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, 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
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
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 North America					Ordovician of Britain				Cambrian of Kazakhstan	Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Ashgill	Hirnantian				Kosovian				443.8
		Katian		Gamachian					Rawtheyan				Kralodvorian	Bohdalec †			445.2
				Richmondian					Rawtheyan								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 *
				Turinian						Actonian †							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 *
										Soudleyan †/Harnagian/Costonian				Liben †			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
				Blackhillsian					Whitlandian								471.1 *
				Tulean					Whitlandian								473.9 *
									Moridunian								474.3 *
		Tremadocian						Tremadoc	Migneintian			Ungurian	Tremadocian				477.7
				Stairsian					Migneintian								480.3 *
				Stairsian					Cressagian								480.8 *
				Skullrockian/Demingian					Cressagian								482 *
				Skullrockian/Demingian													485 *
																	485.4
																	487.5