Coda's copper deposits: the hippo atop an elephant...

That is because this Gawler Craton advanced exploration project - which lies smack in between three of Australia's greatest copper mines - has two different stage and style deposits stacked on top of each other.

First the hippo, which is called Emmie Bluff. This is a sedimentary copper-cobalt deposit which has an Indicated and Inferred Resource - from three deposits - amounting to a total of 1.1 million tonnes of contained copper equivalent.

This is currently subject of a scoping study which is expected to be released in late March or early April this year. It envisages the potential for two open pits and a 400m underground development.

Chief executive officer Chris Stevens explains: "We have already demonstrated through the publication of detailed mine plans that the Elizabeth Creek Project has very real potential as a solid mid-tier 35 to 45,000 tonne per annum producer of both copper and cobalt. 

 "This is a substantial Resource base which has the potential to underpin a long-life open pit and underground mining hub at Elizabeth Creek. We have completed open pit and underground mining studies for Emmie Bluff, base case processing studies are also complete with only final downstream processing trade off studies remaining," Stevens said, adding that the scoping study would pave the way for a full feasibility study.

Second, the elephant, known as Emmie IOCG which lies on the northern boundary of the 700 square kilometres tenure package close to BHP's Oak Dam West, and Olympic Dam and Oz Minerals' Carrapateena.

Coda, in much the same way as Carrapateena was discovered, had a major IOCG intercept in June 2021, hitting about 50m of copper sulphides and 200m of very intense alteration which clearly suggested the discovery of major IOCG system.

Stevens wryly notes that it was after the publication of the first intercept, the market rewarded Coda instantly and strongly, but with time, this enthusiasm has waned somewhat.

He explains: "Subsequent hits unfortunately have not demonstrated Carrapateena or Oak Dam West scale yet but the area covered by drilling is still small and we have had to slow down an aggressive campaign due to the sheer cost of exploring at these depths going to 800m."

Stevens is quick to add that since that stellar hit, Coda has drilled 21 holes into Emmie IOCG for a total of 23,000m, with all but three returning substantial widths of mineralisation, some more than 3% copper and 0.5 grams per tonne gold.

"Emmie IOCG remains entirely open and multiple other IOCG targets across tenure make for high risk, high-reward, exploration," he said, adding that may consider finding a potential partner at some point in the future after completing the next phase of IOCG exploration in the form of geophysics.

This cutting-edge geophysical prorgamme has just kicked off at Emmie IOCG "so watch this space", Stevens said.

Stevens was referring to Ambient Noise Tomography (ANT) survey which began in 2023 at both Emmie IOCG and Emmie Bluff.

Coda says the deployment of Fleet Space Technologies' ExoSphere ANT survey represents a pivotal new phase of exploration aimed at unlocking the broader potential of deposits.

While loving this real-time technology, Stevens is also cautious: "The way I see geophysics, on its own, is nothing more than circumstantial evidence. But when you correlate it with historical and recent drilling - which is what we have right across the tenure - you should be able to present a much more meaningful picture." 

But, having two different stage and style deposits stacked on top of each other sometimes causes confusion the market, Stevens says, but adds that this offers the Elizabeth Creek project with unique upside.

"Two projects in one at Elizabeth Creek provide growth from a near-term copper project with real go- forward potential and the almost uncapped upside from proven intercepts in elephant country with the deeper copper-gold," Stevens said.

Stevens' relationship with Elizabeth Creek goes way back to 2015 with a farm-in of private investors who were looking for a project in a good area but with technical problems to solve. 

 Stevens admits he likes taking on a technical challenge as - unlike political and jurisdictional risk, for example - it can usually be solved. Issues around metallurgy, processability and scale were some of those technical challenges that needed to be overcome at Elizabeth Creek.

All that has changed. From just 280,000t contained copper equivalent Resources on listing, the total has grown to 1.1Mt, metallurgical challenges have been resolved and rather than seeing the presence of cobalt as a challenge, it is a welcome part of the final product, given the global demand for the commodity as a battery mineral.

A big plus for Coda's cobalt resource is that it is carrollite, which is analogous to Zambian cobalt.

Stevens explains: "Carrolite is basically a cobalt sulphide which makes it non-associated with iron sulphide. It is simple to liberate, and we have demonstrated that with getting to final cobalt sulphate recovery of more than 90%."

This is unusual in Australia as most Australian cobalt is locked up with iron or a cobaltiferous pyrite, which can be extremely difficult to separate.

At Elizabeth Creek, Coda finds itself in the enviable position of developing a project with two of the world's most sought-after commodities: copper and cobalt. And with an ever-increasing Resource, demonstrated process-ability and mineablity, Stevens says that the upcoming scoping study will be "more like a prefeasibility study with an NPV and all the details for the first time".

"It puts us squarely in that range of ‘decent scale', not massive, world-class projects. If you look around Australia, you will not find many comparable projects. We are scaled very well.

"We think we are doing the right thing at the right time, we are far from done on the hunt for this massive IOCG on the tenement, it is exciting, it should be very rewarding, the trick is to do it in a carefully risk-assessed manner.

"We also have additional targets that we are following up on the tenements. Obviously, the prize with that is if you are moving down on a main project with plant and everything else, an additional discovery gives you an improved quality of resources to feed in early on, or it lengthens the mine life. In a perfect world, both of course! 

 "We are pushing on with the development of the project and this may attract attention from the miners. You always have to keep your options open but the one thing I have never compromised on is always doing work and progressing studies as if you are going to be the company that will take it right through to rehabilitation in the end. That drives behaviours.

"We have to look at ways of advancing the IOCG exploration without too much dilution to shareholders, and the best way to do this is to continue to work on the technical side to make it very attractive for larger partners to come and work on what could be the fifth major mine on the Gawler Craton," Stevens said.

Like nearly every other explorer or miner making South Australia home, Stevens if full of praise for the way in which the government is supportive of the industry.

"I have worked in every state in Australia in some or other capacity and I have found that the South Australian government is not just better, it is incomparably better. The people who run the department are good people, they are proactive," Stevens said.