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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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

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 126831 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleCambrian of AustraliaOrdovician of North AmericaCarboniferous SubepochsPermian Subages of GermanyOrdovician of Ibero-BohemiaCambrian of North AmericaCarboniferous of North AmericaDevonian of Germany
PermianLopingianChanghsingianBuntsandstein251.902
Wuchiapingian254.14
GuadalupianCapitanianOhre/Aller259.51
WordianLeine264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
AsselianBursumian †293.52
CarboniferousPennsylvanianGzhelianLate PennsylvanianVirgilian298.9
KasimovianMissourian303.7
Desmoinesian305.9 *
MoscovianMiddle Pennsylvanian307
Atokan312.7 *
BashkirianEarly Pennsylvanian315.2
Morrowan318.4 *
MississippianSerpukhovianLate MississippianChesterian323.2
ViseanMiddle Mississippian330.9
Meramecian335.8 *
Osagean343.1 *
TournaisianEarly Mississippian346.7
Kinderhookian351.9 *
DevonianLate DevonianFamennianWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianAdorf372.2
Middle DevonianGivetianGivetian382.7
EifelianEifelian387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
LochkovianGedinnine410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianCincinnatianGamachianKosovian443.8
KatianKralodvorianBohdalec †445.2
Richmondian446 *
Berounian449.7 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Sandbian453
Turinian453.7 *
Zahorany †/ViniceLetna †456.2 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Liben †458 *
Middle OrdovicianDarriwilian458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianKlabava †467.3
Arenigian468
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †470
Tulean473.9 *
TremadocianTremadocian477.7
Stairsian480.3 *
SkullrockianDemingian †482 *
CambrianFurongianStage 10DatsonianFranconian †/Dresbachian/Millardan485.4
Payntonian486.8 *
Sunwaptan487.5
JiangshanianIverian489.5
Steptoean493 *
PaibianIdamean494
MiaolingianGuzhangianMindyallanMarjumianAlbertian †497
Boomerangian499
DrumianUndillan500.5
Floran503
WuliuanTempletonianTopazan504.5
Delamaran506.5
Ordian507.8 *
Series 2Stage 4Waucoban †509
510.8 *
Dyeran511 *
Stage 3514
Montezuman514.8 *
Begadean519.9 *
TerreneuvianStage 2521
Fortunian529
538.8