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
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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 126610 collections

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International Chronostratigraphic TimescaleCenozoic SubepochsCambrian of AustraliaMammal Paleogene ZonesCarboniferous of Western EuropeAmmonite Chrons of North AmericaCarboniferous SubepochsObsolete Names for ICS Units
QuaternaryPleistoceneLate PleistoceneLate Pleistocene0.0117
ChibanianMiddle Pleistocene0.129
CalabrianEarly Pleistocene0.774
Gelasian1.8
NeogenePliocenePiacenzianLate PlioceneTertiary †2.58
ZancleanEarly Pliocene3.6
MioceneMessinianLate Miocene5.333
Tortonian7.246
SerravallianMiddle Miocene11.63
Langhian13.82
BurdigalianEarly Miocene15.98
Aquitanian20.44
PaleogeneOligoceneChattianLate OligoceneMP 30/MP 29/MP 28/MP 27/MP 26MP 2523.03
RupelianEarly OligoceneMP 24/MP 23/MP 22/MP 2127.82
EocenePriabonianLate EoceneMP 20/MP 19/MP 18/MP 17B/MP 17A33.9
BartonianMiddle EoceneMP 1637.71
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
YpresianEarly EoceneMP 10/MP 8 + 9/MP 747.8
PaleoceneThanetianLate PaleoceneMP 6MP 1 - 556
SelandianMiddle Paleocene59.2
DanianEarly Paleocene61.6
CretaceousLate CretaceousMaastrichtian66
Campanian72.1
Santonian83.6
Coniacian86.3
Turonian89.8
Cenomanian93.9
Early CretaceousAlbian100.5
Aptian113
Barremian121.4
Hauterivian125.77
Valanginian132.6
Berriasian139.8
JurassicLate JurassicTithonian145
Kimmeridgian149.2
Oxfordian154.8
Middle JurassicCallovian161.5
Bathonian165.3
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianHowelli/Scissum/Westermanni170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
PermianLopingianChanghsingian251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
Kuzel297.7
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
Kasimovian303.7
Cantabrian305 *
MoscovianMiddle Pennsylvanian307
WestphalianWestphalian D307.4 *
Westphalian C309.8
Westphalian B314.6
BashkirianEarly Pennsylvanian315.2
Westphalian A317 *
NamurianYeadonian318.8 *
Marsdenian320.2 *
Kinderscoutian321.5 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovianLate Mississippian323.2
Arnsbergian324 *
Pendleian327.4 *
ViseanWarnantianBrigantian †Middle Mississippian330.9
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
TournaisianIvorianEarly Mississippian346.7
Hastarian353.7 *
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantian443.8
Katian445.2
Sandbian453
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Early OrdovicianFloian470
Tremadocian477.7
CambrianFurongianStage 10Datsonian485.4
Payntonian486.8 *
JiangshanianIverian489.5
PaibianIdamean494
MiaolingianGuzhangianMindyallanSeries 3 †497
Boomerangian499
DrumianUndillan500.5
Floran503
WuliuanTempletonianStage 5 †504.5
Ordian507.8 *
Series 2Stage 4509
510.8 *