Earth's oldest asteroid strike linked to 'big thaw'

ScienceDaily | 1/22/2020 | Staff
The research, published in the leading journal Nature Communications, used isotopic analysis of minerals to calculate the precise age of the Yarrabubba crater for the first time, putting it at 2.229 billion years old -- making it 200 million years older than the next oldest impact.

Lead author Dr Timmons Erickson, from Curtin's School of Earth and Planetary Sciences and NASA's Johnson Space Center, together with a team including Professor Chris Kirkland, Associate Professor Nicholas Timms and Senior Research Fellow Dr Aaron Cavosie, all from Curtin's School of Earth and Planetary Sciences, analysed the minerals zircon and monazite that were 'shock recrystallized' by the asteroid strike, at the base of the eroded crater to determine the exact age of Yarrabubba.

Team - Impact - Landscape - Volume - Ice

The team inferred that the impact may have occurred into an ice-covered landscape, vaporised a large volume of ice into the atmosphere, and produced a 70km diameter crater in the rocks beneath.

Professor Kirkland said the timing raised the possibility that the Earth's oldest asteroid impact may have helped lift the planet out of a deep freeze.

Yarrabubba - Sandstone - Meekatharra - WA - Impact

"Yarrabubba, which sits between Sandstone and Meekatharra in central WA, had been recognised as an impact structure for many years, but its age wasn't well determined," Professor Kirkland said.

"Now we know the Yarrabubba crater was made right at the end of what's commonly referred to as the early Snowball Earth -- a time when...
(Excerpt) Read more at: ScienceDaily
Wake Up To Breaking News!
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!