Biggest Asteroid Impact Crater Ever Discovered in Australia

We have found evidence of ancient impacts all across the Earth, from the famous Chixulub crater in Mexico to the Sudbury Basin a little bit closer to my home.  From Space the remains look nothing like craters, millions of years of sediment and growth hide the massive regions from obvious detection, but signs remain of these massive events, even after millions of years.  This week, what is possibly the largest impact crater basin ever discovered has been found in central Australia.  And it is thought to originate from the breakup of a massive 400 Km asteroid into two pieces that struck the Earth side by side.

Warburton Basin, from the Australian National University.

A team lead by Dr Andrew Glikson from the Australian National University (ANU) has discovered that the two impact sites known as the East and West Warburton Basin actually resulted from a single impactor.

“The consequences are that it could have caused a large mass extinction event at the time, but we still don’t know the age of this asteroid impact and we are still working on it.” Said Glikson, “”The next step will be more research, hopefully deep crust seismic traverses.”  Currently their seismic information covers five kilometres below the Earth, but a more complete study of the basin will come with a deeper probing of the rock layers beneath the basin.

Seismic Data showing metomorphic deformation in quartz crystals from the Warburton Basin. Credit: ANU

Since further study is required, it is not yet known if the impact could have affected life on Earth, or if its age corresponds to one of the great mass extinctions in the Earth’s history.  But the potential for finding a new key to the Earth’s history is exciting.  Still, with an impactor suspected to be larger than any in history, it would have been catastrophic to whatever environment Earth was sustaining at the time.

It’s always amazing how the study of impacts such as this can give us insights into how life gradually developed on Earth over Billions of years.  As the saying goes, only time will tell.

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