2.7-Billion-Year-Old Diamonds Proves That Life-Giving Elements Appeared Shortly After Earth Was Formed

A study of ancient diamonds showed that the basic chemical composition of the atmosphere, which makes Earth suitable to host life, was laid down at least 2.7 billion years ago.

These volatile gases are found to be conserved in the 2.7-billion-year-old diamonds are also found in today's mantle, suggesting that there has been no fundamental change in the proportions of these volatile gases in the atmosphere for billions of years.

That means that one of the basic conditions to sustain life, which is the presence of life-giving elements, appeared soon after the Earth's formation and has remained constant since then, according to lead researcher Dr. Michael Broadley who presented his findings at the Goldschmidt Geochemistry Conference.

Volatile Gases Trapped in Diamonds

Volatile gases or substances on Earth are mostly brought up to the surface from inside the planet through volcanic eruptions. According to EurekAlert!, understanding how it became part of the atmosphere is the key to studying when the conditions on Earth became suitable for life.

French and Canadian researchers used ancient diamonds as a time capsule to examine conditions deep in the Earth's mantle from billions of years ago. This study showed how volatile gases trapped in ancient diamonds have changed so little over the course of 2.7 billion years.

Broadley said that these diamonds are the key to studying the composition of Earth's modern mantle as they are indestructible, unlike most of the mantle's composition that has mostly been destroyed by the constant churning of Earth's crust via plate tectonics.

The team found the diamonds preserved in a rock in Wawa, on Lake Superior in Canada, which means they could be as old as the rocks where they were found, or perhaps older. These diamonds are incredibly rare and are unlike the beautiful gems that people may think.

They heated it up to 3,600 degrees Fahrenheit (2,000 degrees Celsius) to transform them into granite and measure the volatile gases trapped inside them. They were able to identify Helium, Neon, and Argon, which are chemical elements that are also found in the upper mantle today.

That means there has been no significant change in the proportions of volatile gases generally and that the transfer of gases from the mantle to the atmosphere most likely remained the same.

Since the diamonds found could be much older than 2.7 billion years old, Broadley suggests that these conditions might be set well before the 2.7 billion-year threshold.

Searching for Volatile Gases in Exoplanets

Volatile gases like hydrogen, nitrogen, neon, and others are essential chemical elements and compounds needed to sustain life, especially carbon and nitrogen, according to SciTech Daily.

However, not all planets are volatile-rich like Earth. Mars and the Moon have long lost their volatile gases into space. Generally, scientists look for signs of volatile gases in exoplanets to determine whether they could harbor life or have sustained life before.

According to an article published in Uppsala Universitet's Department of Physics and Astronomy website, the chemical composition of an exoplanet's atmosphere can tell scientists about its physical conditions. Scientists use transit spectroscopy to understand an exoplanet's chemical composition.

Dr. Suzette Timmerman from the University of Alberta, Canada, said that the recent study on ancient diamonds provides important clues of the volatile gases composition during the Neoarchean period. It opens new doors to further questions and research about the first half of Earth's history and its mantle.

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