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
  • 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 126133 collections

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International Chronostratigraphic TimescaleTen Million Year BinsOrdovician of AustraliaDevonian of CzechoslovakiaCenozoic SubepochsAmmonite Chrons of North AmericaCarboniferous of Western EuropeDevonian of FranceCambrian of BritainObsolete Names for ICS Units
QuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneLate Pleistocene0.0117
ChibanianMiddle Pleistocene0.129
CalabrianEarly Pleistocene0.774
Gelasian1.8
NeogenePliocenePiacenzianLate PlioceneTertiary †2.58
ZancleanEarly Pliocene3.6
MioceneMessinianLate Miocene5.333
Tortonian7.246
SerravallianCenozoic 5Middle Miocene11.63
Langhian13.82
BurdigalianEarly Miocene15.98
Aquitanian20.44
PaleogeneOligoceneChattianCenozoic 4Late Oligocene23.03
RupelianEarly Oligocene27.82
EocenePriabonianCenozoic 3Late Eocene33.9
BartonianMiddle Eocene37.71
LutetianCenozoic 241.2
YpresianEarly Eocene47.8
PaleoceneThanetianCenozoic 1Late Paleocene56
SelandianMiddle Paleocene59.2
DanianEarly Paleocene61.6
CretaceousLate CretaceousMaastrichtianCretaceous 866
CampanianCretaceous 772.1
SantonianCretaceous 683.6
Coniacian86.3
Turonian89.8
CenomanianCretaceous 593.9
Early CretaceousAlbianCretaceous 4100.5
AptianCretaceous 3113
BarremianCretaceous 2121.4
Hauterivian125.77
ValanginianCretaceous 1132.6
Berriasian139.8
JurassicLate JurassicTithonianJurassic 6145
KimmeridgianJurassic 5149.2
Oxfordian154.8
Middle JurassicCallovian161.5
BathonianJurassic 4165.3
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianJurassic 3Howelli/Scissum/Westermanni170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
PliensbachianJurassic 2184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
SinemurianJurassic 1192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
Norian208.5
CarnianTriassic 3227
Middle TriassicLadinianTriassic 2237
Anisian242
Early TriassicOlenekianTriassic 1247.2
Induan251.2
PermianLopingianChanghsingianPermian 4251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
RoadianPermian 3266.9
CisuralianKungurianPermian 2273.01
Artinskian283.5
Sakmarian290.1
AsselianPermian 1293.52
Kuzel297.7
CarboniferousPennsylvanianGzhelianCarboniferous 5298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
Kasimovian303.7
Cantabrian305 *
MoscovianCarboniferous 4307
WestphalianWestphalian D307.4 *
Westphalian C309.8
Westphalian B314.6
Bashkirian315.2
Westphalian A317 *
NamurianYeadonian318.8 *
Marsdenian320.2 *
Kinderscoutian321.5 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovianCarboniferous 3323.2
Arnsbergian324 *
Pendleian327.4 *
ViseanCarboniferous 2WarnantianBrigantian †330.9
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
TournaisianCarboniferous 1Ivorian346.7
Hastarian353.7 *
DevonianLate DevonianFamennianDevonian 5Famennian358.9
FrasnianDevonian 4Frasnian372.2
Middle DevonianGivetianDevonian 3SrbskoGivetian382.7
EifelianChotecCouvinien387.7
Early DevonianEmsianDevonian 2Daleje/Zlichovian393.3
PragianDevonian 1Pragian407.6
Coblencien408.2 *
LochkovianLochkovianGedinnine410.8
SilurianPridoliSilurian 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5Bolindian443.8
Katian445.2
Eastonian449 *
Gisbornian452 *
SandbianOrdovician 4453
Middle OrdovicianDarriwilianOrdovician 3Darriwilian458.4
DapingianOrdovician 2Yapeenian467.3
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
TremadocianOrdovician 1477.7
Warendian482.8 *
CambrianFurongianStage 10Cambrian 5MerionethDolgellian/Trempealeauan485.4
Festiniogian489.2 *
Jiangshanian489.5
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianCambrian 4St DavidsSeries 3 †497
Drumian500.5
WuliuanCambrian 3Stage 5 †504.5
Series 2Stage 4Caerfai509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8