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
  • J. A. Lillegraven and M. C. McKenna. 1986. Fossil mammals from the "Mesaverde" Formation (Late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming, with definitions of Late Cretaceous North American Land-Mammal "Ages". American Museum Novitates 2840:1-68 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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 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 126894 collections

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International Chronostratigraphic TimescaleTen Million Year BinsAmmonite Chrons of Northwest EuropeCretaceous North American Land-Mammal AgesSilurian of EnglandPermian of ChinaAmmonite Chrons of North AmericaOrdovician of ChinaCarboniferous SubepochsMesozoic SubagesObsolete Precambrian Ages
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 8Lancian/EdmontonianLate Maastrichtian/Early Maastrichtian66
CampanianCretaceous 7Judithian/AquilanLate Campanian/Middle Campanian/Early Campanian72.1
SantonianCretaceous 6Late Santonian/Middle Santonian/Early Santonian83.6
ConiacianLate Coniacian/Middle Coniacian/Early Coniacian86.3
TuronianLate Turonian/Middle Turonian/Early Turonian89.8
CenomanianCretaceous 5Late Cenomanian/Middle Cenomanian/Early Cenomanian93.9
Early CretaceousAlbianCretaceous 4Late Albian100.5
Middle Albian106.2 *
Early Albian109.9 *
AptianCretaceous 3Late Aptian113
Early Aptian119.5 *
BarremianCretaceous 2Late Barremian/Early Barremian121.4
HauterivianLate Hauterivian/Early Hauterivian125.77
ValanginianCretaceous 1Late Valanginian/Early Valanginian132.6
BerriasianLate Berriasian139.8
Middle Berriasian140.6 *
Early Berriasian142.7 *
JurassicLate JurassicTithonianJurassic 6Late TithonianMiddle Tithonian145
Early Tithonian146.3 *
KimmeridgianJurassic 5Late Kimmeridgian149.2
Early Kimmeridgian152.2 *
OxfordianLate OxfordianMiddle Oxfordian/Early Oxfordian154.8
157.9 *
Middle JurassicCallovianLate Callovian/Middle Callovian/Early Callovian161.5
BathonianJurassic 4Late Bathonian/Middle Bathonian/Early Bathonian165.3
BajocianParkinsoni/Garantiana/Subfurcatum/Sauzei/Laeviuscula/DiscitesEpizigzagicerasLate Bajocian168.2
HumphresianumRotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
Early Bajocian168.6 *
AalenianJurassic 3Concavum/Murchisonae/OpalinumHowelli/Scissum/WestermanniLate Aalenian/Middle Aalenian/Early Aalenian170.9
Early JurassicToarcianLevesquei/Variabilis/BifronsThouarsenseYakounensis/Hillebrandti/CrassicostaLate Toarcian174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
180.1
Middle Toarcian180.4 *
Kanense181.3 *
Serpentinum/Falciferum/Tenuicostatum182
Carlottense182.3 *
Early Toarcian182.9 *
Kunae183.5 *
PliensbachianJurassic 2Spinatum/Margaritatus/Davoei/Ibex/JamesoniLate Pliensbachian/Early Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
SinemurianJurassic 1Raricostatum/Oxynotum/Obtusum/Turneri/Semicostatum/BucklandiLate Sinemurian/Early Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
HettangianAngulata/Liasicus/PlanorbisLate Hettangian/Middle Hettangian/Early Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
NorianSevatian208.5
Alaunian213.2 *
Lacian216.7 *
CarnianTriassic 3Tuvalian227
Julian233.4 *
Middle TriassicLadinianTriassic 2Longobardian237
Fassanian239.7 *
AnisianIllyrian242
Pelsonian243.8 *
Bithynian244.7 *
Aegean245.5 *
Early TriassicOlenekianTriassic 1Spathian247.2
Smithian248.9 *
InduanDienerian251.2
Griesbachian251.4 *
PaleozoicPermianLopingianChanghsingianPermian 4Meishanian251.902
Baoqingian253.4 *
WuchiapingianLaoshanian254.14
Laibinian257.7 *
GuadalupianCapitanianLengwuan259.51
WordianKuhfengian264.28
RoadianPermian 3266.9
CisuralianKungurianPermian 2Luodianian273.01
Artinskian283.5
Longlinian285.4 *
Sakmarian290.1
AsselianPermian 1Zisongian293.52
CarboniferousPennsylvanianGzhelianCarboniferous 5Late Pennsylvanian298.9
300.1
Kasimovian303.7
MoscovianCarboniferous 4Middle Pennsylvanian307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianCarboniferous 3Late Mississippian323.2
ViseanCarboniferous 2Middle Mississippian330.9
TournaisianCarboniferous 1Early Mississippian346.7
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 OrdovicianHirnantianOrdovician 5HirnantianXiaoxita †/ShikouWufeng †443.8
KatianChientangkiangian445.2
Neichianshanian/Hanjiang449.5
SandbianOrdovician 4453
Middle OrdovicianDarriwilianOrdovician 3DarriwilianGuniu †/Hulo458.4
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianOrdovician 2Dapingian467.3
Early OrdovicianFloianYiyangian470
TremadocianOrdovician 1Xinchangian477.7
Lianghekou †477.9 *
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