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
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

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 126700 collections

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International Chronostratigraphic Timescale			Ordovician of Ibero-Bohemia				Ordovician of Britain				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Kosovian				Ashgill	Hirnantian			Cincinnatian	Gamachian				443.8
		Katian	Kralodvorian	Bohdalec †				Rawtheyan				Gamachian				445.2
								Rawtheyan				Richmondian				446 *
								Cautleyan								448.9 *
								Pusgillian								449.3 *
							Caradoc	Streffordian	Onnian †							449.6 *
			Berounian													449.7 *
												Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
												Edenian				450.4 *
											Mohawkian	Chatfieldian				451.1 *
								Cheneyan								451.5 *
								Burrellian								452.7 *
		Sandbian														453
									Actonian †							453.2 *
									Actonian †			Turinian				453.7 *
									Marshbrookian †	Woolstonian †						454.2 *
									Longvillian †							455.2 *
					Zahorany †/Vinice	Letna †										456.2 *
								Aurelucian								456.8 *
											Whiterockian		Canadian †	Chazyan †/Marmor		457 *
									Soudleyan †/Harnagian/Costonian							457.4 *
				Liben †					Soudleyan †/Harnagian/Costonian							458 *
	Middle Ordovician	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 *
		Dapingian		Klabava †												467.3
			Arenigian													468
							Arenig	Fennian								468.4 *
												Rangerian				469.1 *
	Early Ordovician	Floian									Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
								Whitlandian				Blackhillsian				471.1 *
								Whitlandian				Tulean				473.9 *
								Moridunian								474.3 *
		Tremadocian	Tremadocian				Tremadoc	Migneintian								477.7
								Migneintian				Stairsian				480.3 *
								Cressagian				Stairsian				480.8 *
								Cressagian				Skullrockian/Demingian				482 *
												Skullrockian/Demingian				485 *
																485.4
																487.5