There are innumerable proofs and theories regarding how Earth was formed but the timelines for the appearance of freshwater reservoirs on Earth remained uncertain, until now.
Freshwater from atmospheric sources appeared on Earth’s surface about 4 million years ago, which is 500 million years earlier than previously thought, as per a new study published in Nature Geoscience.
Dr Gamaleldien further explained that analysing the ancient zircons pushed back the timeline for the appearance of freshwater on Earth by 500 million years.
“For the zircons we analyzed to have such light oxygen signatures, the rock must have been altered by freshwater, melted, and then solidified again.
This evidence of freshwater 4 billion years ago challenges the theory that Earth was entirely covered by an ocean at that time,” Dr Gamaleldien added.
There are innumerable proofs and theories regarding how Earth was formed but the timelines for the appearance of freshwater reservoirs on Earth remained uncertain, until now. Researchers now have found evidence of freshwater in a major breakthrough.
Freshwater from atmospheric sources appeared on Earth’s surface about 4 million years ago, which is 500 million years earlier than previously thought, as per a new study published in Nature Geoscience.
Researchers found the evidence for the same in ancient zircon crystals from Jack Hills situated in Western Australia. The team conducted oxygen isotope analysis on these crystals which determined when their hydrological cycle might have begun. These zircons were found to be resilient against weathering and environmental changes. The crystals, which are the oldest on Earth, provided rare and deep insights into the planet’s early history.
“We were able to date the origins of the hydrological cycle, which is the continuous movement of water between land, oceans, and the atmosphere through processes like evaporation and precipitation. This cycle is essential for sustaining ecosystems and life on our planet,” said Dr Hamed Gamaleldien, a lead researcher from Curtin University's School of Earth and Planetary Sciences and Khalifa University in the UAE.
Dr Gamaleldien further explained that analysing the ancient zircons pushed back the timeline for the appearance of freshwater on Earth by 500 million years.
“By examining tiny zircon crystals, we found exceptionally light oxygen isotopic signatures, which are indicative of interaction with fresh water rather than salty ocean water, dating back 4 billion years,” he said.
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These light oxygen isotopes were typically the result of interactions between hot, fresh water and rock several kilometres below the Earth's surface.
“For the zircons we analyzed to have such light oxygen signatures, the rock must have been altered by freshwater, melted, and then solidified again. This evidence of freshwater 4 billion years ago challenges the theory that Earth was entirely covered by an ocean at that time,” Dr Gamaleldien added.
Dr. Hugo KH Olierook, another researcher from Curtin University's School of Earth and Planetary Sciences, emphasised the significance of this discovery for understanding Earth’s formation and the origin of life.
“Our research represents a significant advancement in understanding Earth’s early history and opens doors for future studies on the origins of life,” said Olierook.
(With inputs from agencies)
