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Impact Crater Chain Wasn’t a Single Catastrophic Event

Five large meteorite impacts from a North America and Europe crater chain 4500 km long actually occurred randomly over a period of tens of millions of years rather than within seconds 214 million years ago, as originally thought – and none of them caused a mass extinction either according to research led by Curtin University geologist Dr Martin Schmieder.

Previous dating of the aligned impact craters had produced overlapping ages with relatively large error bars, leading scientists to believe that the craters were the result of simultaneous impacts.

However, Dr Fred Jourdan of Curtin University said that new dates for the Lake Saint Martin impact structure in Canada – one of the craters thought to have been formed during the giant multi-impact strike – produced “a fairly precise and meaningful argon-argon age of about 228 million years. Until recently, an uncertainty of 64 million years was associated with the age of the Lake Saint Martin impact, but the new age from our lab has only two million years of error.”

When the new data were combined with recent dating results from other craters in the chain, the researchers concluded that none of the craters are even remotely connected. “The differing refined crater ages are strong evidence that the Late Triassic multiple impact event never happened. Several million years lie between each of these asteroid impacts,” Jourdan said.

The research has been published in Earth and Planetary Science Letters.