Which feature is one of the pieces of evidence that indicates that the boundary between the Cretaceous Period and the Tertiary was marked by the impact of a large meteorite (bolide) ?

The impact gave acid rain, depending on rocks the asteroid struck. Impact hypotheses can only explain very rapid extinctions, since the dust clouds and possible sulphuric aerosols would wash out of the atmosphere. the K-Pg layer consistently show the excess of the iridium.

Explanation:

The meteorite impact and the extinction of the species at the cretaceous boundary are known as the K and T boundary and can be understood using the thin band of rocks. The evidence is given by the Alvarez hypothesis and the higher iridium on the earth's crust.