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
A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 127017 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of China			Cambrian of Kazakhstan	Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Hirnantian	Xiaoxita †/Shikou	Wufeng †		Cincinnatian	Gamachian				443.8
		Katian		Rawtheyan			Chientangkiangian					Gamachian				445.2
				Rawtheyan								Richmondian				446 *
				Cautleyan												448.9 *
				Pusgillian												449.3 *
				Pusgillian			Neichianshanian/Hanjiang									449.5
			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														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			Darriwilian	Guniu †/Hulo								458.4
				Abereiddian/Early Llanvirn				Guniu †/Hulo								461.3 *
								Hunjiang †	Dawan †/Daobaowan/Ningkuo							466.3 *
		Dapingian					Dapingian									467.3
			Arenig	Fennian												468.4 *
												Rangerian				469.1 *
	Early Ordovician	Floian					Yiyangian				Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
				Whitlandian								Blackhillsian				471.1 *
				Whitlandian								Tulean				473.9 *
				Moridunian												474.3 *
		Tremadocian	Tremadoc	Migneintian			Xinchangian			Ungurian						477.7
									Lianghekou †							477.9 *
												Stairsian				480.3 *
				Cressagian								Stairsian				480.8 *
				Cressagian								Skullrockian/Demingian				482 *
												Skullrockian/Demingian				485 *
																485.4
																487.5