'Meteorite storm caused extinction on Earth 12,000 years ago'
London, June 13 2012
Scientists claim to have found new compelling evidence that suggest a meteorite storm hit the Earth more than 12,000 years ago which might have caused the extinction of a prehistoric civilisation and giant animals including mammoths.
An international team of researchers found a substance known as melt glass, which forms at temperatures of 1,7000 to 2,200 degrees Celsius and can result from a “cosmic body” hitting the earth.
The researchers believe the huge cosmic impact triggered a vicious cold snap, which caused widespread destruction.
The material was unearthed in a thin layer of rock in Pennsylvania and South Carolina in the US and in Syria. Tests confirmed the material was not of cosmic, volcanic or human-made origin.
“The extreme temperatures required are equal to those of an atomic bomb blast, high enough to make sand melt and boil,” James Kennett, professor of earth science at UC Santa Barbara, was quoted as saying by the Daily Mail.
The melt-glass seems identical to other material found in Meteor Crater in Arizona, and the Australasian tektite field, and also matches melt-glass produced by the 1945 Trinity nuclear airburst in New Mexico in the US, Prof Kennett said.
The team's findings, published in the Proceedings of the National Academy of Sciences, support the controversial theory that an asteroid impact some 12,900 years ago triggered the start of an unusual cold period on Earth, leading to the mass extinction of human and animal life.
In the cold period, known as the Younger Dryas, North American megafauna including mammoths and giant ground sloths disappeared forever, along with a prehistoric civilisation called the Clovis people who are regarded as the first human inhabitants of the New World.
Evidence supporting the theory has been found on three continents, covering nearly one-third of the planet, from California to Western Europe and into the Middle East.
Melt-glass has been found in rock layers of the same age in Arizona and Venezuela.
The three sites found in the latest study were separated by 1,000 to 10,000 km, suggesting that “a swarm of cosmic objects”, either fragments of a meteorite or comet, had hit the Earth, Prof Kennett said.
He added that the archaeological site in Syria where the melt-glass material was found Abu Hureyra, in the Euphrates Valley is one of the few sites of its kind that record the transition from nomadic hunter-gatherers to farmer-hunters who live in permanent villages.
“Archaeologists and anthropologists consider this area the 'birthplace of agriculture', which occurred close to 12,900 years ago,” Prof Kennett said.
“The presence of a thick charcoal layer in the ancient village in Syria indicates a major fire associated with the melt-glass and impact spherules 12,900 years ago,” he said. “Evidence suggests that the effects on that settlement and its inhabitants would have been severe.”
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Images from the movie, "Melancholia"
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