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
  • 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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. I. Raine, A. G. Beu, A. F. Boyes, H. J. Campbell, R. A. Cooper, J. S. Crampton, M. P. Crundwell, C. J. Hollis, and H. E. G. Morgans. 2015. Revised Calibration of the New Zealand Geological Timescale: NZGT2015/1. GNS Science Report 2012(39) 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 126884 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleAmmonite Chrons of North AmericaOrdovician of ChinaOrdovician of Ibero-BohemiaPermian of the Salt RangeSilurian of EnglandSilurian of North AmericaPermian of North AmericaPermian-Jurassic of New ZealandPermian Subages of GermanyCambrian of North America
JurassicLate JurassicTithonianOtekePuaroan145
Kimmeridgian149.2
KawhiaOhauan150
Heterian154.5
Oxfordian154.8
Middle JurassicCallovian161.5
Temaikan164.3
Bathonian165.3
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianHowelli/Scissum/Westermanni170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
HerangiUruroan176
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
Aratauran188.9
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetianBalfourOtapirian201.4
NorianWarepan208.5
Otamitan217
Oretian221
Carnian227
GoreKaihikuan227.5
Middle TriassicLadinian237
Etalian238
Anisian242
Malakovian246
Early TriassicOlenekian247.2
Nelsonian249
Induan251.2
KathwaiDUrvilleMakarewan251.5 *
PermianLopingianChanghsingianBuntsandstein251.902
252.4 *
Chhidru252.9 *
Waiitian253.2
Wuchiapingian254.14
Puruhauan254.2
Kalabagh255 *
Wargal256 *
GuadalupianCapitanianCapitanianAparimaFlettianOhre/Aller259.51
WordianWordianLeine264.28
265.3 *
Barettian266
Amb266.1 *
RoadianRoadian266.9
270.7 *
CisuralianKungurianLeonardianCathedralian273.01
Mangapirian276
Hessian281.9 *
Artinskian283.5
Telfordian285
WolfcampianLenoxian286.1 *
288.5
Sakmarian290.1
AsselianNealian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/LeintwardineCayugan419.2
Bringewood/Elton421.3
Niagaran422.5 *
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerianLockportian427.4
WychWoolhope428.4 *
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
436.3 *
Aeronian438.5
Alexandrian438.7 *
Cowleigh Park439.3 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHirnantianXiaoxita †/ShikouWufeng †Kosovian443.8
KatianChientangkiangianKralodvorianBohdalec †445.2
Neichianshanian/Hanjiang449.5
Berounian449.7 *
Sandbian453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianGuniu †/Hulo458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingianKlabava †467.3
Arenigian468
Early OrdovicianFloianYiyangian470
TremadocianXinchangianTremadocian477.7
Lianghekou †477.9 *
CambrianFurongianStage 10Franconian †/Dresbachian/Millardan485.4
Sunwaptan487.5
Jiangshanian489.5
Steptoean493 *
Paibian494
MiaolingianGuzhangianMarjumianAlbertian †497
Drumian500.5
WuliuanTopazan504.5
Delamaran506.5
Series 2Stage 4Waucoban †509
Dyeran511 *
Stage 3514
Montezuman514.8 *
Begadean519.9 *
TerreneuvianStage 2521
Fortunian529
538.8