Pilbara rock shelter at Rio Tinto mine site at least 50,000 years old

Stone tools in a rock shelter at one of Rio Tinto’s Pilbara iron ore mines have proved that Aboriginal people lived through the height of the ice age.

The Juukan Gorge has one of the earliest known sights occupied by Aboriginal people in Australia. Picture: PKKP Aboriginal Corporation

Stone tools in a rock shelter at one of Rio Tinto’s iron ore mines have provided the first proof that Aboriginal people lived through the height of the ice age on the edge of what is now Pilbara desert.

A recent excavation of the Yirra rock shelter at Channar mine near the town of Paraburdoo has established human occupation dating back at least 50,000 years. Scientists consider this remarkable and Yirra is now one of the oldest sites yet found in Australia.

The cave could have been destroyed in 2000 when Rio Tinto received permission to blast it under the state’s old Aboriginal heritage laws.

However, the miner committed not to do this in talks with the Yinhawangka people at the time. When the site was excavated for the first time, radiocarbon dating techniques were able to establish that people lived there 23,000 years ago.

Scientists knew the site was older but available testing techniques could not prove it.

The latest excavation of Yirra was more extensive and examined dirt around artefacts grain by grain.

Working with the Yinhawangka people on the latest excavation, consultants and researchers from the University of Western Australia found tools, charcoal and bone in sediment that was then sent to Wollongong University for analysis. There, a technique called optical stimulated luminescence established how long since sunlight last touched the quartz in the dirt in which the artefacts were found. The archaeological team believes that 50,000 years is a conservative result. Further work will establish if some of the artefacts are even older.

Rio Tinto Group operations in the Pilbara. Picture: Ian Waldie/Bloomberg via Getty Images

The project was led by Yinhawangka Aboriginal Corporation and funded by Rio Tinto. It is the first time the miner has taken part in a heritage excavation in the Pilbara that is not linked to mining plans. This is one of a range of responses by Rio Tinto to the Juukan Gorge tragedy in 2020, when the London-based company blew up the ancient Juukan Gorge rock shelters and sparked international furore.

Yinhawangka chairman Halloway Smirke said Yirra had great significance not only to his people but to the wider desert and coastal families.

“We hope that Yirra will help us tell our ancestral story to Australia and our future generations. We would still be visiting this site if it wasn’t for the mining leases,” he said.

“All Pilbara groups should have this kind of science work done on cultural sites. Important sites like Yirraneed to be protected, especially when they turn out to be amongst the oldest known places of human habitation in Australia.”

Rio Tinto Iron Ore chief executive Simon Trott described the discoveries at Yirra as a wonderful outcome for the Yinhawangka people. The miner would fund further cultural research and archaeological excavations with other traditional owners, he said.

“We acknowledge the significance of Yirraand are committed to working in partnership with the Yinhawangka people to ensure it’s preserved for future generations,” he said.