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
  • 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
  • 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.

This timescale is used in the definition of 127682 collections

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International Chronostratigraphic TimescaleAmmonite Chrons of North AmericaOrdovician of AustraliaSilurian of EnglandPermian Subages of GermanyDevonian of GermanyDevonian of FrancePrecambrian of RussiaSilurian Ages of Europe
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 TriassicOlenekian247.2
Induan251.2
PaleozoicPermianLopingianChanghsingianBuntsandstein251.902
Wuchiapingian254.14
GuadalupianCapitanianOhre/Aller259.51
WordianLeine264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianWocklum/Dasberg/Hemberg/NehdenFamennian358.9
FrasnianAdorfFrasnian372.2
Middle DevonianGivetianGivetianGivetian382.7
EifelianEifelianCouvinien387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
Coblencien408.2 *
LochkovianGedinnineGedinnine410.8
SilurianPridoliRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/Leintwardine419.2
Bringewood/Elton421.3
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerianGleedonian427.4
WychWoolhope428.4 *
Whitwellian429.7 *
Sheinwoodian430.5
LlandoveryTelychian433.4
436.3 *
Aeronian438.5
Cowleigh Park439.3 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianBolindian443.8
Katian445.2
Eastonian449 *
Gisbornian452 *
Sandbian453
Middle OrdovicianDarriwilianDarriwilian458.4
DapingianYapeenian467.3
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
Tremadocian477.7
Warendian482.8 *
CambrianFurongianStage 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4509
Stage 3514
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian538.8
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400