From Simple English Wikipedia, the free encyclopedia
The K/T boundary. The intermediate claystone layer contains 1000 times moreiridium than the upper and lower layers. It is the boundary between Cretaceous andTertiary Periods. The rock is fromWyoming, USA.
TheCainozoic (Cenozoic) is the currentgeologicalera. It began 66million years ago and continues today. Before it was theMesozoic.
During the Cainozoic the continents moved into their present positions. The climate started warm, but cooling continued steadily. Finallyice ages occurred.
The word Cainozoic is derived fromGreekkainos = "new", andzoe = "life". 'Cainozoic' may be spelled 'Cenozoic'. It has threeperiods, and the periods are split intostages.
Previously, what is now the Cainozoic was divided into two periods, theTertiary and theQuaternary. The Tertiary corresponded to thePalaeogene+Neogene. Now, the term 'Tertiary' is not used. Officially, it is 'deprecated'.
