The team from Curtin’s School of Earth and Planetary Sciences and the Geological Survey of Western Australia investigated rock layers in the North Pole Dome — an area of the Pilbara region of Western Australia — and found evidence of a major meteorite impact 3.5 billion years ago.
Study co-lead Professor Tim Johnson, from Curtin University, said the discovery significantly challenged previous assumptions about our planet’s ancient history. Previously the oldest impact crater was 2.2 billion years old he notes.
Researchers discovered the crater thanks to ‘shatter cones’, distinctive rock formations only formed under the intense pressure of a meteorite strike. Those shatter cones at the site, about 40 kilometres west of Marble Bar in WA’s Pilbara region, were formed when a meteorite slammed into the area at more than 36,000km/h. This would have been a major planetary event, resulting in a crater more than 100km wide that would have sent debris flying across the globe.
Co-lead author Professor Chris Kirkland, also from Curtin’s School of Earth and Planetary Sciences, said the discovery shed new light on how meteorites shaped Earth’s early environment.
