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 126764 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of the Baltic				Cambrian of Kazakhstan	Ordovician of Britain				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Harju	Porkuni				Ashgill	Hirnantian			Cincinnatian	Gamachian				443.8
		Katian		Pirgu					Rawtheyan				Gamachian				445.2
									Rawtheyan				Richmondian				446 *
									Cautleyan								448.9 *
									Pusgillian								449.3 *
				Vormsi				Caradoc	Streffordian	Onnian †							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 *
				Oandu					Cheneyan								452 *
				Oandu					Burrellian								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 *
				Uhaku	Aluoja †					Soudleyan †/Harnagian/Costonian							457.5 *
	Middle Ordovician	Darriwilian		Uhaku				Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn								458.4
				Lasnamagi													458.9 *
				Aseri													460.4 *
				Aseri					Abereiddian/Early Llanvirn								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					Ungurian	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