Research Uncovers Presence of Ancient Hydrological Processes on Earth Older than 4 billion Years听
Khalifa University of Science and Technology today announced researchers from the Earth Sciences department, College of Engineering and Physical Sciences, are piecing together a more comprehensive picture of our planet’s ancient past. They have uncovered evidence of ancient hydrological processes dating back to 4 billion years, revealing the first evidence of the presence of freshwater and dry land in our planet’s early stages, shedding light into the environmental conditions significant for the development of life on Earth.听
The momentous finding detailed in the manuscript 鈥極nset of the Earth’s hydrological cycle four billion years ago or earlier鈥� by the lead author of the study, Dr. Hamed Gamaleldien, Assistant Professor, Earth Science at Khalifa University, along with an international team of researchers, published 听in Nature Geoscience, a top 1% of Earth and Planetary Science journals.
Dr. Ahmed Al Durra, Associate Provost, Research, Khalifa University, said: 鈥淲e are delighted to announce the groundbreaking discovery made by Dr. Hamed Gamaleldien and his colleagues. The extraordinary research marks a significant milestone in our understanding of Earth’s early history and holds profound implications for the search for evidence of life as early as 600 million years after our planet’s accretion. The findings highlight the intricate relationship between the hydrological cycle, the emergence of land and fresh water, and the potential for life to arise and flourish. This research not only deepens our understanding of Earth’s early development but also has broader implications for astrobiology and the search for life beyond our planet.鈥�
Scientists made significant progress in understanding the origins of life on Earth, with the oldest life on Earth dating back approximately 3.5 billion years, believed to have emerged in hot spring environments on land where fresh water was present. However, the exact timing of the widespread interaction between fresh water and dry land remained uncertain. Through the new study, scientists examined an abundance of different oxygen isotopes in tiny mineral crystals called zircon from the sedimentary particles of Jack Hills from Western Australia, the oldest terrestrial materials found so far, covering a period from the Hadean to the Paleoarchean era (around 4.4 to 3.1 billion years ago).
The researchers measured the ratios of heavy oxygen to light oxygen which are thought to be much lighter in freshwater than in seawater. Measuring this ratio in over 1,000 zircon crystals, a valuable portion from 4.0 and 3.4 billion years ago had unusually light oxygen isotopes, indicating that they are formed from magma originated by interacting fresh water with rocks.听听
Through thousands of computer simulations, the researchers demonstrated that the zircon with very light isotopic values could only result from the interaction between crustal magmatic systems and fresh water. This finding provides valuable insights into the earliest presence of fresh water and dry land on Earth, and the initiation of the hydrological cycle. Moreover, these factors likely created the environmental conditions necessary for life to evolve within a relatively short time span of less than 600 million years after the formation of Earth.
Alisha Roy
Science Writer
6 June 2024
