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
- 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 126762 collections
| International Chronostratigraphic Timescale | Cambrian of Britain | Ammonite Chrons of North America | Cambrian of North America | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Jurassic | Middle Jurassic | Bajocian | Epizigzagiceras | 168.2 | ||||||
| Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense | 168.4 | |||||||||
| Aalenian | Howelli/Scissum/Westermanni | 170.9 | ||||||||
| Early Jurassic | Toarcian | Yakounensis/Hillebrandti/Crassicosta | 174.7 | |||||||
| Planulata | 179.3 * | |||||||||
| Arnioceras arnouldi | 179.8 * | |||||||||
| Kanense | 181.3 * | |||||||||
| Carlottense | 182.3 * | |||||||||
| Kunae | 183.5 * | |||||||||
| Pliensbachian | 184.2 | |||||||||
| Freboldi | 185.1 * | |||||||||
| Whiteavesi/Imlayi | Tetraspidoceras | 186.2 * | ||||||||
| 189.2 * | ||||||||||
| Plesechioceras harbledownense/Asteroceras varians/Coroniceras | Canadensis | 190.3 * | ||||||||
| Sinemurian | 192.9 | |||||||||
| Pseudaetomoceras | Psiloceras | 196.4 * | ||||||||
| Franziceras/Euphyllites | 196.5 * | |||||||||
| Hettangian | 199.5 | |||||||||
| Triassic | Late Triassic | Rhaetian | 201.4 | |||||||
| Norian | 208.5 | |||||||||
| Carnian | 227 | |||||||||
| Middle Triassic | Ladinian | 237 | ||||||||
| Anisian | 242 | |||||||||
| Early Triassic | Olenekian | 247.2 | ||||||||
| Induan | 251.2 | |||||||||
| Permian | Lopingian | Changhsingian | 251.902 | |||||||
| Wuchiapingian | 254.14 | |||||||||
| Guadalupian | Capitanian | 259.51 | ||||||||
| Wordian | 264.28 | |||||||||
| Roadian | 266.9 | |||||||||
| Cisuralian | Kungurian | 273.01 | ||||||||
| Artinskian | 283.5 | |||||||||
| Sakmarian | 290.1 | |||||||||
| Asselian | 293.52 | |||||||||
| Carboniferous | Pennsylvanian | Gzhelian | 298.9 | |||||||
| Kasimovian | 303.7 | |||||||||
| Moscovian | 307 | |||||||||
| Bashkirian | 315.2 | |||||||||
| Mississippian | Serpukhovian | 323.2 | ||||||||
| Visean | 330.9 | |||||||||
| Tournaisian | 346.7 | |||||||||
| Devonian | Late Devonian | Famennian | 358.9 | |||||||
| Frasnian | 372.2 | |||||||||
| Middle Devonian | Givetian | 382.7 | ||||||||
| Eifelian | 387.7 | |||||||||
| Early Devonian | Emsian | 393.3 | ||||||||
| Pragian | 407.6 | |||||||||
| Lochkovian | 410.8 | |||||||||
| Silurian | Pridoli | 419.2 | ||||||||
| Ludlow | Ludfordian | 423 | ||||||||
| Gorstian | 425.6 | |||||||||
| Wenlock | Homerian | 427.4 | ||||||||
| Sheinwoodian | 430.5 | |||||||||
| Llandovery | Telychian | 433.4 | ||||||||
| Aeronian | 438.5 | |||||||||
| Rhuddanian | 440.8 | |||||||||
| Ordovician | Late Ordovician | Hirnantian | 443.8 | |||||||
| Katian | 445.2 | |||||||||
| Sandbian | 453 | |||||||||
| Middle Ordovician | Darriwilian | 458.4 | ||||||||
| Dapingian | 467.3 | |||||||||
| Early Ordovician | Floian | 470 | ||||||||
| Tremadocian | 477.7 | |||||||||
| Cambrian | Furongian | Stage 10 | Merioneth | Dolgellian/Trempealeauan | Franconian †/Dresbachian/Millardan | 485.4 | ||||
| Sunwaptan | 487.5 | |||||||||
| Festiniogian | 489.2 * | |||||||||
| Jiangshanian | 489.5 | |||||||||
| Steptoean | 493 * | |||||||||
| Maentwrogian | 493.1 * | |||||||||
| Paibian | 494 | |||||||||
| Miaolingian | Guzhangian | St Davids | Marjumian | Albertian † | 497 | |||||
| Drumian | 500.5 | |||||||||
| Wuliuan | Topazan | 504.5 | ||||||||
| Delamaran | 506.5 | |||||||||
| Series 2 | Stage 4 | Caerfai | Waucoban † | 509 | ||||||
| Dyeran | 511 * | |||||||||
| Stage 3 | 514 | |||||||||
| Montezuman | 514.8 * | |||||||||
| Begadean | 519.9 * | |||||||||
| Terreneuvian | Stage 2 | 521 | ||||||||
| Fortunian | 529 | |||||||||
| 538.8 | ||||||||||