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, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 127243 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of China			Ten Million Year Bins	Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Ordovician 5	Ashgill	Hirnantian			443.8
		Katian	Chientangkiangian					Rawtheyan			445.2
								Cautleyan			448.9 *
								Pusgillian			449.3 *
			Neichianshanian/Hanjiang					Pusgillian			449.5
							Caradoc	Streffordian	Onnian †		449.6 *
								Cheneyan			451.5 *
								Burrellian			452.7 *
		Sandbian				Ordovician 4					453
									Actonian †		453.2 *
									Marshbrookian †	Woolstonian †	454.2 *
									Longvillian †		455.2 *
								Aurelucian	Longvillian †		456.8 *
								Aurelucian	Soudleyan †/Harnagian/Costonian		457.4 *
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo		Ordovician 3	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			458.4
				Guniu †/Hulo				Abereiddian/Early Llanvirn			461.3 *
				Hunjiang †	Dawan †/Daobaowan/Ningkuo						466.3 *
		Dapingian	Dapingian			Ordovician 2					467.3
		Dapingian	Dapingian				Arenig	Fennian			468.4 *
	Early Ordovician	Floian	Yiyangian					Fennian			470
								Whitlandian			471.1 *
								Moridunian			474.3 *
		Tremadocian	Xinchangian			Ordovician 1	Tremadoc	Migneintian			477.7
					Lianghekou †			Migneintian			477.9 *
								Cressagian			480.8 *
											485 *
											485.4