An unusual, worldwide formation of sedimentary rock called the K-Pg boundary sequence contains rare elements that are associated with a(n) ____.
A) volcanic eruption
B) worldwide flood
C) ice age
D) asteroid impact
E) large earthquake

Question

Quizplus · Accepted Answer

The K-Pg boundary sequence is associated with an asteroid impact. This is evidenced by the presence of iridium, a rare element that is abundant in asteroids but rare on the Earth's surface, found in the K-Pg boundary layer around the world. This layer marks the boundary between the Cretaceous and Paleogene periods, about 66 million years ago, and is linked to the mass extinction event that wiped out the dinosaurs and many other species.

An Unusual, Worldwide Formation of Sedimentary Rock Called the K-Pg