Sunstone Metals Ltd (ASX:STM) has intersected a strongly mineralised porphyry gold-copper system at depth at T3 target within the El Palmar Porphyry Gold-Copper Project in northern Ecuador, which the company believes is a “significant discovery”.
Assays from drill hole EPDD026 demonstrated substantial gold and copper widths and grades in line with other prominent porphyry deposits globally, with results including:
- Higher grade zone of 11.9 metres at 0.97 g/t gold and 0.28% copper for 1.43 g/t gold-equivalent from 1,236 metres within 190 metres at 0.4 g/t gold and 0.11% copper for 0.58 g/t gold-equivalent from 1,171 metres;
- Discrete intervals of 2 metres of up to 0.35% copper and 1.3 g/t gold from 1,240 metres within the higher-grade zone of 11.9 metres; and
- Lower-grade mineralisation continues to the end-of-hole and is open.
Significant value uplift
Sunstone MD Malcolm Norris said: “Drill hole EPDD026 has delivered extremely promising results.
“The strong mineralisation is an incredible result for the first hole into the large T3 target.
“This area is wide open – we should expect mineralisation above this intersection extending towards surface, in addition to mineralisation below this intersection and laterally within a 1-kilometre diameter target.
“That is potentially a very large, mineralised area in an environment with many similarities to the 3 billion tonnes Alpala deposit nearby.
“Further drilling will obviously be aimed at testing the multiple discrete and shallower high amplitude magnetic anomalies within the T3 area, and ultimately the deeper magnetic and MT anomalies.
“It is early days on the El Palmar concession but the potential here is huge.
“We see multiple porphyry systems, mineralisation extending from surface to depths exceeding 1,100 metres and grades locally exceeding 1 g/t gold equivalent (or greater than 0.6 g/t gold and greater than 0.2% copper).
“We believe we are onto a significant discovery at T3 that could deliver significant value uplift to Sunstone shareholders.”
About T3 target
The T3 target is centred on the regionally-significant Toachi Fault zone and its intersection with orthogonal structures – a scenario strongly similar to the Alpala and Tandayama-America copper-gold porphyry deposits within SolGold’s Cascabel Project 65 kilometres to the northeast.
At the surface within the T3 target stockwork veining has been identified in minor local outcrops but the majority of the area, particularly in the northern portion of T3, is covered by up to at least 35 metres of young volcanic cover.
Grid-based auger soil sampling that has penetrated below areas of the thinner cover has returned coincident arsenic and antimony anomalies over the southern and western sectors of the T3 magnetic complex.
These two elements are typically elevated in the altered lithocaps over the top and margins of porphyry copper systems, supporting the concept of a very large target area.