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
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 126844 collections

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International Chronostratigraphic Timescale			Carboniferous of North America	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	Bursumian †		Nealian					293.52
Carboniferous	Pennsylvanian	Gzhelian	Virgilian							298.9
		Kasimovian	Missourian							303.7
		Kasimovian	Desmoinesian							305.9 *
		Moscovian	Desmoinesian							307
		Moscovian	Atokan							312.7 *
		Bashkirian	Atokan							315.2
		Bashkirian	Morrowan							318.4 *
	Mississippian	Serpukhovian	Chesterian							323.2
		Visean	Chesterian							330.9
			Meramecian							335.8 *
			Osagean							343.1 *
		Tournaisian	Osagean							346.7
		Tournaisian	Kinderhookian							351.9 *
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
		Tremadocian				Tremadoc	Cressagian			480.8 *
										485 *