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
  • J. I. Raine, A. G. Beu, A. F. Boyes, H. J. Campbell, R. A. Cooper, J. S. Crampton, M. P. Crundwell, C. J. Hollis, and H. E. G. Morgans. 2015. Revised Calibration of the New Zealand Geological Timescale: NZGT2015/1. GNS Science Report 2012(39) 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, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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 126520 collections

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International Chronostratigraphic TimescaleCambrian of BritainObsolete Names for ICS UnitsCambrian of West Avalonia
CambrianFurongianStage 10MerionethDolgellian/Trempealeauan485.4
Festiniogian489.2 *
Jiangshanian489.5
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianSt DavidsSeries 3 †497
Arcadian498.4
Drumian500.5
WuliuanStage 5 †504.5
Series 2Stage 4CaerfaiBranchian509
Stage 3514
Placentian517.1
TerreneuvianStage 2521
Fortunian529
538.8