This article is a sponsored feature from Mining.com.au partner Petratherm Limited. It is not financial advice. Talk to a registered financial expert before making investment decisions.
A surprise find in the Gawler Craton of South Australia has generated some serious interest in one junior explorer.
The Gawler Craton is one of the largest and oldest geological provinces in the state, spanning 440,000km2 in central South Australia.
It is very well known for major deposits like BHP’s (ASX:BHP) Olympic Dam operation – one of the world’s largest deposits of copper, gold and uranium. But it is not as well recognised for its titanium resources.
Peter Reid, CEO of Petratherm (ASX:PTR), tells Mining.com.au that the company was doing some work to the northeast of its Muckanippie Project area, where it identified a “lot of rare earths” hosted in clay that were associated with the weathering of a particular type of layered intrusion.
“So we started to build a ground position over the Muckanippie area, where the main intrusions occur – which is called the Muckanippie anorthosite, and we could see straight away with this really interesting layered intrusion that there was elevated titanium in several areas,” he says.
Historical drilling undertaken in the late 90s returned thick intercepts of magnetite mineralisation accompanied by titanium grading between 5% and 10%.
A review of the drill core prompted the Petratherm team to expand its search to see if there were higher grades elsewhere, which resulted in the discovery of titanium grades of up to 20% in fresh rock below the surface rocks, and surface samples grading as high as 50% over a 9km trend.
“When we hit the ground with our boots and did some old-fashioned mapping, we actually found we had a bit of luck in that there was actually a younger shoreline sequence deposited on top of these old rocks,” Reid explains.
“An ancient beach was preserved from the inland sea and those surrounding rocks, which were rich in titanium, had broken down and the titanium minerals were washed down ancient streams and concentrated in those beach sands.
“So we found a secondary deposit on top of the high titanium source rock.”
The Muckanippie intrusion has been largely unexplored because it is partially masked by a thin layer of cover material above the layered geological sequence.
Gawler Craton’s hidden critical cache
Reid says the Muckanippie anorthosite intrusion is the first of its type to be uncovered in the Gawler Craton region.
“I think it’s going to be quite unique and this is potentially a world-class discovery,” he says. “We’ve drilled an area now covering 15km2 and every hole was mineralised with really high concentrations, particularly in our Rosewood East area.”
In the Rosewood East area is a zone most likely representing the main shoreline which currently measures 2km wide by 3.6km long and remains open along trend. This zone, averages more than 10% heavy minerals over at least 10m of thickness starting close to the surface.
Of the 10% heavy minerals, 95% are “valuable heavy minerals”, according to Reid.
“Often with a heavy mineral deposit, maybe 50% or 60% is valuable and the rest is gangue and waste,” Reid tells this news service.
“Of our heavy minerals, 95% are valuable, and what is also a bit unique about these heavy mineral sands is that they are purely titanium-bearing minerals.”
Petratherm’s heavy minerals make-up comprises high titanium grade minerals, leucoxene and rutile product. The rutile product has a titanium content around 90% to 95%.
The remaining ore is dominantly a leucoxene ore, which averages about 70% to 75% titanium.
Prior to Petratherm announcing the metallurgical results from the Rosewood Prospect in November 2024, its share price was trading as low as $0.02 giving it a market capitalisation of about $5 million.
The company now trades at about $0.29 and has a market capitalisation of over $100 million.
“So that gives you an idea of the impact that Muckanippie has had,” Reid notes.
“We’ve recently raised $8.1 million, so we’re well financed to do the next round of work there.”
The Muckanippie Project has similar geology and metal associations to the globally significant Bushveld Complex in South Africa – the world’s largest layered mafic intrusion containing vast resources of platinum group metals, chromium, vanadium, and other minerals.
The project also demonstrates similarities to other large intrusions around the world in places like Canada and Norway, including Rio Tinto’s (ASX:RIO) Lac Tio operation in Québec which has been mined for over 70 years.
“So it is known globally that these layered anorthosite complexes are often a host of titanium mineralisation,” Reid says.
Muckanippie has also shown the presence of vanadium and platinum group metals.
“In the basement rock below we have zones which are deeply weathered, maybe down to 50m or 60m from the surface,” Reid explains.
“They are essentially clay and they have high ilmenite mineralisation too, ranging up to 20-30% ilmenite over tens of metres, and that has quite high vanadium. So we think that there’s potentially a commercial operation there as well.”
Heavy minerals, light touch mining
Another advantage of the Muckanippie Project is its low-cost, free dig nature.
No blasting is required and it can be dug up with a bulldozer, with mineralisation starting from near surface typically at 5m to 6m and ore thickness ranging from 5m to 30m. The heavy minerals can then be concentrated using just water and gravity separating.
Petratherm estimates it can drill one hole in about half an hour at a cost of $1,500 per hole.
“So we can drill out this resource really quickly and cheaply,” Reid says.
Petratherm has defined an exploration target for the Rosewood Prospect of 237 to 377 million tonnes @ 5.3% to 7.9% titanium dioxide and aims to start drilling work on delivering a maiden resource later this year.
The exploration target represents just 10% of the total interpreted prospective heavy mineral sands area.
After drilling returned the best results so far at Rosewood in May this year, Petratherm sent a 1-tonne bulk sample off for testing to determine how easily the heavy minerals can be separated to process into individual products.
Reid says the company should have its first 100-kilogram product in the next couple of months.
“We can then go to potential consumers to see what it’s worth,” he says. “So I think that’ll go a long way to de-risking the project once we understand how easy it is to separate and we know what our final products are.”
Titanium is listed as a critical mineral by major economies, including Australia, the US, European Union, Japan, India and South Korea.
While about 90% of titanium product is sold as titanium dioxide to bring the bright, white look to paint, plastic, paper and fibre, it is also in increasing demand for its lightweight but strengthening properties.
Titanium has a high strength to weight ratio that is 45% lighter than steel but is three to five times stronger than stainless steel. This makes it ideal for use in aeronautics, medical implants, defence, sporting goods and high-tech componentry.
In 2022, the titanium market was worth US$28.6 billion ($44 billion) and by 2030 is projected to reach US$52 billion.
Results from 63 remaining holes drilled in a phase-two program at Rosewood are expected this month.
Phase-three drilling will get underway late June to test further extensions of the Rosewood mineralisation and collect more bulk samples for metallurgical testing.
Write to Angela East at Mining.com.au
Images: Mining.com.au & Petratherm
