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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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 126778 collections

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International Chronostratigraphic TimescaleCambrian of AustraliaPermian Subages of GermanyDevonian SubagesSilurian of EnglandCambrian of North AmericaObsolete Carboniferous Ages of ChinaOrdovician of North AmericaOrdovician of AustraliaOrdovician of the BalticSilurian of the Baltic
PermianLopingianChanghsingianBuntsandstein251.902
Wuchiapingian254.14
GuadalupianCapitanianOhre/Aller259.51
WordianLeine264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelianMapingian †298.9
Kasimovian303.7
305.9
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennianLate Famennian358.9
Middle Famennian365.3 *
Early Famennian368.5 *
FrasnianLate Frasnian372.2
Middle Frasnian375.4 *
Early Frasnian379.3 *
Middle DevonianGivetianLate Givetian382.7
Middle Givetian383.7 *
Early Givetian385.9 *
EifelianLate Eifelian387.7
Early Eifelian390.3 *
Early DevonianEmsianLate Emsian393.3
Early Emsian398.3 *
PragianPragian407.6
LochkovianLate Lochkovian410.8
Middle Lochkovian412.8 *
Early Lochkovian415.6 *
SilurianPridoliRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/LeintwardineOhesaare419.2
Bringewood/Elton421.3
Kaugetuma421.7 *
LudlowLudfordianCoalbrookdaleWenlock (England)/TickwoodKuressaare423
Paadla423.4 *
Gorstian425.6
Buildwas426.4 *
WenlockHomerianRootsikula427.4
WychWoolhope428.4 *
Jaagarahu429.2 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychian433.4
Adavere434 *
436.3 *
Aeronian438.5
Cowleigh Park439.3 *
Raikkula439.4 *
Rhuddanian440.8
Juuru441.4 *
OrdovicianLate OrdovicianHirnantianCincinnatianGamachianBolindianHarjuPorkuni443.8
KatianPirgu445.2
Richmondian446 *
Eastonian449 *
Vormsi449.6 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
NabalaJohvi †450 *
Edenian450.4 *
ViruRakvere450.6 *
MohawkianChatfieldian451.1 *
GisbornianOandu452 *
SandbianKeilaIdavere †453
Turinian453.7 *
Haljala453.9
Kukruse456.4 *
WhiterockianCanadian †Chazyan †/Marmor457 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
DapingianYapeenian467.3
Castlemainian468.5 *
Rangerian469.1 *
Billingen469.3 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †Chewtonian470
Latorp †470.1 *
Bendigonian471.8 *
Lancefieldian473.5 *
Hunneberg473.7 *
Tulean473.9 *
Tremadocian477.7
Stairsian480.3 *
Varangu481.3 *
SkullrockianDemingian †482 *
Pakerort482.2 *
Warendian482.8 *
CambrianFurongianStage 10DatsonianFranconian †/Dresbachian/Millardan485.4
486.3 *
486.5
Payntonian486.8 *
Sunwaptan487.5
JiangshanianIverian489.5
Steptoean493 *
PaibianIdamean494
MiaolingianGuzhangianMindyallanMarjumianAlbertian †497
Boomerangian499
DrumianUndillan500.5
Floran503
WuliuanTempletonianTopazan504.5
Delamaran506.5
Ordian507.8 *
Series 2Stage 4Waucoban †509
510.8 *
Dyeran511 *
Stage 3514
Montezuman514.8 *
Begadean519.9 *
TerreneuvianStage 2521
Fortunian529
538.8