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. 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
  • 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
  • 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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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 126610 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleCambrian of SiberiaOrdovician of the BalticOrdovician of North America
OrdovicianLate OrdovicianHirnantianHarjuPorkuniCincinnatianGamachian443.8
KatianPirgu445.2
Richmondian446 *
Vormsi449.6 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
NabalaJohvi †450 *
Edenian450.4 *
ViruRakvere450.6 *
MohawkianChatfieldian451.1 *
Oandu452 *
SandbianKeilaIdavere †453
Turinian453.7 *
Haljala453.9
Kukruse456.4 *
WhiterockianCanadian †Chazyan †/Marmor457 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
Dapingian467.3
Rangerian469.1 *
Billingen469.3 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †470
Latorp †470.1 *
Hunneberg473.7 *
Tulean473.9 *
Tremadocian477.7
Stairsian480.3 *
Varangu481.3 *
Skullrockian/Demingian482 *
Pakerort482.2 *
Mansian †483.55 *
485.4 *
486.3
486.5
487.5