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
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
J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 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 126973 collections

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International Chronostratigraphic Timescale			Ordovician of China			Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Bolindian	443.8
		Katian	Chientangkiangian			Bolindian	445.2
			Chientangkiangian			Eastonian	449 *
			Neichianshanian/Hanjiang			Eastonian	449.5
						Gisbornian	452 *
		Sandbian				Gisbornian	453
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo		Darriwilian	458.4
		Darriwilian	Darriwilian	Hunjiang †	Dawan †/Daobaowan/Ningkuo	Darriwilian	466.3 *
		Dapingian	Dapingian			Yapeenian	467.3
		Dapingian	Dapingian			Castlemainian	468.5 *
	Early Ordovician	Floian	Yiyangian			Chewtonian	470
						Bendigonian	471.8 *
						Lancefieldian	473.5 *
		Tremadocian	Xinchangian				477.7
					Lianghekou †		477.9 *
					Lianghekou †	Warendian	482.8 *
							485.4