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 126701 collections

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International Chronostratigraphic TimescaleTen Million Year BinsCenozoic Subepochs
PaleogeneOligoceneChattianCenozoic 4Late Oligocene23.03
RupelianEarly Oligocene27.82
EocenePriabonianCenozoic 3Late Eocene33.9
BartonianMiddle Eocene37.71
LutetianCenozoic 241.2
YpresianEarly Eocene47.8
PaleoceneThanetianCenozoic 1Late Paleocene56
SelandianMiddle Paleocene59.2
DanianEarly Paleocene61.6
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