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Thu, 14 Nov 2019 22:17 GMT

New Rocks Shed Light on Asteroid that Killed the Dinosaurs

Science & Technology

7Dnews London

Tue, 10 Sep 2019 07:43 GMT

Rock samples extracted from the Chicxulub crater, a seafloor near Mexico, have given scientists a detailed record, through preserved layers, of the day when a giant asteroid hit Earth 65 million years ago, killing off dinosaurs and three-quarters of all life forms, WSJ reported on Tuesday, September 10th.

The samples hold geologic registries of the explosions, severe earthquakes, tsunamis, landslides, and wildfires caused by the asteroid that left a 170km (100 miles) wide, 19.5km (12 miles) deep hole.

The impact sent hundreds of billions of tons of sulfur, from destroyed ocean rock, into the atmosphere which resulted in a global winter with temperatures worldwide at -1.1 Celsius, as evidenced by chemicals in the extracted sediments.

The Chicxulub crater recorded the effects of the impact like a high-speed stop-action camera.

“Here we have 130 metres in a single day,” the study leader geophysicist Sean Gulick, University of Texas in Austin said, “we can read it on the scale of minutes and hours, which is amazing.”

Minutes after it had hit Earth, the asteroid collapsed into itself sending huge lava waves which later cooled down and formed a ring of high peaks. 

About 20 minutes or so later, seawater surged back over the newly formed peaks, covering them in a blanket of impact rocks, the scientists said. As minutes became hours, waves choked with shards of volcanic glass and splintered rock rippled back and forth, coating the peaks in a layer of impact rock called suevite, the scientists said. As the hours passed, the backwash of waves added more and more finely graded debris.

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