Why did scientists FIRST hypothesize that a meteorite impact caused the extinction at the K-T boundary?
A) They found evidence of a giant tsunami on the Gulf coast.
B) They found evidence of an impact crater in Mexico.
C) They found evidence of wildfires in many regions throughout the globe.
D) They found evidence of iridium enrichments in a clay layer that led them to believe that the iridium was the remains of a meteorite impact.
E) They found evidence of acid rain in the rocks in the Southern Hemisphere.

Question

Quizplus · Accepted Answer

The initial hypothesis that a meteorite impact caused the extinction at the K-T boundary was based on the discovery of a worldwide layer of clay enriched with iridium, a rare element on Earth's surface but common in meteorites. This finding suggested an extraterrestrial source for the iridium, pointing to a massive meteorite impact.

Why Did Scientists FIRST Hypothesize That a Meteorite Impact Caused