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 127682 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleCambrian of West AvaloniaOrdovician of BritainSilurian of EnglandPermian Subages of GermanyDevonian of GermanyDevonian of FrancePrecambrian of RussiaSilurian Ages of Europe
PhanerozoicPaleozoicPermianLopingianChanghsingianBuntsandstein251.902
Wuchiapingian254.14
GuadalupianCapitanianOhre/Aller259.51
WordianLeine264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianWocklum/Dasberg/Hemberg/NehdenFamennian358.9
FrasnianAdorfFrasnian372.2
Middle DevonianGivetianGivetianGivetian382.7
EifelianEifelianCouvinien387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
Coblencien408.2 *
LochkovianGedinnineGedinnine410.8
SilurianPridoliRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/Leintwardine419.2
Bringewood/Elton421.3
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerianGleedonian427.4
WychWoolhope428.4 *
Whitwellian429.7 *
Sheinwoodian430.5
LlandoveryTelychian433.4
436.3 *
Aeronian438.5
Cowleigh Park439.3 *
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 *
CambrianFurongianStage 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Arcadian498.4
Drumian500.5
Wuliuan504.5
Series 2Stage 4Branchian509
Stage 3514
Placentian517.1
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian538.8
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400