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
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

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

Show more time

Show linear time

International Chronostratigraphic Timescale			Devonian of Eastern North America		Permian of North America		Silurian of England		Ordovician of Ibero-Bohemia
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	Conewangan/Conneautan/Canadaway										358.9
	Late Devonian	Frasnian	West Fallsian/Sonyean										372.2
	Middle Devonian	Givetian	Geneseean/Taghanican/Tioughniogan	Cazenovian									382.7
	Middle Devonian	Eifelian	Southwoodian	Cazenovian									387.7
	Early Devonian	Emsian	Sawkillian/Deer Parkian	Helderbergian									393.3
		Pragian											407.6
		Lochkovian											410.8
Silurian	Pridoli						Red Downtonian/Temeside Shales/Downton Castle	Whitcliffe/Leintwardine					419.2
	Pridoli						Red Downtonian/Temeside Shales/Downton Castle	Bringewood/Elton					421.3
	Ludlow	Ludfordian					Coalbrookdale	Wenlock (England)/Tickwood					423
		Gorstian											425.6
		Gorstian						Buildwas					426.4 *
	Wenlock	Homerian						Buildwas					427.4
		Homerian					Wych	Woolhope					428.4 *
		Sheinwoodian											430.5
	Llandovery	Telychian											433.4
		Telychian											436.3 *
		Aeronian											438.5
		Aeronian					Cowleigh Park						439.3 *
		Rhuddanian					Cowleigh Park						440.8
Ordovician	Late Ordovician	Hirnantian							Kosovian				443.8
		Katian							Kralodvorian	Bohdalec †			445.2
		Katian							Berounian				449.7 *
		Sandbian											453
											Zahorany †/Vinice	Letna †	456.2 *
										Liben †			458 *
	Middle Ordovician	Darriwilian											458.4
									Dobrotivian				458.5 *
									Oretanian				459.7 *
										Sarka †			461.7 *
		Dapingian								Klabava †			467.3
		Dapingian							Arenigian				468
	Early Ordovician	Floian							Arenigian				470
	Early Ordovician	Tremadocian							Tremadocian				477.7
													485.4