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. 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
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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 126973 collections

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International Chronostratigraphic TimescaleOrdovician of North AmericaCambrian EpochsCambrian of West AvaloniaCambrian of North America
470
482
CambrianFurongianStage 10IbexianSkullrockianLate CambrianFranconian †/Dresbachian/Millardan485.4 *
Sunwaptan487.5
Jiangshanian489.5
Steptoean493 *
Paibian494
MiaolingianGuzhangianMiddle CambrianMarjumianAlbertian †497
Arcadian498.4
Drumian500.5
WuliuanTopazan504.5
Delamaran506.5
Series 2Stage 4Early CambrianBranchianWaucoban †509
Dyeran511 *
Stage 3514
Montezuman514.8 *
Placentian517.1
Begadean519.9 *
TerreneuvianStage 2521
Fortunian529
538.8