The company made a discovery at El Palmar Porphyry Copper-Gold Project in northern Ecuador, intersecting 480 metres of gold-copper mineralised porphyry from the surface in the first hole completed on the project.
Sunstone has also received strong assay results, including 404.8 metres of gold and copper, highlighting the potential of its Brama prospect within the Bramaderos project in southern Ecuador.
Importantly, Sunstone is in a staged acquisition agreement to wholly acquire El Palmar with Ecuadorian company Golden Exploration.
El Palmar progress
During the quarter, Sunstone started its phase 1 drilling program with a total of 2,168 metres drilled targeting the upper portion of a circular magnetic anomaly interpreted to be a mineralised porphyry body.
Four drill holes have been completed to date with the assays received for hole EPDD001 and partial assays for EPDD002 (from 250 metres to 417.5 metres) including:
- 163.55 metres at 0.71 g/t gold and 0.20% copper (1.05 g/t gold equivalent1) from 52.35 metres;
- 480.85 metres at 0.41 g/t gold and 0.15% copper (0.66 g/t gold equivalent1) from 11.3 metres; and
- 167.50 metres at 0.58 g/t gold and 0.26% copper (1.02 g/t gold equivalent1) from 250 metres.
Sunstone is expecting the assays from the remainder of drill holes EPDD002 and EPDD003 in November.
Notably, the presence of bornite and other high-tenor copper sulphide minerals suggest higher copper grades can be expected within the system.
Drill core from EPDD001 from 152.5 to 159.5 metres showing sampling intervals and gold and copper assay results.
Bramaderos Gold-Copper Project
During the quarter, drilling continued at the Brama gold-copper porphyry target with assay results from holes BMDD009, 010 and 011 further highlighting the potential for Brama to host a substantial gold-copper porphyry system.
- 185.3 metres at 0.4 g/t gold and 0.15% copper from 116.8 metres;
- 170.65 metres at 0.46 g/t gold and 0.15% copper from 311.75 metres, including 69.6 metres at 0.65 g/t gold and 0.2% copper from 347 metres; and
- 404.8 metres at 0.32 g/t gold and 0.09% copper from surface, including 51 metres at 0.54 g/t gold and 0.07% copper from surface.
Notably, drill holes BMDD009 and 010 have further defined gold-copper mineralised porphyry and intrusive breccia while BMDD011 has extended the gold-copper mineralised domain to the northwest, below well-mineralised trench sampling.
A detailed 3-D geological model has been completed for Brama and will underpin a mineral resource estimate (MRE) to be undertaken in early 2022.
Drilling is ongoing with six more holes planned as part of the initial MRE drill program.
Brama gold-copper porphyry plan view.
Exploration expenditure for the reporting period was A$2.8 million primarily related to the El Palmar and Bramaderos projects.
During the quarter, A$4.5 million was received from the sale of a portion of the shares held in Copperstone.
Sunstone held 42,815,220 shares in Copperstone Resources valued at approximately A$8.7 million as of September 30, 2021.