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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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 Australia	Ordovician of China			Ordovician of Ibero-Bohemia				Ordovician of the Baltic
Ordovician	Late Ordovician	Hirnantian	Bolindian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Kosovian				Harju	Porkuni			443.8
		Katian	Bolindian	Chientangkiangian			Kralodvorian	Bohdalec †				Pirgu			445.2
			Eastonian	Chientangkiangian											449 *
				Neichianshanian/Hanjiang											449.5
												Vormsi			449.6 *
							Berounian					Vormsi			449.7 *
												Nabala	Johvi †		450 *
											Viru	Rakvere			450.6 *
			Gisbornian									Oandu			452 *
		Sandbian										Keila	Idavere †		453
												Haljala			453.9
									Zahorany †/Vinice	Letna †		Haljala			456.2 *
												Kukruse			456.4 *
												Uhaku	Aluoja †		457.5 *
								Liben †							458 *
	Middle Ordovician	Darriwilian	Darriwilian	Darriwilian	Guniu †/Hulo										458.4
							Dobrotivian								458.5 *
							Dobrotivian					Lasnamagi			458.9 *
							Oretanian					Lasnamagi			459.7 *
												Aseri			460.4 *
								Sarka †				Aseri			461.7 *
											Oeland	Kunda			462.9 *
													Valaste †/Hunderum		464.3 *
					Hunjiang †	Dawan †/Daobaowan/Ningkuo									466.3 *
												Volkhov		Langevoja †/Vaana/Saka	467.1 *
		Dapingian	Yapeenian	Dapingian				Klabava †							467.3
			Yapeenian				Arenigian								468
			Castlemainian												468.5 *
			Castlemainian									Billingen			469.3 *
	Early Ordovician	Floian	Chewtonian	Yiyangian											470
			Chewtonian										Latorp †		470.1 *
			Bendigonian												471.8 *
			Lancefieldian												473.5 *
												Hunneberg			473.7 *
		Tremadocian		Xinchangian			Tremadocian								477.7
						Lianghekou †									477.9 *
												Varangu			481.3 *
												Pakerort			482.2 *
			Warendian									Pakerort			482.8 *
															485.4 *
															486.3
															486.5