Sunstone Metals has kicked off its latest drilling campaign at the Bramaderos Gold-Copper Project with substantial mineralised intersections, reinforcing the potential to expand its 3.6 million ounce resource. The company prepares to release a scoping study that will clarify the project's economic outlook.
- First two drill holes return 200m at 0.45 g/t AuEq and 162m at 0.32 g/t AuEq
- Drilling confirms continuity of mineralisation below surface trench ML-01
- 26-hole, 5000m program underway targeting resource expansion
- Copete-Porotillo exploration target estimated at 1.7 to 3.5 million ounces AuEq
- Scoping study imminent to assess project economics
Strong Early Drilling Results at Copete-Porotillo
Sunstone Metals Ltd (ASX:STM) has delivered an encouraging start to its new drilling campaign at the Bramaderos Gold-Copper Project in southern Ecuador, intersecting broad mineralised zones that underscore the project's growth potential. The first two diamond drill holes at the Copete porphyry system yielded 200 metres at 0.45 g/t gold equivalent (AuEq) and 162 metres at 0.32 g/t AuEq, both with higher-grade intervals nested within these wide intersections.
These results confirm the sub-surface continuity of mineralisation below the previously reported surface trench ML-01, which itself returned a substantial 113 metres at 0.64 g/t AuEq. Notably, hole CPDD001 intersected a 50.6-metre interval grading 0.62 g/t AuEq, including 26.9 metres at 0.75 g/t AuEq, while CPDD002 delivered 58 metres at 0.42 g/t AuEq within its broader mineralised zone.
Expanding a 3.6 Million Ounce Resource
The ongoing 26-hole, 5000-metre drilling program aims to grow the current Bramaderos Mineral Resource, which stands at 3.6 million ounces gold equivalent. The Copete-Porotillo porphyry complex itself hosts an Exploration Target estimated between 135 and 180 million tonnes at 0.40 to 0.60 g/t AuEq, translating to a conceptual 1.7 to 3.5 million ounces AuEq. It remains uncertain if further drilling will convert this target into a formal resource, but the initial results provide a solid foundation for optimism.
Sunstone’s Managing Director Patrick Duffy highlighted that these wide, mineralised intersections are delivering "very good grades by porphyry standards" and that the drilling program will continue to test the strike extension of the southeast-dipping mineralised body. The company is finalising a scoping study that will demonstrate the economics of this large, shallow inventory and showcase Bramaderos’ underlying value relative to its current market valuation.
Strategic Drilling Across Multiple Porphyry Systems
The drilling campaign is not limited to Copete and Porotillo but also includes the Melonal porphyry system, with seven holes completed so far. The Copete and Porotillo systems are adjacent, and ongoing drilling will investigate whether Copete is an offshoot of the larger Porotillo porphyry. Recent surface trenching at Porotillo has revealed extensive mineralisation, including a 462-metre trench averaging 0.55 g/t AuEq, adding weight to the potential scale of the resource expansion at Bramaderos.
This drilling initiative follows a series of announcements earlier this year, including the launch of the 5000-metre campaign in February and the unveiling of high-grade surface discoveries at Bramaderos in early 2026. The company’s methodical approach to expanding its resource base and progressing scoping studies reflects a clear strategy to unlock the value of its world-class gold-copper assets in Ecuador.
Robust Geological and Assay Protocols Underpin Results
Sunstone’s drilling employs industry-standard diamond core techniques with rigorous sampling and assay protocols to ensure data quality and representativity. Core recovery has been excellent, with assays conducted via fire assay and multi-element ICP methods at accredited laboratories. The company’s internal QAQC procedures include certified reference materials, blanks, and field duplicates at regular intervals, bolstering confidence in the reported grades and intervals.
Geologically, the mineralisation is hosted in a southeast-dipping syn-mineral diorite body with pervasive stockwork veining extending into surrounding wallrock, yielding a mineralised package approximately 120 to 150 metres wide. The true widths of mineralised zones are yet to be determined, but the downhole lengths reported indicate substantial volumes of mineralisation remain open at depth and along strike.
Looking Beyond Bramaderos: El Palmar and Funding Considerations
Sunstone’s portfolio also includes the El Palmar Project in northern Ecuador, featuring a 64 million tonne resource at 0.60 g/t AuEq for 1.2 million ounces AuEq. Both projects have significant exploration targets that could evolve into multi-decade mining operations, supported by established infrastructure and strong community engagement.
The company continues to explore funding options to advance its projects and expand its footprint in Ecuador, balancing the need for capital with the goal of maximising shareholder value. The imminent Bramaderos scoping study will be a key milestone in this process, offering a clearer picture of the project’s economic potential and guiding future investment decisions.
Bottom Line?
Sunstone’s early drilling at Bramaderos confirms extensive mineralisation, but the path to resource expansion hinges on upcoming scoping study results and securing funding for continued exploration.
Questions in the middle?
- Will the scoping study validate the economic viability of Bramaderos’ large shallow inventory?
- How will Sunstone prioritise drilling targets within the Copete-Porotillo-Melonal cluster to maximise resource growth?
- What funding strategies will the company pursue to sustain its ambitious exploration and development plans?