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, 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
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 126650 collections

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International Chronostratigraphic Timescale			Ten Million Year Bins	Ordovician of Australia	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	Bolindian	Kosovian				443.8
		Katian		Bolindian	Kralodvorian	Bohdalec †			445.2
				Eastonian	Kralodvorian				449 *
				Eastonian	Berounian				449.7 *
				Gisbornian					452 *
		Sandbian	Ordovician 4						453
							Zahorany †/Vinice	Letna †	456.2 *
						Liben †			458 *
	Middle Ordovician	Darriwilian	Ordovician 3	Darriwilian					458.4
					Dobrotivian				458.5 *
					Oretanian				459.7 *
						Sarka †			461.7 *
		Dapingian	Ordovician 2	Yapeenian		Klabava †			467.3
				Yapeenian	Arenigian				468
				Castlemainian					468.5 *
	Early Ordovician	Floian		Chewtonian					470
				Bendigonian					471.8 *
				Lancefieldian					473.5 *
		Tremadocian	Ordovician 1	Lancefieldian	Tremadocian				477.7
		Tremadocian	Ordovician 1	Warendian	Tremadocian				482.8 *
									485.4