New Evidence Alters Timeline of Major Iron Ore Deposits

Recent research led by Dr. Liam Courtney-Davies from Curtin University has significantly revised the geological timeline of the world's largest iron ore deposits, particularly those in the Hamersley Province of Western Australia. This groundbreaking study, published in the *Proceedings of the National Academy of Sciences* on June 17, 2025, reveals that these deposits are approximately 1.3 billion years younger than previously thought, challenging long-held assumptions regarding their formation.

For decades, geologists believed that the largest iron ore deposits formed shortly after the Great Oxidation Event, around 2.2 billion years ago. However, the new findings suggest that these reserves formed between 1.4 and 1.1 billion years ago, coinciding with significant tectonic activity that reshaped the Earth's crust. Dr. Courtney-Davies explained, "The energy from this epic geological activity likely triggered the production of billions of tons of iron-rich rock across the Pilbara."

The research team utilized uranium-lead dating techniques to determine the ages of hematite crystals from various banded iron formations (BIFs) in the region. This innovative method allows scientists to pinpoint the formation of these minerals more accurately than traditional dating methods, which often rely on surrounding rock layers. According to Associate Professor Martin Danišík, also from Curtin University, "Our research indicates 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."

The implications of this research extend beyond academic interest; they hold significant economic potential for the iron ore mining industry. Australia has been a dominant player in the global iron ore market, accounting for 38 percent of the world's supply in 2023. The value of Western Australia’s iron ore exports reached $136 billion in the year leading up to June 2024, with projections indicating a decrease to about $107 billion for 2024-25 due to falling prices.

The study’s findings could influence the future of iron ore exploration. If deposits formed during a specific tectonic period, industry experts can refine their search for similar geological conditions elsewhere. This could lead to more efficient exploration strategies, potentially increasing profitability for mining companies in a market where profit margins are tightening.

Furthermore, the research aligns with a growing global demand for high-quality iron ore as steel production recovers post-pandemic. As companies strive to reduce emissions, higher-grade iron ore becomes increasingly valuable, as it requires less coke during processing. The development of "green steel" projects, which aim to utilize hydrogen-reduced iron ore, could further enhance the economic viability of these deposits, with estimates suggesting a potential export value exceeding $250 billion annually.

In addition to the economic implications, this research contributes to a deeper understanding of Earth's geological history. By linking iron ore deposits to supercontinent cycles, scientists can better predict where to explore for new resources. Dr. Courtney-Davies noted, "The discovery of a link between these giant iron ore deposits and changes in supercontinent cycles enhances our understanding of ancient geological processes and improves our ability to predict where we should explore in the future."

As the mining industry adapts to new findings and changing market conditions, the study serves as a reminder of the intricate relationship between geological processes and resource availability, shaping not only the landscape of Western Australia but also the global economy. The story of iron is still being written, one geological discovery at a time.