Antilles Gold Ltd (ASX:AAU, OTCQB:ANTMF) has received encouraging copper results from two holes of a six-hole, 1,800-metre core drilling program conducted in September at El Pilar Project in central Cuba, which confirm copper porphyry-style sulphide mineralisation underlying a high-grade copper oxide zone.
The drilling at El Pilar has proven that the oxide mineralisation is related to copper-gold sulphide mineralisation below the oxide blanket.
Potentially significant discovery
The length, continuity and grade of the copper mineralisation in hole PDH-004A, which remains open at depth, gives the company confidence that El Pilar is a potentially significant copper-gold porphyry discovery.
Hole PDH-004A intersected 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 overprint 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 returned 134 metres at 1.23% copper from 49 metres including 18.5 metres at 5.52% copper from 59 metres (oxide zone) including 5.5 metres at 4.17% copper from 166.5 metres (sulphide zone).
Source of all mineralisation
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 are preliminary at this stage – they were conducted at the Cuban government’s LACEMI (Laboratorio Central de Minerales) laboratory in Havana, and while there is no reason to doubt their reliability, they are 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.
What’s next?
An upcoming IP and magnetics program 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 15,000-metre drilling program to a depth of 300 metres vertically will immediately follow this geophysical program.
Executive chairman Brian Johnson said: “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.
“Two new exploration licences are currently being established by Cuban authorities by the excision of specific areas from the 17,800-hectare 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 100 metres with the licence to be transferred to the joint venture company, Minera La Victoria SA (MLV), for the anticipated oxide mine development.
Free cash-flow
“The second licence will encompass the potential El Pilar and Gaspar porphyry deposits below 100 metres 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.”
About El Pilar
El Pilar presents as an ideal site for a major mine development in the future.
It is a flat, unoccupied rural area, close to available labour, HT power, water supply, highway, and a 50-kilometre rail link to a wharf at Palo Alto suitable for concentrate export.
Antilles 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.