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
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 125932 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of China			Ten Million Year Bins	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Ordovician 5	Kosovian				443.8
		Katian	Chientangkiangian		Wufeng †		Kralodvorian	Bohdalec †			445.2
			Neichianshanian/Hanjiang				Kralodvorian				449.5
							Berounian				449.7 *
		Sandbian				Ordovician 4					453
									Zahorany †/Vinice	Letna †	456.2 *
								Liben †			458 *
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo		Ordovician 3					458.4
							Dobrotivian				458.5 *
							Oretanian				459.7 *
								Sarka †			461.7 *
				Hunjiang †	Dawan †/Daobaowan/Ningkuo			Sarka †			466.3 *
		Dapingian	Dapingian			Ordovician 2		Klabava †			467.3
		Dapingian	Dapingian				Arenigian				468
	Early Ordovician	Floian	Yiyangian				Arenigian				470
		Tremadocian	Xinchangian			Ordovician 1	Tremadocian				477.7
		Tremadocian	Xinchangian		Lianghekou †	Ordovician 1	Tremadocian				477.9 *
											485.4