Scientists find ‘smoking gun’ evidence of world’s oldest meteorite strike in Western Australia

A meteorite that struck Earth three billion years ago left behind a “smoking gun” – evidence of the world’s oldest impact crater in a remote part of Australia. Ancient rocks in Western Australia’s Pilbara region record the event, which occurred during the Archean eon, a period 4 to 2.5 billion years ago, when tectonic plates were beginning to form and early life emerging. To establish a precise date, Curtin University scientists analysed the age of rare geological features, called shatter cones, in an area known as the North Pole Dome crater, publishing their findings in Geology journal. Prof Chris Kirkland, a geologist from Curtin’s Timescales of Minerals Systems Group and lead author of the paper, said the well-preserved rock formations were an extremely rare and globally significant archive of geological time, offering “a rare glimpse of the violent processes that shaped the early Earth”. “There’s very few places that are these deep time capsules that let us peer into the formative processes on our planet. That’s why they’re quite special.” The findings revealed the North Pole Dome crater to be older than Yarrabubba , another crater in Western Australia, previously considered the oldest at 2.2 billion years old. Rare geological features were found in the Pilbara. Photograph: Chris Kirkland/Curtin University The researchers used two separate methods to determine when the meteorite strike occurred. …