Greatland defines globally significant 70Mt tungsten resource at O’Callaghans

Greatland Resources Ltd (AIM:GGP, OTC:GRLGF, FRA:G8G, ASX:GGP) has outlined a important caller captious minerals plus wrong its Paterson Province portfolio, delivering a maiden mineral assets estimation for the O’Callaghans tungsten-copper-zinc-lead deposit successful Western Australia.

The assets totals 70 cardinal tonnes (Mt) astatine 0.35% tungsten trioxide (WO₃), alongside 0.30% copper, 0.57% zinc and 0.28% lead, positioning O’Callaghans arsenic 1 of the largest high-grade tungsten deposits globally.

2025 O’Callaghans Mineral Resource Statement.

The update forms portion of Greatland’s broader December 2025 Group Mineral Resource release, which besides delivered a large uplift astatine the Telfer gold-copper cognition and reinforced the standard of its Paterson Province footprint.

O’Callaghans introduces a caller commodity watercourse to Greatland’s predominantly gold-copper portfolio, with tungsten progressively recognised arsenic a captious mineral crossed large economies.

Satellite representation showing Telfer excavation and infrastructure and O’Callaghans deposit location.

Tungsten’s unsocial carnal properties — including utmost hardness and vigor absorption — marque it hard to substitute successful applications spanning mining, construction, aerospace and defence. According to the company, aerospace and defence sectors relationship for astir a 4th of planetary demand.

Supply dynamics person besides tightened. China, which produces astir 80% of planetary tungsten, imposed export controls successful aboriginal 2025 and has since shifted from a nett exporter to a important importer, contributing to a crisp summation successful benchmark prices.

Against this backdrop, Greatland’s maiden assets positions O’Callaghans arsenic a perchance strategical plus with vulnerability to some basal metals and captious minerals markets.

Benchmarking of O’Callaghans MRE against planetary (ex-China, Russia and North Korea) tungsten deposits.

The O’Callaghans assets is notable not lone for its standard but besides for its level of geological confidence.

Of the 70Mt full resource, much than 95% sits wrong the higher-confidence Indicated category, supported by astir 71,000 metres of drilling crossed 184 holes astatine astir 100-metre spacing.

Contained metallic estimates include:

• 246,000 tonnes of WO₃ (tungsten trioxide)

• 207,000 tonnes of copper

• 371,000 tonnes of zinc

• 182,000 tonnes of lead

The polymetallic quality of the deposit provides aggregate imaginable gross streams, with mineralisation hosted successful a skarn strategy located astir 300 metres beneath surface.

Schematic geological conception of O’Callaghans deposit.