Question

observe the line visible across the hell creek area. this line is the boundary between two formations. the top is called the tullock formation and the bottom the hell creek formation. what is the old term for the boundary between the two formations? k-t boundary k-pg boundary asteroid boundary extinction line impact margin

Explanation:

The old - term for the boundary between the two geological formations is the K - T Boundary. The K - T Boundary marks the end of the Cretaceous period and the beginning of the Tertiary period and is associated with the mass extinction event that wiped out the non - avian dinosaurs. The K - Pg Boundary is the modern term. There are no such standard terms as Asteroid Boundary, Extinction Line, or Impact Margin for this formation boundary.

Answer:

A. K-T Boundary