Aldebaran Resources (TSXV: ALDE) has announced a significant resource increase for its Altar copper-gold project in San Juan, Argentina, on the back of nearly 63,000 metres of drilling to expand the deposit over the past few years.
Total measured and indicated resources came to 2.4 billion tonnes grading 0.42% copper, 0.07 g/t gold, 1.22 g/t silver and 42 ppm molybdenum. The M&I tonnage was double that of previous resource estimate in 2021. The contained copper was also close to double at 22 billion lb., while the contained gold rose 48% at 5.1 million oz.
Total inferred resources were 1.22 billion tonnes grading 0.37% copper, 0.04 g/t gold, 1.25 g/t silver and 45 ppm molybdenum. The tonnage represents a 542% increase over the previous estimate, while the contained copper and gold were 462% and 338% higher respectively.
The resource update, according to Aldebaran’s CEO John Black, represents a major milestone for the Altar copper-gold project, demonstrating “is one of the largest undeveloped copper-gold deposits in the world.”
On the back of this resource estimate, the company has begun working towards the first PEA (preliminary economic assessment) on the Altar project, to be completed in the second quarter of 2025. “With our 2024-2025 drill program just underway and lots of catalysts coming, the future is very bright at the Altar copper-gold project,” Black said.
Aldebaran Resources’ stock set a new all-time high of C$2.19 on Monday following the resource update. By 11:40 a.m. ET, it traded at C$2.14 with a market capitalization of C$358.4 million.
The Altar project forms part of a cluster of world-class porphyry copper deposits near the Argentina-Chile border that includes Los Pelambres (Antofagasta Minerals), El Pachón (Glencore) and Los Azules (McEwen Copper).
The new resource estimate includes the three main porphyry discoveries (Altar Central, Altar East and Altar United), reported within a single conceptual open pit. These discoveries are part of a cluster of porphyry centres across 7 km of strike length on the property.
Three other mineralized zones (Altar North, QDM and Radio) have been identified to date, but were excluded from the resource estimation.
Kevin Heather, chief geological officer, said the new resource is a validation of an exploration concept the company had in 2017 while doing the original due diligence on the project before acquiring an option to earn-in on the Altar project.
‘We believed there was geological evidence that the gap between Altar Central and Altar East could host significant mineralization that had never been drilled. Fast-forward to today, after seven years of conviction, hard work, and the discovery and definition of the Altar United porphyry,” Heather said.
Commenting further on the resource update, Black noted: “Just as important as the size of the deposit, 66% of the resource tonnes are classified as measured and indicated, indicating a very high confidence level in the resource estimate.”
This, he says, will prove very valuable while working towards a prefeasibility study (PFS) on Altar, which the company plans to complete in the second half of 2026. “This important milestone clearly adds substantial value and positions Altar as one of the very few truly giant copper-gold projects still in the hands of a junior exploration company,” Black stated.
The Altar project was originally held by Rio Tinto, which completed 2,841 metres of drilling between 1995-2004. The Rio later optioned the project to Peregrine Metals, who subsequently drilled 56,761 metres before being acquired by Sibanye-Stillwater in 2011.
In 2018, Aldebaran, having spun out of Regulus Resources (TSXV: REG) that year, entered an option agreement to acquire an 80% interest in the project. To date, it has earned a 60% interest and is working to formalize the acquisition of the remaining 20% from Sibanye.
Recently, the company partnered up with Nuton, a Rio Tinto technology venture, to advance the Altar project through the PEA and PFS stage. As part of the agreement, Nuton will provide funding of up to $250 million in return for a 20% interest.
