Alvarez hypothesis

From Wikipedia, the free encyclopedia

The Alvarez hypothesis is the theory that the mass extinction of the dinosaurs and many other living things was caused by the impact of a large asteroid on the Earth sixty-five million years ago, called the Cretaceous-Tertiary extinction event. Evidence indicates that the asteroid fell in the Yucatán Peninsula. The hypothesis is named after the father-and-son team of scientists Luis and Walter Alvarez, who first suggested it in 1980.

Also supporting this hypothesis was the finding that a layer of the Earth's crust that was laid down at the time of the hypothesized asteroid impact contained elevated levels of iridium. Iridium levels are generally higher in asteroids and other non-terrestrial objects. The iridium evidence was discovered earlier than the Chicxulub Crater.