PBDB Timescale

Ordovician of North America

The interval definitions in this timescale are derived from the following sources:

F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view

There are 14 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 6005 collections

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International Chronostratigraphic Timescale			Ordovician of North America					Ordovician of China			Cambrian Epochs
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Hirnantian	Xiaoxita †/Shikou	Wufeng †		443.8
		Katian		Gamachian				Chientangkiangian				445.2
				Richmondian				Chientangkiangian				446 *
				Richmondian				Neichianshanian/Hanjiang				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		Rangerian				Dapingian				469.1 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	Yiyangian				470
		Floian		Tulean				Yiyangian				473.9 *
		Tremadocian						Xinchangian				477.7
										Lianghekou †		477.9 *
				Stairsian								480.3 *
				Skullrockian			Demingian †					482 *
Cambrian	Furongian	Stage 10		Skullrockian							Late Cambrian	485.4
		Stage 10										487.5
		Jiangshanian										489.5
		Paibian										494
	Miaolingian	Guzhangian									Middle Cambrian	497
		Drumian										500.5
		Wuliuan										504.5
	Series 2	Stage 4									Early Cambrian	509
	Series 2	Stage 3										514
	Terreneuvian	Stage 2										521
	Terreneuvian	Fortunian										529
												538.8