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
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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			Ordovician of Britain				Silurian of the Baltic	Carboniferous of North America
Permian	Cisuralian	Asselian						Bursumian †	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						Ohesaare		419.2
	Pridoli						Kaugetuma		421.7 *
	Ludlow	Ludfordian					Kuressaare		423
		Ludfordian					Paadla		423.4 *
		Gorstian					Paadla		425.6
	Wenlock	Homerian					Rootsikula		427.4
		Homerian					Jaagarahu		429.2 *
		Sheinwoodian					Jaagarahu		430.5
		Sheinwoodian					Jaani		431.8 *
	Llandovery	Telychian					Jaani		433.4
		Telychian					Adavere		434 *
		Aeronian					Adavere		438.5
		Aeronian					Raikkula		439.4 *
		Rhuddanian					Raikkula		440.8
		Rhuddanian					Juuru		441.4 *
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 *