of resource expansion.
“The 2026 exploration program represents a step forward to unlock the resource potential across the Northern Prospects at Mavis Lake. Recent drilling success, advanced geochemical datasets, and structural modelling give us strong confidence in the potential outside the Mavis Lake Main Zone,” Critical Resources’ managing director, Tim Wither, said.
Location of Critical Resources Mavis Lake project with surrounding lithium prospects.
Drilling track record points to upside beyond current resource
More than 58,000 metres of drilling has been completed by CRR since 2023, which it says confirms large-scale lithium mineralisation extending beyond the current Mineral Resource envelope.
Standout intercepts reported by the company include:
- 74.4 metres at 1.18% Li₂O, including 32.9 metres at 1.81% Li₂O (MF23-207)
- 20.7 metres at 1.21% Li₂O (MF23-209)
- 41.3 metres at 1.25% Li₂O (MF23-210)
- 41.0 metres at 1.18% Li₂O (MF23-211)
- 50.2 metres at 1.28% Li₂O (MF23-213)
- 55.0 metres at 0.95% Li₂O, including 25.85 metres at 1.39% Li₂O (MF23-214)
The upcoming planned work programs will focus on incorporating recent high-grade intercepts into an updated geological model to support future resource growth.
“Importantly, the potential growth opportunity of the Northern Prospects provides the company with enhanced operational flexibility. As these areas have the potential to demonstrate resource scale and development potential, they potentially offer an alternative pathway to reduce long-term dependency on the Main Zone and better align future operations with environmental and community expectations around the Mavis Lake area,” Wither said.
Northern Prospects flagged as a growth corridor
Integrated geological, geochemical and geophysical datasets have identified multiple high-priority spodumene-bearing pegmatites across the Northern Prospects, potentially offering optionality beyond the Main Zone.
The corridor could support a satellite development hub or potentially a standalone lithium operation within the broader project area, which over time may reduce reliance on the existing Main Zone resource.
“With an increasing geological understanding, robust metallurgy pathways, supportive infrastructure and a clear permitting and engagement strategy now underway, Critical are positioning Mavis Lake as a cornerstone asset within the North American lithium supply chain. Our focus during 2026 remains on continued disciplined growth and responsible development to deliver long-term benefit for shareholders, our First Nations partners and all stakeholders.”
2026 drill campaign to tighten targets and lift confidence
The 2026 program is expected to include a phased drill campaign aimed at improving target definition and generating data suitable for future Inferred and Indicated Mineral Resource classification.
Key objectives include improving the geological model around pegmatite thickness, structural controls, mineralisation style and continuity across multiple prospects, including Gullwing, Tot and other priority regional targets.
CRR said Gullwing is one of the most compelling early drill targets, with mapping indicating outcropping pegmatite widths of up to ~80m and strike extent of ~500m.
The campaign is being supported by an integrated dataset including detailed geochemistry, LIBS-based fractionation work, high-resolution UAV aeromagnetics to define structural corridors, and advanced geological modelling.
Key targets include:
- Gullwing: advanced target, characterised by widths up to ~80m, a ~500m exposed strike, strong spodumene mineralisation observed at surface, and an Exploration Target of 7–10Mt @ 0.3–1.2% Li₂O (ASX:CRR announcement 22 May 2024).
- Mavis Lake South Zone: Open along strike and at depth, with contrasting structural environments offering strong discovery potential.
- Pegmatites 18 & 19: Spodumene-bearing systems with minimal historical drilling.
- Tot: Confirmed mineralised system open along southern extensions into newly acquired tenure.
- Little Wing: ~200m x 50m footprint with elevated Li and Rb values.
- Coates & Drope: LIBS fractionation upgrades prospectivity.
- Corona Field: Underexplored 5km-scale lepidolite-bearing pegmatite trend offering major conceptual upside.
Mavis Lake with regional exploration targets.
Metallurgy supports downstream pathway
On the development side, CRR said feasibility-level metallurgical test work has demonstrated strong spodumene recovery, producing a clean, high-grade concentrate it believes is suitable for downstream conversion within the North American lithium supply chain.
CRR highlighted access to highway and rail, clean hydro power and supportive provincial and federal frameworks as potential advantages for project development.
To support the planned 2026 field season, the company has engaged SLR Consulting and Pathway Group to run an integrated permitting and government engagement strategy aimed at streamlining approvals and reducing regulatory lead times.
What’s next?
Critical Resources is advancing the Mavis Lake Lithium Project through a coordinated set of workstreams aimed at driving district-scale growth, strengthening the project’s technical base and positioning the company for multiple future development scenarios with greater operational flexibility.
Key priorities include:
- 2026 drill program finalisation: progressing permitting, final target selection and site access preparations, with ongoing engagement with local communities and First Nations groups embedded in planning to support responsible field operations.
- Main Zone geological model update: incorporating recent high-grade intercepts into an updated model to underpin the next phase of development studies.
- District-scale growth drilling: advancing systematic drilling across high-priority regional targets — including Gullwing, Tot, Little Wing, Coates, Drope and the Corona Field — to define additional spodumene-bearing systems and broaden development options beyond the Mavis Lake Main Zone.
- Technical and metallurgical work: continuing metallurgical test work alongside baseline environmental studies to support project viability and optimise potential development pathways.
- Permitting and regulatory alignment: progressing approvals under a roadmap being developed with SLR Consulting, while Pathway Group undertakes targeted government engagement to support a streamlined approvals pathway aligned with the 2026 exploration program.
- Strategic and commercial pathways: maintaining engagement with First Nations communities, stakeholders, utilities and service providers, while progressing discussions with potential offtake partners to position CRR for opportunities linked to the North American lithium supply chain.