Drone image of the Bunda Cliffs, where the Nullarbor Plain meets the Great Australian Bight. Layering in the cliffs represent different limestone units.
Newswise —
A new approach by Curtin researchers has revealed the timeframe of the drying out of the Australian Nullarbor plain. This discovery sheds light on how ancient climate change impacted some of the world's driest regions.
By analyzing iron-rich layers that formed in ancient sediments, researchers were able to pinpoint when a region dried out in response to climate change, including the significant reduction of groundwater in southern Australia.
The presence of these "relics of drying" indicates that the Nullarbor underwent a significant transition to dry conditions around 2.4 to 2.7 million years ago. This discovery highlights the important role that environmental changes played in shaping the diverse flora and fauna of Australia.
Dr. Maximilian Dröllner, the lead author from Curtin's School of Earth and Planetary Sciences' Timescales of Mineral Systems Group, mentioned that determining the timing of climate change in ancient landscapes has been a challenging task for geoscientists globally.
“Almost half of the Earth’s land surfaces are considered drylands, and they host about three billion people,” Dr Dröllner said.
Dr. Dröllner also emphasized that alterations in arid regions can have a significant impact on both society and regional biodiversity. Aridification has played a critical role in shaping the current landscapes and ecosystems we observe today.
Geoscientists have faced challenges in determining the timing of climate events in arid regions, and have had to rely on indirect observations, such as studying marine sediments in neighboring areas.
Associate Professor Milo Barham, a co-author from Curtin's Timescales of Mineral Systems Group, highlighted that direct measurement of the products of landscape drying can offer a more precise timeline of events.
“The amount of helium trapped in these iron-rich horizons can be used to determine when they were formed,” Associate Professor Barham said.
According to Associate Professor Barham, exposing these "relics" of drying to a small laser causes the release of helium, which can be measured to determine the timing of significant environmental responses to Earth's climate history.
Determining the timeline of these events can help elucidate how they affected the biodiversity of the region. In the case of southern Australia, it also provides a timeframe for the evolution of several native species.
“The drying of Australia’s interior separated the common ancestors of many species that once roamed freely across Australia,” Dr Dröllner said.
Dr. Dröllner added that the drying of Australia's interior caused the separation of the common ancestors of numerous species that once roamed freely across the continent.
Dr. Dröllner also noted that today, we can see many instances of sister species of birds, insects, and plants that share common ancestors but are now separated by thousands of kilometers due to environmental barriers created by ancient climate change.
About Curtin University
Curtin University is Western Australia’s largest university, with close to 60,000 students. In addition to the University’s main campus in Perth, Curtin also has a major regional campus in Kalgoorlie, and a campus in Midland, as well as four global campuses in Malaysia, Singapore, Dubai and Mauritius. Curtin staff and students come from Australia and over 120 other countries around the world, with half our international students studying at Curtin’s offshore campuses.
Curtin is ranked in the top one per cent of universities worldwide, with the University placed 9th in Australia according to the Academic Ranking of World Universities (ARWU) 2022 and has achieved a QS Five Stars Plus rating, the highest available for a tertiary institution, and one of only five to do so in Australia.
The University has built a reputation around innovation and an entrepreneurial spirit, being at the forefront of many high-profile research projects in astronomy, biosciences, economics, mining and information technology. It is also recognised globally for its strong connections with industry, and for its commitment to preparing students for the jobs of the future.
For further information, visit curtin.edu.au.
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