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
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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. 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 126650 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Cambrian of Siberia	Ten Million Year Bins	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian				Ordovician 5	Kosovian				443.8
		Katian		Rawtheyan					Kralodvorian	Bohdalec †			445.2
				Cautleyan									448.9 *
				Pusgillian									449.3 *
			Caradoc	Streffordian	Onnian †								449.6 *
				Streffordian					Berounian				449.7 *
				Cheneyan									451.5 *
				Burrellian									452.7 *
		Sandbian						Ordovician 4					453
					Actonian †								453.2 *
					Marshbrookian †	Woolstonian †							454.2 *
					Longvillian †								455.2 *
											Zahorany †/Vinice	Letna †	456.2 *
				Aurelucian									456.8 *
					Soudleyan †/Harnagian/Costonian								457.4 *
					Soudleyan †/Harnagian/Costonian					Liben †			458 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn				Ordovician 3					458.4
									Dobrotivian				458.5 *
									Oretanian				459.7 *
				Abereiddian/Early Llanvirn									461.3 *
										Sarka †			461.7 *
		Dapingian						Ordovician 2		Klabava †			467.3
									Arenigian				468
			Arenig	Fennian									468.4 *
	Early Ordovician	Floian		Fennian									470
				Whitlandian									471.1 *
				Moridunian									474.3 *
		Tremadocian	Tremadoc	Migneintian				Ordovician 1	Tremadocian				477.7
				Cressagian									480.8 *
				Cressagian			Mansian †						483.55 *
							Mansian †						485 *
													485.4