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
  • 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 126764 collections

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International Chronostratigraphic TimescaleCarboniferous of Western EuropeSilurian of the BalticCarboniferous of North America
PermianCisuralianAsselianBursumian †293.52
Kuzel297.7
CarboniferousPennsylvanianGzhelianVirgilian298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
KasimovianMissourian303.7
Cantabrian305 *
Desmoinesian305.9 *
Moscovian307
WestphalianWestphalian D307.4 *
Westphalian C309.8
Atokan312.7 *
Westphalian B314.6
Bashkirian315.2
Westphalian A317 *
Morrowan318.4 *
NamurianYeadonian318.8 *
Marsdenian320.2 *
Kinderscoutian321.5 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovianChesterian323.2
Arnsbergian324 *
Pendleian327.4 *
ViseanWarnantianBrigantian †330.9
Meramecian335.8 *
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
Osagean343.1 *
TournaisianIvorian346.7
Kinderhookian351.9 *
Hastarian353.7 *
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliOhesaare419.2
Kaugetuma421.7 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianRootsikula427.4
Jaagarahu429.2 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychian433.4
Adavere434 *
Aeronian438.5
Raikkula439.4 *
Rhuddanian440.8
Juuru441.4 *
443.8