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
  • J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 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

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 126691 collections

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International Chronostratigraphic TimescaleCretaceous SubepochsCarboniferous SubepochsOrdovician of the BalticTen Million Year BinsCambrian of West AvaloniaPaleogene Mammal Ages of AsiaNorth American Mammal Subages/ZonesObsolete Names for ICS Units
QuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate 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
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 4TabenbulakianHsandagolian23.03
Monroecreekian23.1 *
Geringian24.7 *
RupelianKekeamuan27.82
29.5
EocenePriabonianCenozoic 3Houldjinian/Ergilian/UlangochuianLate Chadronian/Middle Chadronian/Early Chadronian33.9
37
BartonianSharamurunian/Irdinmanhan/Arshantan37.71
Late Uintan/Early Uintan39.7
LutetianCenozoic 241.2
Twinbuttean/Blacksforkian/Gardnerbuttian46.2
YpresianBumbanian47.8
Lostcabinian/Lysitean/Graybullian/Sandcouleean50.5
Cf3/Cf2/Cf154.9
PaleoceneThanetianCenozoic 1Gashatan56
Ti6/Ti5/Ti4/Ti3/Ti2/Ti156.2
Selandian59.2
To3/To2/To160.9
Danian61.6
Pu3/Pu2/Pu163.8
CretaceousLate CretaceousMaastrichtianSenonianCretaceous 866
CampanianCretaceous 772.1
SantonianCretaceous 683.6
Coniacian86.3
Turonian89.8
CenomanianCretaceous 593.9
Early CretaceousAlbianGallicCretaceous 4100.5
AptianCretaceous 3113
BarremianCretaceous 2121.4
HauterivianNeocomian125.77
ValanginianCretaceous 1132.6
Berriasian139.8
JurassicLate JurassicTithonianJurassic 6145
KimmeridgianJurassic 5149.2
Oxfordian154.8
Middle JurassicCallovian161.5
BathonianJurassic 4165.3
Bajocian168.2
AalenianJurassic 3170.9
Early JurassicToarcian174.7
PliensbachianJurassic 2184.2
SinemurianJurassic 1192.9
Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
Norian208.5
CarnianTriassic 3227
Middle TriassicLadinianTriassic 2237
Anisian242
Early TriassicOlenekianTriassic 1247.2
Induan251.2
PermianLopingianChanghsingianPermian 4251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
RoadianPermian 3266.9
CisuralianKungurianPermian 2273.01
Artinskian283.5
Sakmarian290.1
AsselianPermian 1293.52
CarboniferousPennsylvanianGzhelianLate PennsylvanianCarboniferous 5298.9
Kasimovian303.7
MoscovianMiddle PennsylvanianCarboniferous 4307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianLate MississippianCarboniferous 3323.2
ViseanMiddle MississippianCarboniferous 2330.9
TournaisianEarly MississippianCarboniferous 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 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHarjuPorkuniOrdovician 5443.8
KatianPirgu445.2
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianKeilaIdavere †Ordovician 4453
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 5485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianCambrian 4Series 3 †497
Arcadian498.4
Drumian500.5
WuliuanCambrian 3Stage 5 †504.5
Series 2Stage 4Branchian509
Stage 3Cambrian 2514
Placentian517.1
TerreneuvianStage 2521
FortunianCambrian 1529
538.8