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
  • 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
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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

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 126002 collections

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International Chronostratigraphic TimescaleNorth American Mammal Subages/ZonesMammal Paleogene ZonesMesozoic SubagesSilurian of North AmericaCambrian of KazakhstanCambrian of ChinaCarboniferous of ChinaObsolete Names for ICS Units
QuaternaryPleistoceneLate PleistoceneSheridanian0.0117
Chibanian0.129
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
Serravallian11.63
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
PaleogeneOligoceneChattianMP 30/MP 29/MP 28/MP 27/MP 26MP 2523.03
Monroecreekian23.1 *
Geringian24.7 *
RupelianMP 24/MP 23/MP 22/MP 2127.82
29.5
EocenePriabonianLate Chadronian/Middle Chadronian/Early ChadronianMP 20/MP 19/MP 18/MP 17B/MP 17A33.9
37
BartonianMP 1637.71
Late Uintan/Early Uintan39.7
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
Twinbuttean/Blacksforkian/Gardnerbuttian46.2
YpresianMP 10/MP 8 + 9/MP 747.8
Lostcabinian/Lysitean/Graybullian/Sandcouleean50.5
Cf3/Cf2/Cf154.9
PaleoceneThanetianMP 6MP 1 - 556
Ti6/Ti5/Ti4/Ti3/Ti2/Ti156.2
Selandian59.2
To3/To2/To160.9
Danian61.6
Pu3/Pu2/Pu163.8
CretaceousLate CretaceousMaastrichtianLate Maastrichtian/Early Maastrichtian66
CampanianLate 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
BajocianLate Bajocian168.2
Early Bajocian168.6 *
AalenianLate Aalenian/Middle Aalenian/Early Aalenian170.9
Early JurassicToarcianLate Toarcian174.7
Middle Toarcian180.4 *
Early Toarcian182.9 *
PliensbachianLate Pliensbachian/Early Pliensbachian184.2
SinemurianLate Sinemurian/Early Sinemurian192.9
HettangianLate 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 *
PermianLopingianChanghsingian251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
Xiaodushanian300 *
Kasimovian303.7
Dalaun305.8 *
Moscovian307
Bashkirian315.2
Huashibanian318.5 *
Lousuan321.2 *
MississippianSerpukhovianDewunian323.2
Shangsian330.8 *
Visean330.9
Jiusian335 *
TournaisianTangbagouan346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliCayugan419.2
Niagaran422.5 *
LudlowLudfordian423
Gorstian425.6
WenlockHomerianLockportian427.4
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
Aeronian438.5
Alexandrian438.7 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantian443.8
Katian445.2
Sandbian453
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Early OrdovicianFloian470
TremadocianUngurian477.7
CambrianFurongianStage 10BatyrbaianNiucheheanTaoyuanian †485.4
JiangshanianJiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianAyusokkanianGuzhangianWangcunian †Series 3 †497
499.5
DrumianZhanaarykianDrumian500.5
Tuesaian503
WuliuanWuliuan/TaijangianStage 5 †504.5
505.3
Series 2Stage 4Duyunian509
Toyonian510 *
Botomian512.5 *
Stage 3Nangaoian514
Atdabanian515.6 *
TerreneuvianStage 2TommotianMeishucunian521
525.5
Fortunian529
Jinnigian530.7
538.8