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 126778 collections

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International Chronostratigraphic Timescale			Ordovician of Ibero-Bohemia				Ordovician of China			Devonian of France	Cambrian of North America
Devonian	Late Devonian	Famennian								Famennian			358.9
	Late Devonian	Frasnian								Frasnian			372.2
	Middle Devonian	Givetian								Givetian			382.7
	Middle Devonian	Eifelian								Couvinien			387.7
	Early Devonian	Emsian											393.3
		Pragian											407.6
		Pragian								Coblencien			408.2 *
		Lochkovian								Gedinnine			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	Kosovian				Hirnantian	Xiaoxita †/Shikou	Wufeng †				443.8
		Katian	Kralodvorian	Bohdalec †			Chientangkiangian		Wufeng †				445.2
			Kralodvorian				Neichianshanian/Hanjiang						449.5
			Berounian										449.7 *
		Sandbian											453
					Zahorany †/Vinice	Letna †							456.2 *
				Liben †									458 *
	Middle Ordovician	Darriwilian					Darriwilian	Guniu †/Hulo					458.4
			Dobrotivian										458.5 *
			Oretanian										459.7 *
				Sarka †									461.7 *
				Sarka †				Hunjiang †	Dawan †/Daobaowan/Ningkuo				466.3 *
		Dapingian		Klabava †			Dapingian						467.3
		Dapingian	Arenigian				Dapingian						468
	Early Ordovician	Floian	Arenigian				Yiyangian						470
		Tremadocian	Tremadocian				Xinchangian						477.7
		Tremadocian	Tremadocian				Xinchangian		Lianghekou †				477.9 *
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
		Drumian									Marjumian		500.5
		Wuliuan									Topazan		504.5
		Wuliuan									Delamaran		506.5
	Series 2	Stage 4									Delamaran	Waucoban †	509
		Stage 4									Dyeran		511 *
		Stage 3									Dyeran		514
											Montezuman		514.8 *
											Begadean		519.9 *
	Terreneuvian	Stage 2											521
	Terreneuvian	Fortunian											529
													538.8