Sunstone Metals Assays Highlight Scope for Bramaderos Resource Growth
Sunstone Metals (ASX: STM) has reported fresh surface sampling results from its Bramaderos project in southern Ecuador, underscoring the potential for significant resource expansion.
Channel and rock chip assays from the Copete and Brama prospects have confirmed extensive porphyry and epithermal mineralisation outside the current resource envelope.
Management said the results provide strong confidence that both systems will feed into future resource growth as drilling progresses.
Extended Surface Footprint at Copete
At Copete, geological mapping and channel sampling across 13 ravines identified long intersections of gold–copper mineralisation surrounding the main ridge.
The program outlined two mineralised intrusions covering an area of 300 metres by more than 250m, with results including 63.7m at 0.44 grams per tonne gold equivalent, 105.1m at 0.22 g/t gold equivalent, and 90.8m at 0.24 g/t gold equivalent across different ravines.
Together with the earlier trench ML01 that returned 214m at 0.50 g/t gold equivalent including 113m at 0.64 g/t, these surface assay results outline a coherent mineralised body that extends beneath shallow alluvial cover toward the southwest, where it could link with the Porotillo system.
Assays are pending from six additional ravines, which will guide the placement of the first drill holes into Copete, and managing director Patrick Duffy said the discovery could contribute as a standalone component within the broader Bramaderos development pipeline.
New Gold Corridor at Brama Northeast
Sampling at Brama along an access road northeast of the existing resource block returned 142.3m at 0.29 g/t gold equivalent, including 15.8m at 0.68 g/t.
In addition, a rock chip sample collected adjacent to this channel returned 38.3 g/t gold, pointing to high-grade epithermal veins within the broader system.
This corridor sits outside the current Brama-Alba resource but within the limits of the modelled economic open pit, and Sunstone’s technical team believes the northeast corridor hosts a series of epithermal veins that can deliver grade uplift within the porphyry framework.
The new results demonstrate the interplay between porphyry and epithermal systems at Bramaderos, where gold–copper mineralisation extends beyond the resource wireframe into areas of limited drilling.
The company is using these surface vectors to design step-out programs aimed at increasing both tonnage and grade.
Strategic Corporate Discussions
Sunstone is advancing exploration in parallel with strategic corporate and asset discussions with several parties.
The company holds an initial resource at Bramaderos of 156 million tonnes at 0.53 g/t gold equivalent for 2.7 million ounces, alongside an Exploration Target of between 3.3Moz and 8.6Moz gold equivalent.
At the same time, it is progressing the El Palmar project in northern Ecuador, which carries a resource of 1.2Moz gold equivalent and an Exploration Target of 15–45Moz gold equivalent.
The company has signalled that Bramaderos and El Palmar together could evolve into multi-decade mining centres, with Limon prioritised as a potential near-surface, high-grade starter development.
Both projects benefit from established infrastructure, and management has continued to emphasise community engagement and ESG standards as exploration advances.