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
  • 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 126973 collections

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International Chronostratigraphic TimescaleSilurian Ages of EuropeCambrian EpochsCambrian of KazakhstanPermian of the Salt RangePermian of the PamirsAmmonite Chrons of Northwest EuropeOrdovician of China
JurassicMiddle JurassicBajocianParkinsoni/Garantiana/Subfurcatum/Sauzei/Laeviuscula/Discites168.2
Humphresianum168.4
AalenianConcavum/Murchisonae/Opalinum170.9
Early JurassicToarcianLevesquei/Variabilis/BifronsThouarsense174.7
180.1
Serpentinum/Falciferum/Tenuicostatum182
PliensbachianSpinatum/Margaritatus/Davoei/Ibex/Jamesoni184.2
SinemurianRaricostatum/Oxynotum/Obtusum/Turneri/Semicostatum/Bucklandi192.9
HettangianAngulata/Liasicus/Planorbis199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
Kathwai251.5 *
PermianLopingianChanghsingianDorashamian251.902
252.4 *
Chhidru252.9 *
WuchiapingianDzhulfian254.14
Kalabagh255 *
Wargal256 *
GuadalupianCapitanianMidian259.51
Wordian264.28
265.3 *
Amb266.1 *
Murgabian266.2 *
Roadian266.9
270.7 *
CisuralianKungurianKubergandian273.01
Bolorian279.8
Artinskian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerianGleedonian427.4
Whitwellian429.7 *
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHirnantianXiaoxita †/ShikouWufeng †443.8
KatianChientangkiangian445.2
Neichianshanian/Hanjiang449.5
Sandbian453
Middle OrdovicianDarriwilianDarriwilianGuniu †/Hulo458.4
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingian467.3
Early OrdovicianFloianYiyangian470
TremadocianUngurianXinchangian477.7
Lianghekou †477.9 *
CambrianFurongianStage 10Late CambrianBatyrbaian485.4
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Paibian494
MiaolingianGuzhangianMiddle CambrianAyusokkanian497
499.5
DrumianZhanaarykian500.5
Tuesaian503
Wuliuan504.5
505.3
Series 2Stage 4Early Cambrian509
Toyonian510 *
Botomian512.5 *
Stage 3514
Atdabanian515.6 *
TerreneuvianStage 2Tommotian521
525.5
Fortunian529
538.8