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
  • 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
  • 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 126844 collections

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International Chronostratigraphic TimescalePermian of the Salt RangeOrdovician of AustraliaSilurian of EnglandAmmonite Chrons of Northwest EuropeCarboniferous SubepochsSilurian Ages of EuropeCambrian of West AvaloniaPermian of the PamirsCambrian of North America
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
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
Kasimovian303.7
MoscovianMiddle Pennsylvanian307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianLate Mississippian323.2
ViseanMiddle Mississippian330.9
TournaisianEarly Mississippian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
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 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 10Franconian †/Dresbachian/Millardan485.4
Sunwaptan487.5
Jiangshanian489.5
Steptoean493 *
Paibian494
MiaolingianGuzhangianMarjumianAlbertian †497
Arcadian498.4
Drumian500.5
WuliuanTopazan504.5
Delamaran506.5
Series 2Stage 4BranchianWaucoban †509
Dyeran511 *
Stage 3514
Montezuman514.8 *
Placentian517.1
Begadean519.9 *
TerreneuvianStage 2521
Fortunian529
538.8