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. 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
  • 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
  • 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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 view
  • J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 127343 collections

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International Chronostratigraphic TimescaleOrdovician of North AmericaOrdovician of ChinaOrdovician of Ibero-BohemiaOrdovician of AustraliaOrdovician of Britain
OrdovicianLate OrdovicianHirnantianCincinnatianGamachianHirnantianXiaoxita †/ShikouWufeng †KosovianBolindianAshgillHirnantian443.8
KatianChientangkiangianKralodvorianBohdalec †Rawtheyan445.2
Richmondian446 *
Cautleyan448.9 *
Eastonian449 *
Pusgillian449.3 *
Neichianshanian/Hanjiang449.5
CaradocStreffordianOnnian †449.6 *
Berounian449.7 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Cheneyan451.5 *
Gisbornian452 *
Burrellian452.7 *
Sandbian453
Actonian †453.2 *
Turinian453.7 *
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Zahorany †/ViniceLetna †456.2 *
Aurelucian456.8 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Soudleyan †/Harnagian/Costonian457.4 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianGuniu †/HuloDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.4
Dobrotivian458.5 *
Oretanian459.7 *
Abereiddian/Early Llanvirn461.3 *
Sarka †461.7 *
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingianKlabava †Yapeenian467.3
Arenigian468
ArenigFennian468.4 *
Castlemainian468.5 *
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †YiyangianChewtonian470
Whitlandian471.1 *
Bendigonian471.8 *
Lancefieldian473.5 *
Tulean473.9 *
Moridunian474.3 *
TremadocianXinchangianTremadocianTremadocMigneintian477.7
Lianghekou †477.9 *
Stairsian480.3 *
Cressagian480.8 *
Skullrockian/Demingian482 *
Warendian482.8 *
485 *
485.4
487.5