Scientists have discovered evidence that at early stages of existence of the Earth fell on it with a giant asteroid 20-30 kilometers in diameter. Such a blow people haven’t seen. 400-kilometre area of fall of a giant meteorite, which broke into two parts before the fall, was discovered in Australia. Impact crater hundreds of miles wide has long since disappeared. But a group of geophysicists found two scars from the fall — zone of the biggest meteorite impact ever seen on Earth — hidden deep in the earth’s crust.
“Tiny glass beads, spherules, found in the North-West of Australia, were formed from evaporated material in the process of falling of an asteroid,” said Andrew Glikson from the Australian national University (ANU). — Major strikes like these could have a far more important influence on the evolution of the Earth than previously believed”.
The exact date of these attacks remains unknown. The age of the surrounding rocks 300-600 million years — but such evidence left by other meteors, it is not enough. “It is a mystery — we cannot find the event of the extinction, corresponding to these collisions. There is a suspicion that this fall more than 300 million years.”
“In the bark there are two huge domes formed in the process of restructuring the earth’s crust after serious bumps and rocks rise from the mantle below,” says Glikson. The two strike zone for a total of 400 kilometers in diameter in Warburton basin in Central Australia. They pass through the earth’s crust, whose thickness in this area is 30 kilometers.
“Such exposure was supposed to cause earthquakes are many orders of magnitude stronger than the earth quake and the huge tsunami and destruction of the rocks,” says Glikson. — Material from this blow would spread around the world. These spherules were found in the sediments, which give to 3.46 billion years.”
3.8 to 3.9 billion years ago the moon was dropping a lot of asteroids that formed the craters — the sea is still visible from the Earth. “To say precisely when the asteroid hit the Ground, hard,” says Glikson. — Any craters from these times on the Earth’s surface have been erased by volcanic activity and tectonic movement.”
Glikson, and Arthur Hickman of the Geological survey of Western Australia have found glass beads in the core in the North-West of Australia, one of the oldest known sediments on Earth. The layer of sediment that was originally on the bottom of the ocean, preserved between two volcanic layers, which allowed to accurately determine the time of its origin.
Glikson, who is looking for evidence of ancient falls of more than 20 years, immediately suspected that this glass is of impact origin. Subsequent tests revealed elements such as platinum, Nickel and chromium, corresponding in composition to the asteroids. Such drops could be much more, I just haven’t found them yet.
“This is just the tip of the iceberg. We found traces of a total of 17 strikes older than 2.5 billion years, but their must be hundreds of. The asteroid impact of this size has caused tectonic shifts and powerful currents of magma. They definitely influenced the development of the Earth.”
Scientists have found a place of falling of a giant asteroid that… no one was killed
Ilya Hel