iridium layer
Asteroid impact signature
The iridium layer is a thin stratum of sediment found worldwide, dating to approximately 66 million years ago and marking the boundary between the Cretaceous and Paleogene periods.
Its unusually high concentration of iridium—an element rare on Earth but common in asteroids—provides key evidence for the asteroid impact theory of dinosaur extinction.
Also called the K-Pg boundary or K-T boundary.
- asteroid impactSpace rock collision event
- meteoriteSpace debris reaching Earth
- K-Pg boundaryGeological extinction horizon
- extinction eventCatastrophic biodiversity collapse
- sedimentary rockLayered geological formation
paleontology · platinum · Alvarez · smoking gun · stratigraphy · shocked quartz · fossil record · bolide · dinosaur extinction · geochronology · deep time · cosmic dust · mass extinction · unconformity · radiometric dating · scientific consensus · deposition · cataclysm
- meteor impactscraters, impact crater, impact craters, crater, meteorite
- AlvarezNobel Prize, physicist, K-Pg boundary, dinosaur extinction, asteroid impact
- extinctionmass extinction, dodo, extinct, extinction event, extinction rate
- Cretaceous PeriodVelociraptor, hadrosaur, ceratopsian, titanosaur, K-Pg boundary
- space materialsmeteorites, moon rocks, lunar samples, stardust, space rocks
- Cretaceous GeologyK-Pg boundary