London, Feb 21 (IANS) A gigantic asteroid that slammed into Australia more than 300 million years ago changed the face of the Earth forever, says a British media report.
The nearly 10 km wide asteroid left an impact zone nearly 200 km wide, the third largest such site on the planet, possibly triggering mass extinctions worldwide.
"The dust and greenhouse gases released from the crater, the seismic shock and the initial fireball would have incinerated large parts of the Earth. The greenhouse gases would stay in the atmosphere for tens of thousands of years," said Andrew Glikson, visiting fellow at the Australian National University.
Evidence of the ancient cataclysm was only discovered after another researcher alerted Glikson to unusual mineral deposits in the East Warburton Basin in South Australia.
As the ages have passed, the mammoth impact zone has been buried beneath nearly 2.5 miles of earth, the Daily Mail reports.
To identify it, Glikson and his colleagues analysed quartz grains drawn from the site and studied underground seismic and magnetic anomalies.
However, he added, the impact happened well before the time of the dinosaurs. "It's significant because it's so large. It's the third largest impact terrain anywhere on the Earth found to date," he said.