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
  • 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

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 128235 collections

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International Chronostratigraphic TimescaleOrdovician of ChinaPermian of Western EuropeCarboniferous SubepochsPermian of North AmericaCambrian EpochsOrdovician of AustraliaCambrian of BritainSilurian of North AmericaPermian of the Pamirs
PermianLopingianChanghsingianDorashamian251.902
WuchiapingianZechsteinDzhulfian254.14
GuadalupianCapitanianRotliegendesCapitanianMidian259.51
WordianWordian264.28
Murgabian266.2 *
RoadianRoadian266.9
CisuralianKungurianLeonardianCathedralianKubergandian273.01
Bolorian279.8
Hessian281.9 *
ArtinskianAutunian283.5
Yakhtashian286
WolfcampianLenoxian286.1 *
SakmarianSakmarian290.1
AsselianNealianAsselian293.52
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
Kasimovian303.7
MoscovianMiddle Pennsylvanian307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianLate Mississippian323.2
ViseanMiddle Mississippian330.9
TournaisianEarly Mississippian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliCayugan419.2
Niagaran422.5 *
LudlowLudfordian423
Gorstian425.6
WenlockHomerianLockportian427.4
Sheinwoodian430.5
LlandoveryTelychianOntarian433.4
Aeronian438.5
Alexandrian438.7 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
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 *
CambrianFurongianStage 10Late CambrianMerionethDolgellian/Trempealeauan485.4
Festiniogian489.2 *
Jiangshanian489.5
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianMiddle CambrianSt Davids497
Drumian500.5
Wuliuan504.5
Series 2Stage 4Early CambrianCaerfai509
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8