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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 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

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 China			Ordovician of the Baltic
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Hirnantian	Xiaoxita †/Shikou	Wufeng †	Harju	Porkuni			443.8
		Katian		Rawtheyan			Chientangkiangian				Pirgu			445.2
				Cautleyan										448.9 *
				Pusgillian										449.3 *
				Pusgillian			Neichianshanian/Hanjiang							449.5
			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			Darriwilian	Guniu †/Hulo			Uhaku			458.4
											Lasnamagi			458.9 *
											Aseri			460.4 *
				Abereiddian/Early Llanvirn							Aseri			461.3 *
										Oeland	Kunda			462.9 *
												Valaste †/Hunderum		464.3 *
								Hunjiang †	Dawan †/Daobaowan/Ningkuo					466.3 *
											Volkhov		Langevoja †/Vaana/Saka	467.1 *
		Dapingian					Dapingian							467.3
			Arenig	Fennian										468.4 *
											Billingen			469.3 *
	Early Ordovician	Floian					Yiyangian							470
												Latorp †		470.1 *
				Whitlandian										471.1 *
				Whitlandian							Hunneberg			473.7 *
				Moridunian										474.3 *
		Tremadocian	Tremadoc	Migneintian			Xinchangian							477.7
				Migneintian					Lianghekou †					477.9 *
				Cressagian										480.8 *
											Varangu			481.3 *
											Pakerort			482.2 *
											Pakerort			485 *
														485.4 *
														486.3
														486.5