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
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 126700 collections

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International Chronostratigraphic Timescale			Ordovician of Australia	Cambrian of Kazakhstan	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Bolindian		Kosovian				443.8
		Katian	Bolindian		Kralodvorian	Bohdalec †			445.2
			Eastonian		Kralodvorian				449 *
			Eastonian		Berounian				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	Yapeenian			Klabava †			467.3
			Yapeenian		Arenigian				468
			Castlemainian						468.5 *
	Early Ordovician	Floian	Chewtonian						470
			Bendigonian						471.8 *
			Lancefieldian						473.5 *
		Tremadocian	Lancefieldian	Ungurian	Tremadocian				477.7
		Tremadocian	Warendian	Ungurian	Tremadocian				482.8 *
									485.4