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
  • 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

Show more time

Show linear time

International Chronostratigraphic TimescaleOrdovician of BritainCarboniferous of North AmericaPermian of the Russian PlatformPermian Subages of GermanyCarbo-Permian of the Russian PlatformDevonian of Germany
PermianLopingianChanghsingianBuntsandsteinMelekhovian251.902
Wuchiapingian254.14
TatarianVyatkian256.8 *
GuadalupianCapitanianSeverodvinianOhre/Aller259.51
WordianUrzhumianLeine264.28
Noginskian264.9 *
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKungurianIrenian/Ufimian273.01
Filipovian276.5 *
Pavlovoposadian276.8 *
Saraninian280.1 *
ArtinskianArtinskianSarginian283.5
Irginian285.9 *
Rusavkinian287.6 *
Burtsevian287.8 *
SakmarianSakmarianSterlitamakian290.1
Tastubian291.7 *
AsselianBursumian †AsselianShikhanian293.52
Uskalykian294.8
Surenian297.5
CarboniferousPennsylvanianGzhelianVirgilian298.9
KasimovianMissourianDorogomilovian303.7
Khamovnikian304.8
Krevyakinian305.8 *
Desmoinesian305.9 *
MoscovianMyachkovian307
Podolskian308.9 *
Kashirian311.4 *
Atokan312.7 *
Vereian313.8
Melekessian314.8
Bashkirian315.2
Cheremshanian316.9 *
Morrowan318.4 *
Prikamian318.6 *
Severokeltmian319.9 *
Krasnopolyanian321.2 *
Voznesenian321.9 *
MississippianSerpukhovianChesterianZapaltjubian323.2
Protvian324.4 *
Steshevian326.8 *
Tarusian329 *
ViseanVenevian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
MeramecianTulian335.8 *
Bobrikian339.9 *
Osagean343.1 *
Radaevkian343.4 *
TournaisianKosvian346.7
Kizelian350.7 *
KinderhookianCherepetian351.9 *
Karakubian354.4 *
Upinian356.3 *
Malevkian357.6 *
Gumerovian358 *
DevonianLate DevonianFamennianWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianAdorf372.2
Middle DevonianGivetianGivetian382.7
EifelianEifelian387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
LochkovianGedinnine410.8
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 *