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, 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 126764 collections

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International Chronostratigraphic Timescale			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							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 *