From L. cretaceus, from cret(a) "chalk, clay," + → -aceous, because the geological remains of this period contain heightened chalk deposits.
Gacâsâ, from gac "chalk," Mid.Pers. gac + -âsâ, → -aceous.
Cretaceous-Paleogene extinction event
ruydâd-e xâmuši-ye Gacâsâ-Pârinzâd
Fr.: extinction Crétacé-Tertiaire
The → mass extinction event that destroyed the dinosaurs and a majority of other species on Earth approximately 65 million years ago. This event is believed to have been the impact of a 10 km-size → asteroid or → comet nucleus and its aftereffects, including a severe → impact winter. The collision would have released the energy equivalent to 100 million megatonnes (teratonnes) of → TNT, i.e. more than 109 times the energy of the atomic bomb dropped on Hiroshima on August 6, 1945. Same as the → Cretaceous-Tertiary event.
ruydâd-e K-T (#)
Fr.: événement K-T