Geologic Time Scale: Periods
| Eon | Era | Period | Dates (m.y.) |
| Phanerozoic | Cenozoic | Neogene | 23-0 |
| Paleogene | 66-23 | ||
| Mesozoic | Cretaceous | 146-66 | |
| Jurassic | 200-145 | ||
| Triassic | 251-200 | ||
| Paleozoic | Permian | 299-251 | |
| Carboniferous | 359-299 | ||
| Devonian | 416-359 | ||
| Silurian | 444-416 | ||
| Ordovician | 488-444 | ||
| Cambrian | 542-488 | ||
| Proterozoic | Neoproterozoic | Ediacaran | 630-542 |
| Cryogenian | 850-630 | ||
| Tonian | 1000-850 | ||
| Mesoproterozoic | Stenian | 1200-1000 | |
| Ectasian | 1400-1200 | ||
| Calymmian | 1600-1400 | ||
| Paleoproterozoic | Statherian | 1800-1600 | |
| Orosirian | 2050-1800 | ||
| Rhyacian | 2300-2050 | ||
| Siderian | 2500-2300 | ||
| Archean | Neoarchean | 2800-2500 | |
| Mesoarchean | 3200-2800 | ||
| Paleoarchean | 3600-3200 | ||
| Eoarchean | 4600-3600 | ||
| Eon | Era | Period | Dates (m.y.) |
Back to the top-level geologic time scale
This geologic time scale shows all the defined units of period rank, along with the eras and eons that comprise them. The periods of the Phanerozoic Eon are further subdivided into epochs; see those in the Phanerozoic Eon geologic time scale. Epochs are further subdivided into ages; see those in the Paleozoic Era, Mesozoic Era and Cenozoic Era geologic time scales.
The dates and colors shown on this geologic time scale were specified by the International Commission on Stratigraphy in 2004.
