WA site blast puts other miners on notice

The Western Australian premier says Rio Tinto's destruction of ancient sites in the state's north should serve as a warning to other mining companies.

Rio has faced significant fallout from its destruction of the Juukan Gorge rock shelters on Puutu Kunti Kurrama and Pinikura (PKKP) country in WA's Pilbara region earlier this year.

Chief executive Jean-Sebastien Jacques told a Senate inquiry on Friday the company had decided to proceed with blasting the 46,000-year-old sites so it could extract an additional $US135 million ($A188 million) worth of high-grade iron ore.

Rio had secured consent under WA's Aboriginal Heritage Act in 2013, but has admitted subsequently overlooking information about the sites' deep cultural significance.

Mr Jacques also revealed traditional owners were not told Rio had examined three other options for expanding its Brockman 4 mine which did not involve damaging the rock shelters.

Premier Mark McGowan said he was deeply disappointed by the incident and it should prompt other miners to check their own backyards.

"I'd just urge all of the major miners to take account of what's gone wrong," he said on Monday.

"Have a look at your mining program. Make sure things like this don't happen again."

Mr McGowan said long-awaited reforms to WA's heritage laws, which will provide Aboriginal people with equal rights of appeal, will be introduced to parliament later this year.

PKKP spokesman Burchall Hayes said traditional owners were deeply hurt and traumatised by the destruction of the sacred sites.

"Rio Tinto's submission to the parliamentary inquiry has deepened our hurt as we understand the true extent of the dysfunctional process which led to this desecration and has belittled our heritage," he said.

"The information tabled to date leads us to question the foundations of our relationship with Rio Tinto. In particular, we regret the lack of value being attached to the land we had entrusted to them, beyond short term financial gains."

Mr Jacques told the inquiry he had only learned of the sites' significance after they were blown up.

"The events at Juukan should not have happened," he said.

"This is a defining moment for Rio Tinto and we are absolutely committed to learn and change."

WA's Chamber of Minerals and Energy said it supported the state government's planned heritage reforms after close involvement in the lengthy consultation process.

In its submission, the industry group said the Juukan Gorge incident had highlighted the need for mining companies to continually assess and improve their relationships with traditional owners.

"The incident at Juukan Gorge has brought this into sharp focus for all stakeholders," the submission said.