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 127777 collections

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International Chronostratigraphic TimescaleCambrian of West AvaloniaDevonian of FranceCarboniferous SubepochsOrdovician of Ibero-BohemiaCarbo-Permian of the Russian PlatformPermian of ChinaCambrian of KazakhstanPrecambrian of RussiaCarboniferous of North AmericaDevonian of Germany
PhanerozoicPaleozoicPermianLopingianChanghsingianMelekhovianMeishanian251.902
Baoqingian253.4 *
WuchiapingianLaoshanian254.14
Laibinian257.7 *
GuadalupianCapitanianLengwuan259.51
WordianKuhfengian264.28
Noginskian264.9 *
Roadian266.9
CisuralianKungurianLuodianian273.01
Pavlovoposadian276.8 *
Artinskian283.5
Longlinian285.4 *
Rusavkinian287.6 *
Sakmarian290.1
AsselianZisongianBursumian †293.52
CarboniferousPennsylvanianGzhelianLate PennsylvanianVirgilian298.9
300.1
KasimovianDorogomilovianMissourian303.7
Khamovnikian304.8
Krevyakinian305.8 *
Desmoinesian305.9 *
MoscovianMiddle PennsylvanianMyachkovian307
Podolskian308.9 *
Kashirian311.4 *
Atokan312.7 *
Vereian313.8
Melekessian314.8
BashkirianEarly Pennsylvanian315.2
Cheremshanian316.9 *
Morrowan318.4 *
Prikamian318.6 *
Severokeltmian319.9 *
Krasnopolyanian321.2 *
Voznesenian321.9 *
MississippianSerpukhovianLate MississippianZapaltjubianChesterian323.2
Protvian324.4 *
Steshevian326.8 *
Tarusian329 *
ViseanMiddle MississippianVenevian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
TulianMeramecian335.8 *
Bobrikian339.9 *
Osagean343.1 *
Radaevkian343.4 *
TournaisianEarly MississippianKosvian346.7
Kizelian350.7 *
CherepetianKinderhookian351.9 *
Karakubian354.4 *
Upinian356.3 *
Malevkian357.6 *
Gumerovian358 *
DevonianLate DevonianFamennianFamennianWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianFrasnianAdorf372.2
Middle DevonianGivetianGivetianGivetian382.7
EifelianCouvinienEifelian387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
Coblencien408.2 *
LochkovianGedinnineGedinnine410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
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
TremadocianTremadocianUngurian477.7
CambrianFurongianStage 10Batyrbaian485.4
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Paibian494
MiaolingianGuzhangianAyusokkanian497
Arcadian498.4
499.5
DrumianZhanaarykian500.5
Tuesaian503
Wuliuan504.5
505.3
Series 2Stage 4Branchian509
Toyonian510 *
Botomian512.5 *
Stage 3514
Atdabanian515.6 *
Placentian517.1
TerreneuvianStage 2Tommotian521
525.5
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian538.8
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400