Drilling at Sunstone’s El Palmar gold-copper project in Ecuador has intersected an extensive porphyry copper system with an interpreted vertical extent of more than 1,000m.

Hole EPDD026 intersected the porphyry – assessed on the logging of porphyry stockwork veining, visible chalcopyrite distribution and rock alteration along with portable XRF results – in the domain where the T2 and T3 targets merge.

The mineralised interval is now more than 200m wide from a down-hole depth of 1,060m and remains open with key characteristics strengthening as it extends.

Sunstone Metals (ASX:STM) adds that drilling is continuing beyond the current depth of 1,360m as the drillhole is still in mineralised porphyry drilling.

This could confirm the company’s belief that the intersected magnetic complex has a vertical extent of more than 1,000m extending toward surface and a large lateral extent.

Adding further interest, the magnetic body sits within the broad Toachi fault zone which is a key control on mineralisation at SolGold’s Cascabel project just 65km away.

“Drill hole EPDD026 has tested three targets, firstly the upper gold anomalous zone at T1-T2 drilled in holes EPDD022, 23 and 24, secondly the large MT geophysical anomaly in the southern part of the T2 target at an intermediate depth, and thirdly at depth on the northwest margin of the large cluster of magnetic bodies that make up the T3 target,” managing director Malcolm Norris said.

“It is in this third environment on the margin of the T3 magnetic complex that an extensive porphyry system is now being intersected.

“While it is early days, it is very exciting to have identified a mineralised porphyry copper system at T3 and to have identified a very large domain of potential mineralisation extending towards surface defined by magnetic bodies”.

Highly prospective target

Hole EPDD026 made the porphyry intersection where the T2 and T3 targets merge, suggesting that T3 hosts the most prospective part of the system.

While assays are still pending, the widespread chalcopyrite distribution, transitional potassic alteration, copper-sulphide-bearing A vein and B vein stockworks, and anomalous copper readings in pXRF results are highly indicative of a porphyry copper system.

Additionally, the presence of magnetite veins at depth also give confidence that this system correlates with a large cluster of magnetic bodies at the T3 target, which has a lateral footprint more extensive than the T1 magnetic target footprint.

The company also interprets T3 mineralisation as extending towards the surface as while most of the T3 area is covered by thick, young volcanic cover, surface exploration has identified stockwork veining in minor local outcrops.

This is supported by grid-based auger soil sampling returning coincident arsenic and antimony anomalies, which are typically elevated in the altered lithocaps over the top and margins of porphyry copper systems, over the southern sector of the T3 complex.




This article was developed in collaboration with Sunstone Metals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.