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It's hard to imagine how billions of tons of rock can suddenly behave like a liquid, but that's exactly what happened when an asteroid hit the Earth 66 million years ago.
The samples obtained from the crater formed after the collision made it possible to conclude that the rocks had undergone a process of "fluidification".
In other words, the pulverized material began to behave like a water-like substance
200 km crater
Computer models allowed to determine what would happen if a rocky object, 12 kilometers in diameter from space, collided with the surface of the Earth [19659002] Initially, a concave space of about 30 kilometers deep and 100 kilometers in diameter would be created almost instantly [19659002] The instability of the ground would later cause a collapse in the crater's banks. And this collapse would in turn cause a rebound reaction from the bottom of the crater to heights higher than the Himalayas.
These giant movements would stabilize at one time and what would remain would be a crater about 200 kilometers in diameter.
This model is referred to as the "crater dynamic cracking model" and the impact described is only possible if the rocks lost for a time their strength and flow without friction.
A new study, published in the scientific journal Nature, presents evidence of this process, based on rock drilling material from a peak ring located in the center of the Chicxulub Depression. "What we discovered when looking at the rocks, is that they were fragmented," BBC researcher Ulrich Riller, a researcher at the University of California at Berkeley, told BBC. University of Hamburg, Germany
"The rock was crushed and fragmented into tiny fragments first in millimeters, producing a fluid behavior that explains the flat base of the crater, which characterizes the Chicxulub and other cases of great Des impacts, like what we see on the moon. "
Fluidisation is not a process of melting rocks but a fragmentation of the rock by immense vibratory forces, says Sean Gulick of the # 39, University of Texas at Austin, United States. and one of the leaders of the drilling team.
"It is a pressure effect, a mechanical damage.The amount of energy that pbades through these rocks is equivalent to earthquakes of magnitude 10. or 11. It is estimated that 39; total impact had an energy equivalent to 10 billion bombs of Hiroshima. "
After their fragmentation and their fluidification, the rocks have regained their strength to form the crater ring. This results in discontinuities showing how rocks slide relative to other rocks. These flat structures testify to the strength of the rock at the end of the year. "The asteroid of 12 kilometers in diameter was a hole of 100 kilometers in diameter and 30" of the asteroid of 12 kilometers in diameter. "
Chicxulub Crater – the collision that has changed Life on Earth
– The center of the crater has collapsed again, producing an inner ring.
– Today, the crater center has collapsed, producing an inner ring., a large part of the crater is in the sea, under 600 m of sediment.
– On the mainland, the crater is covered with limestone, but its edges can be identified along an arc of cenotes – natural cavities dissolved by rocks
# Not only in our solar system & # 39;
Research sheds new light on some of the most catastrophic days in the world 39, history of the Earth and on the mbad extinction produced by the i
"We explain a fundamental process that can occur in any rock body," said Gulick.
"For the first time, we have rock samples that show the process of deformation that allowed them to act temporarily as a liquid before becoming rocks again, without melting."
" This process results from the overlap of deformation mechanisms, which is a fundamental process that can alter the surface of planets, not just in our solar system, but probably in other solar systems. "
Riller and Gulick participated in the so-called 364 drilling expedition, which took place between April and May 2016.
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