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
  • 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 126778 collections

Show more time

Show linear time

International Chronostratigraphic TimescalePermian of ChinaPermian of the Salt RangeCarbo-Permian of the Russian PlatformSilurian Ages of EuropeCarboniferous SubepochsOrdovician of BritainOrdovician of Australia
TriassicEarly TriassicInduanKathwai251.5 *
PermianLopingianChanghsingianMeishanianMelekhovian251.902
252.4 *
Chhidru252.9 *
Baoqingian253.4 *
WuchiapingianLaoshanian254.14
Kalabagh255 *
Wargal256 *
Laibinian257.7 *
GuadalupianCapitanianLengwuan259.51
WordianKuhfengian264.28
Noginskian264.9 *
265.3 *
Amb266.1 *
Roadian266.9
270.7 *
CisuralianKungurianLuodianian273.01
Pavlovoposadian276.8 *
Artinskian283.5
Longlinian285.4 *
Rusavkinian287.6 *
Sakmarian290.1
AsselianZisongian293.52
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
300.1
KasimovianDorogomilovian303.7
Khamovnikian304.8
Krevyakinian305.8 *
MoscovianMyachkovianMiddle Pennsylvanian307
Podolskian308.9 *
Kashirian311.4 *
Vereian313.8
Melekessian314.8
BashkirianEarly Pennsylvanian315.2
Cheremshanian316.9 *
Prikamian318.6 *
Severokeltmian319.9 *
Krasnopolyanian321.2 *
Voznesenian321.9 *
MississippianSerpukhovianZapaltjubianLate Mississippian323.2
Protvian324.4 *
Steshevian326.8 *
Tarusian329 *
ViseanVenevianMiddle Mississippian330.9
Mikhailovian331.9 *
Aleksinian333.7 *
Tulian335.8 *
Bobrikian339.9 *
Radaevkian343.4 *
TournaisianKosvianEarly Mississippian346.7
Kizelian350.7 *
Cherepetian351.9 *
Karakubian354.4 *
Upinian356.3 *
Malevkian357.6 *
Gumerovian358 *
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerianGleedonian427.4
Whitwellian429.7 *
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianAshgillHirnantianBolindian443.8
KatianRawtheyan445.2
Cautleyan448.9 *
Eastonian449 *
Pusgillian449.3 *
CaradocStreffordianOnnian †449.6 *
Cheneyan451.5 *
Gisbornian452 *
Burrellian452.7 *
Sandbian453
Actonian †453.2 *
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Aurelucian456.8 *
Soudleyan †/Harnagian/Costonian457.4 *
Middle OrdovicianDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late LlanvirnDarriwilian458.4
Abereiddian/Early Llanvirn461.3 *
DapingianYapeenian467.3
ArenigFennian468.4 *
Castlemainian468.5 *
Early OrdovicianFloianChewtonian470
Whitlandian471.1 *
Bendigonian471.8 *
Lancefieldian473.5 *
Moridunian474.3 *
TremadocianTremadocMigneintian477.7
Cressagian480.8 *
Warendian482.8 *
485 *
485.4