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
  • 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
  • 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 126701 collections

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International Chronostratigraphic TimescalePermian of the PamirsPermian of North AmericaOrdovician of the BalticObsolete Names for ICS Units
NeogenePliocenePiacenzianTertiary †2.58
Zanclean3.6
MioceneMessinian5.333
Tortonian7.246
Serravallian11.63
Langhian13.82
Burdigalian15.98
Aquitanian20.44
PaleogeneOligoceneChattian23.03
Rupelian27.82
EocenePriabonian33.9
Bartonian37.71
Lutetian41.2
Ypresian47.8
PaleoceneThanetian56
Selandian59.2
Danian61.6
CretaceousLate CretaceousMaastrichtian66
Campanian72.1
Santonian83.6
Coniacian86.3
Turonian89.8
Cenomanian93.9
Early CretaceousAlbian100.5
Aptian113
Barremian121.4
Hauterivian125.77
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
PermianLopingianChanghsingianDorashamian251.902
WuchiapingianDzhulfianLongtanian †254.14
GuadalupianCapitanianMidianCapitanian259.51
WordianWordian264.28
Murgabian266.2 *
RoadianRoadian266.9
CisuralianKungurianKubergandianLeonardianCathedralian273.01
Bolorian279.8
Hessian281.9 *
Artinskian283.5
Yakhtashian286
WolfcampianLenoxian286.1 *
SakmarianSakmarian290.1
AsselianAsselianNealian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHarjuPorkuni443.8
KatianPirgu445.2
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianKeilaIdavere †453
Haljala453.9
Kukruse456.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
Dapingian467.3
Billingen469.3 *
Early OrdovicianFloian470
Latorp †470.1 *
Hunneberg473.7 *
Tremadocian477.7
Varangu481.3 *
Pakerort482.2 *
CambrianFurongianStage 10485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianSeries 3 †497
Drumian500.5
WuliuanStage 5 †504.5
509