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
  • D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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 127249 collections

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International Chronostratigraphic TimescaleObsolete Names for ICS UnitsMammal Paleogene Zones
2.58
PaleogeneOligoceneChattianTertiary †MP 30/MP 29/MP 28/MP 27/MP 26MP 2523.03
RupelianMP 24/MP 23/MP 22/MP 2127.82
EocenePriabonianMP 20/MP 19/MP 18/MP 17B/MP 17A33.9
BartonianMP 1637.71
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
YpresianMP 10/MP 8 + 9/MP 747.8
PaleoceneThanetianMP 6MP 1 - 556
Selandian59.2
Danian61.6
66