Summary

Mine Type	Open Pit
Study Completed	Preliminary Economic Assessment
Commodities	Copper Molybdenum
Mining Method	Truck & Shovel / Loader
Mine Life	...
Snapshot	The Antilla Copper Project is Calisto Cobre's flagship property. In June 2018 was published PEA for Antilla Copper Project Heap Leach and SX/EW Operation for the near surface supergene sulphides. In 2022, the mineral resources of the Antilla deposit were updated. Calisto Cobre considers that substantial exploration upside opportunities on the Property exist in three broad categories: Supergene Resource Addition, Lateral extensions, Primary Porphyry Exploration. Calisto is reviewing all available data to refine plans for exploration work under these three broad categories.

Deposit type

• Porphyry
• Vein / narrow vein

Summary:

Quartzite and quartz-arenite of the Soraya Formation outcrop over most of the central and eastern part of the Property and host the intrusive rocks and mineralization defined to date. The clastic sediments are fine- to medium-grained, well laminated on sub-centimetre to metre scale and occasionally show other primary depositional features such as crossbedding. The quartzite and quartzarenite units can be intercalated with centimetre to ten-centimetre scale siltstone or lutite beds.

At the bottom of the canyon in road cuts on the road up to the town of Antilla from the valley floor, and behind Calvario Hill, the Chuquibambilla Formation is exposed, comprising outcrops of mudstone, lutite and arenite.

Sediments are intruded by at least two intrusive rock types: altered and weakly-mineralized main porphyry (Main Porphyry) stocks or aphophyses, and narrow, unaltered late porphyry (Late Porphyry) dykes. The Main Porphyry is exposed as a prominent knob immediately to the west of the mineralized quartzites, and another, smaller intrusive body is exposed to the southeast of the mineralization.

Mineralization
Mineralization on the Property consists of a tabular body of fracture-controlled and disseminated supergene chalcocite dipping approximately -20o to 140o closely following the hill slope. The supergene chalcocite mineralization has a true thickness of 40 to 80 m. and is overlain by a barren, leached zone of variable thickness. The strongest chalcocite mineralization is associated with brittle faults.

Below the chalcocite dominated supergene mineralization, low-grade vein and disseminated chalcopyrite, and molybdenite mineralization occurs. Uncommon altered, weakly–mineralized, porphyritic felsic intrusives occur in drilling and larger porphyry bodies are known from elsewhere in the Property. The general geometric and mineralogical characteristics of the deposit are consistent with a supergene enrichment blanket associated with an Andean-type copper-molybdenum porphyry system.

Mineralization Style
The most economically significant form of mineralization encountered to date on the Property is fracture-controlled and disseminated chalcocite. The chalcocite occurs as:
• sooty or scaly coatings on millimetre wide, filled to partially open fractures
• sooty coatings on rock fragments and rock flour encountered in intense fracture or fault zones over widths of one to ten metres
• selvages on sub-centimetre width quartz veinlets
• occasionally as disseminated grains or coating disseminated grains of primary chalcopyrite in zones of more intense fracturing and silicification.

Molybdenite occurs in fine fractures and as grains within sub-centimetre wide quartz veinlets in the primary sulphide, secondary sulphide, and Main Porphyry.

Chalcopyrite occurs as disseminated grains and surface coatings along fractures and within quartz veinlets. Disseminated grains are also observed. Chalcopyrite in concentrations of up to 1% occur in the Main Porphyry and primary hypogene sulphide zones.

The Antilla Property displays a suite of veins that can be readily placed within the spectrum of typical porphyry style veins (cf. Sillitoe, 2010). Common A-type quartz-being veins occur within the Main Porphyry lithology and are typically fine-grained sulphide-poor granular quartz (with rare K-feldspar) veins in places with diffuse or sinuous boundaries. These veins have been noted across the Property from the supergene mineral resource area to the far west in the vicinity of ANT-15-04. Common molybdenite-bearing quartz (±pyrite-chalcopyrite) B-veins are noted in intrusive and sedimentary lithologies across the Property. Fine molybdenite-pyrite-chalcopyrite quartz-poor fracture veins are also common throughout the Property and comprise a significant proportion of the primary coppermolybdenum mineralization. Abundant pyrite-bearing D-veins often with prominent sericite-quartz halos are common across the Property. The alteration halos are more prominent in the more reactive host rocks.

Deposit Types
The mineralization identified to date on the Property is consistent with a supergene enrichment blanket associated with an Andean-type copper-molybdenum porphyry system. Porphyry deposits are typically large low to moderate grade deposits that are mined through bulk mining open cut or underground methods. Andean-type examples include Antapaccay, Cerro Verde, Escondida, Trapiche, Quebrada Blanca.

The majority of Andean porphyry deposits are hosted in intermediate to felsic volcanic or intrusive lithologies with a lesser number hosted by sedimentary successions. Antilla is an example of a sedimentary-hosted porphyry deposit, being predominantly hosted within quartz-rich sandstone and lesser shale.

Due to the atypical host succession of the Antilla deposit has a number of characteristics which are not common in porphyry systems in the region or in typical porphyry models (Sillitoe, 2010):
• Alteration at the Antilla Deposit heavily influenced by the lack of aluminous mineral phases of the quartz-sandstone hosting the mineralization. These relatively unreactive host rocks have inhibited the development of alteration minerals that define the zoned patterns typical of porphyry volcanic- or intrusion-hosted porphyry deposits. Widespread quartz-molybdenite Aand B-veins as well as biotite alteration of porphyry and shale host rocks indicate the presence of high temperature fluids typical of porphyry deposits globally. The Haquira deposit displays similar subtle alteration patterns in the quartz-sandstone host rocks and lacks the easily defined zoning patterns typical of volcanic or intrusion hosted deposits (Cernuschi, 2015)
• A well-developed hypogene or primary sulphide mineralization zone has not been encountered at the Antilla Deposit. Assays of the primary sulphide zone at the Antilla Deposit grade approximately 0.12% copper and 0.009% molybdenum. The Main Porphyry lithology contains approximately 0.08% copper on average. No large areas of higher-grade hypogene chalcopyrite mineralization have been encountered on the Property. To date, exploration has not located a higher-grade primary porphyry system with which the Antilla Deposit mineralization could be related.

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Comminution

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Commodity Production

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Personnel

Job Title	Name	Phone	Email	Profile	Ref. Date
.......................	.......................	...........	...........		Nov 23, 2024
.......................	.......................				Jun 11, 2018
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