SYDNEY, June 24. /TASS/. Scientists from Australia’s Curtin University have dated the Earth’s oldest asteroid impact at three billion years old.
The team investigated rock formations at the North Pole Dome in the northwestern part of Western Australia, a site long debated as an ancient asteroid impact structure, and discovered ancient minerals, including zircons whose crystals were interpreted as impact-modified and even regrown in places during the intense heating caused by the impact.
The findings helped identify the exact age of the impact structure. "The impact left a 'mineral clock' behind. By dating minerals that were remade or newly grown in the damaged rocks, we can now pin down when this extraordinary event happened," lead author Professor Chris Kirkland explained.
According to co-author Dr. Simon Johnson, the discovery places the North Pole Dome structure as the planet’s oldest known impact crater and "the only recognized example from the Archean eon."