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

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 126689 collections

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International Chronostratigraphic TimescaleDevonian of Eastern North AmericaDevonian SubagesDevonian of France
DevonianLate DevonianFamennianConewangan/Conneautan/CanadawayLate FamennianFamennian358.9
Middle Famennian365.3 *
Early Famennian368.5 *
FrasnianWest Fallsian/SonyeanLate FrasnianFrasnian372.2
Middle Frasnian375.4 *
Early Frasnian379.3 *
Middle DevonianGivetianGeneseean/Taghanican/TioughnioganCazenovianLate GivetianGivetian382.7
Middle Givetian383.7 *
Early Givetian385.9 *
EifelianSouthwoodianLate EifelianCouvinien387.7
Early Eifelian390.3 *
Early DevonianEmsianSawkillian/Deer ParkianHelderbergianLate Emsian393.3
Early Emsian398.3 *
PragianPragian407.6
Coblencien408.2 *
LochkovianLate LochkovianGedinnine410.8
Middle Lochkovian412.8 *
Early Lochkovian415.6 *
419.2