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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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

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 127343 collections

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International Chronostratigraphic TimescaleCambrian of BritainCarboniferous SubepochsPermian of the Salt RangePermian of the Russian PlatformCarboniferous of ChinaOrdovician of the BalticSilurian Ages of EuropeSilurian of the BalticCambrian of KazakhstanCarboniferous of North America
TriassicEarly TriassicInduanKathwai251.5 *
PermianLopingianChanghsingian251.902
252.4 *
Chhidru252.9 *
Wuchiapingian254.14
Kalabagh255 *
Wargal256 *
TatarianVyatkian256.8 *
GuadalupianCapitanianSeverodvinian259.51
WordianUrzhumian264.28
265.3 *
Amb266.1 *
RoadianKazanianPovolzhian266.9
Sokian270.7 *
CisuralianKungurianKungurianIrenian/Ufimian273.01
Filipovian276.5 *
Saraninian280.1 *
ArtinskianArtinskianSarginian283.5
Irginian285.9 *
Burtsevian287.8 *
SakmarianSakmarianSterlitamakian290.1
Tastubian291.7 *
AsselianAsselianShikhanianBursumian †293.52
Uskalykian294.8
Surenian297.5
CarboniferousPennsylvanianGzhelianLate PennsylvanianVirgilian298.9
Xiaodushanian300 *
KasimovianMissourian303.7
Dalaun305.8 *
Desmoinesian305.9 *
MoscovianMiddle Pennsylvanian307
Atokan312.7 *
BashkirianEarly Pennsylvanian315.2
Morrowan318.4 *
Huashibanian318.5 *
Lousuan321.2 *
MississippianSerpukhovianLate MississippianDewunianChesterian323.2
Shangsian330.8 *
ViseanMiddle Mississippian330.9
Jiusian335 *
Meramecian335.8 *
Osagean343.1 *
TournaisianEarly MississippianTangbagouan346.7
Kinderhookian351.9 *
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliOhesaare419.2
Kaugetuma421.7 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianGleedonianRootsikula427.4
Jaagarahu429.2 *
Whitwellian429.7 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychian433.4
Adavere434 *
Aeronian438.5
Raikkula439.4 *
Rhuddanian440.8
Juuru441.4 *
OrdovicianLate OrdovicianHirnantianHarjuPorkuni443.8
KatianPirgu445.2
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
Oandu452 *
SandbianKeilaIdavere †453
Haljala453.9
Kukruse456.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
Dapingian467.3
Billingen469.3 *
Early OrdovicianFloian470
Latorp †470.1 *
Hunneberg473.7 *
TremadocianUngurian477.7
Varangu481.3 *
Pakerort482.2 *
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanBatyrbaian485.4
486.3 *
486.5
Festiniogian489.2 *
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Maentwrogian493.1 *
Paibian494
MiaolingianGuzhangianSt DavidsAyusokkanian497
499.5
DrumianZhanaarykian500.5
Tuesaian503
Wuliuan504.5
505.3
Series 2Stage 4Caerfai509
Toyonian510 *
Botomian512.5 *
Stage 3514
Atdabanian515.6 *
TerreneuvianStage 2Tommotian521
525.5
Fortunian529
538.8