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
  • 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

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 126848 collections

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International Chronostratigraphic TimescalePermian of the Russian PlatformPermian of ChinaPermian of Western EuropeSilurian of North AmericaCambrian of KazakhstanDevonian of FranceCambrian of North America
PermianLopingianChanghsingianMeishanian251.902
Baoqingian253.4 *
WuchiapingianLaoshanianZechstein254.14
TatarianVyatkian256.8 *
Laibinian257.7 *
GuadalupianCapitanianSeverodvinianLengwuanRotliegendes259.51
WordianUrzhumianKuhfengian264.28
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKungurianIrenian/UfimianLuodianian273.01
Filipovian276.5 *
Saraninian280.1 *
ArtinskianArtinskianSarginianAutunian283.5
Longlinian285.4 *
Irginian285.9 *
Burtsevian287.8 *
SakmarianSakmarianSterlitamakian290.1
Tastubian291.7 *
AsselianAsselianShikhanianZisongian293.52
Uskalykian294.8
Surenian297.5
CarboniferousPennsylvanianGzhelian298.9
300.1
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianFamennian358.9
FrasnianFrasnian372.2
Middle DevonianGivetianGivetian382.7
EifelianCouvinien387.7
Early DevonianEmsian393.3
Pragian407.6
Coblencien408.2 *
LochkovianGedinnine410.8
SilurianPridoliCayugan419.2
Niagaran422.5 *
LudlowLudfordian423
Gorstian425.6
WenlockHomerianLockportian427.4
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
Aeronian438.5
Alexandrian438.7 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantian443.8
Katian445.2
Sandbian453
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Early OrdovicianFloian470
TremadocianUngurian477.7
CambrianFurongianStage 10BatyrbaianFranconian †/Dresbachian/Millardan485.4
Sunwaptan487.5
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Steptoean493 *
Paibian494
MiaolingianGuzhangianAyusokkanianMarjumianAlbertian †497
499.5
DrumianZhanaarykian500.5
Tuesaian503
WuliuanTopazan504.5
505.3
Delamaran506.5
Series 2Stage 4Waucoban †509
Toyonian510 *
Dyeran511 *
Botomian512.5 *
Stage 3514
Montezuman514.8 *
Atdabanian515.6 *
Begadean519.9 *
TerreneuvianStage 2Tommotian521
525.5
Fortunian529
538.8