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, 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
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 126831 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of the Baltic				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Harju	Porkuni			Cincinnatian	Gamachian				443.8
		Katian		Pirgu				Gamachian				445.2
				Pirgu				Richmondian				446 *
				Vormsi				Richmondian				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 *
				Rakvere			Mohawkian	Chatfieldian				451.1 *
				Oandu								452 *
		Sandbian		Keila	Idavere †							453
				Keila				Turinian				453.7 *
				Haljala								453.9
				Kukruse								456.4 *
				Kukruse			Whiterockian		Canadian †	Chazyan †/Marmor		457 *
				Uhaku	Aluoja †							457.5 *
	Middle Ordovician	Darriwilian		Uhaku								458.4
				Lasnamagi								458.9 *
				Aseri								460.4 *
			Oeland	Kunda								462.9 *
				Kunda	Valaste †/Hunderum							464.3 *
				Volkhov		Langevoja †/Vaana/Saka						467.1 *
		Dapingian										467.3
								Rangerian				469.1 *
				Billingen				Rangerian				469.3 *
	Early Ordovician	Floian					Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
					Latorp †							470.1 *
				Hunneberg								473.7 *
								Tulean				473.9 *
		Tremadocian						Tulean				477.7
								Stairsian				480.3 *
				Varangu				Stairsian				481.3 *
				Varangu				Skullrockian/Demingian				482 *
				Pakerort				Skullrockian/Demingian				482.2 *
												485.4 *
												486.3
												486.5
												487.5