The world’s largest mineral exploration collaboration is challenging perceptions of Australia as a mature destination with few opportunities for discoveries. TONY HESELEV reports

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A multi-disciplinary team of researchers from across the country aims to unlock mineral wealth in Australia. They are linking innovative, cost-effective drilling technologies and sophisticated, real-time data collection, with a better understanding of the mineral systems in target areas under deep rock cover.

Officially launched in late-2018, the $218 million MinEx Cooperative Research Centre (CRC) brings together CSIRO, Geoscience Australia, six universities, all state and territory geological surveys, industry and government.

MinEx CRC will tackle the industry's main challenge – the decline in the discovery of major new mineral deposits that are required to deliver a pipeline of mineral resource projects.

Its work to improve the effectiveness of drilling, while at the same time collecting data, will drive down the time and cost of mineral discovery and deposit "drill-outs" and bring forward production.

New talent and new technology for new mineral discoveries

MinEx CRC will also support about 50 PhD researchers and establish a vocational education and training program focused on new technologies in minerals exploration.

The CRC will begin work early in 2019 and run for 10 years. It will build up a picture of the geological framework of Australia to enable explorers to more accurately target mineral deposits. This work is a key part of the national drilling initiative (NDI), the third of the CRC’s three major research programs.

Research and development trialled and tested through to commercialisation in the first two programs, drilling technologies and data from drilling, will be available for use by the NDI and by explorers.

The key to the NDI will be solving the puzzle, piece by piece, of what lies under our feet in Australia. An estimated 70 to 80 per cent of the country’s land surface has transported cover which challenges exploration for potential underlying mineralisation.

"Australia may have a reputation as a well-explored, mature exploration destination, however large covered parts of the country are under-explored and poorly understood," acting MinEx CRC program coordinator from Geoscience Australia, Angela O'Rourke, says.

"There is great potential for significant discoveries in these areas."

Exploring regions under cover

"We really haven’t explored the regions that are under cover in Australia at all, and if we can access that ground, it will drive a revolution in minerals exploration," MinEx CRC chief scientist, professor David Giles of the University of South Australia, says.

The state and territory geological surveys, working with Geoscience Australia, have identified case study areas for the NDI using pre-competitive geophysical datasets. These areas vary greatly. For example, New South Wales (NSW) has selected five or six areas that are in under-cover extensions of known as endowed mineral belts.

Western Australia (WA) has chosen to investigate areas within the covered terrain of the north-central region of the state along the Northern Territory (NT) and South Australian (SA) borders, referred to as "the Gap", with a particular focus on the Paterson Orogen and the west Arunta. South Australia has selected the Fowler-Flinders Corridor in the central-south of that state.

However, the NDI's first drilling area, selected by Geoscience Australia and the Queensland and Northern Territory geological surveys, is likely to extend from the central east of the NT into the Mt Isa Inlier in north-western Queensland, with drilling expected to begin in 2020.

Drilling down to depth to uncover geology

Ms O'Rourke says this first NDI case study area lies between the Tennant Creek gold-copper mineral province in the west and the Carpentaria zinc belt in the east.

"This area is hidden by younger cover and there has been limited prior exploration and drilling tests of the basement geology at depth.

"These are vast and remote areas where we know little about the covered geology.

"They haven't been very well explored in the past because drilling through thick sequences of cover to test the prospectivity of the basement rocks is risky and expensive."

The next wave of NDI drilling is likely to occur in WA and the Fowler- Flinders corridor in SA in 2021, and the extensions of the Cobar Province in NSW in 2022.

The Geological Survey of Victoria will also undertake a drilling program and will investigate areas of gold prospectivity highlighted by new geodynamic models that  have the potential to re-define the tectonic evolution and mineral prospectivity of southeast Australia.

Research to reduce investor risk

Geologist Yulia Uvarova, who is CSIRO’s acting exploration research director, says the NDI would reduce the risks for companies exploring in these areas.

Researchers would analyse multidimensional datasets, including regional geophysical datasets supplied by the geological surveys and Geoscience Australia, surface geochemistry, as well as any historic drillcores. They would do this before drilling holes in these areas to capture geochemical, petrophysical and seismic data and build up a better understanding of each mineral system.

Dr Uvarova says little knowledge existed of the sub-surface geology of these largely unexplored areas, and it was exciting to think that MinEx CRC's work could extract new geological information such as the age and alteration of rocks.

This information could provide clues to the mineral potential of the region, which could eventually lead to it being opened up for exploration.

Professor Giles says companies have traded off the risk and cost of the unknown – exploring under cover in Australia – with the sovereign risks of exploring in places such as Africa. Australia's share of global mineral exploration has slumped from about 25 per cent in the 1990s to about 12 per cent now.

To bring exploration expenditure back to Australia, and eventually deliver more discoveries, Professor Giles says drilling has to be more productive so that explorers get "more shots in the chamber". The technology also needs to be developed to a point where explorers received better information from the drillholes.

"We have to get down there quicker, cheaper, safer and with a smaller environmental footprint," professor Giles says.

"Companies have to know that they can go out there and get loads of samples and good value for money."

He says MinEx CRC would demonstrate how an integrated approach – combining agile, inexpensive drill rigs with the collection, analysis and interpretation of data using specialised software to obtain 3D geological models in realtime – would enable companies to make cost-effective exploration decisions.

Coiled drilling technology

Further development of coiled tubing drilling technology is a key focus of the CRC because it is more productive than conventional diamond drilling methods. Coiled tubing technology is estimated to be one-sixth the cost of conventional drilling, which means explorers can drill many more holes to obtain more samples and geological information for the same cost.

The technology eliminates manual handling, which is the root cause of most incidents at conventional drilling sites. It is also energy efficient, using less fuel and recycled water.

Ms O'Rourke says the NDI could completely change the perspective of mineral prospectivity of large swathes of Australia. It could lead to an increase in discovery rates to fill the pipeline of mineral resource developments that are required for a sustainable minerals industry and a strong economy in Australia, and bring development, income-earning opportunities and infrastructure to regional Australia.

"We just need a focused and collaborative effort to applying new technologies and ideas to these under-explored and poorly understood areas," Ms O'Rourke says.

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