Clay layers enriched in _______ found in the rock record at the Cretaceous-Tertiary boundary provide evidence of an asteroid impact.
A)uranium
B)potassium
C)iridium
D)plutonium

Question

Quizplus · Accepted Answer

Clay layers enriched in iridium at the Cretaceous-Tertiary (K-T) boundary are evidence of an asteroid impact, as iridium is rare in the Earth's crust but abundant in asteroids and comets.

Clay Layers Enriched in _______ Found in the Rock Record