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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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 127681 collections

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International Chronostratigraphic TimescaleDevonian of Eastern North AmericaCarboniferous of North AmericaPermian of North AmericaObsolete Carboniferous Ages of ChinaOrdovician of AustraliaCambrian of BritainPermian of the PamirsObsolete Precambrian AgesCambrian of ChinaPrecambrian of Russia
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
AsselianBursumian †NealianAsselian293.52
CarboniferousPennsylvanianGzhelianVirgilianMapingian †298.9
KasimovianMissourian303.7
Desmoinesian305.9 *
Moscovian307
Atokan312.7 *
Bashkirian315.2
Morrowan318.4 *
MississippianSerpukhovianChesterian323.2
Visean330.9
Meramecian335.8 *
Osagean343.1 *
Tournaisian346.7
Kinderhookian351.9 *
DevonianLate DevonianFamennianConewangan/Conneautan/Canadaway358.9
FrasnianWest Fallsian/Sonyean372.2
Middle DevonianGivetianGeneseean/Taghanican/TioughnioganCazenovian382.7
EifelianSouthwoodian387.7
Early DevonianEmsianSawkillian/Deer ParkianHelderbergian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianBolindian443.8
Katian445.2
Eastonian449 *
Gisbornian452 *
Sandbian453
Middle OrdovicianDarriwilianDarriwilian458.4
DapingianYapeenian467.3
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
Tremadocian477.7
Warendian482.8 *
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanNiucheheanTaoyuanian †485.4
Festiniogian489.2 *
JiangshanianJiangshanian489.5
Maentwrogian493.1 *
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianSt DavidsGuzhangianWangcunian †497
DrumianDrumian500.5
WuliuanWuliuan/Taijangian504.5
Series 2Stage 4CaerfaiDuyunian509
Stage 3Nangaoian514
TerreneuvianStage 2Meishucunian521
Fortunian529
Jinnigian530.7
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †Vendian538.8
Wonokan †571.7 *
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400