PBDB Interval

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
P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 view
J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 126701 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of Australia	Ordovician of China			Ten Million Year Bins	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Bolindian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Ordovician 5	Kosovian				443.8
		Katian		Rawtheyan				Chientangkiangian				Kralodvorian	Bohdalec †			445.2
				Cautleyan												448.9 *
				Cautleyan			Eastonian									449 *
				Pusgillian												449.3 *
				Pusgillian				Neichianshanian/Hanjiang								449.5
			Caradoc	Streffordian	Onnian †											449.6 *
				Streffordian								Berounian				449.7 *
				Cheneyan												451.5 *
				Cheneyan			Gisbornian									452 *
				Burrellian												452.7 *
		Sandbian									Ordovician 4					453
					Actonian †											453.2 *
					Marshbrookian †	Woolstonian †										454.2 *
					Longvillian †											455.2 *
														Zahorany †/Vinice	Letna †	456.2 *
				Aurelucian												456.8 *
					Soudleyan †/Harnagian/Costonian											457.4 *
					Soudleyan †/Harnagian/Costonian								Liben †			458 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			Darriwilian	Darriwilian	Guniu †/Hulo		Ordovician 3					458.4
												Dobrotivian				458.5 *
												Oretanian				459.7 *
				Abereiddian/Early Llanvirn												461.3 *
													Sarka †			461.7 *
									Hunjiang †	Dawan †/Daobaowan/Ningkuo			Sarka †			466.3 *
		Dapingian					Yapeenian	Dapingian			Ordovician 2		Klabava †			467.3
												Arenigian				468
			Arenig	Fennian												468.4 *
							Castlemainian									468.5 *
	Early Ordovician	Floian					Chewtonian	Yiyangian								470
				Whitlandian			Chewtonian									471.1 *
							Bendigonian									471.8 *
							Lancefieldian									473.5 *
				Moridunian												474.3 *
		Tremadocian	Tremadoc	Migneintian				Xinchangian			Ordovician 1	Tremadocian				477.7
				Migneintian						Lianghekou †						477.9 *
				Cressagian												480.8 *
				Cressagian			Warendian									482.8 *
							Warendian									485 *
																485.4