Friday , August 19 2022

Did the dinosaurs disappear by asteroids or folcanoes? It's complicated


Every child in the school knows that dinosaurs they were abolished by a asteroid and crash against the Earth about 66 million years ago.

But scientists say the story could not be so simple, and that the huge volcanic battles hundreds of thousands of years may have contributed to disappearance dinosaurs at the end of the Cretaceous period.

Two studies published on Thursday in the magazine Science contributed to a long scientific debate about what just ended the powerful one reptiles.

Before the 1980's, the most obvious theory had been huge and long volcanic combat they caused rapid and deadly change in the planet's climate by sending vast clouds of ash, gas and dust to the atmosphere.

Then the scientists discovered the massive Chicxulub Crater, product of old effect asteroid on the Caribbean coast Mexico, they had claimed that they had sent so much waste to the atmosphere that they blocked photosynthesis in plants and killed three quarters of life on Earth.

The authors of both reports published on Thursday could dateluxury lava mass with much more detail, reducing them from around a million years up to a tens of thousands of years.

"We were able to accurately recreate the event sequence at the end of the period Cretaceous period"he said AFP Loyc Vanderkluysen, science science professor at Drexel University in Philadelphia.

Vanderkluysen was part of a team that was out of date lava flow called Traps (or stairs) and Deccan in the India using radiation measurements. The other team used a different dating method.

He left the lava there more than a million years ago, he left Deccan more than 1,200 meters thick in many places today, volume is large enough to cover the size of the area France at a depth of several hundred meters, he said.

The new date made by the two teams coincides: one finds that a "pulse" of volcanic combat It happened just before the great extinguishment.

The other is less detailed, but it's most suggestive lava flow happened after the asteroid hit the Earth, supporting the idea that the effect causes earthquake so strong that he would have registered 11 on the scale of the size of the minute, something never seen by people.

In turn, he toned a tone volcanic combat which lasted about 300,000 years.

"That reinforces the theory that the main cause was an impact," said Vanderkluysen. "It's like shaking Orangina bottle, it can accelerate volcanic activity"continued.

The researchers claim that the close relationship of both incidents, explosions and extensions, is not a coincidence.

Other intense periods volcanic activity They have coincided with major extinguishing events, says Blair Schoene, a science science professor at Princeton and another co-authored study.

"The big question is whether the extinguisher would have taken place without the effect, given the volcanicism, or vice versa, the dumping would have occurred without the hypothesis, given the effect? I think we know that answer, "he said. AFP.

"The main point is that it is not so simple. nature It's complicated, "he added." By studying both phenomena as much detail as possible, we can try to find out what the whole story is. "

Arrange a timeline of that disappear A huge back-back event is essential, Schoene said, to understand the consequences of the "sixth eradication", as it is called, which people are causing at the moment.

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