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
J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 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
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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, 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 126585 collections

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International Chronostratigraphic Timescale			Ordovician of China			Ordovician of Britain				Cambrian of Kazakhstan	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Ashgill	Hirnantian				Kosovian				443.8
		Katian	Chientangkiangian				Rawtheyan				Kralodvorian	Bohdalec †			445.2
							Cautleyan								448.9 *
							Pusgillian								449.3 *
			Neichianshanian/Hanjiang				Pusgillian								449.5
						Caradoc	Streffordian	Onnian †							449.6 *
							Streffordian				Berounian				449.7 *
							Cheneyan								451.5 *
							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 *
								Soudleyan †/Harnagian/Costonian				Liben †			458 *
	Middle Ordovician	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 *
				Hunjiang †	Dawan †/Daobaowan/Ningkuo							Sarka †			466.3 *
		Dapingian	Dapingian									Klabava †			467.3
											Arenigian				468
						Arenig	Fennian								468.4 *
	Early Ordovician	Floian	Yiyangian				Fennian								470
							Whitlandian								471.1 *
							Moridunian								474.3 *
		Tremadocian	Xinchangian			Tremadoc	Migneintian			Ungurian	Tremadocian				477.7
					Lianghekou †		Migneintian								477.9 *
							Cressagian								480.8 *
															485 *
															485.4