Sunstone Metals has delivered robust drilling results at its Bramaderos Gold-Copper Project in Ecuador, expanding the Melonal porphyry system with long mineralised intervals and strong grades, setting the stage for a resource update.
- 296.7m at 0.43 g/t AuEq from surface in MEDD004
- 102m at 0.52 g/t AuEq from surface in MEDD006
- Porotillo trench PO-8 returns 109.7m at 0.61 g/t AuEq
- All five Melonal drill holes assayed are mineralised
- Bramaderos 2026 Mineral Resource update pending
Melonal Porphyry System Expands with Long, Consistent Mineralisation
Sunstone Metals Ltd (ASX:STM) has reported significant drilling success at the Melonal porphyry system within its Bramaderos Gold-Copper Project in southern Ecuador. The latest assays from drill holes MEDD004 and MEDD006, completed in the 2026 program, reveal long intervals of gold equivalent (AuEq) mineralisation outside the current 3.6 million ounce Bramaderos resource.
Hole MEDD004 returned a standout 296.7 metres grading 0.43 g/t AuEq from surface, including a higher-grade 64.3 metres at 0.69 g/t AuEq starting right at the collar, and a further 82.3 metres at 0.50 g/t AuEq from 83.7 metres depth. MEDD006 added 102 metres at 0.52 g/t AuEq from surface with a 48.5-metre sub-interval at 0.62 g/t AuEq. These results confirm substantial mineralisation south and below the planned southern pit wall, extending the known footprint of Melonal significantly.
Porotillo Trenching Strengthens Surface Mineralisation Profile
Alongside drilling, Sunstone has advanced trenching at Porotillo, another key deposit in the Bramaderos cluster. Trench PO-8 returned 109.7 metres grading 0.61 g/t AuEq near the northeast margin of Porotillo’s mineralised zone, reinforcing the prospect’s surface potential. Additional trenches (PO-10 to PO-14) are awaiting assay results, with visible quartz stockwork veining noted in trenches PO-13 and PO-14, suggesting further upside.
Resource Growth Potential Outside Existing 3.6 Moz AuEq Base
The Melonal and Porotillo systems are part of a five-deposit porphyry cluster at Bramaderos that lies outside the current resource boundary. Sunstone has now drilled 28 mineralised holes in this cluster, supporting the company’s view of considerable resource growth potential. All five Melonal holes assayed to date in the current program have returned mineralisation, with two more holes pending assays.
Managing Director Patrick Duffy emphasised Melonal’s emergence as a large-scale system, noting ongoing modelling that points to significant depth extensions towards the south and southeast. He also highlighted the open-ended nature of Porotillo mineralisation at surface, underlined by trenching results.
Upcoming Bramaderos Resource Update and Strategic Outlook
The Bramaderos 2026 Mineral Resource update is expected in the coming quarter, incorporating the latest drilling and trenching data from Melonal, Porotillo, and Copete. Pending assays from additional Melonal holes and Porotillo trenches will feed into this update, which could reshape the known resource base.
Sunstone’s broader strategy remains focused on advancing Bramaderos towards development while continuing exploration to unlock further value. The company also oversees the El Palmar Project in northern Ecuador, targeting deep porphyry systems with drilling set to recommence imminently.
With strong infrastructure nearby and a track record of significant discoveries, Sunstone is positioning itself to capitalise on its extensive Ecuador portfolio. The recent drill results at Bramaderos, combined with improved metallurgical recoveries reported earlier in August, signal positive momentum as the company approaches its next resource milestone.
Bottom Line?
Sunstone’s latest drilling at Melonal and trenching at Porotillo reinforce the potential for a materially larger Bramaderos resource, but final assay results and the upcoming resource update will be critical to validate this growth.
Questions in the middle?
- How will pending assays from Melonal and Porotillo influence the scale of the Bramaderos 2026 resource update?
- What impact will the expanded mineralisation footprint have on project economics and mine planning?
- How might Sunstone’s strategic funding decisions affect the pace of development at Bramaderos and El Palmar?