What is the iridium anomaly?

A: a type of dinosaur fossil.
B: an unusually high concentration of iridium in clay layer.
C: a volcanic ash layer.
D: a type of meteorite.

1 answer

B: an unusually high concentration of iridium in a clay layer.

The iridium anomaly is primarily associated with the boundary layer between the Cretaceous and Paleogene periods, marking the extinction event that struck the Earth about 66 million years ago, often linked to the impact of a large asteroid or comet.