Highlights

  • Sunstone reported additional broad gold-copper intersections from the Bramaderos Project in Ecuador.
  • All eight holes assayed so far in the current drilling campaign have intersected mineralisation outside the existing 3.6Moz AuEq resource.
  • Drilling at Porotillo returned intersections of up to 200.5m at 0.42 g/t AuEq and 150.1m at 0.53 g/t AuEq.
  • Melonal drilling intersected 250.4m at 0.43 g/t AuEq from surface.
  • Fourteen holes have now been completed in the ongoing 27-hole drilling campaign.
  • Sunstone aims to convert portions of the existing exploration target into future resource growth.

Sunstone Metals Ltd (ASX:STM) has reported additional broad gold-copper mineralised intersections from ongoing drilling at its Bramaderos Project in southern Ecuador, with the latest results continuing to support the company’s strategy of expanding the existing 3.6Moz gold-equivalent resource.

The new drilling outcomes came from the Porotillo and Melonal prospects, both located adjacent to the existing Bramaderos Mineral Resource area. According to Sunstone, all eight holes assayed so far in the current drilling campaign have intersected extensive mineralisation outside the present resource boundary, reinforcing the broader growth potential of the project.

On 14 May 2026, Sunstone shares traded at AUD 0.34, up 1.49% for the session, although the stock remains down 19.05% over the past year.

The company stated that the latest assays form part of a larger 27-hole drilling campaign designed to convert sections of the Bramaderos Exploration Target into future resource additions. Sunstone currently estimates the exploration target within the Copete-Porotillo complex at between 135 million tonnes and 180 million tonnes grading between 0.40 g/t and 0.60 g/t gold equivalent, representing a conceptual exploration range of approximately 1.7 million to 3.5 million ounces of gold equivalent.

Porotillo Delivers Additional Broad Mineralised Intersections

Three of the four newly reported drill holes were completed at the Porotillo prospect, where Sunstone continues to outline extensive gold-copper mineralisation associated with intrusion breccias and porphyry systems.

The first reported hole, PTDD001, intersected 200.55 metres at 0.42 g/t gold equivalent, including a higher-grade interval of 54.67 metres at 0.57 g/t gold equivalent.

PTDD002 returned 140.45 metres at 0.45 g/t gold equivalent, including 60.25 metres at 0.65 g/t gold equivalent.

Meanwhile, PTDD003 delivered 150.15 metres at 0.53 g/t gold equivalent, including 19.8 metres at 0.69 g/t gold equivalent at the end of the hole.

The company noted that mineralisation at Porotillo occurs within high-level intrusion breccias containing porphyry-related quartz stockwork veining and sulphide mineralisation. Copper sulphides identified within the drilling include chalcopyrite and lesser bornite, alongside smaller quantities of supergene chalcocite and native copper.

Sunstone stated that early drilling at Porotillo is focused on establishing an initial shallow resource extending to depths of approximately 200 metres before progressing to deeper drilling aimed at testing a substantial underlying magnetic anomaly.

According to the company, the magnetic target occupies a Volume approximately 700 metres by 400 metres laterally and around 400 metres vertically, indicating potential for further mineralisation beneath current drilling levels.

Melonal Hole Extends Mineralisation Beyond Existing Resource

The fourth reported hole, MEDD003, was drilled at the Melonal prospect and returned a broad mineralised intersection from surface.

The hole intersected 250.45 metres at 0.43 g/t gold equivalent, including a near-surface higher-grade interval of 44.03 metres at 0.71 g/t gold equivalent.

Sunstone stated that a substantial proportion of the mineralisation identified in MEDD003 sits outside and south of the current modelled open-pit area and beyond the limits of the November 2025 Bramaderos resource model.

Management described the result as further evidence that the Melonal system remains open both at depth and laterally toward the south.

The hole targeted the upper portion of a magnetic anomaly extending vertically for approximately one kilometre beneath the Melonal area. Although drilling difficulties associated with fractured ground resulted in the hole being terminated at around 271 metres instead of the planned 400 metres depth, the company indicated the intersection still demonstrated significant mineralisation potential.

Sunstone also highlighted that only a small proportion of the broader Melonal target area has been drill tested so far, with approximately 85% of the mapped stockwork veining zone remaining untested.

Ongoing Program Continues to Advance

Sunstone confirmed that two drill rigs are currently operating at Bramaderos, with fourteen holes completed so far from the planned 27-hole program.

