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
  • 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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 127057 collections

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International Chronostratigraphic TimescaleDevonian of CzechoslovakiaPermian of the PamirsPermian of the Russian PlatformDevonian SubagesPermian of Western EuropeCambrian of West AvaloniaCarbo-Permian of the Russian PlatformCretaceous SubepochsOrdovician of Britain
CretaceousLate CretaceousMaastrichtianSenonian66
Campanian72.1
Santonian83.6
Coniacian86.3
Turonian89.8
Cenomanian93.9
Early CretaceousAlbianGallic100.5
Aptian113
Barremian121.4
HauterivianNeocomian125.77
Valanginian132.6
Berriasian139.8
JurassicLate JurassicTithonian145
Kimmeridgian149.2
Oxfordian154.8
Middle JurassicCallovian161.5
Bathonian165.3
Bajocian168.2
Aalenian170.9
Early JurassicToarcian174.7
Pliensbachian184.2
Sinemurian192.9
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
PermianLopingianChanghsingianDorashamianMelekhovian251.902
WuchiapingianDzhulfianZechstein254.14
TatarianVyatkian256.8 *
GuadalupianCapitanianMidianSeverodvinianRotliegendes259.51
WordianUrzhumian264.28
Noginskian264.9 *
Murgabian266.2 *
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKubergandianKungurianIrenian/Ufimian273.01
Filipovian276.5 *
Pavlovoposadian276.8 *
Bolorian279.8
Saraninian280.1 *
ArtinskianArtinskianSarginianAutunian283.5
Irginian285.9 *
Yakhtashian286
Rusavkinian287.6 *
Burtsevian287.8 *
SakmarianSakmarianSakmarianSterlitamakian290.1
Tastubian291.7 *
AsselianAsselianAsselianShikhanian293.52
Uskalykian294.8
Surenian297.5
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 DevonianFamennianLate Famennian358.9
Middle Famennian365.3 *
Early Famennian368.5 *
FrasnianLate Frasnian372.2
Middle Frasnian375.4 *
Early Frasnian379.3 *
Middle DevonianGivetianSrbskoLate Givetian382.7
Middle Givetian383.7 *
Early Givetian385.9 *
EifelianChotecLate Eifelian387.7
Early Eifelian390.3 *
Early DevonianEmsianDaleje/ZlichovianLate Emsian393.3
Early Emsian398.3 *
PragianPragianPragian407.6
LochkovianLochkovianLate Lochkovian410.8
Middle Lochkovian412.8 *
Early Lochkovian415.6 *
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianAshgillHirnantian443.8
KatianRawtheyan445.2
Cautleyan448.9 *
Pusgillian449.3 *
CaradocStreffordianOnnian †449.6 *
Cheneyan451.5 *
Burrellian452.7 *
Sandbian453
Actonian †453.2 *
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Aurelucian456.8 *
Soudleyan †/Harnagian/Costonian457.4 *
Middle OrdovicianDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.4
Abereiddian/Early Llanvirn461.3 *
Dapingian467.3
ArenigFennian468.4 *
Early OrdovicianFloian470
Whitlandian471.1 *
Moridunian474.3 *
TremadocianTremadocMigneintian477.7
Cressagian480.8 *
485 *
CambrianFurongianStage 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Arcadian498.4
Drumian500.5
Wuliuan504.5
Series 2Stage 4Branchian509
Stage 3514
Placentian517.1
TerreneuvianStage 2521
Fortunian529
538.8