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
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 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

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