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 Australia	Ordovician of Ibero-Bohemia				Ordovician of China			Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Bolindian	Kosovian				Hirnantian	Xiaoxita †/Shikou	Wufeng †	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					Darriwilian	Guniu †/Hulo		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	Yapeenian		Klabava †			Dapingian							467.3
				Arenigian											468
											Arenig	Fennian			468.4 *
			Castlemainian												468.5 *
	Early Ordovician	Floian	Chewtonian					Yiyangian							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