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
- 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
- J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 view
- M. O. Woodburne. 1987. A prospectus of the North American Mammal Ages. In: Woodburne, M. O. (ed.), Cenozoic Mammals of North America. University of California Press, Berkelery, CA 285-290 view
- J. Alroy. 2000. New methods for quantifying macroevolutionary patterns and processes. Paleobiology 26(4):707-733 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
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 126699 collections
| International Chronostratigraphic Timescale | Obsolete Names for ICS Units | North American Mammal Subages/Zones | Cenozoic Subepochs | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2.58 | |||||||||||
| 18.5 | |||||||||||
| Paleogene | Oligocene | Chattian | Tertiary † | late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early Arikareean | Harrisonian | Late Oligocene | 23.03 | ||||
| Monroecreekian | 23.1 * | ||||||||||
| Geringian | 24.7 * | ||||||||||
| Rupelian | Early Oligocene | 27.82 | |||||||||
| 29.5 | |||||||||||
| Eocene | Priabonian | Late Chadronian/Middle Chadronian/Early Chadronian | Late Eocene | 33.9 | |||||||
| 37 | |||||||||||
| Bartonian | Middle Eocene | 37.71 | |||||||||
| Late Uintan/Early Uintan | 39.7 | ||||||||||
| Lutetian | 41.2 | ||||||||||
| Twinbuttean/Blacksforkian/Gardnerbuttian | 46.2 | ||||||||||
| Ypresian | Early Eocene | 47.8 | |||||||||
| Lostcabinian/Lysitean/Graybullian/Sandcouleean | 50.5 | ||||||||||
| Cf3/Cf2/Cf1 | 54.9 | ||||||||||
| Paleocene | Thanetian | Late Paleocene | 56 | ||||||||
| Ti6/Ti5/Ti4/Ti3/Ti2/Ti1 | 56.2 | ||||||||||
| Selandian | Middle Paleocene | 59.2 | |||||||||
| To3/To2/To1 | 60.9 | ||||||||||
| Danian | Early Paleocene | 61.6 | |||||||||
| Pu3/Pu2/Pu1 | 63.8 | ||||||||||
| 66 | |||||||||||