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 126864 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleOrdovician of Ibero-BohemiaPermian of North AmericaObsolete Precambrian AgesPermian of the PamirsCarboniferous of North AmericaPrecambrian of RussiaDevonian of Germany
PhanerozoicPaleozoicPermianLopingianChanghsingianDorashamian251.902
WuchiapingianDzhulfian254.14
GuadalupianCapitanianCapitanianMidian259.51
WordianWordian264.28
Murgabian266.2 *
RoadianRoadian266.9
CisuralianKungurianLeonardianCathedralianKubergandian273.01
Bolorian279.8
Hessian281.9 *
Artinskian283.5
Yakhtashian286
WolfcampianLenoxian286.1 *
SakmarianSakmarian290.1
AsselianNealianAsselianBursumian †293.52
CarboniferousPennsylvanianGzhelianVirgilian298.9
KasimovianMissourian303.7
Desmoinesian305.9 *
Moscovian307
Atokan312.7 *
Bashkirian315.2
Morrowan318.4 *
MississippianSerpukhovianChesterian323.2
Visean330.9
Meramecian335.8 *
Osagean343.1 *
Tournaisian346.7
Kinderhookian351.9 *
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 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 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4509
Stage 3514
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †Vendian538.8
Wonokan †571.7 *
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400