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
  • M. O. Woodburne. 1987. A prospectus of the North American Mammal Ages. In: Woodburne, M. O. (ed.), Cenozoic Mammals of North America. University of California Press, Berkelery, CA 285-290 view
  • J. Alroy. 2000. New methods for quantifying macroevolutionary patterns and processes. Paleobiology 26(4):707-733 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
  • P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 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 126699 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleObsolete Names for ICS UnitsNorth American Mammal Subages/ZonesAmmonite Chrons of North AmericaPermian of the PamirsCenozoic Subepochs of Southern EuropeTen Million Year BinsDevonian of France
QuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneSheridanianTarantian0.0117
ChibanianIonian0.129
Cudahyan/Sappan0.21
Calabrian0.774
Senecan/Rexroadian1.4
Gelasian1.8
NeogenePliocenePiacenzianTertiary †2.58
Zanclean3.6
Late Hemphillian/late Early Hemphillian/early Early Hemphillian4.7
MioceneMessinian5.333
Tortonian7.246
Late Clarendonian/Early Clarendonian9.4
SerravallianCenozoic 511.63
late Late Barstovian/early Late Barstovian/Early Barstovian12.5
Langhian13.82
Burdigalian15.98
Late Hemingfordian/Early Hemingfordian16.3
late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early ArikareeanHarrisonian18.5
Aquitanian20.44
PaleogeneOligoceneChattianCenozoic 423.03
Monroecreekian23.1 *
Geringian24.7 *
Rupelian27.82
29.5
EocenePriabonianLate Chadronian/Middle Chadronian/Early ChadronianCenozoic 333.9
37
Bartonian37.71
Late Uintan/Early Uintan39.7
LutetianCenozoic 241.2
Twinbuttean/Blacksforkian/Gardnerbuttian46.2
Ypresian47.8
Lostcabinian/Lysitean/Graybullian/Sandcouleean50.5
Cf3/Cf2/Cf154.9
PaleoceneThanetianCenozoic 156
Ti6/Ti5/Ti4/Ti3/Ti2/Ti156.2
Selandian59.2
To3/To2/To160.9
Danian61.6
Pu3/Pu2/Pu163.8
CretaceousLate 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
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianHowelli/Scissum/WestermanniJurassic 3170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
PliensbachianJurassic 2184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
SinemurianJurassic 1192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
Norian208.5
CarnianTriassic 3227
Middle TriassicLadinianTriassic 2237
Anisian242
Early TriassicOlenekianTriassic 1247.2
Induan251.2
PermianLopingianChanghsingianDorashamianPermian 4251.902
WuchiapingianLongtanian †Dzhulfian254.14
GuadalupianCapitanianMidian259.51
Wordian264.28
Murgabian266.2 *
RoadianPermian 3266.9
CisuralianKungurianKubergandianPermian 2273.01
Bolorian279.8
Artinskian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselianPermian 1293.52
CarboniferousPennsylvanianGzhelianCarboniferous 5298.9
Kasimovian303.7
MoscovianCarboniferous 4307
Bashkirian315.2
MississippianSerpukhovianCarboniferous 3323.2
ViseanCarboniferous 2330.9
TournaisianCarboniferous 1346.7
DevonianLate DevonianFamennianDevonian 5Famennian358.9
FrasnianDevonian 4Frasnian372.2
Middle DevonianGivetianDevonian 3Givetian382.7
EifelianCouvinien387.7
Early DevonianEmsianDevonian 2393.3
PragianDevonian 1407.6
Coblencien408.2 *
LochkovianGedinnine410.8
SilurianPridoliSilurian 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5443.8
Katian445.2
SandbianOrdovician 4453
Middle OrdovicianDarriwilianOrdovician 3458.4
DapingianOrdovician 2467.3
Early OrdovicianFloian470
TremadocianOrdovician 1477.7
CambrianFurongianStage 10Cambrian 5485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianSeries 3 †Cambrian 4497
Drumian500.5
WuliuanStage 5 †Cambrian 3504.5
Series 2Stage 4509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8