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, 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
  • M. Harzhauser and W. E. Piller. 2004. Integrated stratigraphy of the Sarmatian (Upper Middle Miocene) in the western Central Paratethys. Stratigraphy 1(1):65-86 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.

This timescale is used in the definition of 126973 collections

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International Chronostratigraphic TimescaleSilurian of North AmericaSilurian of England
SilurianPridoliCayuganRed Downtonian/Temeside Shales/Downton CastleWhitcliffe/Leintwardine419.2
Bringewood/Elton421.3
Niagaran422.5 *
LudlowLudfordianCoalbrookdaleWenlock (England)/Tickwood423
Gorstian425.6
Buildwas426.4 *
WenlockHomerianLockportian427.4
WychWoolhope428.4 *
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
436.3 *
Aeronian438.5
Alexandrian438.7 *
Cowleigh Park439.3 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
443.8