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 126654 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Cambrian of Kazakhstan	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian				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										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								458.4
								Dobrotivian				458.5 *
								Oretanian				459.7 *
				Abereiddian/Early Llanvirn								461.3 *
									Sarka †			461.7 *
		Dapingian							Klabava †			467.3
								Arenigian				468
			Arenig	Fennian								468.4 *
	Early Ordovician	Floian		Fennian								470
				Whitlandian								471.1 *
				Moridunian								474.3 *
		Tremadocian	Tremadoc	Migneintian			Ungurian	Tremadocian				477.7
			Tremadoc	Cressagian								480.8 *
												485 *
												485.4