Santo Domingo

Location

The fully-permitted Santo Domingo copper-iron project is located near the town of Diego de Almagro in the Atacama region in Chile, approximately 35 kilometers northeast of Capstone’s Mantoverde mine and 130 kilometers north-northeast of the city of Copiapó. Elevation at the site ranges from 1,000 to 1,280 masl, with relatively gentle topographic relief.

Capstone’s Mantoverde-Santo Domingo District Integration Plan, aims to unlock the potential to produce over 250,000 tonnes per year of low-cost copper production.

Geology and exploration

The Santo Domingo deposits are located within the Cretaceous Iron Belt (“CIB”) of the Atacama fault zone. The CIB is a segment of the Atacama fault zone approximately 630 km by 40 km in dimension that hosts numerous iron oxide–copper–gold (IOCG) type deposits. The deposits lie on the east side of the Atacama fault complex, which, in this area, consists of numerous clusters of generally north–south structural breaks in a belt approximately 30 km wide. The geology underlying the property is divided into a number of structural blocks with different lithological characteristics suggesting that the blocks are part of different stratigraphic levels.

An exploration program completed in 2021 totaling 8,500 m confirmed the extension of the mineralized sequence between the Santo Domingo and Iris Norte pits. Additional oxide potential exists within Santo Domingo property on top of the current sulphides orebody in Santo Domingo and Estrellita deposits. Capstone is evaluating this oxide potential and is planning to delineate both oxides resources in the near future. In 2024, Capstone Copper acquired 100% of the shares of Sierra Norte, located approximately 15 kilometers northwest of the Santo Domingo Project. The Company is advancing opportunities to incorporate the recently acquired Sierra Norte project ore material into the mine plan.

Growth – Santo Domingo Project

Santo Domingo represents the next phase of transformational growth for Capstone Copper, in the world-class Mantoverde-Santo Domingo (“MV-SD”) district. The Feasibility Study for the 100% owned and full-permitted project was released in 2024, including an optimized mine plan, updated capital and operating cost estimates. The study was informed by experience gained throughout the engineering and construction of the nearby Mantoverde Development Project. The project is being prepared for a sanctioning decision, with an assessment of optimal financing progressing and detailed engineering advancing.