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
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 127258 collections

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International Chronostratigraphic Timescale			Cambrian of North America		Carboniferous Subepochs	Cambrian of West Avalonia	Ordovician of Britain
Carboniferous	Pennsylvanian	Gzhelian			Late Pennsylvanian						298.9
		Kasimovian			Late Pennsylvanian						303.7
		Moscovian			Middle Pennsylvanian						307
		Bashkirian			Early Pennsylvanian						315.2
	Mississippian	Serpukhovian			Late Mississippian						323.2
		Visean			Middle Mississippian						330.9
		Tournaisian			Early Mississippian						346.7
Devonian	Late Devonian	Famennian									358.9
	Late Devonian	Frasnian									372.2
	Middle Devonian	Givetian									382.7
	Middle Devonian	Eifelian									387.7
	Early Devonian	Emsian									393.3
		Pragian									407.6
		Lochkovian									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					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
							Tremadoc	Cressagian			480.8 *
											485 *
Cambrian	Furongian	Stage 10		Franconian †/Dresbachian/Millardan							485.4
		Stage 10	Sunwaptan								487.5
		Jiangshanian	Sunwaptan								489.5
		Jiangshanian	Steptoean								493 *
		Paibian	Steptoean								494
	Miaolingian	Guzhangian	Marjumian	Albertian †							497
		Guzhangian				Arcadian					498.4
		Drumian									500.5
		Wuliuan	Topazan								504.5
		Wuliuan	Delamaran								506.5
	Series 2	Stage 4	Delamaran	Waucoban †		Branchian					509
		Stage 4	Dyeran								511 *
		Stage 3	Dyeran								514
			Montezuman								514.8 *
			Montezuman			Placentian					517.1
			Begadean								519.9 *
	Terreneuvian	Stage 2									521
	Terreneuvian	Fortunian									529
											538.8