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
  • 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 127258 collections

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International Chronostratigraphic TimescaleOrdovician of North AmericaOrdovician of ChinaPermian Subages of GermanyPermian of the Russian PlatformPermian of the PamirsOrdovician of Britain
PermianLopingianChanghsingianBuntsandsteinDorashamian251.902
WuchiapingianDzhulfian254.14
TatarianVyatkian256.8 *
GuadalupianCapitanianOhre/AllerSeverodvinianMidian259.51
WordianLeineUrzhumian264.28
Murgabian266.2 *
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKungurianIrenian/UfimianKubergandian273.01
Filipovian276.5 *
Bolorian279.8
Saraninian280.1 *
ArtinskianArtinskianSarginian283.5
Irginian285.9 *
Yakhtashian286
Burtsevian287.8 *
SakmarianSakmarianSterlitamakianSakmarian290.1
Tastubian291.7 *
AsselianAsselianShikhanianAsselian293.52
Uskalykian294.8
Surenian297.5
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 OrdovicianHirnantianCincinnatianGamachianHirnantianXiaoxita †/ShikouWufeng †AshgillHirnantian443.8
KatianChientangkiangianRawtheyan445.2
Richmondian446 *
Cautleyan448.9 *
Pusgillian449.3 *
Neichianshanian/Hanjiang449.5
CaradocStreffordianOnnian †449.6 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Cheneyan451.5 *
Burrellian452.7 *
Sandbian453
Actonian †453.2 *
Turinian453.7 *
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Aurelucian456.8 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Soudleyan †/Harnagian/Costonian457.4 *
Middle OrdovicianDarriwilianDarriwilianGuniu †/HuloLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.4
Abereiddian/Early Llanvirn461.3 *
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingian467.3
ArenigFennian468.4 *
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †Yiyangian470
Whitlandian471.1 *
Tulean473.9 *
Moridunian474.3 *
TremadocianXinchangianTremadocMigneintian477.7
Lianghekou †477.9 *
Stairsian480.3 *
Cressagian480.8 *
SkullrockianDemingian †482 *
485 *
CambrianFurongianStage 10485.4
487.5