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
M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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

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 126650 collections

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International Chronostratigraphic Timescale			Ordovician of North America					Ordovician of China			Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Hirnantian	Xiaoxita †/Shikou	Wufeng †	Kosovian				443.8
		Katian		Gamachian				Chientangkiangian			Kralodvorian	Bohdalec †			445.2
				Richmondian				Chientangkiangian							446 *
								Neichianshanian/Hanjiang							449.5
											Berounian				449.7 *
				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian										449.8 *
				Edenian											450.4 *
			Mohawkian	Chatfieldian											451.1 *
		Sandbian		Chatfieldian											453
				Turinian											453.7 *
				Turinian									Zahorany †/Vinice	Letna †	456.2 *
			Whiterockian		Canadian †	Chazyan †/Marmor							Zahorany †/Vinice		457 *
												Liben †			458 *
	Middle Ordovician	Darriwilian						Darriwilian	Guniu †/Hulo						458.4
											Dobrotivian				458.5 *
											Oretanian				459.7 *
												Sarka †			461.7 *
									Hunjiang †	Dawan †/Daobaowan/Ningkuo		Sarka †			466.3 *
		Dapingian						Dapingian				Klabava †			467.3
											Arenigian				468
				Rangerian											469.1 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	Yiyangian							470
		Floian		Tulean				Yiyangian							473.9 *
		Tremadocian						Xinchangian			Tremadocian				477.7
										Lianghekou †					477.9 *
				Stairsian											480.3 *
				Skullrockian/Demingian											482 *
															485.4
															487.5