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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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
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

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 126844 collections

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International Chronostratigraphic Timescale			Ordovician of China			Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Cincinnatian	Gamachian				443.8
		Katian	Chientangkiangian				Gamachian				445.2
			Chientangkiangian				Richmondian				446 *
			Neichianshanian/Hanjiang				Richmondian				449.5
							Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
							Edenian				450.4 *
						Mohawkian	Chatfieldian				451.1 *
		Sandbian					Chatfieldian				453
							Turinian				453.7 *
						Whiterockian		Canadian †	Chazyan †/Marmor		457 *
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo							458.4
		Darriwilian	Darriwilian	Hunjiang †	Dawan †/Daobaowan/Ningkuo						466.3 *
		Dapingian	Dapingian								467.3
		Dapingian	Dapingian				Rangerian				469.1 *
	Early Ordovician	Floian	Yiyangian			Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
		Floian	Yiyangian				Tulean				473.9 *
		Tremadocian	Xinchangian								477.7
					Lianghekou †						477.9 *
							Stairsian				480.3 *
							Skullrockian/Demingian				482 *
											485.4
											487.5