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, 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

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 North America
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				443.8
		Katian		Gamachian				445.2
				Richmondian				446 *
				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						458.4
		Dapingian						467.3
		Dapingian		Rangerian				469.1 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
		Floian		Tulean				473.9 *
		Tremadocian		Tulean				477.7
				Stairsian				480.3 *
				Skullrockian/Demingian				482 *
								485.4
								487.5