Capstone Copper Expands Mantoverde District with San Pietro Acquisition

Strategic District Consolidation in Chile's Atacama

Capstone Copper Corp (ASX:CSC) has completed a significant expansion of its Chilean copper portfolio with the acquisition of the San Pietro project, a sprawling 16,000-hectare copper-gold-iron-cobalt concession nestled between its Mantoverde, Santo Domingo, and Sierra Norte properties. This move consolidates Capstone’s footprint in the highly prospective Mantoverde-Santo Domingo district, a region already hosting nearly 1.6 billion tonnes of measured and indicated mineral resources.

The $25 million transaction was settled entirely with Capstone shares issued to New Golden Exploration Chile SpA, a joint venture majority-owned by Golden Arrow Resources Corp. The deal underscores Capstone’s strategy to build a contiguous, district-scale copper operation leveraging existing infrastructure and local expertise.

Immediate Resource Boost and Exploration Upside

San Pietro’s Rincones and Colla deposits contribute an inferred mineral resource of 492 million tonnes grading 0.23% copper and 0.05 g/t gold, according to a NI 43-101 compliant estimate. This includes 83 million tonnes of oxide and 410 million tonnes of sulphide material, providing a substantial addition to Capstone’s mineral inventory and a platform for future resource growth.

Capstone plans to refine this resource through targeted exploration, aiming to delineate higher-grade zones within the existing footprint. The project’s proximity to Capstone’s other assets offers multiple pathways to integrate processing and infrastructure, potentially unlocking operational synergies and cost efficiencies.

Building on Prior Acquisitions and Partnerships

This acquisition follows Capstone’s 2024 purchase of Sierra Norte and its 2025 exploration option agreement with Empresa Nacional de Minería (ENAMI), expanding the company’s control over approximately 60,000 hectares in the district, with an additional 18,000 hectares under option. The growing land position positions Capstone to pursue a coordinated development strategy across the district, enhancing its ability to optimise resource extraction and infrastructure use.

Capstone’s President and CEO Cashel Meagher highlighted the strategic fit of San Pietro within the district, noting the company’s deep geological knowledge and operational experience in the Atacama region. He emphasised the potential for "transformational copper production growth" as the company integrates the new asset into its exploration and development plans.

Technical and Economic Considerations

The San Pietro resource estimate is based on a copper price assumption of US$4.80 per pound and a 0.3% copper equivalent cut-off grade. While the inferred resource classification indicates geological confidence, further drilling and evaluation are required to confirm economic viability and upgrade resource categories.

Capstone’s broader district includes the Mantoverde and Santo Domingo mines, which together hold measured and indicated resources exceeding 1.5 billion tonnes with proven and probable reserves. The company’s technical team, led by Senior VP Peter Amelunxen, is responsible for ongoing resource and reserve estimations, ensuring compliance with NI 43-101 standards.

What This Means for Capstone and Investors

Capstone’s acquisition of San Pietro represents a cost-effective expansion that strengthens its position in one of the world’s premier copper districts. The enlarged land package not only adds immediate mineral resources but also enhances exploration optionality near existing and planned infrastructure, which could accelerate future development timelines.

The deal comes on the back of Capstone’s recent operational momentum, including record adjusted EBITDA and ongoing growth projects at Mantoverde, positioning the company for sustained copper production growth amid a tightening global supply environment. Investors will be watching how Capstone integrates San Pietro with its existing assets and whether exploration efforts can upgrade and expand the resource base.