It has been about 20 years since the exploration area has been considered by miners, but a recently completed drilling initiative piqued the interest of eight companies keen on the potential copper and uranium deposits in the Delamerian basement.

Of those firms, Lodestone Mines Limited, Boss Uranium and Coda Minerals (joint venture), Peel Far West and Trachre were successful bidders and will now progress to the next stage in securing exploration tenure over the sought-after area.

The spatial extent of the Delamerian basement. Photo: SA Government.

The Delamerian basement spans an area covering most of the eastern side of South Australia and part of the north, and hosts three of the state’s active, recently active and emerging mines – the Angus, Kanmantoo, and Bird-in-Hand deposits respectively.

The third is subject to legal action in the Supreme Court after miner Terramin sought to restart gold mining at a site near the Bird In Hand winery which was vetoed by Mining Minister Tom Koutsantonis.

However, the government said the area identified via the drilling program encompasses a patch of land stretching westward from the eastern border of SA.

The area identified by the South Australian Government

Restarting exploration of the Delamerian region follows a state government and MinEx Cooperative Research Centre national drilling initiative which provided new insights into the under-explored area of South Australia.

The government said the drilling program provided a better understanding of the geology and mineral potential of both the Delamerian basement and the overlying Murray Basin cover.

Drilling was carried out with a MinEx-designed specialist drill dig, allowing the Geological Survey of South Australia to gather new data on the area.

According to the government, data collected confirms the presence of rock types favourable for copper, lead, zinc, silver deposits, uranium mineralisation and the potential for heavy mineral sands.

The area has not been explored for 20 years due to the lack of available information prior to the latest drilling program.

Energy and Mining Minister Tom Koutsantonis said it was exciting to see companies eager to explore the Murray Basin, and that data gathered gives miners confidence to “explore an almost-forgotten but now newly-prospective part of our state”.

“The development and use of new techniques and technologies in mineral exploration are opening up literal new frontiers and opportunities for South Australia,” Koutsantonis said.

“Our state’s exploration and mining is poised to help fuel the world’s shift to cleaner technologies and energy.

“The more we understand about what lies beneath the ground in South Australia, the greater our role in the world’s decarbonisation efforts can be.”

Copper mining is proving big business in South Australia, with resources giant BHP recently acquiring major local firm OZ Minerals for $9.6 billion.

As part of that acquisition, BHP is looking to establish a “copper province” which will include its Olympic Dam and Oak Dam assets and OZ Minerals’ copper and gold mines at Prominent Hill and Carrapateena.

The acquired company’s operations proved a boon to BHP in the new parent’s latest financial results, which detailed a $20.1 billion profit buoyed by results from the copper province.

Overall, earnings from the SA copper province were 72 per cent higher at $1 billion due to higher sales volumes at Olympic Dam, supported by record production of the metal at the site according to BHP.

Record gold production in the last financial year also drove the earnings rise, as well as the contribution of sales from both OZ Minerals’ Prominent Hill and Carrapateena operations in the post-acquisition period.

When announcing the results in August, BHP CEO Mike Henry said the copper precinct’s prospects were “compelling”.

“As we’ve seen in other assets like iron ore and coal in Queensland, when you can have a number of different mines feeding common infrastructure, not only does it open up efficiencies it opens up optionality,” Henry said.

“The copper resources in South Australia – both Olympic Dam and Oak Dam as well as the OZ Minerals assets – are big resources and so the inherent opportunity to grow is quite compelling.”