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
  • 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
  • F. J. Prevosti, C. O. Romano, A. M. Forasiepi, S. Hemming, R. Bonini, A. M. Candela, E. Cerdeño, M. C. Madozzo Jaén, P. E. Ortiz, F. Pujos, L. Rasia, G. I. Schmidt, M. Taglioretti, R. D. E. MacPhee, and U. F. J. Pardiñas. 2021. New radiometric 40Ar–39Ar dates and faunistic analyses refine evolutionary dynamics of Neogene vertebrate assemblages in southern South America. Scientific Reports 2021(11):9830 view
  • J. J. Flynn and C. C. Swisher, III. 1995. Cenozoic South American Land Mammal Ages: correlation to global geochronology. Geochronology Time Scales and Global Stratigraphic Correlation, SEPM Special Publication 54:317-333 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 126163 collections

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International Chronostratigraphic TimescaleTen Million Year BinsNorth American Land Mammal AgesCambrian of West AvaloniaSouth American Land Mammal AgesCambrian of North AmericaCambrian of KazakhstanAmmonite Chrons of North AmericaCarboniferous of ChinaObsolete Names for ICS Units
QuaternaryHoloceneMeghalayanCenozoic 6Saintaugustinean0
Santarosean0.0004
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneLujanian0.0117
Rancholabrean0.014
Chibanian0.129
Irvingtonian0.21
Ensenadan0.3 *
Calabrian0.774
Blancan1.4
SanandresianUquian †1.7 *
Gelasian1.8
NeogenePliocenePiacenzianVorohueanTertiary †2.58
Chapadmalalan2.9 *
Zanclean3.6
Montehermosan3.7 *
Hemphillian4.7
Huayquerian4.9 *
MioceneMessinian5.333
Tortonian7.246
Chasicoan7.9 *
Clarendonian9.4
Mayoan9.9 *
Laventan10.9 *
SerravallianCenozoic 511.63
Barstovian12.5
Colloncuran13.7 *
Langhian13.82
Friasian15.4 *
Burdigalian15.98
Santacrucian16.2 *
Hemingfordian16.3
Colhuehuapian17.4 *
Arikareean18.5
Aquitanian20.44
Deseadan20.9 *
PaleogeneOligoceneChattianCenozoic 423.03
Rupelian27.82
Tinguirirican28.9 *
Whitneyan29.5
Orellan31.8
EocenePriabonianCenozoic 3Chadronian33.9
Divisaderan35.9 *
Duchesnean37
Bartonian37.71
Uintan39.7
LutetianCenozoic 241.2
Mustersan41.9 *
Bridgerian46.2
Ypresian47.8
Casamayoran47.9 *
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianCenozoic 1Riochican56
Tiffanian56.2
Itaboraian56.9 *
Peligran58.9 *
Selandian59.2
Torrejonian60.9
Danian61.6
Tiupampan62.4 *
Puercan63.8
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
CarboniferousPennsylvanianGzhelianCarboniferous 5298.9
Xiaodushanian300 *
Kasimovian303.7
Dalaun305.8 *
MoscovianCarboniferous 4307
Bashkirian315.2
Huashibanian318.5 *
Lousuan321.2 *
MississippianSerpukhovianCarboniferous 3Dewunian323.2
Shangsian330.8 *
ViseanCarboniferous 2330.9
Jiusian335 *
TournaisianCarboniferous 1Tangbagouan346.7
DevonianLate DevonianFamennianDevonian 5358.9
FrasnianDevonian 4372.2
Middle DevonianGivetianDevonian 3382.7
Eifelian387.7
Early DevonianEmsianDevonian 2393.3
PragianDevonian 1407.6
Lochkovian410.8
SilurianPridoliSilurian 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5443.8
Katian445.2
SandbianOrdovician 4453
Middle OrdovicianDarriwilianOrdovician 3458.4
DapingianOrdovician 2467.3
Early OrdovicianFloian470
TremadocianOrdovician 1Ungurian477.7
CambrianFurongianStage 10Cambrian 5Franconian †/Dresbachian/MillardanBatyrbaian485.4
Sunwaptan487.5
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Steptoean493 *
Paibian494
MiaolingianGuzhangianCambrian 4MarjumianAlbertian †AyusokkanianSeries 3 †497
Arcadian498.4
499.5
DrumianZhanaarykian500.5
Tuesaian503
WuliuanCambrian 3TopazanStage 5 †504.5
505.3
Delamaran506.5
Series 2Stage 4BranchianWaucoban †509
Toyonian510 *
Dyeran511 *
Botomian512.5 *
Stage 3Cambrian 2514
Montezuman514.8 *
Atdabanian515.6 *
Placentian517.1
Begadean519.9 *
TerreneuvianStage 2Tommotian521
525.5
FortunianCambrian 1529
538.8