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
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
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 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 126610 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of the Baltic				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Harju	Porkuni			Cincinnatian	Gamachian				443.8
		Katian		Rawtheyan				Pirgu				Gamachian				445.2
				Rawtheyan								Richmondian				446 *
				Cautleyan												448.9 *
				Pusgillian												449.3 *
			Caradoc	Streffordian	Onnian †			Vormsi								449.6 *
								Vormsi				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
								Nabala	Johvi †			Maysvillian				450 *
								Nabala				Edenian				450.4 *
							Viru	Rakvere				Edenian				450.6 *
											Mohawkian	Chatfieldian				451.1 *
				Cheneyan												451.5 *
				Cheneyan				Oandu								452 *
				Burrellian				Oandu								452.7 *
		Sandbian						Keila	Idavere †							453
					Actonian †											453.2 *
												Turinian				453.7 *
								Haljala								453.9
					Marshbrookian †	Woolstonian †										454.2 *
					Longvillian †											455.2 *
								Kukruse								456.4 *
				Aurelucian												456.8 *
											Whiterockian		Canadian †	Chazyan †/Marmor		457 *
					Soudleyan †/Harnagian/Costonian											457.4 *
					Soudleyan †/Harnagian/Costonian			Uhaku	Aluoja †							457.5 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn				Uhaku								458.4
								Lasnamagi								458.9 *
								Aseri								460.4 *
				Abereiddian/Early Llanvirn				Aseri								461.3 *
							Oeland	Kunda								462.9 *
								Kunda	Valaste †/Hunderum							464.3 *
								Volkhov		Langevoja †/Vaana/Saka						467.1 *
		Dapingian														467.3
			Arenig	Fennian												468.4 *
												Rangerian				469.1 *
								Billingen				Rangerian				469.3 *
	Early Ordovician	Floian									Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
									Latorp †							470.1 *
				Whitlandian												471.1 *
								Hunneberg								473.7 *
												Tulean				473.9 *
				Moridunian												474.3 *
		Tremadocian	Tremadoc	Migneintian												477.7
				Migneintian								Stairsian				480.3 *
				Cressagian												480.8 *
								Varangu								481.3 *
								Varangu				Skullrockian/Demingian				482 *
								Pakerort								482.2 *
								Pakerort								485 *
																485.4 *
																486.3
																486.5
																487.5