Rio Tinto chair to step down after controversy sparked by Juukan Gorge destruction

Rio Tinto chairman Simon Thompson said he held himself "ultimately accountable" for the failing that led to the destruction of the 46,000-year-old Juukan Gorge caves in Western Australia.

Rio Tinto Chairman Simon Thompson. Source: AAP

Rio Tinto chairman Simon Thompson will step down within the next year, bowing to pressure over the destruction of the 46,000-year-old Juukan Gorge caves in Western Australia.

The blasting of the Indigenous heritage site - and Rio Tinto's initial response to the scandal - prompted severe backlash from Indigenous groups, company shareholders and political leaders.

The mining giant destroyed the site in the Pilbara region last year to extract iron ore against the wishes of traditional owners, the Puutu Kunti Kurrama and Pinikura (PKKP). 

Mr Thompson said he took responsibility for the Juukan caves destruction, which he called a source of "deep regret". 

"As chairman, I am ultimately accountable for the failings that led to this tragic event," he said in a statement. 

"While I am pleased with the progress we have made in many areas, the tragic events at Juukan Gorge are a source of personal sadness and deep regret, as well as being a clear breach of our values as a company.” 

The decision comes after a board-led review of the incident initially determined no one should be stood down.

The leader of the review, Rio director Michael L’Estrange, also announced on Wednesday he would step down from the board. 

The backlash from Rio Tinto's actions last year also prompted the resignation of CEO Jean-Sebastien Jacques and two deputies.

Rio had legal approval to go ahead with the destruction under WA's Aboriginal Heritage Act as part of a long-planned expansion of Rio’s Brockman 4 iron ore mine.

The miner has since apologised for the incident and conceded the blast should not have happened.     

A parliamentary inquiry into the destruction called the outcome "inexcusable" in an interim report examining the process leading up to Rio Tinto's decision. 

It criticised Rio Tinto for acting despite being aware of the cultural value of the site they were destroying, and also failing to pursue other options that would have preserved the caves. 

The miner has promised to address "weaknesses" identified in its risk management processes and governance. 

It last month outlined a revamped cultural heritage management process, acknowledging its destruction of the sacred site had badly damaged its standing among stakeholders and its employees.