Bramaderos Project Shows 142m Continuous Gold Mineralisation Outside Resource

Exploration Breakthroughs at Bramaderos

Sunstone Metals Limited (ASX – STM) has announced compelling new results from its ongoing surface sampling program at the Bramaderos Project in southern Ecuador. The recent geological mapping and channel sampling at two key prospects, Copete and Brama porphyry systems, have revealed significant expansions in mineralisation footprints, reinforcing the project's potential for substantial resource growth.

At Copete, the exploration team conducted detailed sampling across 13 ravines surrounding a previously mineralised trench. These efforts uncovered a coherent and extensive zone of porphyry-related alteration and vein mineralisation spanning approximately 300 by 250 metres. The findings suggest that the Copete system remains largely preserved beneath shallow alluvial cover, offering a promising target for upcoming exploratory drilling aimed at delineating the sub-surface core of this newly identified porphyry system.

High-Grade Gold Discovery at Brama Northeast

Meanwhile, at the Brama porphyry deposit’s northeast margin, surface sampling along an access road intersected a broad zone of gold mineralisation within an epithermal corridor. Notably, a rock chip sample returned an exceptional assay of 38.3 grams per tonne gold associated with epithermal veins. Additionally, a continuous channel sample spanning over 142 metres averaged 0.29 g/t gold equivalent, with a higher-grade interval of 15.8 metres at 0.68 g/t AuEq. These mineralised zones lie outside the current Brama-Alba resource but within the limits of the economically modelled open pit, indicating strong potential for resource expansion once further drilling is undertaken.

Strategic Progress and Future Outlook

Sunstone’s Managing Director, Patrick Duffy, emphasised the significance of these results, highlighting the confidence they bring to the company’s development pipeline. The Copete discovery is poised to become an integral part of Bramaderos’ future resource base, while the Brama Northeast findings underscore the likelihood of expanding the existing resource envelope. Concurrently, Sunstone is advancing strategic corporate and asset discussions with multiple parties, positioning itself to maximise shareholder value as exploration progresses.

Complementing these exploration advances, Sunstone is conducting detailed topographic surveying and geological mapping across Bramaderos, including contiguous blocks at Melonal and Copete. These efforts aim to refine target areas and support the planning of future drilling campaigns. The Bramaderos Project currently boasts a Mineral Resource estimate of 156 million tonnes at 0.53 g/t gold equivalent, containing approximately 2.7 million ounces of gold equivalent, with exploration targets suggesting potential for significant increases.

Broader Project Context and Strategy

Sunstone’s portfolio also includes the El Palmar Project in northern Ecuador, which holds a substantial mineral resource and exploration target. The company’s strategy prioritises near-surface, high-grade epithermal deposits like Limon at Bramaderos for initial development, providing a scalable foundation before advancing larger porphyry systems. Supported by robust infrastructure and strong community engagement, Sunstone is well-positioned to unlock the full potential of its Ecuadorian assets.