The new plan was unveiled two weeks ago by Geoscience Australia’s chief executive officer, Dr Chris Pigram, in a presentation to the Australian National Conference on Resources and Energy in Canberra.
Under the new national strategy, GA and the state and Northern Territory geological surveys will apply new computer modelling and drilling technologies to produce pre-competitive data of unprecedented detail and coverage.
Dr Pigram told MiningNewsPremium that GA was seeking to counter the perception that Australia is a mature exploration destination.
“The way we’re going about that is to demonstrate that a lot of the major provinces that have been thoroughly worked over do extend under cover. So areas like the Tropicana area belt in the eastern Yilgarn and east of Mt Isa are quite large extensions of these provinces that have not been explored properly because they have barren rock on top of them.”
He said the new strategy aimed to produce what was effectively a prospectus of Australia’s natural mineral endowment.
“It’s exactly the same as if you were selling off Telstra, when the government spent many millions putting a prospectus together to convince investors of the value proposition.
“And that’s essentially what we are doing with the state and territory surveys. We’re attempting to put that prospectus together, which will get investors sufficiently excited to put their money on the table.”
The new greenfields strategy will “roll back the carpet” over the 80% of Australia that is under cover, particularly those areas adjacent to mineral provinces.
While there’s nothing new about targeting these areas for pre-competitive surveys, the new plan will see more drilling by government and innovative use of technologies.
“The thing that will be novel and different is build the model and then actually drill targeted sites to obtain samples to do age dating and geochemistry. And part of the trick in this will be is the understanding of pathfinders. We will be working with the CSIRO on that. It’s basically bringing all of the technologies together and applying it in this integrated and comprehensive way to effectively roll that carpet back,” Dr Pigram said.
One of the foundations of the new approach is the use of data-intensive geophysical inversions to build computer models over entire regions.
Inversion is a relatively new technique for producing 3D models of the subsurface by integrating the results of multiple geophysical surveys, such as gravity, magnetic, electromagnetic and magnetotelluric.
Geophysical researchers are developing more sophisticated modelling techniques and can now access cloud computing to process volumes of data that rival those used in the petroleum exploration industry.
“If we can do the geophysical inversions with high-performance computing, and turn out geological models which we can then go out and test with drilling, and if we got hold of samples and then throw every sophisticated laboratory technique we have at it, we can build geological models that are well founded as opposed to the ones at the moment that are essentially speculative,” he said.
“Effectively, what we would do through that process is strip the cover off and produce a map of the geological basement which would allow companies to make much more sophisticated targeting decisions and would remove a lot of the risk in this business.”
Dr Pigram said the use of inversion on the scale proposed would be world leading.
“No one else is doing anything like this,” he said.
He said many of the methodologies were developed for mine site activities, but GA and the state and Northern Territory surveys would be applying them on a regional scale.
“Historically, we have degraded data so we can manage it on desktop computing or a small distributed network. What we can do now is do it at full resolution and we can look at an entire area.
“We can look at the entire southern Mt Isa province in one go, and that’s fundamentally important because all of the information influences your understanding when you are inverting.
“So rather than doing it on a 1 km block, we can do it on 100km at much better resolution. Out of all that we effectively get a basement map that we can then test.”
Another foundation of the new greenfields strategy is the use of new drilling technologies under development by the Federal Government’s Deep Exploration Technologies Cooperative Research Centre (DET CRC), based in Adelaide.
DET CRC is developing a coiled tube drilling rig, similar that that used in coal seam gas but capable of drilling through hard rocks. The project is targeting a drilling cost of $50 per metre, which would revolutionise the use of drilling to scout for mineralisation under cover.
DET CRC is also working on downhole sensors that are built into the drill string to provide real-time feedback. This information could be used by the drill operator to change direction towards the location of mineralisation or its alteration halo.
Dr Pigram said the new greenfield strategy had been agreed between GA, and the state and Northern Territory geological surveys.
“The strategic focus for all of us is to get those exploration bucks back in the country and find our next generation of world-class deposits.”
The greenfields strategy was endorsed in June by the Standing Council on Energy and Resources, which is chaired by Federal Minister for Resources and Energy, Martin Ferguson, and comprised of the resource ministers for each of the states and territories.
Dr Pigram said ministerial sign-off on the strategy gave authority for all the states and the Northern Territory to get underway, but the level of activity would be determined by the availability of funds and the timing of new drilling technology.
“Western Australia is able to give very good support through their Exploration Incentive Scheme, which is part of Royalties for Regions. We are going to work with them to pilot some of the methodology. There’s also strong support in South Australia.”
He said WA would fund some of the drilling and “we will bring to bear all our laboratory capabilities and our modelling capabilities in partnership. So I think we will get to see that in action next winter.”
Dr Pigram said the states and the Northern Territory were at different phases of their funding.
“We are in a down phase at the moment, but we hope to do something about that. We will partner with the states and territories as we begin to roll this out.
“We can very much draw on our recent initiative around the Onshore Energy Security Program, where we gathered a lot of data and we have yet to fully realise its potential.
“We can apply these new techniques to that as part of the initial targeting. So we will look at provinces like the Eucla, Murchison, Paterson, southern Mt Isa — there’s a whole host of places where we can already go and apply this methodology.”
Pre-competitive data has recently led to some significant discoveries by mineral explorers, including Kentor Gold’s Jervois project in the Northern Territory and the discovery of a copper gossan by Mithril Resources east of Alice Springs.
GA and the state and Northern Territory surveys will hope this is just the start of a new wave of discoveries over the next few years. With luck, it might include some world-class discoveries and make Australia a global hotspot for base metal exploration once again.
This article first appeared in ILN's sister publication MiningNews.net.