Back in 2001, Minotaur Resources — now Minotaur Exploration (ASX: MEP) — put the Gawler Craton back on the mining investor’s map when it discovered the huge Prominent Hill copper-gold deposit south-east of Coober Pedy in South Australia.
At the time, it set off a land rush from other juniors wanting to peg anything in proximity to Prominent Hill.
It was, says the present Prominent Hill mine operator, OZ Minerals (ASX: OZL), “a stand-out greenfield discovery in Australia”.
Then, around 2015, part of the Craton was being boosted as being the “Pilbara of graphite”, as a host of juniors sought tenements to explore for that new “wonder” material.
But 19 years after the discovery of Prominent Hill, the vast, 440,000 square kilometre geological structure than underlies most of South Australia, remains still under-explored — largely because so many potential targets are under thick sedimentary cover.
The South Australia Government has recently launched “ExploreSA: The Gawler Challenge” which has involved a call for geologists and companies to make new discoveries in the craton.
SA targeting different geology and commodities
The government is opening up the resources of the Geological Survey of South Australia — historical records, primary data and research in its quest to find the next Olympic Dam and Carrapateena.
While South Australian mining is dominated by Olympic Dam owned by BHP (ASX: BHP) and Prominent Hill, Carrapateena — another OZ minerals copper-gold project 160km north of Port Augusta — that produced its first concentrate late last year. But, the government believes there are other deposit styles and commodities to be identified.
South Australia’s Department for Mining and Energy has also released 21 mineral exploration areas, a third of which are within the Gawler Craton region.
South Australia has been a leader in putting the government’s shoulder behind the exploration sector, with a long history of financial backing to the industry.
(In fact, as far back as 1933 the South Australian Government chartered an aircraft to take prospectors to work over a group of old gold mines around Tarcoola.)
Since the discovery of Prominent Hill, exploration technology has advanced considerably, an important factor when so much of the Gawler Craton is under cover.
But, for all pegging following Minotaur’s big discovery, the impetus did fade — as it did with the graphite “boom”.
Juniors gearing up efforts across the Craton
There is an increasing number of exploration announcements coming out of the ASX that include the words “Gawler Craton”.
Earlier this week, Renascor Resources (ASX: RNU) announced it has expanded its Carnding gold project in the central craton by acquiring a tenement that includes a large magnetic anomaly north of the Soyuz prospect, that latter prospect having returned 7m at 5.14g/t gold from 26m to end of hole, and 6m at 4.94g/t gold under previous ownership.
It should be noted that Renascor is sticking by graphite, stressing in its announcements that it “remains focused” on its Siviour project in the Eyre Peninsula.
One of the newer players is Indiana Resources (ASX: IDA) which this month acquired 14 contiguous exploration licences and one mining licence in the central Gawler Craton – the land area totalling 2,660sq km. Historical drilling results include 12m at 10.36g/t gold and 34m at 1.18g/t gold.
There is also a private player in the mix. Barton Gold owns the mothballed Tarcoola mine and the 588,000oz Tunkillia resource along the Challenger gold deposit. Barton Gold is expected to list on the ASX next year.
Latitude exercises option over Skye gold project
Cashed up gold project hunter Latitude Consolidated (ASX: LCD) last week exercised an option over the Skye project Gawler Craton.
Skye was drilled in 2008 by Tasman Resources (ASX: TAS) when a limited work program identified several areas of bedrock mineralisation. Latitude says the Skye ground, located north of Tarcoola, is an excellent exploration address with multiple greenfield targets close to several large-scale gold systems in “a proven million-ounce gold terrain”.
Skye is located close to the Aurora Tank Goshawk Zone discovery and the Golf Bore deposit which is within 2km of the boundary with Latitude’s new ground.
Aurora Tank, owned by Marmota (ASX: MEU), earlier this year returned what that company describes as “outstanding high-grade” intersections, including 1m at 74g/t gold from 64m below surface.
Marmota as also been bidding to acquire the Jumbuck gold deposit in the craton, the deposit now owned by Tyranna Resources (ASX: TYX).
Uranium also being revived
Alligator Energy (ASX: AGE) has just completed its acquisition of a uranium resource in South Australia holding 46.6 million pounds of uranium oxide that has languished since its 2007 discovery.
The company will issue 679.6 million shares to privately owned Samphire Uranium to acquire the Blackbush and Plumbush resources, with Samphire’s owners ending up with 32% of the expanded capital of Alligator Energy.
Samphire was previously owned by UraniumSA, the former listed company that discovered Blackbush along with the Plumbush uranium deposit in 2007.
Going after the traditional (for South Australia) iron oxide copper gold deposit is Taruga Minerals (ASX: TAR).
It has a 12-month option over the Flinders project, which is located on the eastern edge of the Gawler Craton region and — the company says — is in a similar structural setting to the nearby Olympic Dam, Carrapateena and Prominent Hill mines.
While mapping and sampling has been done at surface, the main target is covered by several hundred metres of sedimentary cover.
Copper mining has been conducted within the project area between 1863 and 1909, and iron oxide was mined there in the 1980s.
South Australia produces 68% of Australia’s copper output and Richard Shodde of MinEx Consulting has remarked that the success rate for copper exploration in South Australia is twice the world average.