By Dr Geoffrey Batt, Minerals Research Institute of Western Australia
A police officer walking the beat on a dark night sees a man down on his hands and knees searching for something under a streetlight.
‘Excuse me sir,’ he says – helpful servant of the public that he is – ‘what seems to be the problem?’
‘Hello oshi … offi … officer,’ replies the man – obviously a little the worse for a night of drinking, ‘I … I appear to have lost my keys.’
The kind-hearted police officer lends a hand, and the two spend a few minutes scouring the ground to no effect, before the police officer asks, ‘Are you sure this is where you lost them?’
‘No, no, no,’ replies the man. ‘Didn’t lost them here officer – I lost them across the road.’
‘Then why are you looking here?’
‘The light’s better.’
Ba-dum-tss, as my daughter likes to say – the classic cabaret drum-and-cymbals punctuation to an obvious punchline.
Forms of this particular parable, though – variously termed ‘the streetlight effect’ or ‘the drunkard’s search’ – have been codified in social science theory since at least the 1960s, pointing to some useful philosophical bones beneath its vaudevillian exterior.
The crux of the tale here is to illustrate the logical trap of focusing our investigative effort in the areas where it is easiest to make observations, rather than in those that hold the greatest potential for discovery. This holds particular relevance for the business of mineral exploration as the national discussion in Australia turns to how to find the resource wealth that will sustain the country through the 21st century and beyond.
To quote Andrew Bailey, CEO of the MinEx Cooperative Research Centre: ‘Only 30 per cent of the Australian continent has been explored for mineral resources. The remaining 70 per cent is hidden beneath layers of sediment that have long-hindered discovery. These concealed regions may hold the key to the next generation of mineral discoveries – including those critical to our transition to a low-carbon economy.’
Bailey’s research centre is working to address this challenge by illuminating these hidden spaces beneath the vast and trackless sands of our national interior. Supported by more than $220 million in industry and government backing, the centre is eight years into its 10-year mission, uniting top minerals research organisations and thought leaders across Australia to pioneer innovative drilling and sensing technologies.
Thought leaders include Professor Brett Harris at Curtin University in Perth. Working as part of the dynamic MinEx research community, Harris and his team have created a robust new sensor to measure the electromagnetic (EM) properties of rock. Different minerals – the quartz of a sandstone, veins or layers of sulphide minerals, or the magnetite in a halo of geochemical alteration surrounding an ancient intrusion – respond differently to the presence of an electric current. Deployed behind a drill head actively cutting through the cover rock, Harris’s sensor can penetrate the darkness of its surroundings and detect these changes in physical properties to understand the nature of the encompassing geology. Even more significantly, by rapidly cycling through measurements at different frequencies, this tool can recognise whether the changes it detects in rock properties are nearby (high frequencies) or further away (lower frequencies).
With Harris’s new EM sensor, a geologist can literally see into the surrounding rocks and make important decisions while the drill is still turning.
Consider the kind of sliding doors opportunity this capacity offers.
Lying 500 metres below Western Australia’s Paterson Province, the Havieron gold-copper deposit was discovered by Greatland Resources (then Greatland Gold) in 2019. Currently in development, and with first production anticipated in the 2027–28 financial year, Havieron has a total contained mineral resource estimated at seven million ounces of gold and 275,000 tonnes of copper1. It’s a big beast: around $48.9 billion in metal value at current prices.
Here’s the thing, though: back between 1991 and 2003, (long before that happy discovery story) the target that was to become Havieron was drilled by the exploration team at Newcrest – former owners and operators of the nearby Telfer mine, where Havieron’s rich gold and copper bounty will now be processed over at least the next 20 years. And I don’t just mean they were interested in the general region and put a few holes down nearby. Newcrest’s geologists had identified the distinct magnetic anomaly that (had they but known) marks out Havieron’s riches, deployed an exploration drill rig directly over the high-grade heart of the deposit, and the very first hole was directly on track to intercept the motherlode. But they stopped 40 metres short, pulled up the drill and moved on.
Viewed through the lens of hindsight, we might see this as a missed opportunity – but in exploration terms, it’s hard to fault the contemporary decision-making. Five-hundred metres is deep for an economic discovery, even today – and was much more so in the 1990s – and the Newcrest team made a logical call with the technology and economic constraints of the times. Probing beneath the surface for hidden mineralisation, the fundamental process of mineral exploration, then as now, essentially consists of pouring money into holes in the ground – albeit in the refined forms of employee wages, equipment hire, consumable resources and the other costs of exploration. Successful exploration companies – of which there are many in Australia – continually walk the line of managing this workflow to turn up paydirt before their resources run out.
But what if in the final metres of that hole (and the others they subsequently drilled), the Newcrest team could have seen a changing signal showing they were approaching a mineralised mass? In the exploration game, knowledge is power, and time is money. And maybe if we re-create the exploration program with that extra awareness and ability to respond in real time while the drill is still in the ground, a different decision is made and Havieron’s riches are discovered 30 years earlier.
Maybe it isn’t more streetlights that we need to invest in to expand our search for Australia’s next generation of mineral deposits. Maybe the work of Harris, Bailey and their colleagues at the MinEx Cooperative Research Centre can help us see in the dark instead.
1 Havieron Mineral Resource Estimate Update, published 21 December 2023,
www.londonstockexchange.com/news-article/GGP/havieron-mineral-resource-estimate-update/16261474.
About the author
Dr Geoffrey Batt is a Research Portfolio Manager at the Minerals Research Institute of Western Australia, a state government body working to catalyse and support impactful minerals research for the benefit of Western Australia. Batt leads the institute’s focus on exploration amplification, working with leading scientists and research groups to address the challenges and opportunities facing the future of the mineral exploration industry.
