Bonanza gold grades snagged at Antilles Cuban porphyry deposit

Australian explorer Antilles Gold’s El Pilar deposit in Cuba has returned some bonanza gold grades, with one interval returning an eye-watering 2m at 84.82 g/t gold. The latest drill campaign points to two distinctive zones – one for gold and one for copper, with both showing promising stand-alone grades.

Four diamond cores taken from its El Pilar oxide deposit in central Cuba have intersected several intervals of extremely high-grade gold along with broader intervals of high-grade gold at depths from surface to 50m, with strong copper grades from the deeper material at depths of 50-70m. One hole returned 9m at an eye-catching 20.1 g/t gold from 34m, which includes the two metre hit at 84.82 g/t.

Another 10.5m intersection came in at a spectacular ounce to the tonne gold g/t gold from 46.5m, which included a 6m section going a stunning 53.53 g/t gold.

At deeper levels under the gold rich domain, assays returned copper hits in a separate domain that include 14.5m at 1.35 per cent copper from 47m, with 17m of that running at 0.72 per cent copper.

The El Pilar copper-gold porphyry deposit in central Cuba has an 80m to 100m overlying oxide zone with high grade gold and copper domains that are expected to be developed as a low cap-ex open pit mine initially to produce gold and copper-gold concentrates.

The project encapsulates three copper-gold porphyry-deposits (El Pilar, Gaspar and San Nicholas) within the 17,800ha El Pilar concession which were originally explored by Canadian mining companies in the 1990’s. The surficial hydrothermal alteration evident at El Pilar is representative of a classic porphyry deposit and the dimensions of the alteration potentially indicate a substantial porphyry intrusion that extends to depths greater than 1,000m according to the company.

Antilles says the new results reaffirm the near-term development potential of El Pilar. It says chalcopyrite and chalcocite, which are known high-grade copper sulphide minerals, were seen in the deeper zone. The shallower gold zones are well defined and the copper domains may extend into porphyry-type mineralisation.

Management says the intention now is to get a second drill rig on site for additional holes for the underlying porphyry exploration so as not to interrupt the oxide drilling.

So far around 7700m have been drilled at the project with only 2300m remaining to define an initial mineral resources estimate. The beauty of the El Pilar deposit is that it is metallurgically simple, which means processing will be relatively easy the company says. Metallurgical test work to-date suggests an overall gold recovery of 85 per cent from a simple rougher flotation circuit, with a concentrate grading 53.1 g/t produced from ore grading 2.11 g/t. Test work also indicates a copper concentrate grading 25 per cent copper will be achievable.

Following the mineral resource estimate for El Pilar, which Antilles says will be complete by the end of the year, it then expects to finalise a prefeasibility study for its Nueva Sabana project.

The Nueva Sabana and El Pilar projects are owned by Antilles and Minera La Victoria SA in a 50:50 joint venture (JV) company it shares with the Cuban Government-owned GeoMinera. The JV intends to fast-track the development of the Nueva Sabana mine via a 10-month construction phase starting in next year’s second quarter, with a proposed mining rate of 500,000 tonnes per annum and first product sales in early 2025.

The proposed mine benefits from being adjacent to HT power mains, water supply and easy rail and road access to the nearest port for concentrate export.

The mine is being planned as a copper-focussed project but will get a shot in the arm from high-grade gold in the shallow domain during initial operations, in addition to a low strip ratio. Planning and permitting has already commenced for the mine development.

The company says it has started discussions for advanced sales of gold concentrate from Nueva Sabana. Management believes the project could produce significant returns from first sales on a total outlay of just $6.2 million. It expects the outstanding 50 per cent of costs for its planned construction to be met this year.

The Antilles story is set to continue with more assays expected in about three weeks from the deeper deeper porphyry drilling.

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