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
A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. 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				Cambrian of Siberia	Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian				Bolindian	443.8
		Katian		Rawtheyan					445.2
				Cautleyan					448.9 *
				Cautleyan				Eastonian	449 *
				Pusgillian					449.3 *
			Caradoc	Streffordian	Onnian †				449.6 *
				Cheneyan					451.5 *
				Cheneyan				Gisbornian	452 *
				Burrellian					452.7 *
		Sandbian							453
					Actonian †				453.2 *
					Marshbrookian †	Woolstonian †			454.2 *
					Longvillian †				455.2 *
				Aurelucian	Longvillian †				456.8 *
				Aurelucian	Soudleyan †/Harnagian/Costonian				457.4 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn				Darriwilian	458.4
		Darriwilian		Abereiddian/Early Llanvirn				Darriwilian	461.3 *
		Dapingian		Abereiddian/Early Llanvirn				Yapeenian	467.3
			Arenig	Fennian				Yapeenian	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					477.7
				Cressagian					480.8 *
								Warendian	482.8 *
							Mansian †		483.55 *
							Mansian †		485 *
									485.4