Permit Expiry Puts Spotlight on Langdons’ Untapped High-Grade Antimony-Gold Risks

Langdons Project Enters New Phase

Siren Gold Limited (ASX, SNG) has provided a significant update on its Langdons Antimony-Gold Project near Reefton, New Zealand, marking a pivotal moment as its prospecting permit expired on 25 May 2025 and has been replaced by an exploration permit application. This transition signals Siren’s intent to deepen exploration efforts in a region historically known for high-grade mineralisation.

The Langdons mineralisation is structurally centred around a tightly folded antiform, mirroring the geological setting of the nearby Reefton goldfield, where substantial antimony-gold deposits have been documented. Siren’s recent surface sampling from the Langdons Antimony Lode mullock heap revealed gold grades ranging from 4 to an extraordinary 506 grams per tonne, alongside antimony concentrations reaching 9.3%. These results underscore the potential for economically significant mineralisation.

Expanding the Exploration Footprint

Further geological investigation identified the Langdons Quartz Reef approximately 90 vertical metres below the Antimony Lode, with assays confirming 4.5 grams per tonne of gold over a thickness of at least 1.2 metres. Nearby, the Liberty Reef returned trenching results of 1.75 metres at 4.5 grams per tonne gold, reinforcing the prospectivity of the area.

Geochemical soil surveys, including Ionic Leach methods, have detected anomalous gold and antimony signatures extending along a 400-metre trend and further 200 metres beneath cover rocks to the northwest. This suggests that the mineralised system may be more extensive than surface observations alone indicate, presenting compelling targets for future drilling.

Strategic Positioning in Critical Minerals

Chairman and Acting Managing Director Brian Rodan emphasized the strategic importance of antimony, a critical metal with supply dominated by China and Russia. With growing demand driven by renewable energy technologies, defence applications, and high-tech industries, securing diversified sources is vital. Siren’s Langdons project, alongside its other New Zealand assets and a 22% stake in Rua Gold, positions the company well within this critical minerals landscape.

Rodan highlighted the challenges facing the antimony market, including supply chain vulnerabilities and geopolitical risks, underscoring the need for new extraction and processing initiatives in stable jurisdictions like New Zealand.

Next Steps and Outlook

Siren plans to undertake trenching and channel sampling to better define the thickness and grade of the Langdons reefs. Expanded soil sampling and geochemical surveys will continue to refine exploration targets, with drilling access agreements pending approval from the Department of Conservation. These steps aim to unlock the full potential of the Langdons mineralisation and advance the project toward resource definition.

While historical drilling data is limited, the combination of high-grade surface samples and geochemical anomalies provides a strong foundation for Siren’s exploration strategy. The company’s integrated approach across multiple New Zealand projects reflects a broader ambition to become a key player in the gold and antimony sectors amid evolving market dynamics.