Table 1: Eons and Eras of geologic time
| Eon | Era | Beginning of Era (MA) | |||
| Phanerozoic | Cenozoic | 66 | |||
| Mesozoic | 245 | ||||
| Paleozoic | 570 | ||||
| Proterozoic | Late | 900 | |||
| Middle | 1600 | ||||
| Early | 2500 | ||||
| Archean | Late | 3000 | |||
| Middle | 3400 | ||||
| Early | 3900 (?) | ||||
| (Earth formation) | 4550 |
Table 2: Eras, Periods, and Epochs of Phanerozoic time
| Era | Period | Epoch | Beginning of Era (MA) | ||||
| Cenozoic | Quaternary | Holocene | 0.01 | ||||
| Pleistocene | 1.7 | ||||||
| Tertiary | Pliocene | 5 | |||||
| Miocene | 24 | ||||||
| Oligocene | 37 | ||||||
| Eocene | 58 | ||||||
| Paleocene | 66 | ||||||
| Mesozoic | Cretaceous | 144 | |||||
| Jurassic | 208 | ||||||
| Triassic | 245 | ||||||
| Paleozoic | Permian | 286 | |||||
| Carboniferous (Pennsylvanian) | 320 | ||||||
| Carboniferous (Mississippian) | 360 | ||||||
| Devonian | 408 | ||||||
| Silurian | 438 | ||||||
| Ordivician | 505 | ||||||
| Cambrian | 570 |
