Opinion: Seeing the district for the deposit 

But sometimes they form clusters or groups of deposits. It’s these types of places where the geology is so fertile that one discovery is not the end of the story but the beginning of several new ones.  

Chile’s Atacama Desert is a good example. A single porphyry copper system, cracked open by explorers last century, went on to spawn the Escondida, Chuquicamata and Collahuasi mines. Between them, these mines have contributed a major share of global copper production for well over 100 years, and they’re still in operation today. 

Zambia’s Copperbelt tells a similar story. Early 20th century discoveries gave rise to a string of mines that have now operated for generations, underpinning an entire national economy along the way. 

So, what did they have in common? 

These regions didn’t come to fame from a single discovery. They gave birth to multiple major discoveries over several years, fuelling the national income of their host countries.   

Those are two examples of what giant mineral frontiers can look like: a handful of early discoveries prove up a large, mineralized belt, and from there, decades of follow-on mines emerge. 

And if you thought the days of discovering regions like this were over, you’d be wrong. 

High Andes frontier

Sitting high up in the Andes of Argentina is an area vastly underexplored compared with the heavily trodden ground across the border in Chile. It’s a region called the Vicuña District, and it bears striking parallels to the historic copper provinces of the past.  

To date, the district hosts only one moderate-sized mine: Caserones. So, it’s not there yet; the region is still in its infancy.  

But nearby, Filo del Sol and Josemaría, two advanced copper-gold-silver projects, are being carried toward development by a joint venture between major players Lundin Mining and BHP. These miners bought out the original discoverer, Filo Mining.  

In February, Lundin Mining released a technical study describing a project capable of ranking among the top five copper, gold and silver mining complexes on the planet, with an initial mine life stretching beyond 70 years.  

But that’s unlikely to be the last we hear of the Vicuña. 

Discovery pattern

One sign of a giant mineral frontier is repetition: new discoveries keep turning up along the same trend. Vicuña has already delivered that pattern.  

Explorer NGEx Minerals, working a target called Lunahuasi just a few kilometres from Filo del Sol, has returned some of the highest-grade copper-gold-silver intercepts seen anywhere in the world, including a high-grade core running above 30% copper-equivalent. 

Then came a discovery hole that intersected more than 1,600 continuous metres of copper-gold mineralization, opening up an entirely new porphyry target beneath the high-grade veins already being drilled. And with that, a swarm of smaller explorers moved in. 

Several companies have since staked claims along the same structural corridor, within a few kilometres of Filo del Sol and Lunahuasi. Chasing the same geological trend that’s rapidly building this district into a major new copper district.   

That’s how Chile’s Atacama and Zambia’s world-famous Copperbelt unfolded: a major discovery, followed by a wave of explorers proving that the fertility extends well beyond the original find. 

Why frontiers matter

Individual mines get depleted. Mineral frontiers don’t, at least not on any timeframe that matters to an investor. As one deposit moves toward development, exploration continues along the rest of the trend, and new discoveries keep the region relevant for decades. 

When companies of the size of BHP and Lundin Mining commit capital to a district this early, it’s usually because they see the same pattern we’ve described here. 

None of this means every company in the district will succeed. Exploration is exploration, and plenty of ground here remains untested. 

But the ingredients that turned the Atacama and the Copperbelt into mining provinces that lasted a century are visible in Vicuña today: a major early discovery, repeat success along the same trend, and majors willing to commit for the long haul. 

James Cooper is a geologist based in Australia who runs the commodities investment service Diggers and Drillers. You can also follow him on X @JCooperGeo.