Sunstone Metals (ASX:STM) has outlined gold–copper mineralisation across a 520m by 230m area at the Porotillo prospect within its Bramaderos Gold-Copper Project in southern Ecuador.
Porotillo sits outside Bramaderos’ existing resource and is among the areas Sunstone plans to include in a mineral resource estimate (MRE) update during the December quarter.
The latest four holes extended mineralisation along the northeast, southeast, and southwest margins of the system.
Hole PTDD017 returned 196m @ 0.62 grams per tonne gold equivalent (AuEq) from surface, comprising 0.35g/t gold (Au) and 0.16% copper (Cu). This included 143m @ 0.72g/t AuEq from surface and 4.80m @ 2.29g/t AuEq from 130.8m.
Hole PTDD018 intersected 137m @ 0.58g/t AuEq from surface, including 95m @ 0.68g/t AuEq, while PTDD016 returned 128.92m @ 0.37g/t AuEq from surface, including 39.90m @ 0.51g/t AuEq.
Surface trenching has also extended the mineralised footprint. Trench PO-6 returned 145.48m @ 0.45g/t AuEq and forms a contiguous extension of PO-5, producing a combined intersection of 607.71m @ 0.52g/t AuEq. The result remains open to the northwest.
According to the company, all 24 holes assayed from the recent program across Porotillo, Copete, and Melonal have returned mineralised intersections outside the existing resource.
Managing Director Patrick Duffy says Porotillo adjoins another body of mineralisation for inclusion in the upcoming estimate.
“The Porotillo discovery adds to the extensive mineralisation beyond the resource which we have identified elsewhere across the cluster of outcropping gold-copper porphyry systems at Bramaderos,” Duffy says.
Assays remain pending for six holes, nine channels at Melonal, and four trenches at Porotillo. Sunstone says it expects to receive the remaining results during August before beginning the resource update.
The company notes it is also mobilising a rig to Limon for a 1,200m hole targeting a deeper porphyry gold-copper system beneath and southwest of the shallow Limon gold-silver deposit.
Bramaderos hosts a November 2025 MRE of 220 million tonnes @ 0.50g/t AuEq, containing 3.6 million ounces AuEq.
Write to France Pinzon at Mining.com.au
Images: Sunstone Metals
