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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • J. A. Lillegraven and M. C. McKenna. 1986. Fossil mammals from the "Mesaverde" Formation (Late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming, with definitions of Late Cretaceous North American Land-Mammal "Ages". American Museum Novitates 2840:1-68 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

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 126762 collections

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International Chronostratigraphic TimescaleTen Million Year BinsCambrian of BritainCambrian of North America
CambrianFurongianStage 10Cambrian 5MerionethDolgellian/TrempealeauanFranconian †/Dresbachian/Millardan485.4
Sunwaptan487.5
Festiniogian489.2 *
Jiangshanian489.5
Steptoean493 *
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianCambrian 4St DavidsMarjumianAlbertian †497
Drumian500.5
WuliuanCambrian 3Topazan504.5
Delamaran506.5
Series 2Stage 4CaerfaiWaucoban †509
Dyeran511 *
Stage 3Cambrian 2514
Montezuman514.8 *
Begadean519.9 *
TerreneuvianStage 2521
FortunianCambrian 1529
538.8