English Wikipedia - The Free Encycl...
הורד מילון זה
Era (geology)
A geologic era is a subdivision of geologic time that divides an eon into smaller units of time. The Phanerozoic Eon is divided into three such time frames: the PaleozoicMesozoic, and Cenozoic represent the major stages in the macroscopic fossil record. These eras are separated by catastrophic extinction boundaries, the P-T boundary between the Paleozoic and the Mesozoic and the K-T boundary between the Mesozoic and the Cenozoic. There is evidence that catastrophic meteorite impacts played a role in demarcating the differences between the eras.

See more at Wikipedia.org...


© This article uses material from Wikipedia® and is licensed under the GNU Free Documentation License and under the Creative Commons Attribution-ShareAlike License