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
  • 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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.

This timescale is used in the definition of 127017 collections

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International Chronostratigraphic TimescaleDevonian of Eastern North AmericaAmmonite Chrons of North AmericaCambrian EpochsPermian of ChinaDevonian of GermanyDevonian of CzechoslovakiaSilurian of North AmericaSilurian of the Baltic
JurassicMiddle 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 TriassicOlenekian247.2
Induan251.2
PermianLopingianChanghsingianMeishanian251.902
Baoqingian253.4 *
WuchiapingianLaoshanian254.14
Laibinian257.7 *
GuadalupianCapitanianLengwuan259.51
WordianKuhfengian264.28
Roadian266.9
CisuralianKungurianLuodianian273.01
Artinskian283.5
Longlinian285.4 *
Sakmarian290.1
AsselianZisongian293.52
CarboniferousPennsylvanianGzhelian298.9
300.1
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianConewangan/Conneautan/CanadawayWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianWest Fallsian/SonyeanAdorf372.2
Middle DevonianGivetianGeneseean/Taghanican/TioughnioganCazenovianGivetianSrbsko382.7
EifelianSouthwoodianEifelianChotec387.7
Early DevonianEmsianSawkillian/Deer ParkianHelderbergianEmsianDaleje/Zlichovian393.3
PragianSiegenPragian407.6
LochkovianGedinnineLochkovian410.8
SilurianPridoliCayuganOhesaare419.2
Kaugetuma421.7 *
Niagaran422.5 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianLockportianRootsikula427.4
Jaagarahu429.2 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychianOntarian433.4
Adavere434 *
Aeronian438.5
Alexandrian438.7 *
Raikkula439.4 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
Juuru441.4 *
OrdovicianLate OrdovicianHirnantian443.8
Katian445.2
Sandbian453
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Early OrdovicianFloian470
Tremadocian477.7
CambrianFurongianStage 10Late Cambrian485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianMiddle Cambrian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4Early Cambrian509
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8