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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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

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 127980 collections

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International Chronostratigraphic TimescaleOrdovician of the BalticCarboniferous of North AmericaCarbo-Permian of the Russian PlatformAmmonite Chrons of Northwest EuropeCarboniferous 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
PermianLopingianChanghsingianMelekhovian251.902
Wuchiapingian254.14
GuadalupianCapitanian259.51
Wordian264.28
Noginskian264.9 *
Roadian266.9
CisuralianKungurian273.01
Pavlovoposadian276.8 *
Artinskian283.5
Rusavkinian287.6 *
Sakmarian290.1
AsselianBursumian †293.52
CarboniferousPennsylvanianGzhelianVirgilian298.9
Xiaodushanian300 *
KasimovianMissourianDorogomilovian303.7
Khamovnikian304.8
KrevyakinianDalaun305.8 *
Desmoinesian305.9 *
MoscovianMyachkovian307
Podolskian308.9 *
Kashirian311.4 *
Atokan312.7 *
Vereian313.8
Melekessian314.8
Bashkirian315.2
Cheremshanian316.9 *
Morrowan318.4 *
Huashibanian318.5 *
Prikamian318.6 *
Severokeltmian319.9 *
KrasnopolyanianLousuan321.2 *
Voznesenian321.9 *
MississippianSerpukhovianChesterianZapaltjubianDewunian323.2
Protvian324.4 *
Steshevian326.8 *
Tarusian329 *
Shangsian330.8 *
ViseanVenevian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
Jiusian335 *
MeramecianTulian335.8 *
Bobrikian339.9 *
Osagean343.1 *
Radaevkian343.4 *
TournaisianKosvianTangbagouan346.7
Kizelian350.7 *
KinderhookianCherepetian351.9 *
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 OrdovicianHirnantianHarjuPorkuni443.8
KatianPirgu445.2
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianKeilaIdavere †453
Haljala453.9
Kukruse456.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
Dapingian467.3
Billingen469.3 *
Early OrdovicianFloian470
Latorp †470.1 *
Hunneberg473.7 *
Tremadocian477.7
Varangu481.3 *
Pakerort482.2 *
CambrianFurongianStage 10485.4
486.3 *
486.5