Peering beneath the surface: how Geoscience Australia is using big data and AI to help explorers find what the eye — and drill — can’t see
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Explorers operating in Australia's greenfield and undercover regions face a common challenge: how to make confident decisions when the surface reveals so little. For decades, Geoscience Australia has worked to overcome this hurdle by building public geoscience datasets, tools and collaborations that turn the invisible into something visible, or at least inferable.
In a recent interview with The Rock Wrangler, Dr Geoff Fraser, Director of Geochronology and Stratigraphy, and Philip Main, Geochemical Data Analyst, explained how Geoscience Australia is using analytical innovation, national data coverage and new technologies like machine learning to help exploration professionals prioritise targets, reduce risk, and make sense of what lies beneath the regolith.
"We're fortunate to have such a wide range of independent geoscience datasets," Dr Fraser explained. "From geophysics and geological mapping to isotopic data and regional geochemistry, the strength lies in integrating these layers. It allows us to see patterns and trends at the national scale that just aren't obvious at smaller, project-level resolutions."
For explorers in search of the next big find, Geoscience Australia's role is to provide what Dr Fraser calls "pre-competitive science" — data that is freely available, accessible, and structured in a way that enables companies to build their own project-specific knowledge on top of it.
Setting the Baseline
Mr Main works closely with Geoscience Australia's surface geochemistry datasets, which span both regional and national scales. These are particularly helpful in areas with little historical data or outcrop exposure. "Our datasets act as the foundation that companies can build on," Mr Main said. "We typically use low-density, regional sampling approaches, but we throw a lot at each sample: multi-element geochemistry, weak acid digests, whole rock analysis, trace elements."
The rationale is simple: by analysing a full suite of elements, the datasets remain relevant not just for today’s commodity priorities but also for the materials of tomorrow. As Mr Main noted, "In Northern Australia, our geochemistry initially supported copper-gold exploration. But rare earth element data embedded in the same datasets led to tenement applications for entirely different mineral systems."
Bridging the Surface and the Subsurface
Geoscience Australia's datasets are most valuable when used in tandem with company-collected data. As Mr Main put it, "Everything we do is documented: sample preparation, methodologies, QA/QC procedures. Companies can see exactly what's been done, and either build upon it or plan their sampling programs accordingly."
A key component of Geoscience Australia's collaborative approach is its work with hyperspectral mineralogy and the HyLogger® platform, originally developed by CSIRO. Geoscience Australia doesn't own a HyLogger itself, but it has access to spectral data through the National Virtual Core Library and works closely with state surveys that operate these systems.
"We're helping enhance the spectral libraries used to interpret that data," said Dr Fraser. "For instance, Geoscience Australia's mineral specimen collection contributes to the calibration process. That means better identification and classification of minerals in unknown samples."
More recently, Geoscience Australia has been involved in semi-automated drill core logging using spectral mineralogy, reducing subjectivity and speeding up core analysis. "It standardises core logging, which is especially important when you're operating across jurisdictions or working with different field teams," Dr Fraser added.
Mapping Alteration, Modelling Prospects
Spectral data has also proven valuable for mapping alteration systems at regional scales. Geoscience Australia has supported research into tools like LithoBound, developed at UNSW in partnership with the MinEx CRC, which uses hyperspectral logging to define mineralogical and lithological boundaries in stratigraphic drilling cores.
"It helps you vector towards the core of the mineral system," Dr Fraser said. "By comparing proximal and distal alteration signatures, explorers can better understand where they are in the system and where they might go next."
This feeds directly into one of Geoscience Australia’s core mandates: helping companies find value under deep cover, where traditional surface geochemistry often fails.
Seeing Through the Cover
"One of the big challenges with deep regolith cover is that mineral systems can become geochemically blind," said Mr Main. "There's no signal, or at least not one you can easily interpret."
To combat this, Geoscience Australia has employed techniques such as mobile metal ion (MMI) analysis and hydrogeochemistry. MMI detects trace metals that migrate upward through groundwater, while hydrogeochemistry collects and analyses borehole water to look for anomalies that might suggest hidden mineralisation.
Mr Main also highlighted the recent release of Geoscience Australia’s Heavy Mineral Map of Australia — a first-of-its-kind national dataset that provides insight into the dispersion of heavy minerals across landscapes. "It adds another layer of evidence for explorers to tap into, especially in data-poor regions," he said.
On a larger scale, Geoscience Australia combines datasets to direct stratigraphic drilling programs in frontier regions. One major example is the work conducted between Tennant Creek and Mount Isa in the Northern Territory.
"We did the geophysics first, then drilled to collect physical rock samples," Dr Fraser explained. "What we found east of Tennant Creek was strikingly similar to the rocks in Tennant Creek itself — same event histories, same alterations. That gave companies the confidence to peg ground and start exploring in a region with no previous activity."
Tools for Technical and Economic Decision-Making
Geoscience Australia's Economic Fairways Tool complements this technical data by adding commercial context. The tool lets users model a discovery scenario based on commodity price, deposit depth, infrastructure access, and transport costs.
"It helps companies or policymakers ask, 'If I find a deposit here, is it actually viable?'" said Dr Fraser. "It’s not just about geology anymore. You need to model whether a discovery is economically sensible."
Pathfinder Elements and Isotopic Fingerprints
While Geoscience Australia does not develop ultra-trace detection techniques per se, its datasets often contain the level of detail needed for Pathfinder element applications.
"Most of our datasets operate at low ppm to ppb levels," Mr Main explained. "That’s enough for others to use in Pathfinder-style modelling. We released a reanalysed legacy dataset of stream sediment samples that researchers have since used to vector toward possible mineral systems."
Dr Fraser added that isotope studies remain a significant part of Geoscience Australia's work. "Our long-running geochronology program, using uranium-lead dating, has created a vast archive of known-age samples. We now apply additional isotopic systems like lutetium-hafnium and lead-lead to those same rocks."
This enables Geoscience Australia to map crustal evolution and boundaries—key structural controls on mineralisation. "The neodymium map of Australia is a great example. It shows the age of the crust, and gradients in that map often correspond to major mineral provinces," said Dr Fraser.
Future Focus: AI, Drones, and Critical Minerals
Looking forward, Geoscience Australia sees increasing value in applying machine learning to integrate datasets and predict mineralisation in unsampled areas.
"We can’t sample the whole country at high density," said Mr Main. "So we use machine learning with geochemistry, geophysics, satellite data and climate variables to predict concentrations across unsampled terrain."
This also helps guide smarter sampling strategies. "We use AI to identify sample sites that maximise data variability, which strengthens future models," he added.
The team is also interested in deploying drones with LiDAR and spectral sensors to capture localised features at sample sites. These could provide high-resolution context to complement geochemical datasets.
As for what lies beyond the horizon, Dr Fraser said, "Ten years ago, no one predicted high-purity quartz would become a priority. But now we’re working with the Australian Critical Minerals Research and Development Hub to release new datasets on quartz, rare earths and critical mineral by-products from major deposits. We have to stay ready for the next commodity trend."
Their strategy? Keep collecting full-suite data so it remains relevant, no matter what the future holds.
"The data we're generating today may end up being used in ways we can't yet imagine," Dr Fraser said. "That's why we're committed to making it as comprehensive, accessible and useful as possible."
For explorers looking to navigate uncertainty and map the subsurface with confidence, Geoscience Australia continues to offer something unique: tools to see the unseen, and the expertise to make sense of it.
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