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
  • 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 128057 collections

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International Chronostratigraphic TimescaleCarboniferous of Western EuropeOrdovician of Ibero-BohemiaSilurian of North AmericaDevonian of Eastern North AmericaSilurian Ages of EuropePermian of the Russian PlatformCambrian of China
PermianLopingianWuchiapingianTatarianVyatkian256.8 *
GuadalupianCapitanianSeverodvinian259.51
WordianUrzhumian264.28
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKungurianIrenian/Ufimian273.01
Filipovian276.5 *
Saraninian280.1 *
ArtinskianArtinskianSarginian283.5
Irginian285.9 *
Burtsevian287.8 *
SakmarianSakmarianSterlitamakian290.1
Tastubian291.7 *
AsselianAsselianShikhanian293.52
Uskalykian294.8
Surenian297.5
Kuzel297.7
CarboniferousPennsylvanianGzhelian298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
Kasimovian303.7
Cantabrian305 *
Moscovian307
WestphalianWestphalian D307.4 *
Westphalian C309.8
Westphalian B314.6
Bashkirian315.2
Westphalian A317 *
NamurianYeadonian318.8 *
Marsdenian320.2 *
Kinderscoutian321.5 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovian323.2
Arnsbergian324 *
Pendleian327.4 *
ViseanWarnantianBrigantian †330.9
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
TournaisianIvorian346.7
Hastarian353.7 *
DevonianLate DevonianFamennianConewangan/Conneautan/Canadaway358.9
FrasnianWest Fallsian/Sonyean372.2
Middle DevonianGivetianGeneseean/Taghanican/TioughnioganCazenovian382.7
EifelianSouthwoodian387.7
Early DevonianEmsianSawkillian/Deer ParkianHelderbergian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliCayugan419.2
Niagaran422.5 *
LudlowLudfordian423
Gorstian425.6
WenlockHomerianLockportianGleedonian427.4
Whitwellian429.7 *
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
Aeronian438.5
Alexandrian438.7 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianKosovian443.8
KatianKralodvorianBohdalec †445.2
Berounian449.7 *
Sandbian453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilian458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianKlabava †467.3
Arenigian468
Early OrdovicianFloian470
TremadocianTremadocian477.7
CambrianFurongianStage 10NiucheheanTaoyuanian †485.4
JiangshanianJiangshanian489.5
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianGuzhangianWangcunian †497
DrumianDrumian500.5
WuliuanWuliuan/Taijangian504.5
Series 2Stage 4Duyunian509
Stage 3Nangaoian514
TerreneuvianStage 2Meishucunian521
Fortunian529
Jinnigian530.7
538.8