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, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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 126762 collections

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International Chronostratigraphic TimescaleObsolete Precambrian AgesOrdovician of AustraliaCarboniferous of Western EuropeTen Million Year BinsSilurian of EnglandOrdovician of Ibero-Bohemia
PhanerozoicCenozoicQuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate Pleistocene0.0117
Chibanian0.129
Calabrian0.774
Gelasian1.8
NeogenePliocenePiacenzian2.58
Zanclean3.6
MioceneMessinian5.333
Tortonian7.246
SerravallianCenozoic 511.63
Langhian13.82
Burdigalian15.98
Aquitanian20.44
PaleogeneOligoceneChattianCenozoic 423.03
Rupelian27.82
EocenePriabonianCenozoic 333.9
Bartonian37.71
LutetianCenozoic 241.2
Ypresian47.8
PaleoceneThanetianCenozoic 156
Selandian59.2
Danian61.6
MesozoicCretaceousLate 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
PaleozoicPermianLopingianChanghsingianPermian 4251.902
Wuchiapingian254.14
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 *
ViseanWarnantianBrigantian †Carboniferous 2330.9
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
TournaisianIvorianCarboniferous 1346.7
Hastarian353.7 *
DevonianLate DevonianFamennianDevonian 5358.9
FrasnianDevonian 4372.2
Middle DevonianGivetianDevonian 3382.7
Eifelian387.7
Early DevonianEmsianDevonian 2393.3
PragianDevonian 1407.6
Lochkovian410.8
SilurianPridoliSilurian 2Red Downtonian/Temeside Shales/Downton CastleWhitcliffe/Leintwardine419.2
Bringewood/Elton421.3
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerian427.4
WychWoolhope428.4 *
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
436.3 *
Aeronian438.5
Cowleigh Park439.3 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianBolindianOrdovician 5Kosovian443.8
KatianKralodvorianBohdalec †445.2
Eastonian449 *
Berounian449.7 *
Gisbornian452 *
SandbianOrdovician 4453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianOrdovician 3458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianYapeenianOrdovician 2Klabava †467.3
Arenigian468
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
TremadocianOrdovician 1Tremadocian477.7
Warendian482.8 *
CambrianFurongianStage 10Cambrian 5485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianCambrian 4497
Drumian500.5
WuliuanCambrian 3504.5
Series 2Stage 4509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †538.8
Wonokan †571.7 *
635