The mysterious impact results in a 400 km crater
It is about a crater of 400 kilometers that doesn’t exist anymore nowadays. A group of researchers, digging for more than two miles below the earth’s crust, found traces of this violent impact that can be traced back over 300 million years ago.
In central Australia were found fragments of a huge meteorite that smashed into two parts and has impacted the Earth millions of years ago, producing a crater of 400 kilometers wide (the impact zone is largest ever found on our planet ). Crater that was hidden by the track of time.
Credit: D. Seymour
Despite this, however, the researchers found two traces of the impact, as the scars on the surface, hidden deep in the crust. The two impact zones covering the huge area of 400 km in the Warburton Basin in central Australia and extend vertically into the depths of the earth’s crust, which is about 30 km thick in this area. The recovered material was classified as Suevite, namely a rock formed in part of melted material and which typically contains glass and crystal or rock fragments, resulting from a violent impact.
The study leader, Andrew Glikson from the ANU School of Archaeology and Anthropology, said that the impact zone was discovered during a drill in a geothermal research area on the border with South Australia, Queensland and Tasmania. “The two great objects were to measure 10 km in width,” said Glikson. By having discovered an event of this scope and violence, in future, it will help geologists understand something more about the origins of our planet. “Big impacts as these may have had a role in the evolution of the Earth much more significant than previously thought,” he added.
It is about of millions of years ago, but the precise date has not been reached yet. The surrounding rocks have from 300 to 600 million years, but it is still hard to see when these two meteorites have fallen in Australia. For example, 66 million years ago a large meteorite and its tail of hot ashes scattered sediment on the rocks around the world. And experts believe that this trail of “death” has led to the extinction of a large number of living beings then existing on Earth, starting from dinosaurs. It must be said, however, such a test was not found on the rocks of 300 million years ago in the area of the discovery in Central Australia.
And researchers led by Glikson have stumbled by chance on these impacts down to a depth of over two miles into the earth’s crust. The extracted sample contained traces of rocks that had been turned into glass due to extreme temperature and pressure caused by the violent impact. Magnetic models of the Earth’s crust have traced bulges (as pockets) hidden in the depths of the Earth and rich in iron and magnesium (materials that are identical to the Earth’s mantle – i.e. at depths well above). Glikson explained that “there are two huge domes and deep in the crust, which were formed just by” bouncing “of the same crust caused by the many impacts, which have also brought” on the surface “material from the underlying mantle.”
This is a mystery: “We are not able to find a destructive event” in the history of life on Earth, “which corresponds to this double collision. My suspicion is that the impact may be older than 300 million years,” added Glikson.