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, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
  • J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 126691 collections

Show less time

Show linear time

International Chronostratigraphic TimescaleCarbo-Permian of the Russian PlatformDevonian of FranceAmmonite Chrons of North AmericaObsolete Names for ICS Units
PhanerozoicCenozoicQuaternaryHoloceneMeghalayan0
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate Pleistocene0.0117
Chibanian0.129
Calabrian0.774
Gelasian1.8
NeogenePliocenePiacenzianTertiary †2.58
Zanclean3.6
MioceneMessinian5.333
Tortonian7.246
Serravallian11.63
Langhian13.82
Burdigalian15.98
Aquitanian20.44
PaleogeneOligoceneChattian23.03
Rupelian27.82
EocenePriabonian33.9
Bartonian37.71
Lutetian41.2
Ypresian47.8
PaleoceneThanetian56
Selandian59.2
Danian61.6
MesozoicCretaceousLate CretaceousMaastrichtian66
Campanian72.1
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
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianHowelli/Scissum/Westermanni170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
PaleozoicPermianLopingianChanghsingianMelekhovian251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
Noginskian264.9 *
Roadian266.9
CisuralianKungurian273.01
Pavlovoposadian276.8 *
Artinskian283.5
Rusavkinian287.6 *
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
KasimovianDorogomilovian303.7
Khamovnikian304.8
Krevyakinian305.8 *
MoscovianMyachkovian307
Podolskian308.9 *
Kashirian311.4 *
Vereian313.8
Melekessian314.8
Bashkirian315.2
Cheremshanian316.9 *
Prikamian318.6 *
Severokeltmian319.9 *
Krasnopolyanian321.2 *
Voznesenian321.9 *
MississippianSerpukhovianZapaltjubian323.2
Protvian324.4 *
Steshevian326.8 *
Tarusian329 *
ViseanVenevian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
Tulian335.8 *
Bobrikian339.9 *
Radaevkian343.4 *
TournaisianKosvian346.7
Kizelian350.7 *
Cherepetian351.9 *
Karakubian354.4 *
Upinian356.3 *
Malevkian357.6 *
Gumerovian358 *
DevonianLate DevonianFamennianFamennian358.9
FrasnianFrasnian372.2
Middle DevonianGivetianGivetian382.7
EifelianCouvinien387.7
Early DevonianEmsian393.3
Pragian407.6
Coblencien408.2 *
LochkovianGedinnine410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantian443.8
Katian445.2
Sandbian453
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Early OrdovicianFloian470
Tremadocian477.7
CambrianFurongianStage 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianSeries 3 †497
Drumian500.5
WuliuanStage 5 †504.5
Series 2Stage 4509
Stage 3514
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaran538.8
Cryogenian635
Tonian720
MesoproterozoicStenian1000
Ectasian1200
Calymmian1400
PaleoproterozoicStatherian1600
Orosirian1800
Rhyacian2050
Siderian2300
ArcheanNeoarchean2500
Mesoarchean2800
Paleoarchean3200
Eoarchean3600
Hadean4000
4600