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
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
F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 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 127245 collections

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