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
J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 126701 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of the Baltic
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Harju	Porkuni			443.8
		Katian		Rawtheyan				Pirgu			445.2
				Cautleyan							448.9 *
				Pusgillian							449.3 *
			Caradoc	Streffordian	Onnian †			Vormsi			449.6 *
								Nabala	Johvi †		450 *
							Viru	Rakvere			450.6 *
				Cheneyan				Rakvere			451.5 *
				Cheneyan				Oandu			452 *
				Burrellian				Oandu			452.7 *
		Sandbian						Keila	Idavere †		453
					Actonian †			Keila			453.2 *
					Actonian †			Haljala			453.9
					Marshbrookian †	Woolstonian †					454.2 *
					Longvillian †						455.2 *
								Kukruse			456.4 *
				Aurelucian							456.8 *
					Soudleyan †/Harnagian/Costonian						457.4 *
					Soudleyan †/Harnagian/Costonian			Uhaku	Aluoja †		457.5 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn				Uhaku			458.4
								Lasnamagi			458.9 *
								Aseri			460.4 *
				Abereiddian/Early Llanvirn				Aseri			461.3 *
							Oeland	Kunda			462.9 *
								Kunda	Valaste †/Hunderum		464.3 *
								Volkhov		Langevoja †/Vaana/Saka	467.1 *
		Dapingian									467.3
			Arenig	Fennian							468.4 *
								Billingen			469.3 *
	Early Ordovician	Floian									470
									Latorp †		470.1 *
				Whitlandian							471.1 *
				Whitlandian				Hunneberg			473.7 *
				Moridunian							474.3 *
		Tremadocian	Tremadoc	Migneintian							477.7
				Cressagian							480.8 *
								Varangu			481.3 *
								Pakerort			482.2 *
								Pakerort			485 *
											485.4 *
											486.3
											486.5