Antilles Gold Limited (ASX: AAU) has received promising copper assays from two holes of a six hole (1,800m) cored drilling programme at El Pilar in central Cuba.
The results from the programme completed September 2022 confirm copper porphyry style sulphide mineralisation underlying a high-grade copper oxide zone.
Highlight
- Hole PDH-004A intercepted continuous oxide and sulphide copper mineralisation as breccias, veins, and stockworks of chalcopyrite-pyrite, and minor bornite associated with strongly sericite-chlorite altered diorite intrusives that overprints earlier secondary biotite.
- The alteration also extends outwards into the mafic tuff host rocks, and this style of hydrothermal system is typical of porphyry copper-gold deposits.
- The mineralisation is open at depth.
Hole PDH-004A downhole: 134m at 1.23%Cu from 49.0m
including 18.5m at 5.52%Cu from 59.0m (oxide zone) including 5.5m at 4.17%Cu from 166.5m (sulphide zone)
This drill hole confirms that sulphide copper mineralisation is related to porphyry intrusives underlying the oxide copper-gold zone, which are the source of all mineralisation at El Pilar.
The assays must be considered as preliminary as they were undertaken at the Cuban Government’s LACEMI (Laboratorio Central de Minerales) laboratory in Havana which though capable and with modern equipment, is not qualified under the JORC Code. All assays will be replicated at one of SGS’s certified laboratories and be included at a later date in calculations for JORC compliant resources. The cost of duplicating these assays is justified as it will permit a follow-up ~50 hole drilling programme on the oxide deposit to commence several months earlier.
Antilles Gold’s Exploration Director, Dr Christian Grainger, said:
- The drilling at El Pilar has proven that the oxide mineralisation is related to copper-gold sulphide mineralisation below the oxide blanket.
- The intersection of strongly hydrothermally altered, and mineralised intrusives with high contents of chalcopyrite indicate that a porphyry copper-gold system is the source for both the oxide and sulphide mineralisation, and the grades of copper, both within the oxide and sulphide zones, are very encouraging.
- As the oxide copper blanket is entirely related to secondary chalcocite and minor native copper, and with the sulphide mineralisation being chalcopyrite and minor bornite, this indicates the mineralisation is arsenic-poor, and should be amenable to producing a quality copper concentrate.
- The length, continuity, and grade of the copper mineralisation in hole PDH-004A, which remains open at depth, is indicative that El Pilar is potentially a significant copper-gold porphyry discovery.
- The upcoming IP and magnetics programme will identify the extent and distribution of sulphide mineralisation given the high content of sulphide mineralisation present and define the size and extent of the target porphyry coper-gold mineralisation at depth.
- A follow up 15,000m drilling programme to a depth of 300m vertically will immediately follow this geophysical programme.
In addition to progressing exploration of the exciting El Pilar copper porphyry deposit, the company intends to complete JORC Resources and a Scoping Study for a proposed low cap-ex open cut oxide gold-copper mine at El Pilar to produce gold and copper concentrates, by October 2023,” Executive Chairman, Brian Johnson, said.
“Two new exploration licences are currently being established by Cuban authorities by the excision of specific areas from the 17,800ha El Pilar concession included in the company’s Exploration Agreement with GeoMinera.
“One licence will cover the El Pilar oxide deposit and surrounding outcropping mineralisation, and permit mining to a depth of approximately 100m with the licence to be transferred to the joint venture company, Minera La Victoria SA (MLV), for the anticipated oxide mine development.
“The second licence will encompass the potential El Pilar and Gaspar porphyry deposits below 100m and allow its transfer to a separate joint venture with GeoMinera which would facilitate possible participation in this project by a major mining company at some time in the future, while maintaining MLV’s objective of developing a series of mid sized mines to grow near-term profits, and free cash flow.
“The proposed La Demajagua gold-silver mine should be development-ready in Q2 2023, and the planned El Pilar oxide mine could potentially follow within 12 months.
“El Pilar presents as an ideal site for a major mine development in the future being a flat, unoccupied rural area but close to available labour, HT power, water supply, highway, and a 50km rail link to a wharf at Palo Alto suitable for concentrate export.
“The company has established facilities in the town of Ciego de Avila, which can support the ongoing exploration programs on the El Pilar oxide and sulphide deposits.”