Assays have already been received for the first three Porotillo holes and the Melonal hole, while samples from several additional holes remain pending laboratory analysis.

The company stated that drilling plans continue to be refined as geological logging, magnetic interpretation and assay reconciliation work progresses.

Current drilling activities are focused across the Copete, Porotillo and Melonal porphyry systems, which form part of a broader cluster of five porphyry gold-copper systems identified within the Bramaderos concessions.

Management believes the latest results continue to support the strategy of expanding the existing resource footprint through ongoing drilling and conversion of exploration targets.

Managing Director Points to Resource Growth Potential

Sunstone Managing Director Patrick Duffy said the latest drill outcomes remain consistent with the company’s broader strategy of growing the Bramaderos resource through continued exploration success.

According to Duffy, the company believes it has developed a clearer understanding of the geometry and controls associated with mineralisation across the project area.

Management also noted that the scale of the ongoing 27-hole campaign provides multiple opportunities to define additional mineralisation ahead of the next planned resource update later in 2026.

The company stated that Bramaderos represents one of the larger undeveloped gold-copper systems currently being advanced in Ecuador, with significant exploration upside still remaining across multiple porphyry targets.

Bramaderos Resource Base Remains Significant

Sunstone’s Bramaderos Project already hosts a November 2025 Mineral Resource estimate of 220 million tonnes grading 0.50 g/t gold equivalent for 3.6 million ounces of gold equivalent.

The current resource includes 40 million tonnes in the indicated category grading 0.56 g/t gold equivalent for approximately 0.6 million ounces gold equivalent, alongside 190 million tonnes in the inferred category grading 0.49 g/t gold equivalent for approximately 2.9 million ounces.

In addition to the existing resource, Sunstone also maintains a broader porphyry exploration target at Bramaderos estimated at between 315 million tonnes and 505 million tonnes grading between 0.41 g/t and 0.68 g/t gold equivalent.

The company has also outlined a separate epithermal gold-silver exploration target at Limon estimated at between 0.9 million and 1.7 million ounces gold equivalent.

Management cautioned that exploration targets remain conceptual in nature and that further drilling will be required before additional resources can be formally estimated.

Broader Ecuador Portfolio Supports Long-Term Strategy

Beyond Bramaderos, Sunstone continues advancing its El Palmar Project in northern Ecuador.

El Palmar currently hosts an initial Mineral Resource estimate of 64 million tonnes grading 0.60 g/t gold equivalent for approximately 1.2 million ounces gold equivalent.

The project also contains a larger conceptual porphyry exploration target estimated at between 15 million and 45 million ounces gold equivalent.

Sunstone’s strategy remains focused on advancing both Bramaderos and El Palmar toward potential long-term gold-copper Mining operations while continuing to evaluate funding and Partnership opportunities capable of supporting project development.

The company stated that both projects benefit from existing regional infrastructure, including road, power and port access, while management continues to emphasise ESG engagement and community relationships within Ecuador.

What This Means for Investors?

Sunstone’s latest drilling results continue to reinforce the scale potential of the Bramaderos Project, with all eight assayed holes from the current campaign intersecting mineralisation outside the existing 3.6Moz resource area.

Broad gold-copper intercepts from both Porotillo and Melonal suggest further resource growth opportunities may remain available as the company advances its 27-hole drilling program.

With additional assays pending and another resource update planned later this year, investor attention is likely to remain focused on the company’s ability to convert exploration targets into expanded mineral resources across the Bramaderos district.

FAQs

Q: What did Sunstone announce on 14 May 2026?
A: Sunstone announced additional broad gold-copper drill intersections from the Bramaderos Project in Ecuador, including results from the Porotillo and Melonal prospects.

Q: What was the largest intersection reported in the latest drilling results?
A: The Melonal hole MEDD003 returned 250.45 metres at 0.43 g/t gold equivalent from surface, including 44.03 metres at 0.71 g/t gold equivalent.

Q: How many holes have been completed in the current drilling campaign?
A: Sunstone stated that fourteen holes have been completed so far as part of the planned 27-hole program.

Q: What is the current Bramaderos Mineral Resource size?
A: The Bramaderos Project hosts a November 2025 Mineral Resource estimate of 220 million tonnes at 0.50 g/t gold equivalent for 3.6 million ounces gold equivalent.

Q: What is Sunstone aiming to achieve with the current drilling program?
A: The company aims to convert portions of the existing exploration target at Copete and Porotillo into future mineral resource growth.