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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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, 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
  • 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

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 126778 collections

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International Chronostratigraphic TimescaleTen Million Year BinsObsolete Names for ICS UnitsCambrian EpochsPermian of Western EuropeSilurian of North AmericaOrdovician of the BalticMesozoic SubagesPermian of the Salt Range
QuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate Pleistocene0.0117
Chibanian0.129
Calabrian0.774
Gelasian1.8
NeogenePliocenePiacenzianTertiary †2.58
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
CretaceousLate CretaceousMaastrichtianCretaceous 8Late Maastrichtian/Early Maastrichtian66
CampanianCretaceous 7Late 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
BajocianLate Bajocian168.2
Early Bajocian168.6 *
AalenianJurassic 3Late Aalenian/Middle Aalenian/Early Aalenian170.9
Early JurassicToarcianLate Toarcian174.7
Middle Toarcian180.4 *
Early Toarcian182.9 *
PliensbachianJurassic 2Late Pliensbachian/Early Pliensbachian184.2
SinemurianJurassic 1Late Sinemurian/Early Sinemurian192.9
HettangianLate 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 *
Kathwai251.5 *
PermianLopingianChanghsingianPermian 4251.902
252.4 *
Chhidru252.9 *
WuchiapingianLongtanian †Zechstein254.14
Kalabagh255 *
Wargal256 *
GuadalupianCapitanianRotliegendes259.51
Wordian264.28
265.3 *
Amb266.1 *
RoadianPermian 3266.9
270.7 *
CisuralianKungurianPermian 2273.01
ArtinskianAutunian283.5
Sakmarian290.1
AsselianPermian 1293.52
CarboniferousPennsylvanianGzhelianCarboniferous 5298.9
Kasimovian303.7
MoscovianCarboniferous 4307
Bashkirian315.2
MississippianSerpukhovianCarboniferous 3323.2
ViseanCarboniferous 2330.9
TournaisianCarboniferous 1346.7
DevonianLate DevonianFamennianDevonian 5358.9
FrasnianDevonian 4372.2
Middle DevonianGivetianDevonian 3382.7
Eifelian387.7
Early DevonianEmsianDevonian 2393.3
PragianDevonian 1407.6
Lochkovian410.8
SilurianPridoliSilurian 2Cayugan419.2
Niagaran422.5 *
LudlowLudfordian423
Gorstian425.6
WenlockHomerianLockportian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1Ontarian433.4
Aeronian438.5
Alexandrian438.7 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5HarjuPorkuni443.8
KatianPirgu445.2
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianOrdovician 4KeilaIdavere †453
Haljala453.9
Kukruse456.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilianOrdovician 3458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
DapingianOrdovician 2467.3
Billingen469.3 *
Early OrdovicianFloian470
Latorp †470.1 *
Hunneberg473.7 *
TremadocianOrdovician 1477.7
Varangu481.3 *
Pakerort482.2 *
CambrianFurongianStage 10Cambrian 5Late Cambrian485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianCambrian 4Series 3 †Middle Cambrian497
Drumian500.5
WuliuanCambrian 3Stage 5 †504.5
Series 2Stage 4Early Cambrian509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8