New geochronology techniques reshape understanding of Hamersley iron ore formation

Researchers at Curtin University have significantly revised the age of Western Australia's Hamersley iron ore deposits. 

Curtin University researchers have discovered that Western Australia’s Hamersley iron ore deposits are about one billion years younger than previously thought, dating from 1.4 to 1.1 billion years ago instead of the earlier estimate of 2.2 billion years. This new finding, achieved through advanced geochronology techniques, may significantly enhance efforts to locate additional iron ore resources, Caliber.Az reports, citing foreign media.

Geological Activity and Iron Ore Formation Dr. Liam Courtney-Davies, the lead author of the study and former Postdoctoral Research Associate at Curtin University’s John de Laeter Centre (now at the University of Colorado, Boulder), explained that the new findings reveal the iron deposits were formed during a period of intense geological activity, characterized by the fragmentation of ancient supercontinents and the formation of new ones. Dr. Courtney-Davies noted, “The immense energy from these geological events likely led to the creation of billions of tonnes of iron-rich rock across the Pilbara region.”

He added that linking these massive iron ore deposits to supercontinent cycles enhances our understanding of ancient geological processes and improves our ability to target future exploration efforts. Dating of Banded Iron Formations (BIFs) Associate Professor Martin Danišík, a co-author of the study from the John de Laeter Centre, explained that the research precisely dated minerals from banded iron formations (BIFs), which are ancient layers of iron-rich rock formed underwater. 

These formations are crucial for understanding Earth's deep geological history. “Previously, the exact timeline for the transformation of these formations from their original iron content of 30 percent to over 60 percent today was not well understood, which limited our grasp of the processes behind the formation of the world's largest ore deposits,” said Associate Professor Danišík.

“By employing a new technique that uses uranium and lead isotope analysis to date iron oxide minerals within the BIF grains, we were able to directly date the major iron ore deposits in the Hamersley Province. Our findings suggest these deposits were formed alongside significant tectonic events, underscoring the dynamic nature of Earth's history and the intricate processes of iron ore mineralization.”