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
  • D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. view
  • Z.-X. Qiu and Z.-D. Qiu. 1995. Chronological sequence and subdivision of Chinese Neogene mammalian faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 116(1-2):41-70 view
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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 126699 collections

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International Chronostratigraphic TimescaleCambrian of BritainCambrian of ChinaCambrian of SiberiaOrdovician of the BalticCambrian of KazakhstanCambrian of North America
462.9
482.2
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanNiucheheanTaoyuanian †BatyrbaianTavgian †Ketyan †/YurakianOelandPakerortBatyrbaianFranconian †/Dresbachian/Millardan485.4 *
486.3 *
486.5
Sunwaptan487.5
Festiniogian489.2 *
JiangshanianJiangshanian489.5
AksaianAksaian490.7 *
SakianSakian492.2 *
Steptoean493 *
Maentwrogian493.1 *
PaibianPaibian494
Ensyan †/Maduan/Nganasanian494.7 *
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianSt DavidsGuzhangianWangcunian †AyusokkanianAyusokkanianMarjumianAlbertian †497
Mayan/Menevian499.5
DrumianDrumianZhanaarykian500.5
Tuesaian503
WuliuanWuliuan/TaijangianAmgan/SolvanTopazan504.5
505.3
Delamaran506.5
Series 2Stage 4CaerfaiDuyunianWaucoban †509
ToyonianLenian †Toyonian510 *
Dyeran511 *
BotomianBotomian512.5 *
Stage 3Nangaoian514
Montezuman514.8 *
AtdabanianAtdabanian515.6 *
Begadean519.9 *
TerreneuvianStage 2MeishucunianTommotianTommotian521
Nemakit-Daldynian525.5
FortunianManykaian †529
Jinnigian530.7
538.8