Castle Minerals to Acquire 90% Stake in Nielle Gold Project Covering 212 km²

Strategic Acquisition in a Tier-One Gold District

Castle Minerals Limited (ASX:CDT) has executed a binding terms sheet to acquire a 90% interest in the Nielle Gold Project, a high-grade gold asset spanning approximately 212 km² in northern Côte d'Ivoire. This acquisition places Castle firmly within one of West Africa’s most prolific gold belts, just 50 kilometres north of the 5 million ounce Tongon Gold Mine, formerly operated by Barrick and recently acquired by the Atlantic Group for US$305 million. The region also hosts significant deposits such as Sissingué (1.5Moz) and Wahgnion (3.2Moz), underscoring the strategic value of the Nielle tenure.

The project sits within the Birimian greenstone belt, a geological province renowned for hosting major orogenic gold deposits. Castle’s existing Côte d'Ivoire portfolio, which recently expanded to 1,842 km², now gains a flagship asset with Nielle, offering substantial exploration upside along a 4.5-kilometre mineralisation corridor that remains open along strike and at depth. This builds on Castle’s ongoing efforts to ramp up exploration in the region, supported by a proven West African leadership team with over 50 years of combined experience, including Mohamed Niaré’s 25 years across Mali and Côte d'Ivoire. The Company’s recent Côte d’Ivoire exploration leadership appointments have been instrumental in securing this competitive acquisition.

Compelling Historical Drilling Highlights Point to High-Grade Potential

Historical drilling conducted by previous operators, including Kodal Minerals and Resolute Mining, has revealed multiple shallow, high-grade gold intercepts at Nielle. Notable results include 5 metres at 15.42 grams per tonne (g/t) gold from just 7 metres depth, including 2 metres at 31.54 g/t; and 13 metres at 5.07 g/t from 12 metres, with a 3-metre section hitting 16.33 g/t. These intercepts are part of a broader mineralised corridor showing consistent gold mineralisation, with zones of 26 metres at 1.95 g/t and 16 metres at 1.96 g/t also reported. The shallow, contiguous nature of these zones supports the potential for a future JORC-compliant Mineral Resource estimate, pending further drilling to improve geological confidence.

While the historical data has not yet been independently verified by Castle, the Company is in advanced discussions to acquire the full technical data package from Corvette CIV SARL, the prior permit holder. This will underpin a near-term drilling program and supplementary soil geochemistry to fully characterise the gold system. The project’s open strike and depth potential provide a clear runway for exploration growth, complementing Castle’s broader regional soil sampling and auger drilling campaigns underway in Côte d'Ivoire and Western Australia, as highlighted in the recent soil geochemistry and aeromagnetic surveys progress reports.

Transaction Terms and Portfolio Rationalisation

The acquisition terms include an upfront payment of US$500,000 in cash and shares, followed by staged payments totalling US$1.35 million linked to the delineation of JORC-compliant Mineral Resources of 250,000 and 500,000 ounces at a minimum grade of 1.2 g/t gold. Additionally, a 2% net smelter return royalty is payable to the vendor, with Castle retaining the option to buy back half of this royalty for US$3 million. The initial option fee of US$50,000 secures exclusive rights for four months pending regulatory approvals and due diligence.

Coinciding with this acquisition, Castle is advancing a strategic divestment of its Ghanaian gold assets, including several permits and a 4% net smelter royalty over Azumah Resources’ Julie West licence. The proposed sale to a private international exploration company for US$400,000 aims to streamline Castle’s capital and management focus toward Côte d'Ivoire and its Western Australian Meeka South Project. This divestment remains indicative and subject to definitive agreements and customary conditions.

Rebranding to TerraNova Metals Reflects New Strategic Focus

Reflecting its evolution into a diversified explorer across gold and critical minerals, Castle intends to seek shareholder approval to rebrand as TerraNova Metals Limited. This change aligns with the company’s expanding footprint in Côte d'Ivoire and Western Australia and its ongoing portfolio optimisation. The name change will be considered at a shareholder meeting anticipated in late June 2026.