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
  • 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 128152 collections

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International Chronostratigraphic TimescaleCarboniferous of Western EuropeCarbo-Permian of the Russian PlatformAmmonite Chrons of Northwest EuropePermian of the Salt RangeOrdovician 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 *
PermianLopingianChanghsingianMelekhovian251.902
252.4 *
Chhidru252.9 *
Wuchiapingian254.14
Kalabagh255 *
Wargal256 *
GuadalupianCapitanian259.51
Wordian264.28
Noginskian264.9 *
265.3 *
Amb266.1 *
Roadian266.9
270.7 *
CisuralianKungurian273.01
Pavlovoposadian276.8 *
Artinskian283.5
Rusavkinian287.6 *
Sakmarian290.1
Asselian293.52
Kuzel297.7
CarboniferousPennsylvanianGzhelian298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
KasimovianDorogomilovian303.7
Khamovnikian304.8
Cantabrian305 *
Krevyakinian305.8 *
MoscovianMyachkovian307
WestphalianWestphalian D307.4 *
Podolskian308.9 *
Westphalian C309.8
Kashirian311.4 *
Vereian313.8
Westphalian B314.6
Melekessian314.8
Bashkirian315.2
Cheremshanian316.9 *
Westphalian A317 *
Prikamian318.6 *
NamurianYeadonian318.8 *
Severokeltmian319.9 *
Marsdenian320.2 *
Krasnopolyanian321.2 *
Kinderscoutian321.5 *
Voznesenian321.9 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovianZapaltjubian323.2
Arnsbergian324 *
Protvian324.4 *
Steshevian326.8 *
Pendleian327.4 *
Tarusian329 *
ViseanWarnantianBrigantian †Venevian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
Tulian335.8 *
LivianAsbian †336.3 *
Bobrikian339.9 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
Radaevkian343.4 *
TournaisianIvorianKosvian346.7
Kizelian350.7 *
Cherepetian351.9 *
Hastarian353.7 *
Karakubian354.4 *
Upinian356.3 *
Malevkian357.6 *
Gumerovian358 *
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
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
TremadocianXinchangian477.7
Lianghekou †477.9 *
485.4