A study published in ‘Nature geoscience’ provides revealing evidence. The appearance of fresh water on Earth would have occurred 500 million years earlier than estimated. When? 4000 million years ago.
The lead author is Dr. Hamed Gamaleldien. He is a research associate in the Curtin School of Earth and Planetary Sciences. He is also an assistant professor at Khalifa University, United Arab Emirates. He notes that ancient crystals were analyzed from Jack Hills in the Mid-West region of Western Australia. Thus, the researchers were able to delay the timeline for the appearance of fresh water on Earth. It is now a few hundred million years after the planet formed.
Evidence underground
«We were able to date the origins of the hydrological cycle. It is the continuous process through which water moves around the Earth. And it is crucial to sustain ecosystems and sustain life on our planet,” says Dr. Gamaleldien.
‘We examined the age and oxygen isotopes in small crystals of the mineral zircon. And we found unusually light isotopic signatures dating back four billion years. These light oxygen isotopes typically result from the alteration of rocks by hot, fresh water several kilometers below the Earth’s surface. So there is evidence of fresh water at this depth in the Earth’s interior. “It challenges the existing theory that the Earth was completely covered by an ocean four billion years ago,” he notes.
Blooming life
Co-author of the study is Dr Hugo Olierook, from Curtin University’s School of Earth and Planetary Sciences. He emphasizes that the discovery was crucial to understanding how the Earth formed and how life emerged. «This discovery not only sheds light on the early history of the Earth. It also suggests that land masses and fresh water set the stage. Thus life could flourish in a relatively short period of time. “Less than 600 million years after the planet formed,” he says.
“The findings mark an important step forward in our understanding of Earth’s early history. And they open doors for further exploration of the origins of life », he concludes.
