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

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 127533 collections

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International Chronostratigraphic Timescale			Devonian Subages	Ordovician of Britain
Devonian	Late Devonian	Famennian	Late Famennian					358.9
			Middle Famennian					365.3 *
			Early Famennian					368.5 *
		Frasnian	Late Frasnian					372.2
			Middle Frasnian					375.4 *
			Early Frasnian					379.3 *
	Middle Devonian	Givetian	Late Givetian					382.7
			Middle Givetian					383.7 *
			Early Givetian					385.9 *
		Eifelian	Late Eifelian					387.7
		Eifelian	Early Eifelian					390.3 *
	Early Devonian	Emsian	Late Emsian					393.3
		Emsian	Early Emsian					398.3 *
		Pragian	Pragian					407.6
		Lochkovian	Late Lochkovian					410.8
			Middle Lochkovian					412.8 *
			Early Lochkovian					415.6 *
Silurian	Pridoli							419.2
	Ludlow	Ludfordian						423
	Ludlow	Gorstian						425.6
	Wenlock	Homerian						427.4
	Wenlock	Sheinwoodian						430.5
	Llandovery	Telychian						433.4
		Aeronian						438.5
		Rhuddanian						440.8
Ordovician	Late Ordovician	Hirnantian		Ashgill	Hirnantian			443.8
		Katian			Rawtheyan			445.2
					Cautleyan			448.9 *
					Pusgillian			449.3 *
				Caradoc	Streffordian	Onnian †		449.6 *
					Cheneyan			451.5 *
					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			458.4
		Darriwilian			Abereiddian/Early Llanvirn			461.3 *
		Dapingian			Abereiddian/Early Llanvirn			467.3
		Dapingian		Arenig	Fennian			468.4 *
	Early Ordovician	Floian			Fennian			470
					Whitlandian			471.1 *
					Moridunian			474.3 *
		Tremadocian		Tremadoc	Migneintian			477.7
		Tremadocian		Tremadoc	Cressagian			480.8 *
								485 *