(CN) – Volcanic eruptions have brought superdeep diamonds to the surface of the Earth, which contain gases scientists say are proof there is a subterranean reservoir untouched by man and at least as old as the moon.
The face of Earth today is nothing like what it was at its formation, and scientists have long believed somewhere between Earth’s crust and its core there is a reservoir of rock relatively unbothered by the commotion on the surface. In a study published Thursday in the journal Science, research leader Suzette Timmerman and her colleagues looked at superdeep diamonds from Brazil and found they held clues about this mysterious reservoir.
Researchers studied volcanic rocks called basalts from deep underground for a glimpse into the mantle below us. In specific locations, these basalts show helium isotope readings strikingly similar to extremely old meteorites, furthering the suspicion of a reservoir billions of years old.
Timmerman honed in on ocean island basalts, which is lava that formed islands like Hawaii and Iceland, for reference because they hold these same characteristics. Unfortunately, while these basalts show a glimpse into their past, they don’t show much about where they came from.
Superdeep diamonds, however, show a much clearer picture. They are found deeper below the surface than average diamonds and act as miniature time capsules that hold information about the world below us. While forming, they encapsulate elements of their surroundings like a snapshot of their environment at the time.
Timmerman and her team of international scientists extracted helium isotopes from 23 superdeep diamonds and found their compositions are exactly what they expected from an ancient reservoir. These findings confirm there is a reservoir as old or even older than the moon, and also points to its location being either in the transition zone or below it – 250 to 400 miles beneath our feet.
With this work, Timmerman and her team present a never-before-seen inside look at Earth’s interior. While several questions remain, scientists now have solid proof of possibly the oldest and most well-preserved material on the planet.
This research will be presented Friday at the Goldschmidt conference in Barcelona to scientists from around the world, and is just the beginning to understanding what exactly lies beneath Earth’s mantle.