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
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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
  • 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
  • D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. 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 126884 collections

Show more time

Show linear time

International Chronostratigraphic TimescaleOrdovician of ChinaCambrian of SiberiaOrdovician of Australia
OrdovicianLate OrdovicianHirnantianHirnantianXiaoxita †/ShikouWufeng †Bolindian443.8
KatianChientangkiangian445.2
Eastonian449 *
Neichianshanian/Hanjiang449.5
Gisbornian452 *
Sandbian453
Middle OrdovicianDarriwilianDarriwilianGuniu †/HuloDarriwilian458.4
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingianYapeenian467.3
Castlemainian468.5 *
Early OrdovicianFloianYiyangianChewtonian470
Bendigonian471.8 *
Lancefieldian473.5 *
TremadocianXinchangian477.7
Lianghekou †477.9 *
Warendian482.8 *
Mansian †483.55 *
485.4