Tuesday, 21 February 2023

Sunstone intersects gold and copper mineralisation on edge of ‘huge’ T2 geophysical anomaly

by Berkeley Lovelace

Sunstone intersects gold and copper mineralisation on edge of ‘huge’ T2 geophysical anomaly

Sunstone Metals (ASX:STM) has reported new gold and copper intercepts following drilling at the El Palmar Project in northern Ecuador.

The company says ‘extremely’ positive assays for drilling at the T2 geophysical anomaly has returned gold grades of up to 2m @ 3.2g/t Au, and 13.5m @ 1.1g/t Au from 97.5m from the edge of the anomaly, which is 1km long by 450m wide.

This anomaly is bound by the regionally significant Toachi Fault zone and is associated with orthogonal structures, a scenario the company says is similar to the 3 billion tonne SolGold Alpala copper gold porphyry deposit located within the Cascabel Project located 65km to the northeast.

Independent datasets show that T2 could deliver a significant gold-copper porphyry discovery”

Recent preliminary age dating has also confirmed that the mineralised gold-copper porphyry at El Palmar is the same geological age as the Alpala copper-gold porphyry deposit.

Commenting on the results, Sunstone Metals Managing Director Malcolm Norris said: “These results are highly significant. They confirm the T2 target is mineralised, is very prospective and is very large.

Independent datasets show that T2 could deliver a significant gold-copper porphyry discovery. The team at Sunstone are very excited by these recent results and look forward to drilling the target in March.

In the meantime, we will complete the current program at the Tituana epithermal target, where we have drilled an epithermal system that is mineralised. Assay results from the first 3 holes are expected in late March.”

Sunstone reports the T2 target is located east of the El Palmar T1 porphyry system and is developing into a very ‘compelling’ large porphyry gold-copper target based on several independent datasets. The company says 3 drillholes have been completed and further drilling to test the target is planned to begin in late-March.

Surface rock chip sampling defined an area of at least 220m by 50m averaging 0.4g/t Au, and 0.1% copper (Cu) in a ‘strong’ porphyry stockwork underlying a silica-clay altered cap.

The rock chip samples were consistently mineralised and included 6 samples which returned assays of greater than 1g/t Au, which the company says is ‘encouragingly very high’ for porphyry systems. The geological interpretation is that this outcrop is part of the upper zones of a large porphyry system.

Sunstone reports soil sampling at T2 defined a ‘significant’ and ‘coherent’ gold-copper-molybdenum anomaly coincident with an ‘extensive’ alteration cap. Geophysical surveying defined a conductive body coincident with the surface metal anomalism and recent drilling results. The company says this conductive body plunges, expands, and intensifies southward for a further 80m where it joins the regional Toachi Fault zone.

Sunstone says the recent drilling results reinforce the concept of an upper-level porphyry/epithermal system with ‘significant’ gold mineralisation grading down to a copper-gold system with porphyry B veins in the lower parts of hole EPDD024.

Additionally, the company reports drillhole EPDD021 was drilled into the T1 target, intersecting 866.6m @ 0.26g/t Au and 0.1% Cu from 501m. This result confirms the ‘significant’ vertical extent of the mineralisation at T1 which requires follow-up drilling.

3D geological modelling is being undertaken at T1 based on the 21 drillholes completed to date, and follow-up drilling will be planned to target mineralisation in the down-plunge extent. The company says hole EPDD025 has been completed into the T5 target, with assays expected in late-March. Another hole is also planned to be drilled into the T4 porphyry target in Q2 2023.

Sunstone also reports several epithermal gold targets have also been defined within the El Palmar concession, with the ‘highest priority’ being the Tituana target. The company says 3 drillholes have been completed here, and assays are expected in late-March.

Sunstone Metals is an ASX-listed mineral exploration company with ‘high-quality’ gold and copper assets in Ecuador. These assets are the Bramaderos Gold-Copper Project, and the El Palmar Copper-Gold Project.