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
  • J. A. Lillegraven and M. C. McKenna. 1986. Fossil mammals from the "Mesaverde" Formation (Late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming, with definitions of Late Cretaceous North American Land-Mammal "Ages". American Museum Novitates 2840:1-68 view
  • A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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

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 126689 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleOrdovician of ChinaOrdovician of the BalticOrdovician of Ibero-Bohemia
OrdovicianLate OrdovicianHirnantianHirnantianXiaoxita †/ShikouWufeng †HarjuPorkuniKosovian443.8
KatianChientangkiangianPirguKralodvorianBohdalec †445.2
Neichianshanian/Hanjiang449.5
Vormsi449.6 *
Berounian449.7 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianKeilaIdavere †453
Haljala453.9
Zahorany †/ViniceLetna †456.2 *
Kukruse456.4 *
UhakuAluoja †457.5 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianGuniu †/Hulo458.4
Dobrotivian458.5 *
Lasnamagi458.9 *
Oretanian459.7 *
Aseri460.4 *
Sarka †461.7 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
DapingianDapingianKlabava †467.3
Arenigian468
Billingen469.3 *
Early OrdovicianFloianYiyangian470
Latorp †470.1 *
Hunneberg473.7 *
TremadocianXinchangianTremadocian477.7
Lianghekou †477.9 *
Varangu481.3 *
Pakerort482.2 *
485.4 *
486.3
486.5