Introduction
The Cobre Antofalla I project is geographically located in the Antofagasta de la Sierra department, Catamarca province, which is geologically classified as part of the Puna region. It sits at an average altitude of 4,700 meters above sea level, slightly south of the Salar de Archibarca and approximately 30 km south of the border with Salta. The project is 707 km from the city of San Fernando del Valle de Catamarca and about 69 km northwest of the Antofalla community.
In the study area, outcrops of clean sandstones, quartzites, and fine to medium-grained graywackes are observed, intruded by fine-grained igneous rocks and porphyritic units of rhyolitic composition. Additionally, dacitic ignimbrites containing Ordovician lithic fragments altered by silicification and argillization have been identified.
Tectonics
The Antofalla I Copper area is located on the Archibarca-Galán lineament, a regional structure with a northwest-southeast (NW-SE) orientation that also hosts important copper projects, such as Río Grande, Arizaro, and Lindero, among others.
This lineament, together with NNE-trending faults and the lower-order fractures derived from them, plays a fundamental role in the structural control of the porphyritic systems and the presence of polymetallic veins in the region. It is also associated with the formation of multiple-event volcanic complexes, dike swarms, breccias, and extensive zones of hydrothermal alteration, such as those identified at Cobre Antofalla I.
It is worth noting that this lineament is also linked to large-scale deposits, such as La Escondida (Chile) , which reinforces its importance in regional metallogeny and its potential to host economically relevant copper deposits.
Main Features
The ANTOFALLA I COPPER Project is made up of a total area of 4,193 hectares where the 100% concessionaire of the property is Tamar Mining SA
There is no history of previous on-site exploration in recent years, except for old mining operations near the Antofalla volcano. The field validation campaigns carried out by Tamar Mining SA represent the first systematic mapping and sampling effort on the property .
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138 rock samples (read with reflectance spectroradiometer) and 256 soil samples covering a portion of the hydrothermal alteration were taken. All samples were sent to the laboratory for chemical analysis.
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The area corresponds to the upper levels of a low sulfidation epithermal system , with an estimated extension of at least 6 km² .
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The area presents a strong hydrothermal alteration, mostly of smectite-illite type or vice versa. The study by means of satellite image processing provides more targets to explore in future campaigns.
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The alteration is located in a sequence of crystalline-lithic tuffites of dacitic to rhyolitic composition , with the presence of quartz phenocrystals.
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At the southern end of the alteration zone, a distal flow zone was identified, defined by the presence of silica sinter with lobular morphology.
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Structurally controlled acid leaching was observed, attributed to the collapse of acidic fluids of vadose origin in localized areas.
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The predominant structural orientations within the alteration area are EO , while the system appears to be bounded on both sides by NS oriented structures.
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Terraspec analyses indicate the dominant presence of low-temperature smectite , with localized detection of illite and buddingtonite , and a minimal presence of supergene alunite .
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Geochemical results reveal significant anomalies, particularly of Zinc and Silver. Rock samples between 100 and 2400 ppm of Zinc are distributed throughout the area.
