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
  • 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
  • J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 view
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 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.

This timescale is used in the definition of 127258 collections

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International Chronostratigraphic TimescaleTen Million Year BinsCenozoic SubepochsPaleogene Mammal Ages of AsiaNorth American Land Mammal Ages
18.5
PaleogeneOligoceneChattianCenozoic 4Late OligoceneTabenbulakianHsandagolianArikareean23.03
RupelianEarly OligoceneKekeamuan27.82
Whitneyan29.5
Orellan31.8
EocenePriabonianCenozoic 3Late EoceneHouldjinian/Ergilian/UlangochuianChadronian33.9
Duchesnean37
BartonianMiddle EoceneSharamurunian/Irdinmanhan/Arshantan37.71
Uintan39.7
LutetianCenozoic 241.2
Bridgerian46.2
YpresianEarly EoceneBumbanian47.8
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianCenozoic 1Late PaleoceneGashatan56
Tiffanian56.2
SelandianMiddle Paleocene59.2
Torrejonian60.9
DanianEarly Paleocene61.6
Puercan63.8
66