Question

The purpose of calculating the ratio of iridium AT the K-Pg boundary vs ABOVE or BELOW the boundary is

A.to show that the largest amounts of iridium were in the K-Pg boundary, supporting the hypothesis of an asteroid strike.
B.to prove that the iridium levels were the same throughout all layers.
C.to show that the smallest amounts of iridium were in the K-Pg boundary, supporting the hypothesis of an asteroid strike.

Answer 1

The purpose is to support the asteroid impact hypothesis for the K-Pg mass extinction by demonstrating higher iridium levels at the K-Pg boundary, suggesting asteroid material was deposited there. Thus option A is correct.

Step-by-step explanation:

The purpose of calculating the ratio of iridium at the K-Pg boundary versus above or below the boundary is to show that the largest amounts of iridium were in the K-Pg boundary, supporting the hypothesis of an asteroid strike. This is because iridium is relatively rare in the Earth's crust, but abundant in asteroids, so an elevated concentration at the K-Pg boundary could indicate an asteroid impact that coincides with the mass extinction event at the end of the Cretaceous Period.

The discovery of elevated iridium levels, along with other evidence like the crater found in the Yucatan peninsula, supports the idea that an asteroid impact played a significant role in the mass extinction at the K-Pg boundary.