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
  • 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

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 126662 collections

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International Chronostratigraphic TimescaleDevonian SubagesDevonian of France
DevonianLate DevonianFamennianLate FamennianFamennian358.9
Middle Famennian365.3 *
Early Famennian368.5 *
FrasnianLate FrasnianFrasnian372.2
Middle Frasnian375.4 *
Early Frasnian379.3 *
Middle DevonianGivetianLate GivetianGivetian382.7
Middle Givetian383.7 *
Early Givetian385.9 *
EifelianLate EifelianCouvinien387.7
Early Eifelian390.3 *
Early DevonianEmsianLate Emsian393.3
Early Emsian398.3 *
PragianPragian407.6
Coblencien408.2 *
LochkovianLate LochkovianGedinnine410.8
Middle Lochkovian412.8 *
Early Lochkovian415.6 *
419.2