PBDB Interval

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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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
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 126700 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of Australia	Ordovician of China			Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Bolindian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Kosovian				443.8
		Katian	Bolindian	Chientangkiangian			Kralodvorian	Bohdalec †			445.2
			Eastonian	Chientangkiangian							449 *
				Neichianshanian/Hanjiang							449.5
							Berounian				449.7 *
			Gisbornian								452 *
		Sandbian									453
									Zahorany †/Vinice	Letna †	456.2 *
								Liben †			458 *
	Middle Ordovician	Darriwilian	Darriwilian	Darriwilian	Guniu †/Hulo						458.4
							Dobrotivian				458.5 *
							Oretanian				459.7 *
								Sarka †			461.7 *
					Hunjiang †	Dawan †/Daobaowan/Ningkuo		Sarka †			466.3 *
		Dapingian	Yapeenian	Dapingian				Klabava †			467.3
			Yapeenian				Arenigian				468
			Castlemainian								468.5 *
	Early Ordovician	Floian	Chewtonian	Yiyangian							470
			Bendigonian								471.8 *
			Lancefieldian								473.5 *
		Tremadocian		Xinchangian			Tremadocian				477.7
						Lianghekou †					477.9 *
			Warendian			Lianghekou †					482.8 *
											485.4