What hypothesis did Luis Alvarez propose to explain the Iridium rich clay layer located at the Cretaceous Teritary boundary?
asteroid impact
Curiosity about the clay layer at the Cretaceous-Tertiary (K-T) boundary prompted investigators to measure the amount of iridium within that layer to calculate the rate at which it was deposited. That experiment yielded a surprising result that led to the hypothesis that the iridium came from an asteroid impact.
What is the most common reason of mass extinction?
Mass extinctions happen because of climate change, asteroid impacts, massive volcanic eruptions or a combination of these causes. One famous mass extinction event is the one that lead to the extinction of dinosaurs, 65 million years ago.
What are the major theories explaining the disappearance of the dinosaurs?
Today, paleontologists have discerned that most dinosaur lineages disappeared by about 66 million years ago after intense volcanic activity, climate change and a catastrophic asteroid impact triggered one of the worst mass extinctions in our planet’s history. Many forms of life disappeared.
Which of the following is the only event that did not occur immediately following the Tunguska impact?
Which of the following is the only event that did not occur immediately following the Tunguska impact? The Tunguska event did not leave an impact crater.
What conclusion did Luis and Walter Alvarez draw from the spike in iridium that occurs in rocks at the end of the Cretaceous?
His panel concluded that the asteroid struck a sulfate-rich area that released deadly sulfur aerosols, making the global cocoon of dust even more toxic. “We conclude that the Chicxulub impact was the ultimate cause for the mass extinctions of the dinosaurs,” Schulte told the media.
What does the Alvarez hypothesis tell us about how the dinosaurs became extinct?
The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. They had determined that a 10–15 km (6–9 mi) space rock hurtled into earth at Chicxulub.
What does mass extinction represent?
The extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.
What really happened to dinosaurs?
Sixty-six million years ago, an asteroid struck eastern Mexico and wiped out the dinosaurs.
What happened between dinosaurs and humans?
No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs.
How big was Tunguska?
830 square miles
Bottom line: The Tunguska explosion on June 30, 1908, was the largest asteroid impact in recorded history. It flattened 830 square miles (2150 sq km) of Siberian forest.
How big was Tunguska meteor?
The exploding meteoroid was determined to have been an asteroid that measured about 17–20 metres (56–66 ft) across. It had an estimated initial mass of 11,000 tonnes and exploded with an energy release of approximately 500 kilotons.