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, 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

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 126864 collections

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International Chronostratigraphic TimescaleDevonian of FranceCarboniferous of ChinaOrdovician of the BalticSilurian Ages of EuropeSilurian of the BalticCambrian of KazakhstanCarboniferous of North America
PermianCisuralianAsselianBursumian †293.52
CarboniferousPennsylvanianGzhelianVirgilian298.9
Xiaodushanian300 *
KasimovianMissourian303.7
Dalaun305.8 *
Desmoinesian305.9 *
Moscovian307
Atokan312.7 *
Bashkirian315.2
Morrowan318.4 *
Huashibanian318.5 *
Lousuan321.2 *
MississippianSerpukhovianDewunianChesterian323.2
Shangsian330.8 *
Visean330.9
Jiusian335 *
Meramecian335.8 *
Osagean343.1 *
TournaisianTangbagouan346.7
Kinderhookian351.9 *
DevonianLate DevonianFamennianFamennian358.9
FrasnianFrasnian372.2
Middle DevonianGivetianGivetian382.7
EifelianCouvinien387.7
Early DevonianEmsian393.3
Pragian407.6
Coblencien408.2 *
LochkovianGedinnine410.8
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 10Batyrbaian485.4
486.3 *
486.5
Jiangshanian489.5
Aksaian490.7 *
Sakian492.2 *
Paibian494
MiaolingianGuzhangianAyusokkanian497
499.5
DrumianZhanaarykian500.5
Tuesaian503
Wuliuan504.5
505.3
Series 2Stage 4509
Toyonian510 *
Botomian512.5 *
Stage 3514
Atdabanian515.6 *
TerreneuvianStage 2Tommotian521
525.5