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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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

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 126689 collections

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International Chronostratigraphic TimescaleCambrian of BritainCarboniferous of North AmericaTen Million Year BinsOrdovician of Ibero-BohemiaNorth American Land Mammal AgesObsolete Names for ICS Units
QuaternaryHoloceneMeghalayanCenozoic 6Saintaugustinean0
Santarosean0.0004
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate Pleistocene0.0117
Rancholabrean0.014
Chibanian0.129
Irvingtonian0.21
Calabrian0.774
Blancan1.4
Gelasian1.8
NeogenePliocenePiacenzianTertiary †2.58
Zanclean3.6
Hemphillian4.7
MioceneMessinian5.333
Tortonian7.246
Clarendonian9.4
SerravallianCenozoic 511.63
Barstovian12.5
Langhian13.82
Burdigalian15.98
Hemingfordian16.3
Arikareean18.5
Aquitanian20.44
PaleogeneOligoceneChattianCenozoic 423.03
Rupelian27.82
Whitneyan29.5
Orellan31.8
EocenePriabonianCenozoic 3Chadronian33.9
Duchesnean37
Bartonian37.71
Uintan39.7
LutetianCenozoic 241.2
Bridgerian46.2
Ypresian47.8
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianCenozoic 156
Tiffanian56.2
Selandian59.2
Torrejonian60.9
Danian61.6
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
Bajocian168.2
AalenianJurassic 3170.9
Early JurassicToarcian174.7
PliensbachianJurassic 2184.2
SinemurianJurassic 1192.9
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
AsselianBursumian †Permian 1293.52
CarboniferousPennsylvanianGzhelianVirgilianCarboniferous 5298.9
KasimovianMissourian303.7
Desmoinesian305.9 *
MoscovianCarboniferous 4307
Atokan312.7 *
Bashkirian315.2
Morrowan318.4 *
MississippianSerpukhovianChesterianCarboniferous 3323.2
ViseanCarboniferous 2330.9
Meramecian335.8 *
Osagean343.1 *
TournaisianCarboniferous 1346.7
Kinderhookian351.9 *
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 5Kosovian443.8
KatianKralodvorianBohdalec †445.2
Berounian449.7 *
SandbianOrdovician 4453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianOrdovician 3458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianOrdovician 2Klabava †467.3
Arenigian468
Early OrdovicianFloian470
TremadocianOrdovician 1Tremadocian477.7
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanCambrian 5485.4
Festiniogian489.2 *
Jiangshanian489.5
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianSt DavidsCambrian 4Series 3 †497
Drumian500.5
WuliuanCambrian 3Stage 5 †504.5
Series 2Stage 4Caerfai509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8