Increasingly in recent years, scientists began to argue that the meteorite fall was for the dinosaurs kind of an act of mercy. The fact that they were so at the time were on the verge of extinction as a result of a changing climate due to volcanic eruptions.
In support of this theory, American scientists from the University of California at Berkeley under the direction of Paul Rennie presented a study of the crater in the Yucatan peninsula in Mexico.
Scientists, using the technique of high-precision dating studied tektites from Haiti, which were formed under the impact of a meteorite. In the analysis, they concluded that the impact of a meteorite occurred 66,038,000 years ago, so much later than previously thought. Given the uncertainty, the date almost coincides with the approximate time of the extinction of dinosaurs from the surface of our planet. Thus, according to Paul Rennie, there remains little doubt that it was a meteorite has played a role in the death of the dinosaurs.
Of course, this does not mean that the fall of the planet of the celestial body was the main cause of the mass extinction of the giant lizards. However, the fall of the meteorite was preceded by numerous volcanic eruptions in India, who changed the climate and led to the deaths of many groups of dinosaurs. For example, the researchers found no neptichego dinosaur that existed at the time of impact.
Volcanic hypothesis was proposed long before the meteor. In addition, it is consistent with what was known about the other mass extinctions. The first meteor theory in the 1980s, offered the father and son Luis and Walter Alvarez. This theory quickly gained popularity in the scientific community. Alvarez pointed out that the world is common layer of clay, which is on the structure of education coincides with the end of the Cretaceous period. This layer is unique in that it is rich in iridium, which is rare on earth, but are almost always part of the small space bodies.
10 years later, this hypothesis was further spread when when the Yucatan Chicxulub crater was discovered diameter of 180 km. Scientists have found out then that he was also formed at the Cretaceous-Paleogene boundary. Size craters indicate that the meteorite was about 10 kilometers across.
According to experts, a collision with such a large space body was then have disastrous consequences in the form of tsunamis, fires, devastating shock waves and rain of molten rock, since the substantial impact of the meteorite fragments could fly beyond the atmosphere, and then come back. Besides, a lot of particulate matter in the atmosphere could be weeks, months, or even years, thereby blocking the rays of the sun. As a result, the air temperature could decrease substantially, and many of the plants die.
At one time, the meteorite theory was considered predominant among scientists. However, it turned out that the extinction of the dinosaurs began long before the fall of the meteorite. Over time, among the experts was nominated hybrid hypothesis. Thus, experts have argued that the massive volcanic eruptions quite capable of causing the extinction of species on the planet, but the final blow, still belonged intruder from space.
Since then, none of the hypotheses was decisive. Until now, scientists argue about which way and how much climate change volcanoes. So, some remember the eruption of Mount Pinatubo in 1991 and claim that the emissions from the sun it was closed, thereby causing global cooling. Others, however, believe that the volcanic gases have contributed to the greenhouse effect.
The same is still not clear and the way in which formed the Deccan Traps, by which to judge the strength of eruptions. Some scientists believe that the eruption had a uniform character and place in the end of the Cretaceous and early Paleogene, in a few million years. For others, a massive eruption occurred several thousand years, and then for a long time there came a lull.
The research results were published in the journal Science.
Category: Mystery stories