James Kennett, along with ETH Zurich researcher Gerald Haug, cut into the ice sheet in Greenland to retrieve samples from the glacial layers. The ice sheets serve as a striated window into the Earth’s past.
According to James Kennett, the expedition involved traversing a good amount of difficult terrain, as the ice sheets of Greenland are significantly remote.
“The area is cold, remote and [mostly] inaccessible,” James Kennett said. “Looking for a potential layer of diamonds in an ice sheet is like trying to find a needle in a haystack.”
The results provide more evidence for the controversial hypothesis that a comet struck the Earth approximately 12,900 years ago, causing massive changes to the climate and resulting in the mass extinction of approximately 35 mammal species, 19 bird species, and the human Clovis culture of North America.
The nanodiamonds were found in the Younger Dryas Boundary, or YDB, layer, which dates to the approximate time of the comet impact and has been of great interest to Kennett and his team. The Greenland expedition is a continuation of the team’s research, which included a find of the nanodiamonds in the YDB layer on Santa Rosa Island, providing scientists with a better look into the state of the planet at the time.
The nanodiamonds were also found with hexagonal diamonds, which have only been known to form as a result of the intense conditions produced by a cosmic impact — such as one produced by a comet colliding with the Earth.
In addition to their findings, the team was the first to locate free diamonds within a glacial ice sheet.
“The most exciting thing that has emerged from this expedition is that we have discovered free diamonds in glacial ice for the first time on Earth,” Kennett said.