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
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 127308 collections

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International Chronostratigraphic TimescaleOrdovician of North AmericaPermian of Western EuropeSilurian of the BalticDevonian of CzechoslovakiaOrdovician of AustraliaCambrian of BritainPermian of the PamirsObsolete Precambrian AgesCambrian of ChinaPrecambrian of Russia
PhanerozoicPaleozoicPermianLopingianChanghsingianDorashamian251.902
WuchiapingianZechsteinDzhulfian254.14
GuadalupianCapitanianRotliegendesMidian259.51
Wordian264.28
Murgabian266.2 *
Roadian266.9
CisuralianKungurianKubergandian273.01
Bolorian279.8
ArtinskianAutunian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetianSrbsko382.7
EifelianChotec387.7
Early DevonianEmsianDaleje/Zlichovian393.3
PragianPragian407.6
LochkovianLochkovian410.8
SilurianPridoliOhesaare419.2
Kaugetuma421.7 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianRootsikula427.4
Jaagarahu429.2 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychian433.4
Adavere434 *
Aeronian438.5
Raikkula439.4 *
Rhuddanian440.8
Juuru441.4 *
OrdovicianLate OrdovicianHirnantianCincinnatianGamachianBolindian443.8
Katian445.2
Richmondian446 *
Eastonian449 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Gisbornian452 *
Sandbian453
Turinian453.7 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Middle OrdovicianDarriwilianDarriwilian458.4
DapingianYapeenian467.3
Castlemainian468.5 *
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †Chewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
Tulean473.9 *
Tremadocian477.7
Stairsian480.3 *
SkullrockianDemingian †482 *
Warendian482.8 *
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanNiucheheanTaoyuanian †485.4
487.5
Festiniogian489.2 *
JiangshanianJiangshanian489.5
Maentwrogian493.1 *
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianSt DavidsGuzhangianWangcunian †497
DrumianDrumian500.5
WuliuanWuliuan/Taijangian504.5
Series 2Stage 4CaerfaiDuyunian509
Stage 3Nangaoian514
TerreneuvianStage 2Meishucunian521
Fortunian529
Jinnigian530.7
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †Vendian538.8
Wonokan †571.7 *
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400