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
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
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