PBDB Timescale

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
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
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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 126844 collections

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International Chronostratigraphic Timescale			Devonian of France	Ordovician of Australia	Permian of North America		Ordovician of Britain
Permian	Guadalupian	Capitanian			Capitanian						259.51
		Wordian			Wordian						264.28
		Roadian			Roadian						266.9
	Cisuralian	Kungurian			Leonardian	Cathedralian					273.01
		Kungurian				Hessian					281.9 *
		Artinskian				Hessian					283.5
		Artinskian			Wolfcampian	Lenoxian					286.1 *
		Sakmarian				Lenoxian					290.1
		Asselian				Nealian					293.52
Carboniferous	Pennsylvanian	Gzhelian									298.9
		Kasimovian									303.7
		Moscovian									307
		Bashkirian									315.2
	Mississippian	Serpukhovian									323.2
		Visean									330.9
		Tournaisian									346.7
Devonian	Late Devonian	Famennian	Famennian								358.9
	Late Devonian	Frasnian	Frasnian								372.2
	Middle Devonian	Givetian	Givetian								382.7
	Middle Devonian	Eifelian	Couvinien								387.7
	Early Devonian	Emsian									393.3
		Pragian									407.6
		Pragian	Coblencien								408.2 *
		Lochkovian	Gedinnine								410.8
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		Bolindian			Ashgill	Hirnantian			443.8
		Katian						Rawtheyan			445.2
								Cautleyan			448.9 *
				Eastonian				Cautleyan			449 *
								Pusgillian			449.3 *
							Caradoc	Streffordian	Onnian †		449.6 *
								Cheneyan			451.5 *
				Gisbornian				Cheneyan			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		Darriwilian			Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			458.4
		Darriwilian		Darriwilian				Abereiddian/Early Llanvirn			461.3 *
		Dapingian		Yapeenian				Abereiddian/Early Llanvirn			467.3
				Yapeenian			Arenig	Fennian			468.4 *
				Castlemainian							468.5 *
	Early Ordovician	Floian		Chewtonian							470
				Chewtonian				Whitlandian			471.1 *
				Bendigonian							471.8 *
				Lancefieldian							473.5 *
								Moridunian			474.3 *
		Tremadocian					Tremadoc	Migneintian			477.7
								Cressagian			480.8 *
				Warendian				Cressagian			482.8 *
				Warendian							485 *
											485.4