Traditional Owners have halted a heritage survey on Rio Tinto's Brockman Syncline project in the Pilbara after blasting impacted an Indigenous rock shelter.
The Muntulgura Guruma people, represented by the Wintawari Guruma Aboriginal Corporation, had previously warned the global miner the rock shelter - somewhere between 40,000 and 50,000 years old - was an important area that required protection.
Rio Tinto was conducting blasting 150m from the sacred site on August 6 and later discovered from images taken before and after the blast that a large rock and scrub tree had fallen from an overhang above the cave entrance.
The company and representatives of the Muntulgura Guruma people last weekend conducted a visit to the Nammuldi iron ore site - 60km north-west of Tom Price - to inspect the impact of the blast.
The WGAC said any impact on ancient sites of cultural significance are unwelcome, with 87 rock shelter sites subject to blast management.
"Regrettably, it seems as though Rio's blast management plan has failed on this occasion, leaving the Muntulgura Guruma People to pick up the pieces," it said in a statement.
Rio Tinto, who National Indigenous Times has contacted for comment, had earlier reported the blasting led to the fall of a Pilbara scrub tree and one square metre of rock from the overhang of a rock shelter the Muntulgura Guruma people had once inhabited.
The incident occurred three years after Rio Tinto was globally condemned for its destruction of ancient rock shelters at Juukan Gorge in the same region, which had showed evidence of human habitation stretching back 46,000 years.
Rio Tinto said it had taken steps to inform appropriate parties and had reformed its practices since Juukan.
This was the first time in more than 1,800 blasts it had detected such a disturbance, said the company, which operates 17 mines in the Pilbara region.
"In August 2023, as part of our cultural heritage monitoring and management processes, we identified the fall of a Pilbara scrub tree and a one square metre rock from the overhang of a rock shelter in an area adjacent to the Nammuldi mine site in Western Australia," Rio Tinto said in a statement.
"As soon as we identified this, we paused nearby blasting work which was occurring 150 metres away, and notified the Traditional Owners of the land.
"On 8 October, representatives from the Muntulgura Guruma people and Rio Tinto visited the rock shelter together. Assessments found no structural damage to the rock shelter itself, and no damage to cultural materials.
"We deeply respect the Muntulgura Guruma people and have apologised for this incident. We will continue to work closely together to better understand what has happened."
After the blast, the WGAC expressed concern at how the incident was reported in the media.
"The WGAC board is deeply disappointed and concerned with the media reports about impacts to a heritage site in the Hamersley Ranges on Muntulgura Guruma country," it said on September 27.
"WGAC is working to independently establish the scale of the damage and will report back to members at the earliest opportunity."
Rio's destruction of rock shelters at Juukan Gorge in 2020 prompted the departure of top executives and a parliamentary inquiry, which recommended an overhaul of Aboriginal heritage protection laws across Australia.
WA introduced a new Aboriginal Cultural Heritage Act on July 1, but it was met with a chorus of criticism over its complexity and consultation shortfalls, forcing the state government to amend them five weeks later.
The latest incident at the Rio site in WA's north and controversy over the state's heritage legislation comes amid fading support for Saturday's referendum on a Voice to Parliament. A yes vote would recognise Indigenous people in Australia's constitution and set up a First Nations body to advise the federal government on issues that impact Aboriginal people.
