Earth's primer for life's explosion, as suggested by ancient diamonds, dates back approximately 2.7 billion years.
In a groundbreaking study, researchers have delved into the depths of the Earth's past by analysing the isotopes of Helium, Neon, and Argon in ancient diamonds. These findings suggest that the volatile composition of the Earth's mantle has remained relatively unchanged for over 2.7 billion years.
The study, led by a team from ETH Zurich, focused on a unique collection of diamonds known as the Wawa fibrous diamonds. These diamonds, more than 2.7 billion years old, were used as a time capsule to examine the conditions deep inside the Earth's mantle during the Neoarchean period.
Diamonds, being comparatively indestructible, are ideal for studying the deep past. By heating these ancient diamonds to over 2000 degrees Celsius, the team was able to release tiny quantities of gas for measurement. The results showed that the volatile gases conserved in these diamonds were present in similar proportions to those found in today's mantle.
This finding contradicts the belief that the Earth's atmosphere and mantle have undergone significant changes over time. Studies of the gases trapped in these diamonds, as well as other evidence, indicate that there has probably been little change in the proportion of volatiles generally over the last few billion years.
The Earth's mantle, the part between the crust and the core, comprises around 84% of the Earth's volume. The upper mantle appears to have been degassed more than 2.7 billion years ago, suggesting a stable period of volatile distribution since then.
Dr Suzette Timmerman, an independent commentator, hails this study as an important step towards understanding the mantle and atmosphere in the first half of Earth's history. She believes that this research could help us better understand the conditions that were suitable for the origin and development of life on our planet.
The findings of this study were presented at the 2021 Goldschmidt Conference, the World's main geochemistry conference, which took place virtually from 4-9 July. The 2022 conference is scheduled to take place in Hawaii. This research, led by A. Giuliani, D. Phillips, and D.G. Pearson, among others from ETH Zurich, has provided a fundamental law for the chemical composition of the Earth's atmosphere suitable for life to at least 2.7 billion years ago.
It is widely accepted that a planet rich in volatiles has a better chance of sustaining life. This study provides evidence that the Earth's atmosphere has been rich in volatiles such as hydrogen, nitrogen, neon, and carbon-bearing species since at least 2.7 billion years ago. This suggests that the conditions on Earth were suitable for the origin and development of life at least 2.7 billion years ago.
In conclusion, the study of ancient diamonds has provided valuable insights into the stability of the Earth's mantle and atmosphere over billions of years. These findings could help us better understand the conditions that were conducive to the origin and development of life on our planet.
