Researchers from Curtin University have utilized helium dating of iron-rich sediments to determine that the Nullarbor Plain transitioned to arid conditions between 2.4 and 2.7 million years ago. This shift was a result of significant climate changes leading to substantial drops in groundwater levels in southern Australia. The findings highlight how this ancient aridification played a crucial role in shaping Australia’s biodiversity by isolating species and driving their evolution.
Lead author Dr. Maximilian Dröllner emphasized the challenges geoscientists face in dating climate change events in dryland regions, which comprise nearly half of Earth’s land surface inhabited by approximately three billion people. The study introduces a method to directly measure helium trapped in iron-rich strata, providing a clearer understanding of the timing of environmental shifts. These “relics of drying” indicate how the separation of species due to climatic changes led to the development of distinct species adapted to varying conditions on Australia’s coasts.
Co-author Associate Professor Milo Barham noted that leveraging direct measurements of drying landscapes can enhance insights into how these environmental changes impact biodiversity. The research underscores the complex relationship between ancient climate dynamics and the evolution of flora and fauna in Australia’s unique ecosystems.
