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
- F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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
- F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 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 126700 collections
| International Chronostratigraphic Timescale | Ammonite Chrons of North America | Mesozoic Subages | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Jurassic | Late Jurassic | Tithonian | Late Tithonian | Middle Tithonian | 145 | |||||
| Early Tithonian | 146.3 * | |||||||||
| Kimmeridgian | Late Kimmeridgian | 149.2 | ||||||||
| Early Kimmeridgian | 152.2 * | |||||||||
| Oxfordian | Late Oxfordian | Middle Oxfordian/Early Oxfordian | 154.8 | |||||||
| 157.9 * | ||||||||||
| Middle Jurassic | Callovian | Late Callovian/Middle Callovian/Early Callovian | 161.5 | |||||||
| Bathonian | Late Bathonian/Middle Bathonian/Early Bathonian | 165.3 | ||||||||
| Bajocian | Epizigzagiceras | Late Bajocian | 168.2 | |||||||
| Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense | 168.4 | |||||||||
| Early Bajocian | 168.6 * | |||||||||
| Aalenian | Howelli/Scissum/Westermanni | Late Aalenian/Middle Aalenian/Early Aalenian | 170.9 | |||||||
| Early Jurassic | Toarcian | Yakounensis/Hillebrandti/Crassicosta | Late Toarcian | 174.7 | ||||||
| Planulata | 179.3 * | |||||||||
| Arnioceras arnouldi | 179.8 * | |||||||||
| Middle Toarcian | 180.4 * | |||||||||
| Kanense | 181.3 * | |||||||||
| Carlottense | 182.3 * | |||||||||
| Early Toarcian | 182.9 * | |||||||||
| Kunae | 183.5 * | |||||||||
| Pliensbachian | Late Pliensbachian/Early Pliensbachian | 184.2 | ||||||||
| Freboldi | 185.1 * | |||||||||
| Whiteavesi/Imlayi | Tetraspidoceras | 186.2 * | ||||||||
| 189.2 * | ||||||||||
| Plesechioceras harbledownense/Asteroceras varians/Coroniceras | Canadensis | 190.3 * | ||||||||
| Sinemurian | Late Sinemurian/Early Sinemurian | 192.9 | ||||||||
| Pseudaetomoceras | Psiloceras | 196.4 * | ||||||||
| Franziceras/Euphyllites | 196.5 * | |||||||||
| Hettangian | Late Hettangian/Middle Hettangian/Early Hettangian | 199.5 | ||||||||
| 201.4 | ||||||||||