Sunstone Metals Ltd (ASX:STM) has discovered another significant gold-copper porphyry at its Bramaderos Project in southern Ecuador, taking the mineralised cluster to 2 kilometres by 1.8 kilometres and highlighting the scope for a large open pit operation.
This latest discovery, Copete, is in addition to the previously released porphyry exploration target of 3.3-8.6 million ounces of gold equivalent at Bramaderos, presenting significant scope to increase the project’s exploration target.
Discovery adds to Bramaderos large-scale potential
“The Copete porphyry is another exciting new discovery that adds to the large-scale potential at Bramaderos, and we don’t expect it to be the last," Sunstone managing director Patrick Duffy said.
“Copete is located next to the 2.7 million ounce gold-equivalent Brama-Alba resource and the large Melonal exploration target, which further highlights the potential scale of the opportunity at Bramaderos.
“Taken together, it reinforces that Bramaderos is a world-class multi-decade mining opportunity and increases the project’s value to third parties looking for hard-to-find gold and copper projects with genuine scale.”
Trench sampling results from the new Copete gold-copper porphyry target have confirmed significant surface porphyry gold-copper mineralisation:
- 113 metres at 0.64 g/t gold-equivalent (0.51 g/t gold, 0.07% copper and 1.2 g/t silver) in trench ML-01, within 214 metres at 0.50 g/t gold equivalent (0.37 g/t gold, 0.08% copper and 1.1g/t silver).
Distribution of porphyry gold-copper targets at Bramaderos.
The discovery means Sunstone has now outlined a 1.8-kilometre-long cluster of porphyry gold-copper mineralised intrusions across the Melonal-Copete trend. This trend runs parallel to the Brama-Alba trend and is only a few hundred metres to the south.
Cross-section view along the Melonal-Copete trend.
The Copete target remains largely under-explored, with no drilling by Sunstone. But it has a coherent and wide mineralised trench intersection, a 3-D modelled magnetic anomaly plunging to the southeast comparable to that seen at Brama, and mapped stockwork veining interpreted to represent the upper levels of an intact porphyry system.
It is interpreted that copper is leached at surface and that higher grades of copper are expected in drilling, which is supported by individual 2-metre intervals returning up to 0.28% copper.
Partnership discussions
Bramaderos, along with Sunstone’s El Palmar project in northern Ecuador, is currently the subject of partnership discussions with third parties.
These discussions are aimed at accelerating exploration and resource growth to help unlock the full value of the projects.