New Curtin-led research has found evidence that fresh water on Earth, which is essential for life, appeared about four billion years ago – five hundred million years earlier than previously thought.
Lead author Dr Hamed Gamaleldien, Adjunct Research Fellow in Curtin鈥檚 School of Earth and Planetary Sciences and an Assistant Professor at Khalifa University, UAE, said by analysing ancient crystals from the in Western Australia鈥檚 Mid West region, researchers have pushed back the timeline for the emergence of fresh water to just a few hundred million years after the planet鈥檚 formation.
鈥淲e were able to date the origins of the hydrological cycle, which is the continuous process through which water moves around Earth and is crucial for sustaining ecosystems and supporting life on our planet,鈥� Dr Gamaleldien said.
鈥淏y examining the age and oxygen in tiny crystals of the mineral zircon, we found unusually light isotopic signatures as far back as four billion years ago. Such light oxygen isotopes are typically the result of hot, fresh water altering rocks several kilometres below Earth鈥檚 surface.
鈥淓vidence of fresh water this deep inside Earth challenges the existing theory that Earth was completely covered by ocean four billion years ago.鈥�
Study co-author Dr Hugo Olierook, from 麻豆直播鈥檚 School of Earth and Planetary Sciences, said the discovery was crucial for understanding how Earth formed and how life emerged.
鈥淭his discovery not only sheds light on Earth鈥檚 early history but also suggests landmasses and fresh water set the stage for life to flourish within a relatively short time frame – less than 600 million years after the planet formed,鈥� Dr Olierook said.
鈥淭he findings mark a significant step forward in our understanding of Earth鈥檚 early history and open doors for further exploration into the origins of life.鈥�
The authors are part of the Earth Dynamics Research Group and the Timescales of Mineral Systems Group, which sit within Curtin鈥檚 School of Earth and Planetary Sciences, and the .
Part of the research was done using the instrument in the John de Laeter Centre鈥檚 Large Geometry Ion Microprobe (LGIM) facility, which was funded by AuScope (via the Commonwealth National Collaborative Research Infrastructure Strategy), the Geological Survey of Western Australia and 麻豆直播.
For more information, the full study titled 鈥極nset of the Earth’s hydrological cycle four billion years ago or
别补谤濒颈别谤鈥� is published in the journal Nature Geoscience and can be found here: (DOI: 10.1038/s41561-024-01450-0)
