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. 2024. The ICS International Chronostratigraphic Chart v2024/12. International Commission on Stratigraphy view
  • L. Ezquerro, A. Luzón, J. L. Simón and C. L. Liesa. 2022. A review of the European Neogene Mammal zones from integration of litho-, bio- and magnetostratigraphy in the Teruel Basin. Earth-Science Reviews 234(78):104223 view
  • F. F. Steininger, W. A. Berggren, D. V. Kent, R. L. Bernor, S. Sen and J. Agusti. 1996. Circum-Mediterranean Neogene (Miocene and Pliocene) marine-continental chronologic correlations of European mammal units. The Evolution of Western Eurasian Neogene Mammal Faunas (eds. R. L. Bernor, V. Fahlbusch, and H.-W. Mittmann) 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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view

There are 61 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 128797 collections

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International Chronostratigraphic TimescaleOrdovician of Britain
OrdovicianLate OrdovicianHirnantianAshgillHirnantian443.1
KatianRawtheyan445.2
Cautleyan448.8
Pusgillian449.2
CaradocStreffordianOnnian †449.5
Cheneyan451.3
Burrellian452.5
Sandbian452.8
Actonian †453
Marshbrookian †Woolstonian †454
Longvillian †455
Aurelucian456.6
Soudleyan †/Harnagian/Costonian457.2
Middle OrdovicianDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.2
Abereiddian/Early Llanvirn461.1
ArenigFennian468
Dapingian469.4
Whitlandian470.7
Early OrdovicianFloian471.3
Moridunian473.8
TremadocianTremadocMigneintian477.1
Cressagian481.1 *
486.4 *
486.85