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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 126973 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ten Million Year Bins	Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Ordovician 5	Cincinnatian	Gamachian				443.8
		Katian		Rawtheyan					Gamachian				445.2
				Rawtheyan					Richmondian				446 *
				Cautleyan									448.9 *
				Pusgillian									449.3 *
			Caradoc	Streffordian	Onnian †								449.6 *
									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					Ordovician 4						453
					Actonian †								453.2 *
					Actonian †				Turinian				453.7 *
					Marshbrookian †	Woolstonian †							454.2 *
					Longvillian †								455.2 *
				Aurelucian									456.8 *
								Whiterockian		Canadian †	Chazyan †/Marmor		457 *
					Soudleyan †/Harnagian/Costonian								457.4 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			Ordovician 3						458.4
		Darriwilian		Abereiddian/Early Llanvirn			Ordovician 3						461.3 *
		Dapingian		Abereiddian/Early Llanvirn			Ordovician 2						467.3
			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	Tremadoc	Migneintian			Ordovician 1						477.7
				Migneintian					Stairsian				480.3 *
				Cressagian					Stairsian				480.8 *
				Cressagian					Skullrockian/Demingian				482 *
									Skullrockian/Demingian				485 *
													485.4
													487.5