a few 55 million years, the Earth went through a period of extremely warm called the Thermal Maximum of the Paleocene-Eocene (PETM, for its acronym in English), in which emissions of carbon dioxide was fired and temperatures went up an average of 6ºC.
The specialists explained that the causes of this global event, which caused an extinction gradual and affected the evolution of many groups of mammals, have until now been the subject of debate, attributed commonly to a gigantic volcanic eruption prolonged for thousands of years.
But time, researchers from the Earth Institute at Columbia University published in the journal Science a theory of their own. The scientists found evidence off the coast of New Jersey, united States, that an object alien, probably a comet hit our planet at that time, which could be related to the phenomenon.
"This could very well be the ground zero" of the PETM, said Dennis Kent, a co-author of the study. This researcher already suggested in 2003 that the phenomenon could have been caused by a comet, but many of his colleagues rapidly rejected the hypothesis.
The new study offers as evidence a small spherical beads of glass calls microtectitas, which are formed when an object of extraterrestrial comes to Earth and sprayed vaporized material that solidifies during the flight through the air.
The samples came from drill cores taken in the suburbs of Millville and Wilson Lake, and a shore in the vicinity of Medford, all in New Jersey. Section 9-metre thickness of fine material, known as clay Marlboro, found in several areas along the East coast of the US, and it seems that it has quickly established.
The majority of scientists say that the carbon release at the onset of the PETM lasted from 5 thousand to 20 thousand years. Many suspect that it was the increase of volcanic activity massive. The warming resulting could have been instigated by a sudden release of frozen methane from the seabed, due to the heating of the carbon, changes in the Earth’s orbit or changes in the ocean circulation.
The temperatures rose 5 to 9 ° C, during a period of warming, almost simultaneous, which lasted for about 200 thousand years. The planet had barely any ice, and sea levels were dramatically higher than it is now. Many small single-cell creatures of the bottom of the ocean is extinct, but on the surface, many species are adapted to moving toward the poles.
The mammals, including primates, have evolved quickly. “It was almost a happy time for some, but of course there were winners and losers,” says Kent.
In 2013, Schaller and James Wright of Rutgers University, (also co-author of the new paper) published a study that claimed that the carbon release at the PETM was almost instant. Your evidence: extremely high levels of carbon isotopes that appear in a narrow band of clay Marlboro, which represents nearly a dozen years. This band is located near the material expelled from the impact of newly discovered.
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