International Chronostratigraphic Timescale

The interval definitions in this timescale are derived from the following sources:

  • K. M. Cohen, S.C. Finney, P.L. Gibbard and J.-X. Fan. 2023. The ICS International Chronostratigraphic Chart v2023/09. view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 view
  • J. A. Lillegraven and M. C. McKenna. 1986. Fossil mammals from the "Mesaverde" Formation (Late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming, with definitions of Late Cretaceous North American Land-Mammal "Ages". American Museum Novitates 2840:1-68 view
  • F. F. Steininger, W. A. Berggren, D. V. Kent, R. L. Bernor, S. Sen and J. Agusti. 1996. Circum-Mediterranean Neogene (Miocene and Pliocene) marine-continental chronologic correlations of European mammal units. The Evolution of Western Eurasian Neogene Mammal Faunas (eds. R. L. Bernor, V. Fahlbusch, and H.-W. Mittmann) view
  • W. B. Harland, R. L. Armstrong, A. V. Cox, L. E. Craig, A. G. Smith and D. G. Smith. 1990. A Geologic Time Scale 1989. view

There are 59 timescales which overlap this one. show

Interval boundaries marked with * have been interpolated based on the differences between the ages for international timescale boundaries quoted in the source and the currently accepted ages for those boundaries.

Interval names marked with † are no longer in current use.

This timescale is used in the definition of 126175 collections

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International Chronostratigraphic TimescaleCambrian EpochsPermian of the PamirsCenozoic Subepochs of Southern EuropeCretaceous North American Land-Mammal AgesEuropean Faunal UnitsPermian of the Salt RangeOrdovician of Ibero-BohemiaObsolete Names for ICS Units
QuaternaryPleistoceneLate PleistoceneTarantian0.0117
ChibanianIonian0.129
Calabrian0.774
Gelasian1.8
NeogenePliocenePiacenzianVillanyianTertiary †2.58
Ruscinian3.1 *
Zanclean3.6
MioceneMessinianTurolian5.333
Tortonian7.246
Vallesian8.7
SerravallianAstaracian11.63
Langhian13.82
BurdigalianOrleanian15.98
Agenian20
Aquitanian20.44
PaleogeneOligoceneChattian23.03
Rupelian27.82
EocenePriabonian33.9
Bartonian37.71
Lutetian41.2
Ypresian47.8
PaleoceneThanetian56
Selandian59.2
Danian61.6
CretaceousLate CretaceousMaastrichtianLancian/Edmontonian66
CampanianJudithian/Aquilan72.1
Santonian83.6
Coniacian86.3
Turonian89.8
Cenomanian93.9
Early CretaceousAlbian100.5
Aptian113
Barremian121.4
Hauterivian125.77
Valanginian132.6
Berriasian139.8
JurassicLate JurassicTithonian145
Kimmeridgian149.2
Oxfordian154.8
Middle JurassicCallovian161.5
Bathonian165.3
Bajocian168.2
Aalenian170.9
Early JurassicToarcian174.7
Pliensbachian184.2
Sinemurian192.9
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
Kathwai251.5 *
PermianLopingianChanghsingianDorashamian251.902
252.4 *
Chhidru252.9 *
WuchiapingianDzhulfianLongtanian †254.14
Kalabagh255 *
Wargal256 *
GuadalupianCapitanianMidian259.51
Wordian264.28
265.3 *
Amb266.1 *
Murgabian266.2 *
Roadian266.9
270.7 *
CisuralianKungurianKubergandian273.01
Bolorian279.8
Artinskian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianKosovian443.8
KatianKralodvorianBohdalec †445.2
Berounian449.7 *
Sandbian453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilian458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianKlabava †467.3
Arenigian468
Early OrdovicianFloian470
TremadocianTremadocian477.7
CambrianFurongianStage 10Late Cambrian485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianMiddle CambrianSeries 3 †497
Drumian500.5
WuliuanStage 5 †504.5
Series 2Stage 4Early Cambrian509
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8