1.4 billion-year-old discovery changes scientists' understanding of Earth's geographical history

The world's largest iron ore deposits, located in the Hamersley Province of Western Australia, were formed between 1.4 and 1.1 billion years ago, significantly later than previously thought a new study has discovered.

These deposits are situated on the Pilbara Craton, an ancient and stable part of Earth's crust. This piece of crust is one of two pieces that are part of Archaean Eon, which dates back 3.8 billion to 2.5 billion years ago. The second piece is in Kaapvaal Craton in southern Africa.

Now a study published in the journal PNAS claims the formation process of these iron deposits was triggered by the breakup of the supercontinent Columbia, which caused massive tectonic activity.

Columbia existed between 1.4 billion and 1.1 billion years ago and its break-up helped form the country we now know as Australia. The new study suggests that the link between Columbia and Australia could explain why there are huge iron ore reserves in the Hamersley Province.

It is proposed that the activity when Columbia broke up released vast amounts of mineral-rich fluids from deep within the Earth, essential for creating the iron ore deposits.

The study's lead author Liam Courtney-Davis, a geochronologist and postdoctoral associate at the University of Colorado, Boulder, said in a statement: "The energy from this epic geological activity likely triggered the production of billions of tons of iron-rich rock across the Pilbara."

Courtney-Davis's team used advanced dating techniques, specifically uranium-lead dating, to provide this new timeline. These techniques allowed researchers to date the zircon minerals within the iron ore deposits accurately.

This finding links the deposits' formation to the breakup of Columbia, which caused the continents to drift and reshaped Earth's geological landscape. The tectonic shifts during this period led to the creation of extensive volcanic activity and rift basins, where the iron deposits eventually formed.

Understanding the precise age and formation process of these deposits is crucial for multiple reasons.

It sheds light on the geological history of the Earth and offers valuable insights into the processes that can lead to the formation of significant mineral deposits.

This knowledge can aid in future exploration and mining, providing a more targeted approach to finding new iron ore resources. Iron ore is a critical component in steel production, which is essential for various industries globally.

This research underscores the importance of tectonic movements in forming major mineral deposits and highlights the dynamic nature of Earth's surface.

The insights gained from studying these ancient deposits help geologists predict where other large mineral deposits might be found, contributing to more efficient and sustainable mining practices in the future.

Courtney-Davis adds: "The discovery of a link between these giant iron ore deposits and changes in supercontinent cycles enhance our understanding of ancient geological processes and improves our ability to predict where we should explore in the future."

HT LiveScience