As the world sits back and wonders where on Earth all the copper required for net zero is going to come from, it’s a good time to examine where most of it comes from right now – good old porphyry deposits. They currently account for over 60% of global copper production.

Massive porphyry style deposits form some of the biggest copper mines in the world, including Escondida – the world’s largest copper mine. They are frequently found in North and South America, with most of the world’s biggest copper mines notably being located in the south of the continent – especially Chile.

Copper porphyry deposits can typically be worked on at a low cost, provided it is at a large scale. It is the only style of deposit that can accommodate what would normally be considered a low grade of ore, and gives the old mining adage of ‘grade is king’ a run for its money. A perfect example is the Aitik mine in Sweden, where they processed 43.3 Mt of ore in 2022 at a head grade of 0.20% Cu, 0.10 g/t Au, and 0.9 g/t Ag. Production started in 1968 with a 2Mtpa mill processing copper at a head grade of 0.51%.

A simple way to think about how copper porphyry deposits form is to imagine them as a byproduct of failed volcanic eruptions. They originally form several kilometres below Earth’s surface, just above molten hot magma chambers. As these magmas cool and begin to rise toward surface, they release vast amounts of fluid – of which copper is precipitated from.

Copper is frequently found alongside gold and molybdenum in porphyry deposits. In fact, more than 90% of the world’s molybdenum is found in porphyry deposits. Due to the depth that these resources usually sit, there are issues with discovering them. Upon getting into porphyry depth territory, geophysics are to a certain extent unreliable. To complicate matters further, it is a generally held consensus that most of the large nearer surface deposits have already been found. 

There hasn’t been a whole lot of new exploration techniques that have greatly aided these efforts in recent times, and a large part of modern discovery involves reinterpreting data in fresh, innovative ways. This is especially true when assigning certain levels of prosperity to outcroppings. Collecting big data sets and refining machine learning capabilities that are used for analysis has been a modern technique that can yield success when combined with significant geological expertise. But in the end, it takes guts to put the drill in the ground and hope to pull out a core with an economical amount of copper.

It’s the type of courage that the legendary David Lowell showed when he ran a little drill program at Escondida, after five previous companies did not drill a single hole, and managed to pull out 52m @ 1.51% copper – which was the start of the biggest copper mine in the world that is now largely owned by BHP and Rio Tinto.

It’s also the same type of gusto the members of Mine Discovery Fund Pty Ltd (MDF), a company at the forefront of discovering Tier 1 metals deposits, showed during the Resolution deposit discovery. Some of MDF’s expert geological advisory board have led teams responsible for some of the biggest discoveries in the world, including the 1.5Bt @ 1.5% Cu, 0.04% Mo (+Au, Ag) porphyry Resolution deposit in Arizona, USA. The first hole returned over 400m at above 1% copper, and it is currently a US$64 billion project that will run over 60 years as a joint venture between Rio Tinto and BHP. 

The same team are aiming to replicate their success with a new Alaskan venture – Wiseman Metals Pty Ltd. They have developed MineralEyes AI, a system that conducts proprietary computational analysis of big geoscience datasets.

Depending on the host rock and distance from the magma, other associated mineral deposits can form in porphyry deposits, including high grade skarn – the addition of which can drastically boost the profitability of mining operations.

Their flagship project, Wiseman East, is highly prospective for multiple copper porphyry centres, with associated high grade copper-gold-silver skarn systems. The company has drilled a few near surface holes that have all intersected extensive mineralisation, with insignificant patches of overburden. All holes end in mineralisation and are open in all directions.

A standout assay achieved was 12.2m @ 0.7% Cu, 7.6 g/t Ag, and 0.37 ppm Au. Across two of the holes, one of which extends up to 45m in width, there are 3 instances of 1.5m intercepts that are above 1% Cu. Wiseman has also collected a litany of rock chip samples across the project with results up to 25.3% Cu, 0.33 g/t Au, and 44.7g/t Ag.

The company believes there are about half a dozen porphyry centres in the tenement area that are currently in focus, and the drill holes to date have clipped parts of them. Wiseman is excited to drill to a depth required to understand the orebody.

With copper demand expected to explode out to a whopping 50Mt in 2035, a year in which the annual deficit could be as much as 9.9Mt, there is a critical need for large discoveries to be made – and porphyry is the perfect candidate.

Join Joseph Webb, Chairman of Wiseman Metals and MD of the Mine Discovery Fund Pty Ltd (MDF), for a live investor briefing this Thursday, 27th July at 1pm (AEST), where he will discuss why MDF picked copper as the top metal to capitalise on the energy transition. Click here to book in or request the replay.

Mine Discovery Fund Pty Ltd is a private investment vehicle that has interests in Felix Gold Ltd and Wiseman Metals Pty Ltd.

Reach Markets have been engaged by Wiseman Metals Pty Ltd and may receive fees for its services.

Reach Corporate provides Corporate Advisory Services, including managing investor communications on behalf of Felix Gold Ltd and may receive fees for its services.

Past performance is not a reliable indicator of future performance.