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
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, 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, 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 126606 collections

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