Geochem points Critical Resources towards next Canadian lithium prize

Critical Resources has unearthed a compelling new set of clues pointing to the next lithium discovery at its Mavis Lake project in Ontario, Canada. New geochemistry results have confirmed the presence of highly fertile lithium-caesium-tantalum (LCT) pegmatites in a recently expanded exploration area.

Geological markers from the company’s 10-day field program have successfully outlined the most prospective ground, identifying granitic-hosted pegmatites as the high-priority targets for follow-up drilling.

Whole-rock geochemical analysis, testing for a range of elements from 106 rock samples, returned potassium-to-rubidium ratios as low as 17.4, a key indicator of pegmatite fertility and the kind of result that tends to get lithium explorers reaching for the drill rig.

Accompanying pathfinder element results were also strong, with up to 5510 parts per million (ppm) rubidium, 221ppm caesium and 53ppm tantalum, all but confirming the presence of a highly evolved LCT system.

‘With an exploration target of 18-29Mt, our objective remains to build Mavis Lake into a multi deposit lithium district.’

Notably, Critical says the strongest fractionation signatures were found within the northern claims it picked up 12 months ago. The outcome has proved a neat piece of validation for the company’s exploration strategy, confirming a highly prospective corridor and suggesting its geos are on the right track.

The recent field program was designed to systematically test the lithium potential across the project’s Corona pegmatite field and the adjacent Northern prospects area.

Critical’s geos mapped 161 outcrops, identifying six new pegmatite bodies all within four kilometres north of the company’s existing eight-million-tonne resource, grading 1.07 per cent lithium oxide.

The latest results will now be integrated into the company’s existing geological, structural and geophysical datasets to rank and prioritise future drill targets.

The company says the work underpins its district-scale strategy at Mavis Lake, which previously identified a similar pipeline of targets including Gullwing, Tot, Little Wing, Coates, Drope and Corona.

The company’s goal is to build on its existing resource and chase down a more substantial JORC-compliant resource to back up a current exploration target of between 18 and 29 million tonnes grading 0.8 to 1.2 per cent lithium oxide.

Critical Resources managing director Tim Wither said: “These results continue to advance our exploration strategy at Mavis Lake. The 2026 field program was designed to systematically evaluate pegmatites identified during our regional exploration program, and the whole-rock geochemistry has successfully identified the most prospective targets for the next phase of exploration.”

Whilst Mavis Lake is the flagship project, Critical is anything but a one-trick pony. The company holds a diversified portfolio in New South Wales and in New Zealand.

At Halls Peak in NSW, the company has an existing inferred resource of 840,000 tonnes at 3.7 per cent zinc, 1.5 per cent lead and 0.44 per cent copper.

However, it’s the spectacular silver grades that are causing pulses to quicken, with one historical drill hole returning a stunning 1.15-metre intercept at a bonanza 3.780 kilograms per tonne silver.

Across the ditch in New Zealand, the company holds an extensive 1694-square-kilometre ground package prospective for gold at its Cap Burn and Rock and Pillar projects, alongside an antimony and, in particular, high-grade tungsten discovery at its Granite Creek prospect that returned a stunning 16.63 per cent tungsten trioxide channel sample.

Additionally, Critical continues to advance its exciting solid-state battery technology in the USA, which recently achieved significant milestones.

With the geochemical smoke pointing to a potential lithium fire, the company has now defined a clear exploration path forward. Whilst the geochemist’s work is done for now, the data has provided a robust technical framework that will pave the way for the drill bit to deliver the final verdict on just what might be lurking beneath the surface at Mavis Lake.

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