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. Freudenthal. 2006. Mammal Paleogene zones. personal communication view
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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
  • 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. 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
  • A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 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 126710 collections

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International Chronostratigraphic TimescaleMammal Paleogene ZonesOrdovician of the BalticAmmonite Chrons of Northwest EuropeCambrian EpochsMesozoic SubagesOrdovician of BritainCretaceous North American Land-Mammal AgesNorth American Land Mammal Ages
QuaternaryHoloceneMeghalayanSaintaugustinean0
Santarosean0.0004
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate Pleistocene0.0117
Rancholabrean0.014
Chibanian0.129
Irvingtonian0.21
Calabrian0.774
Blancan1.4
Gelasian1.8
NeogenePliocenePiacenzian2.58
Zanclean3.6
Hemphillian4.7
MioceneMessinian5.333
Tortonian7.246
Clarendonian9.4
Serravallian11.63
Barstovian12.5
Langhian13.82
Burdigalian15.98
Hemingfordian16.3
Arikareean18.5
Aquitanian20.44
PaleogeneOligoceneChattianMP 30/MP 29/MP 28/MP 27/MP 26MP 2523.03
RupelianMP 24/MP 23/MP 22/MP 2127.82
Whitneyan29.5
Orellan31.8
EocenePriabonianMP 20/MP 19/MP 18/MP 17B/MP 17AChadronian33.9
Duchesnean37
BartonianMP 1637.71
Uintan39.7
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
Bridgerian46.2
YpresianMP 10/MP 8 + 9/MP 747.8
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianMP 6MP 1 - 556
Tiffanian56.2
Selandian59.2
Torrejonian60.9
Danian61.6
Puercan63.8
CretaceousLate CretaceousMaastrichtianLate Maastrichtian/Early MaastrichtianLancian/Edmontonian66
CampanianLate Campanian/Middle Campanian/Early CampanianJudithian/Aquilan72.1
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/DiscitesLate Bajocian168.2
Humphresianum168.4
Early Bajocian168.6 *
AalenianConcavum/Murchisonae/OpalinumLate Aalenian/Middle Aalenian/Early Aalenian170.9
Early JurassicToarcianLevesquei/Variabilis/BifronsThouarsenseLate Toarcian174.7
180.1
Middle Toarcian180.4 *
Serpentinum/Falciferum/Tenuicostatum182
Early Toarcian182.9 *
PliensbachianSpinatum/Margaritatus/Davoei/Ibex/JamesoniLate Pliensbachian/Early Pliensbachian184.2
SinemurianRaricostatum/Oxynotum/Obtusum/Turneri/Semicostatum/BucklandiLate Sinemurian/Early Sinemurian192.9
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 *
PermianLopingianChanghsingian251.902
Wuchiapingian254.14
GuadalupianCapitanian259.51
Wordian264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianHarjuPorkuniAshgillHirnantian443.8
KatianPirguRawtheyan445.2
Cautleyan448.9 *
Pusgillian449.3 *
VormsiCaradocStreffordianOnnian †449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Cheneyan451.5 *
Oandu452 *
Burrellian452.7 *
SandbianKeilaIdavere †453
Actonian †453.2 *
Haljala453.9
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Kukruse456.4 *
Aurelucian456.8 *
Soudleyan †/Harnagian/Costonian457.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.4
Lasnamagi458.9 *
Aseri460.4 *
Abereiddian/Early Llanvirn461.3 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
Dapingian467.3
ArenigFennian468.4 *
Billingen469.3 *
Early OrdovicianFloian470
Latorp †470.1 *
Whitlandian471.1 *
Hunneberg473.7 *
Moridunian474.3 *
TremadocianTremadocMigneintian477.7
Cressagian480.8 *
Varangu481.3 *
Pakerort482.2 *
485 *
CambrianFurongianStage 10Late Cambrian485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianMiddle Cambrian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4Early Cambrian509
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8