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
  • 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
  • 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 126949 collections

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International Chronostratigraphic TimescaleDevonian of CzechoslovakiaAmmonite Chrons of Northwest EuropeCretaceous North American Land-Mammal AgesSilurian of EnglandPermian of ChinaAmmonite Chrons of North AmericaOrdovician of ChinaCarboniferous SubepochsMesozoic SubagesObsolete Precambrian Ages
PhanerozoicMesozoicCretaceousLate CretaceousMaastrichtianLancian/EdmontonianLate Maastrichtian/Early Maastrichtian66
CampanianJudithian/AquilanLate Campanian/Middle Campanian/Early Campanian72.1
SantonianLate Santonian/Middle Santonian/Early Santonian83.6
ConiacianLate Coniacian/Middle Coniacian/Early Coniacian86.3
TuronianLate Turonian/Middle Turonian/Early Turonian89.8
CenomanianLate Cenomanian/Middle Cenomanian/Early Cenomanian93.9
Early CretaceousAlbianLate Albian100.5
Middle Albian106.2 *
Early Albian109.9 *
AptianLate Aptian113
Early Aptian119.5 *
BarremianLate Barremian/Early Barremian121.4
HauterivianLate Hauterivian/Early Hauterivian125.77
ValanginianLate Valanginian/Early Valanginian132.6
BerriasianLate Berriasian139.8
Middle Berriasian140.6 *
Early Berriasian142.7 *
JurassicLate JurassicTithonianLate TithonianMiddle Tithonian145
Early Tithonian146.3 *
KimmeridgianLate Kimmeridgian149.2
Early Kimmeridgian152.2 *
OxfordianLate OxfordianMiddle Oxfordian/Early Oxfordian154.8
157.9 *
Middle JurassicCallovianLate Callovian/Middle Callovian/Early Callovian161.5
BathonianLate Bathonian/Middle Bathonian/Early Bathonian165.3
BajocianParkinsoni/Garantiana/Subfurcatum/Sauzei/Laeviuscula/DiscitesEpizigzagicerasLate Bajocian168.2
HumphresianumRotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
Early Bajocian168.6 *
AalenianConcavum/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 *
PliensbachianSpinatum/Margaritatus/Davoei/Ibex/JamesoniLate Pliensbachian/Early Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
SinemurianRaricostatum/Oxynotum/Obtusum/Turneri/Semicostatum/BucklandiLate Sinemurian/Early Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
HettangianAngulata/Liasicus/PlanorbisLate Hettangian/Middle Hettangian/Early Hettangian199.5
TriassicLate TriassicRhaetian201.4
NorianSevatian208.5
Alaunian213.2 *
Lacian216.7 *
CarnianTuvalian227
Julian233.4 *
Middle TriassicLadinianLongobardian237
Fassanian239.7 *
AnisianIllyrian242
Pelsonian243.8 *
Bithynian244.7 *
Aegean245.5 *
Early TriassicOlenekianSpathian247.2
Smithian248.9 *
InduanDienerian251.2
Griesbachian251.4 *
PaleozoicPermianLopingianChanghsingianMeishanian251.902
Baoqingian253.4 *
WuchiapingianLaoshanian254.14
Laibinian257.7 *
GuadalupianCapitanianLengwuan259.51
WordianKuhfengian264.28
Roadian266.9
CisuralianKungurianLuodianian273.01
Artinskian283.5
Longlinian285.4 *
Sakmarian290.1
AsselianZisongian293.52
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
300.1
Kasimovian303.7
MoscovianMiddle Pennsylvanian307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianLate Mississippian323.2
ViseanMiddle Mississippian330.9
TournaisianEarly Mississippian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetianSrbsko382.7
EifelianChotec387.7
Early DevonianEmsianDaleje/Zlichovian393.3
PragianPragian407.6
LochkovianLochkovian410.8
SilurianPridoliRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/Leintwardine419.2
Bringewood/Elton421.3
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerian427.4
WychWoolhope428.4 *
Sheinwoodian430.5
LlandoveryTelychian433.4
436.3 *
Aeronian438.5
Cowleigh Park439.3 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHirnantianXiaoxita †/ShikouWufeng †443.8
KatianChientangkiangian445.2
Neichianshanian/Hanjiang449.5
Sandbian453
Middle OrdovicianDarriwilianDarriwilianGuniu †/Hulo458.4
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingian467.3
Early OrdovicianFloianYiyangian470
TremadocianXinchangian477.7
Lianghekou †477.9 *
CambrianFurongianStage 10485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4509
Stage 3514
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian †Poundian †538.8
Wonokan †571.7 *
635