Ancient iron shows climate shift
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Iron nuggets in Western Australia’s Pinnacles have revealed secrets of ancient climate shifts.
In new research conducted by Curtin University, scientists studied the unique iron-rich formations in WA’s Nambung National Park.
This area forms part of the largest wind-blown limestone belt globally, stretching over 1000 kilometres.
The research indicates that the Pinnacles formed around 100,000 years ago during a period that was the wettest in the last 500,000 years.
This period was notably different from the Mediterranean climate currently experienced in Western Australia.
Dr Matej Lipar, the lead author and Adjunct Research Fellow at Curtin University, noted that the Pinnacles' karst landscape was shaped by the dissolution of limestone due to significant water presence.
“These formations offer crucial insights into ancient climates and environments, but accurately dating them has been extremely challenging until now,” Dr Lipar said.
Through innovative dating techniques, researchers have been able to better understand this significant climatic event.
Dr Martin Danišík, a co-author from Curtin’s John de Laeter Centre, says that iron-rich nodules found in the Pinnacles act as “geological clocks”, preserving helium produced by the radioactive decay of uranium and thorium.
“Measuring this helium provides a precise record of when the nodules formed,” Dr Danišík said.
The nodules date back approximately 100,000 years, marking this era as an unusually wet period.
Associate Professor Milo Barham, another co-author from Curtin’s Timescales of Mineral Systems Group, highlighted the broader implications of these findings for understanding climate change and its effects on human evolution and ecosystems.
Barham says this research could help scientists prepare for the impacts of a warming planet by providing a clearer understanding of past environmental changes.
The study, an international collaboration with the Slovenian Research and Innovation Agency, is published in Science Advances.