Triassic Choiyoi Belt

Location and Geology

Our presence in this Belt is through the Casposo District, located on the eastern edge of the Cordillera Frontal (Calingasta Department), about 150 km NW of San Juan City. 

The tectonic style of the Cordillera Frontal is characterized by a blocky structure bounded by high-angle normal faults originated during the Permian-Triassic Gondwanic extension and inverted during the Cenozoic Andean compression.

At the Casposo District, the geology is dominated by a complex of volcanic sequences of the Choiyoi Group consisting of a Lower Sequence dominated by thick andesitic pyroclastic units and an upper sequence by dacitic to rhyolitic lavas and pyroclastic rocks. Additionally, it is intruded by at least four magmatic events characterized by subvolcanics, domes, and dykes.

The dominant structurally controlled epithermal quartz veins (NW-SE, N-S, and E-W) are associated with banded quartz–chalcedony veins, typical of LS epithermal environments.

Exploration Proyect - Argentina - Triassic Choiyoi Belt - Austral Gold

Exploration Projects

Exploration Projects - Argentina - Triassic Choiyoi Belt - Casposo Mine - Austral Gold

Casposo Mine Project

The Casposo Project is a Permian epithermal LS deposit. Its main mineralized veins are throughout a 10 km long NW-SE regional structural corridor encompassing the Kamila pit, which hosts the Aztec, Inca, and B veins, forming a sigmoidal set of 500 m long near the center. The Inca 1, 2, and 3 veins are at the SE extension. In contrast, the Mercado vein system is the north-westerly continuation of Kamila, separated by an east–west fault from the Kamila deposit. A series of east–west veins appear to splay off these major sets to the east and northeast. The mineralization is present from an elevation of 2,500 to 2,300 m, and the vein system identified to date covers an area of about 35 km2.

Since 2011, the Casposo Mine has produced approximately 325k ounces of gold and 12.5m ounces of silver. The Mine has been on care and maintenance since 2019. We aim to consolidate ~250 koz of gold mineral reserves to restart mining operations.

Manantiales Project

The Manantiales project, located north Casposo area, has a lithology dominated by andesitic to rhyolitic tuffs, rhyolitic domes, dacitic subvolcanic bodies of the Choiyoi Group and post-mineral intrusions of rhyolitic-trachytic and andesitic dikes.

Exploration activities were focused in the southern area of Manantiales, bordering the Casposo mine.

At the Cerro Amarillo area, preliminary exploration activities consisted of rock chip and channel sampling showed high gold values in Awada, Fabiola, and La Puerta. These results are related to multiple centimeter veinlets in at least three main directions.

Exploration Projects - Argentina - Triassic Choiyoi Belt - Manantials Project - Austral Gold

Manantiales Vein - Longitudinal Section. Exploring for blind ore-shoots.