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
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
M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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 126606 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