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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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 126973 collections

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International Chronostratigraphic Timescale			Ordovician of Ibero-Bohemia				Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Kosovian				Bolindian	443.8
		Katian	Kralodvorian	Bohdalec †			Bolindian	445.2
			Kralodvorian				Eastonian	449 *
			Berounian				Eastonian	449.7 *
							Gisbornian	452 *
		Sandbian						453
					Zahorany †/Vinice	Letna †		456.2 *
				Liben †				458 *
	Middle Ordovician	Darriwilian					Darriwilian	458.4
			Dobrotivian					458.5 *
			Oretanian					459.7 *
				Sarka †				461.7 *
		Dapingian		Klabava †			Yapeenian	467.3
			Arenigian				Yapeenian	468
							Castlemainian	468.5 *
	Early Ordovician	Floian					Chewtonian	470
							Bendigonian	471.8 *
							Lancefieldian	473.5 *
		Tremadocian	Tremadocian				Lancefieldian	477.7
		Tremadocian	Tremadocian				Warendian	482.8 *
								485.4