One of the strongest lines of evidence of a meteor or comet impact in the late Cretaceous is
A)the extinction of the dinosaurs.
B)a thin layer of potassium-40 in late Cretaceous fossil strata.
C)a thin layer of iridium-enriched clay in late Cretaceous fossil strata.
D)the warming of Earth's climate in the late Cretaceous.

Question

Quizplus · Accepted Answer

The thin layer of iridium-enriched clay in late Cretaceous fossil strata is a strong line of evidence for a meteor or comet impact. Iridium is a rare element on Earth's surface but is abundant in meteorites, indicating that a large amount of iridium in the Earth's crust likely came from an extraterrestrial source. The iridium-enriched layer is found worldwide and corresponds to the time of the extinction of the dinosaurs. This provides strong evidence that a meteor impact occurred and caused the mass extinction event.

One of the Strongest Lines of Evidence of a Meteor