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
  • D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. 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 128338 collections

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International Chronostratigraphic TimescaleOrdovician of ChinaPermian of North AmericaCarboniferous SubepochsDevonian of GermanySilurian of North AmericaPermian of the PamirsCambrian of SiberiaOrdovician of Ibero-Bohemia
PermianLopingianChanghsingianDorashamian251.902
WuchiapingianDzhulfian254.14
GuadalupianCapitanianCapitanianMidian259.51
WordianWordian264.28
Murgabian266.2 *
RoadianRoadian266.9
CisuralianKungurianLeonardianCathedralianKubergandian273.01
Bolorian279.8
Hessian281.9 *
Artinskian283.5
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 DevonianFamennianWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianAdorf372.2
Middle DevonianGivetianGivetian382.7
EifelianEifelian387.7
Early DevonianEmsianEmsian393.3
PragianSiegen407.6
LochkovianGedinnine410.8
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 †Kosovian443.8
KatianChientangkiangianKralodvorianBohdalec †445.2
Neichianshanian/Hanjiang449.5
Berounian449.7 *
Sandbian453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianGuniu †/Hulo458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
Hunjiang †Dawan †/Daobaowan/Ningkuo466.3 *
DapingianDapingianKlabava †467.3
Arenigian468
Early OrdovicianFloianYiyangian470
TremadocianXinchangianTremadocian477.7
Lianghekou †477.9 *
Mansian †483.55 *
CambrianFurongianStage 10BatyrbaianTavgian †Ketyan †/Yurakian485.4
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Paibian494
Ensyan †/Maduan/Nganasanian494.7 *
MiaolingianGuzhangianAyusokkanian497
Mayan/Menevian499.5
Drumian500.5
WuliuanAmgan/Solvan504.5
Series 2Stage 4509
ToyonianLenian †510 *
Botomian512.5 *
Stage 3514
Atdabanian515.6 *
TerreneuvianStage 2Tommotian521
Nemakit-Daldynian525.5
FortunianManykaian †529
538.8