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
  • A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 127731 collections

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International Chronostratigraphic TimescalePermo-Triassic Subages of Eastern EuropeDevonian of Eastern North AmericaAmmonite Chrons of North AmericaCambrian of ChinaPermian of Western EuropeCambrian of BritainPermian of the PamirsObsolete Precambrian AgesPrecambrian of Russia
PhanerozoicMesozoicJurassicMiddle JurassicBajocianEpizigzagiceras168.2
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 TriassicOlenekianVokhmian247.2
Induan251.2
PaleozoicPermianLopingianChanghsingianDorashamian251.902
WuchiapingianLate Vyatkian/Early VyatkianZechsteinDzhulfian254.14
GuadalupianCapitanianLate Severodvinian/Early SeverodvinianRotliegendesMidian259.51
WordianLate Urzhumian/Early Urzhumian264.28
Murgabian266.2 *
RoadianLate Kazanian/Early Kazanian266.9
CisuralianKungurianKubergandian273.01
Bolorian279.8
ArtinskianAutunian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianConewangan/Conneautan/Canadaway358.9
FrasnianWest Fallsian/Sonyean372.2
Middle DevonianGivetianGeneseean/Taghanican/TioughnioganCazenovian382.7
EifelianSouthwoodian387.7
Early DevonianEmsianSawkillian/Deer ParkianHelderbergian393.3
Pragian407.6
Lochkovian410.8
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 10NiucheheanTaoyuanian †MerionethDolgellian/Trempealeauan485.4
Festiniogian489.2 *
JiangshanianJiangshanian489.5
Maentwrogian493.1 *
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianGuzhangianWangcunian †St Davids497
DrumianDrumian500.5
WuliuanWuliuan/Taijangian504.5
Series 2Stage 4DuyunianCaerfai509
Stage 3Nangaoian514
TerreneuvianStage 2Meishucunian521
Fortunian529
Jinnigian530.7
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †Vendian538.8
Wonokan †571.7 *
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400