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Geologic Time Scale: Periods

EonEraPeriodDates (m.y.)
PhanerozoicCenozoicNeogene23-0
Paleogene66-23
MesozoicCretaceous146-66
Jurassic200-145
Triassic251-200
PaleozoicPermian299-251
Carboniferous359-299
Devonian416-359
Silurian444-416
Ordovician488-444
Cambrian542-488
ProterozoicNeoproterozoicEdiacaran630-542
Cryogenian850-630
Tonian1000-850
MesoproterozoicStenian1200-1000
Ectasian1400-1200
Calymmian1600-1400
PaleoproterozoicStatherian1800-1600
Orosirian2050-1800
Rhyacian2300-2050
Siderian2500-2300
ArcheanNeoarchean
2800-2500
Mesoarchean
3200-2800
Paleoarchean
3600-3200
Eoarchean
4600-3600
EonEraPeriodDates (m.y.)
(c) 2005 Andrew Alden, licensed to About.com, Inc. (fair use policy). Data from Geologic Time Scale of 2004.

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.

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