Geologic evidence for the cause of the extinction event at the end of the Cretaceous includes:
A) a silicate-rich layer.
B) glacier deposits.
C) iron-nickel deposits.
D) an iridium-rich layer.

Question

Quizplus · Accepted Answer

An iridium-rich layer found in sedimentary rocks is the most widely accepted evidence for the cause of the extinction event at the end of the Cretaceous. This layer is thought to have formed as a result of an asteroid impact, which released large amounts of iridium into the atmosphere and caused widespread environmental changes.

Geologic Evidence for the Cause of the Extinction Event at the End