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
  • M. Harzhauser and W. E. Piller. 2004. Integrated stratigraphy of the Sarmatian (Upper Middle Miocene) in the western Central Paratethys. Stratigraphy 1(1):65-86 view
  • P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 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

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 125957 collections

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International Chronostratigraphic TimescaleOrdovician of AustraliaTen Million Year BinsOrdovician of Ibero-Bohemia
OrdovicianLate OrdovicianHirnantianBolindianOrdovician 5Kosovian443.8
KatianKralodvorianBohdalec †445.2
Eastonian449 *
Berounian449.7 *
Gisbornian452 *
SandbianOrdovician 4453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianOrdovician 3458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianYapeenianOrdovician 2Klabava †467.3
Arenigian468
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
TremadocianOrdovician 1Tremadocian477.7
Warendian482.8 *
485.4