Massive Copper Deposit Discovered in Andes, But Extraction Poses Environmental Risks

Geologists estimate the Filo del Sol site in Argentina contains one of the world's largest copper, gold, and silver reserves, but mining it could violate environmental laws.

Mar. 30, 2026 at 3:23pm by Ben Kaplan

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A bold, abstract painting in earthy tones depicting the complex geological forces and mineral deposits deep within the Andes mountains, conveying the structural order and fragility of the Andean landscape.A massive trove of copper, gold, and silver lies beneath the Andes, but extracting it could come with a dark price for the fragile Andean ecosystem.Portland Today

Geologists have discovered that the Filo del Sol copper deposit in northwest Argentina likely contains five times more metals than previously believed, making it one of the largest mineral reserves in the world. However, extracting these valuable resources from the high-altitude Andes region poses significant environmental challenges, including concerns about violating Argentina's Glacier Law and depleting scarce water resources.

Why it matters

The Filo del Sol deposit could provide a major boost to industries in need of copper, gold, and silver for green energy, aerospace, and telecommunications. But the environmental impact of mining operations in this fragile Andean ecosystem raises concerns about the long-term sustainability of extracting these resources.

The details

An initial mineral resource estimate completed in 2025 found that the Filo del Sol site likely contains up to 13 million tonnes of copper, 907,000 kilograms (32 million ounces) of gold, and 18.6 million kilograms (659 million ounces) of silver. This represents a significant increase from previous estimates, as deeper exploration revealed far more extensive mineralization than expected. However, mining at such high altitudes, around 5,000 meters (16,400 feet) above sea level, poses major logistical challenges and health risks for workers. There are also concerns that mining operations could violate Argentina's Glacier Law, which is designed to protect the country's glaciers, a critical source of freshwater. Additionally, the mining process requires large amounts of water, which could deplete scarce resources in the arid Atacama Desert region.

  • In 2025, an initial mineral resource estimate was completed for the Filo del Sol site.
  • In 2022, Lundin Mining announced plans to build high-voltage power lines to bring renewable energy to the mining area and reduce diesel consumption.
  • In December 2024, Argentina's largest private electricity generator, Central Puerto, began a feasibility study to build transmission lines for renewable energy to power mining sites in the northwest.

The players

Lundin Mining

A U.S.-based mining company that is one of the companies in charge of the Filo del Sol mining operations.

BHP

A multinational mining company that is also involved in the Filo del Sol mining operations.

Fundación Ambiente y Recursos Naturales (FARN)

An environmental NGO that has accused Lundin Group of violating Argentina's Glacier Law, which prohibits mining within the country's periglacier areas.

Central Puerto

Argentina's largest private electricity generator, which began a feasibility study in 2024 to build transmission lines for renewable energy to power mining sites in the northwest.

La Alumbrera

One of Argentina's biggest mining sites, which uses 25 billion liters of water per year, equal to 34% of the water consumed by the region's nearly half a million inhabitants annually.

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What they’re saying

“Filo del Sol has been one of the most significant greenfield discoveries in the last 30 years and an amazing journey for all those that have been involved.”

— Jack Lundin, CEO of Lundin Mining

“The initial Mineral Resource has highlighted the potential for one of the highest grade undeveloped open pit copper projects in the world and one of the largest gold and silver resources globally.”

— Jack Lundin, CEO of Lundin Mining

What’s next

Lundin Mining and BHP will continue to explore the northern and southern boundaries of the Filo del Sol deposit to determine the full extent of the mineral resources. The companies will also need to address environmental concerns and obtain the necessary permits before beginning any large-scale mining operations.

The takeaway

The discovery of the massive Filo del Sol copper, gold, and silver deposit highlights the growing global demand for these critical minerals, especially for the green energy transition. However, extracting these resources from the fragile Andean ecosystem raises serious environmental concerns that must be carefully weighed against the economic benefits.