New date for Earth’s largest iron deposit offers clues for future exploration

Research led by Curtin University reveals that the largest iron ore deposits on Earth – in Western Australia’s Hamersley Province – are about one billion years younger than previously believed, a discovery that could significantly boost the search for other resources.

Using a new geochronological technique to accurately measure the age of iron oxide minerals, scientists found the Hamersley deposits formed between 1.4 and 1.1 billion years ago, rather than 2.2 billion years ago as previously estimated.

Lead author Dr. Liam Courtney-Davies, who was a postdoctoral researcher at Curtin University’s John de Laeter Center at the time of the research and is now at the University of Colorado, Boulder, said the findings showed that the iron deposits formed during a period of major geological activity when ancient supercontinents broke up and new ones formed.

“The energy from this epic geological activity likely triggered the production of billions of tonnes of iron-rich rock across the Pilbara,” said Dr. Courtney-Davies.

“Discovering the link between these giant iron ore deposits and changes in supercontinent cycles improves our understanding of ancient geological processes and improves our ability to predict where we should explore in the future.”

Co-author of the study, Associate Professor Martin Danišík from the John de Laeter Center, said the research accurately dated minerals from banded iron formations (BIFs), which are ancient, iron-rich undersea layers of rock that can provide significant insight into Earth’s deep geology. past.

“Until now, the exact timeline of these formations changing from 30% iron as they were originally to more than 60% iron as they are today has been unclear, hindering our understanding of the processes that led to the formation of the world’s largest ore deposit ,” said associate professor Danišík.

“Using an emerging technique to date iron oxide minerals using uranium and lead isotope analysis in mineral grains, we have directly dated all of the large giant iron ore deposits in the Hamersley Province hosted by BIF.

“Our research suggests that these deposits formed in conjunction with major tectonic events, highlighting the dynamic nature of our planet’s history and the complexity of iron ore mineralization.”

Western Australia is the world’s leading producer of iron ore, which is Australia’s biggest exporter at $131 billion last financial year. The research was carried out in collaboration with researchers from The University of Western Australia, Rio Tinto and CSIRO Mineral Resources.

The entire study, entitled “A billion shift in the formation of the largest ore deposits on Earth” is published in Proceedings of the National Academy of Sciences.