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
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 126884 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of Ibero-Bohemia				Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Kosovian				Bolindian	443.8
		Katian		Rawtheyan			Kralodvorian	Bohdalec †				445.2
				Cautleyan								448.9 *
				Cautleyan							Eastonian	449 *
				Pusgillian								449.3 *
			Caradoc	Streffordian	Onnian †							449.6 *
				Streffordian			Berounian					449.7 *
				Cheneyan								451.5 *
				Cheneyan							Gisbornian	452 *
				Burrellian								452.7 *
		Sandbian										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							Darriwilian	458.4
							Dobrotivian					458.5 *
							Oretanian					459.7 *
				Abereiddian/Early Llanvirn								461.3 *
								Sarka †				461.7 *
		Dapingian						Klabava †			Yapeenian	467.3
							Arenigian					468
			Arenig	Fennian								468.4 *
											Castlemainian	468.5 *
	Early Ordovician	Floian									Chewtonian	470
				Whitlandian							Chewtonian	471.1 *
											Bendigonian	471.8 *
											Lancefieldian	473.5 *
				Moridunian								474.3 *
		Tremadocian	Tremadoc	Migneintian			Tremadocian					477.7
				Cressagian								480.8 *
				Cressagian							Warendian	482.8 *
											Warendian	485 *
												485.4