Iron formations in Western Australia's Pinnacles shed light on past climates

Written by Copernical Team Friday, 04 October 2024 20:35

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Sydney, Australia (SPX) Oct 03, 2024

New research on small iron-rich formations within the Pinnacles in Western Australia, part of the world's largest wind-blown limestone region, has uncovered valuable insights into Earth's ancient climate and shifting landscapes. The study reveals that these formations developed approximately 100,000 years ago during the wettest period experienced in the region over the past half-million years, a

Iron formations in Western Australia's Pinnacles shed light on past climates
by Simon Mansfield
Sydney, Australia (SPX) Oct 03, 2024

New research on small iron-rich formations within the Pinnacles in Western Australia, part of the world's largest wind-blown limestone region, has uncovered valuable insights into Earth's ancient climate and shifting landscapes. The study reveals that these formations developed approximately 100,000 years ago during the wettest period experienced in the region over the past half-million years, a stark contrast to the Mediterranean climate seen today.

Lead researcher Dr. Matej Lipar, Adjunct Research Fellow at Curtin University and now with the Research Centre of the Slovenian Academy of Sciences and Arts (ZRC SAZU), explained that the Pinnacles, located in Nambung National Park, are a form of karst created by water dissolving rocks. "These formations offer crucial insights into ancient climates and environments, but accurately dating them has been extremely challenging until now," said Dr. Lipar.

"Karst landscapes, like those in Nambung National Park, are sensitive indicators of environmental change globally. Accurately dating them helps us understand how Earth's geological systems respond to climate shifts."

The study highlighted that this period, around 100,000 years ago, marked the wettest time in the region's history over the last 500,000 years. It was very different from other parts of Australia and is far removed from Western Australia's present-day Mediterranean climate. "The abundance of water at that time caused the limestone to dissolve, forming the Pinnacles' distinctive pillars and providing ideal conditions for iron nodules to develop," added Dr. Lipar.

Associate Professor Martin Danisik from Curtin's John de Laeter Centre further explained the significance of these iron-rich nodules. The formations acted as "geological clocks," trapping helium from the decay of naturally occurring uranium and thorium. "Measuring this helium provides a precise record of when the nodules formed," Dr. Danisik said. "The innovative dating techniques used in this study show that these nodules formed around 100,000 years ago during an exceptionally wet climate period."

Dr. Milo Barham, Associate Professor at Curtin's Timescales of Mineral Systems Group, emphasized the broader implications of this research. "Reconstructing past climate changes is vital as it provides context for understanding human evolution and how ecosystems have responded to dramatic climate shifts over millions of years," Dr. Barham noted. "This research not only enhances scientific knowledge but also offers practical insights into climate history and environmental change, which are crucial for preparing for the impacts of a warming planet."

The research was an international collaboration with ZRC SAZU and was supported by the Slovenian Research and Innovation Agency.

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