K-T Boundary: A thin band of sedimentation found in various parts of the world, which marks the boundary between the Cretaceous and Paleogene periods.
Chicxulub Crater: An impact crater on Mexico’s Yucatán Peninsula believed to be associated with the asteroid or comet that caused this mass extinction.
Iridium Enrichment: Iridium is a rare element on Earth but common in asteroids and comets. Its high concentration at K-T boundary sites around Earth provides evidence for an extraterrestrial impact causing this mass extinction.