CSIRO and Geoscience Australia are bringing together multi-disciplinary teams to build the nation’s world-leading science expertise and tools to predict where deep orebodies lie. DAVID SIMPSON reports.

Australia's competitive advantage in the global mining economy is changing. As readily accessible deposits are all either identified or in production, other countries are becoming increasingly attractive as lower cost exploration destinations for international mining companies. The challenge for Australia to overcome is how to find less-accessible deposits in a more cost-effective way.

A challenge of this scale requires collaboration from across the research sector, industry and government.

That's why the $218 million MinEX Collaborative Research Centre was launched in 2018, involving the mining services sector, major miners and research organisations including CSIRO, Geoscience Australia and universities (read more in Uncovering new frontiers).

Deep Earth Imaging Future Science Platform

A second key initiative focused on developing the scientific skills and expertise required, is the CSIRO-led $17 million Deep Earth Imaging Future Science Platform. It aims to develop world-leading geophysics skills, expertise and tools to predict where ore deposits lie in the deep earth.

Deep Earth Imaging is focused on four themes including data assimilation and value of information, advanced inverse methods, seismic imaging, and potential field and electromagnetic imaging. The research being undertaken through Deep Earth Imaging has the twin benefits of not only contributing to the challenge of 21st century exploration, but also helping to develop the next generation of Australian scientists.

Through Deep Earth Imaging, Geoscience Australia and CSIRO are working together to further understand the wealth of Australia’s geoscience data, so that more can be done with it than has traditionally been possible. They have also shared expertise, by embedding researchers within each other’s organisation on placements that strengthen collaboration and research outcomes.

Making predictions about where to find new deposits

Richard Chopping, a CSIRO computational geophysicist with more than 10 years’ experience in the government and research sectors, leads the team researching potential field and electromagnetic imaging.

Mr Chopping explains that his experience is in method development and application of geophysics to attract exploration investment, which fits in neatly with the work of Deep Earth Imaging.

"To reduce the risk, and therefore the cost, of new exploration, we need to go further underneath the surface and change our approach from the direct detection of deposits, to making predictions about where they might be."

"When an orebody is produced, a range of chemical and physical changes are made to the earth around it, that's how a mineral system expresses itself," Mr Chopping says.

"The idea is that by simulating how a mineral system is formed, you can make predictions about where you might expect to find new ones and what they might look like. We're part of the true science of hypothesis testing."

Mining existing data

For Deep Earth Imaging this involves taking existing data and using sophisticated analytical and processing techniques to extract more information from it.

"It's not what people generally refer to as data mining, which is too simplistic and one-dimensional," Mr Chopping says.

"Our initiative is about understanding how to look at data differently and interpret it differently.

"Rather than saying one piece of information tells us one thing and another piece of information tells us another, we look at both and ask: what explanation doesn't conflict with either of them? In this way we can create a more complete picture, often at a more granular level."

One of the data types the team are investigating is magnetotellurics – which is how current – created by natural phenomenon – flows through the Earth. For example, the solar wind interacting with the Earth's ambient magnetic field produces electrical currents within the Earth. This is the process that, when the current is strong enough, affects light in the atmosphere to create the southern and northern lights.

Another area tackled within Deep Earth Imaging is seismic data.

"We have a project, working with around 30 years of onshore and offshore seismic data, relating to the Lord Howe Rise. We're developing an understanding of how we can get more information out of it with new analytical techniques," Mr Chopping says.

Improving data resolution

He explains that scale is the significant difference between the work the team is doing and previous analysis done on the data.

"Previously, the data may have been examined at a regional level, so areas of potentially 100 by 100 kilometres, through to 150 by 250 kilometres.

"Now, we are targeting things much closer to the area in which a prospective miner might find a deposit – say 20 by 20 kilometres – an order of magnitude smaller.

"An example is an area in Queensland, north of Mount Isa. Geoscience Australia are tackling the chemistry and the expression at around the 200 kilometre scale, while we're looking at the expression at individual mines, down to a 10 by 10 kilometre scale.”

Looking at the commercial objectives of their work, Mr Chopping says that they were aiming to develop tools that either researchers or industry will use.

"To do this, we need to get results that demonstrate the use of our techniques.

"We're purposely trying to be quite general with our research to show there’s a broad application of the processes we’re developing and to encourage industry uptake in both pre-competitive and post-competitive scenarios."

Mineral, energy and groundwater resources

In global terms, CSIRO’s activities in the area are unique.

"There are other initiatives that are similar, but without the same broad focus.

"We don't just look at minerals, but also resources like energy and groundwater, where we’re trying to understand the use of mature analytic, statistics, and computer techniques."

When asked what the outcomes of Deep Earth Imaging's research were likely to be, Mr Chopping was optimistic.

"In an ideal world it would be fantastic if we could deliver results that were immediately applicable to industry in a particular location.

"But for now, we want to publish research that the industry will take up and use the findings to explore and develop new orebodies.

"On the other hand, the outcome may be a situation where we look more broadly at what we’ve learned, elements of our research that fold more broadly into CSIRO, who use it to collaborate with industry participants."

"Hopefully, it's a bit of both, because we are only a small part of a much bigger picture at CSIRO and that delivers benefits for everyone."

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