Antilles Gold (ASX:AAU) reports it has completed 4 preliminary diamond drillholes totaling 1,110m downhole on the El Pilar copper-gold porphyry, and its overlying gold-copper oxide deposit in central Cuba.
The company reports all 4 drillholes have been collared along 300m of strike of the El Pilar porphyry copper-gold oxide exposure and have tested both the ‘high-grade’ gold domain (upper oxide zone) and the lower leached copper domain (lower oxide zone).
Additionally, all of the drillholes continue into fresh rock where porphyry-style hydrothermal alteration, veining and copper sulphide mineralisation was encountered in varying amounts, representing the outer mineralised halo of a prospective copper-gold porphyry system.
An additional 3 drillholes in the current preliminary program will target both the oxide and sulphide zones to better define the extent and style of the alteration system for the upcoming ground Induced Polarisation (IP) and ground magnetometry surveys over an area 3km by 2km that will cover the ‘very large’ El Pilar surface geochemical and alteration footprint.
The 4 drillholes in the oxidised cap indicate continuous gold mineralisation from near surface to over 40m downhole in the upper gold domain dominated by iron-oxides after primary sulphides, and then over 45m of oxide copper mineralisation in the underlying copper domain that is almost entirely composed of secondary chalcocite, and lesser chalcopyrite.
All drillholes in fresh rock have intersected visual copper sulphide (chalcopyrite) mineralisation
All drillholes in fresh rock have intersected visual copper sulphide (chalcopyrite) mineralisation in what is interpreted as the outer zone of the porphyry deposit dominated by intense chlorite-sericite hydrothermal alteration associated with veins, breccias and stockworks of chalcopyrite-pyrite which is indicative of a porphyry copper-gold system.
Earlier potassic alteration (secondary biotite) is present locally in diorite dykes that display pervasive chlorite overprinting and chalcopyrite mineralisation.
A 15,000m drilling program is planned to commence in Q2 2023, and target the porphyry copper-gold mineralisation that is not exposed in the flat terrain which has little outcropping exposure outside of the oxide cap as it is a topographic high.
The targets will be generated by the upcoming ground IP and magnetics program.
A separate 7,000m shallow (100m vertically) program will be undertaken on the oxide cap, commencing in Q1 2023.
Antilles Gold Executive Chairman Brian Johnson said the early positive indications of the potential of both the El Pilar copper-gold porphyry deposit, and its overlying oxide deposit, will become more certain once preliminary drilling results are received next month.
Johnson is predicting an important phase in the company’s progress next year with the proposed development of the La Demajagua gold-silver mine, and a significant exploration campaign being carried out concurrently.
The El Pilar copper-gold porphyry deposit is one of 3 (El Pilar, Gaspar and San Nicholas) in a cluster within a 17,800ha concession in central Cuba which is included in an Exploration Agreement between Antilles Gold and the Cuban Government’s mining company, GeoMinera.
The three deposits have undergone a total of 48,000m of shallow drilling by Canadian explorers which confirmed the existence of copper-gold mineralisation in weathered saprolite near the surface.
Antilles’ initial focus will be on the El Pilar deposit where the evident surficial hydrothermal alteration represents a classic porphyry phyllic cap and the dimensions of the phyllic alteration indicate the porphyry intrusion has large dimensions with a potential depth greater than 1,000m, and could exceed a 500Mt open pit target.
Results from the current preliminary drilling program are expected to justify the 15,000m program planned for next year.
If the planned drilling program for the oxide deposits establishes Indicated JORC Resources within, or larger than the Exploration Target Range for the deposit advised to the ASX in July, it is possible a low cap-ex mine could be developed by the joint venture with GeoMinera, on the oxide deposit to produce gold and copper concentrates.
The concentrates are not expected to be metallurgically complex, and should be easily sold, and attract a high level of payables.
The flat terrain of the El Pilar site is within 2km of the township of Gaspar, and adjacent to HT power lines, water supply, and a rail link to a 9m deep dedicated wharf, which will contribute to minimising development costs for the oxide deposit.
Antilles has agreed with GeoMinera that this project should be considered a priority development with the prospect of its commissioning by mid 2024.
Antilles Gold is an Australian mining company operating in Cuba, developing three near-term mid-sized open pit mines to produce gold, silver, copper and zinc concentrates in a joint venture with GeoMinera SA.
