An unprecedented study of ancient diamonds revealed that the Earth's basic chemical composition, which allows for the explosion of life's diversity, was established at least 2.7 billion year ago. The proportions of volatile gases found in ancient diamonds were similar to those in today's mantle. This indicates that there has not been a fundamental change in the atmospheric composition over the past few billion years. This indicates that the essential conditions for life support, sufficient quantities of life-giving elements, were present soon after the formation of Earth. They have remained relatively constant since then.Lead researcher Dr Michael Broadly presented the results at the Goldschmidt Geochemistry Conference. He stated, "The composition and make-up volatiles in the atmosphere mirrors that found in mantle and we have not evidence of any significant change since these diamonds formed 2.7 billion year ago."Volatiles such as nitrogen, hydrogen, and neon are light chemical elements that can easily be vaporized by heat or pressure changes. They are essential for life, particularly carbon and nitrogen. Volatilities are not all common on planets. Venus and Earth are both volatile-rich, while Mars and the Moon have lost most of their volatiles to space. A planet with high levels of volatiles is more likely to sustain life. This is why so much of the exoplanet search has been focused on volatiles.Volatile substances are mostly produced from within the Earth's atmosphere and brought to the surface by volcanic eruptions. Understanding when these volatiles entered the Earth's atmosphere can help us understand when conditions were right for life to develop. However, we don't know how this happened in the past.French and Canadian researchers now use ancient diamonds to study the conditions deep within the Earth's mantle from the distant past. The volatile composition of mantle gases found in these diamonds has not changed over the past 2.7 billion years, according to studies.Michael Broadley, a lead researcher at the University of Lorraine in France, stated that "Studying Earth's current mantle composition is quite simple." The mantle layer is approximately 30km beneath the Earth's surface. This allows us to collect samples from volcanoes, as well as study the gases and fluids trapped within. Older samples are mostly destroyed due to the Earth's constant churning via plate tectonics. However, diamonds are relatively indestructible and make excellent time capsules.We were able to examine diamonds found in Wawa's 2.7 billion-year-old, highly preserved rock. This is located on Lake Superior in Canada. This means that the diamonds are probably at least as old and likely older than the rocks they are found in. It is difficult to date diamonds so we were able to determine the minimum age. These diamonds are extremely rare and not as beautiful as the gems we associate with diamonds. To transform them into graphite at over 2000 C, we heated them. Then, tiny amounts of gas were released for measurement.The team measured the Helium, Neon and Argon isotopes and found similar amounts to the ones found in the upper mantle. This suggests that there has been very little change in volatiles overall, and that the distributions of essential volatile elements between mantle and atmosphere have likely remained relatively stable over the course of Earth's entire life. It is located between the Earth's core and crust, and accounts for around 84% of Earth's total volume.Dr Broadley said, "This was an unexpected result. This means that the volatile-rich environment in which we live today is not an unforeseen development. It provides the right conditions for life's development. These conditions existed at least 2.5 billion years ago. However, the diamonds that we use today may have been created much earlier, which means that they were likely established well before our 2.7-billion year threshold.Commenting, Dr Suzette (University of Alberta Canada) stated:Because they are unique, diamonds can be considered unique because of the way that they retain their compositions. Particularly, the Wawa fibrous diamonds were an excellent selection to study. They are more than 2.5 billion years old and provide valuable clues into the volatile composition during this period, known as the Neoarchean period. It is fascinating that the upper mantle was already degassed over 2.7 billion years ago. This research is an important step in understanding the mantle and atmosphere during the first half of Earth’s history. It also opens the door to more questions and research.This is not a work by Dr Timmerman. It is an independent comment.###
