MNN Awards: Coda hunting for elephants in South Australia

THE past 12 months have been transformative for copper explorer Coda Minerals.
MNN Awards: Coda hunting for elephants in South Australia MNN Awards: Coda hunting for elephants in South Australia MNN Awards: Coda hunting for elephants in South Australia MNN Awards: Coda hunting for elephants in South Australia MNN Awards: Coda hunting for elephants in South Australia

Drilling at Emmie Bluff in South Australia's Gawler Craton

Coda only listed on the ASX in late 2020, with its key focus an earn-in over the Elizabeth Creek copper project in South Australia's Gawler Craton.

It already had a solid foundation, with existing resources of 159,000 tonnes of copper and 9400t of cobalt at the MG14 and Windabout deposits.

But the most exciting target at Elizabeth Creek has been Emmie Bluff - for two reasons.

While Coda already knew it had a Zambian-style copper-cobalt deposit on its hands at Emmie Bluff, it attracted major market attention in June 2021 when it drilled Emmie Bluff Deeps.

The company's shares jumped 180% in a day when it reported the discovery of a thick zone of iron oxide-copper-gold mineralisation in the first deep hole at Emmie Bluff Deeps, 400m below the shallow Emmie Bluff deposit.

The discovery hole returned multiple mineralised zones, containing an aggregate 35m grading above 1% copper, starting with 4.7m at 1.01% copper, 0.17 grams per tonne gold and 3.6gpt silver from 797m, and ending in 2.6m at 2.11% copper, 0.30gpt gold and 13.2gpt silver from 842m, including 1.45m at 3.44% copper, 0.42gpt gold and 22.1gpt silver. 

What excited the market is that Emmie Bluff is just 30km west of OZ Minerals' Carrapateena copper-gold mine and only 15km from BHP's exciting Oak Dam discovery.

"The best place to find an IOCG is right next to IOCG mineralisation that looks like mineralisation from world-class IOCG deposits," Coda CEO Chris Stevens said.

"That's something we've done over the past year, taken completely greenfields ground and hit a major IOCG system in this area

"It proves targeting is good and it also proves the area is good."

Well-known geologist Colin Moorhead sits on the board of Coda.

"The way I look at these things is that Emmie Bluff is a significant copper province and a significant system in what is elephant country," he said.

"There's a lot of copper floating around and clearly the IOCG mineralisation and the more strata-bound Zambian-style mineralisation is related.

"In my past, when you hit ore-grade intercepts you start to get excited. When every other hole is ore-grade intercepts, you get very excited and whilst we haven't been able to put together an economic accumulation of metal yet, arguably it's not far away. You can't see it but you can smell it.

Moorhead said Coda's geologists had done a fantastic job.

"The model's evolving, they are historically quite difficult things to resolve and I'm personally quite excited about the prospectivity - not only the Emmie IOCG but other targets that we have in the district," he said.

Just last month, the company hit a new copper-rich bornite zone with a best intercept of 16m at 2.66% copper and 37.5 grams per tonne silver from 812m.

Coda has paused drilling to conduct geophysical surveys for targeting.

"If it's down there, geophysics will find it and I believe there's something big down there," Stevens said.

"It is without doubt higher risk, but also higher reward."

Meanwhile, the company reported the maiden resource for Emmie Bluff in December.

The initial indicated and inferred resource for Emmie Bluff is 43 million tonnes at 1.3% copper, 470 parts per million cobalt, 11gpt silver and 0.15% zinc, or 1.84% copper equivalent, using a 1% copper equivalent cut-off grade.

Contained metal is 560,000 tonnes of copper, 20,000t of cobalt, 15.5 million ounces of silver and 66,000t of zinc, or 800,000t of copper equivalent.

About 90% of the tonnage and 92% of the metal sits in the indicated category.

According to Coda, the resource makes Emmie Bluff one of the largest known sediment-hosted copper deposits in Australia.

"We've got a very strong handle on the geology and the resource at Emmie Bluff," Moorhead said.

Total resources now stand at 43Mt at 1.8% copper equivalent for 1.1Mt of copper equivalent.

Coda earned a 70% stake in Elizabeth Creek from Torrens Mining and in February, the two announced a $23.2 million scrip takeover offer for Torrens, which gave it 100% of the project.

Shaw and Partners analyst Michael Clark noted earlier this year the difficulty of exploring in the area.

"Over the past year, Coda has refined and calibrated its exploration techniques, and this has resulted in drill-backed success," he said.

Stevens said there were misconceptions Emmie Bluff was too deep and unmineable, something the company is keen to prove wrong.

The deposit is about 400m deep and flat-lying.

"In terms of lateral extent, it's about the size of Kings Park in Perth, it's about the size of two-and-a-half Centennial Parks - it's huge," Stevens said.

A scoping study is well advanced and is expected to be released by October.

Coda Minerals is a nominee for Explorer of the Year in the 2022 MNN Awards.

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