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 128235 collections

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International Chronostratigraphic TimescalePrecambrian of RussiaOrdovician of the BalticPermian of the PamirsCarboniferous of Western EuropeObsolete Carboniferous Ages of ChinaSilurian of the BalticDevonian of CzechoslovakiaCarboniferous of North AmericaDevonian of Germany
PhanerozoicPaleozoicPermianLopingianChanghsingianDorashamian251.902
WuchiapingianDzhulfian254.14
GuadalupianCapitanianMidian259.51
Wordian264.28
Murgabian266.2 *
Roadian266.9
CisuralianKungurianKubergandian273.01
Bolorian279.8
Artinskian283.5
Yakhtashian286
SakmarianSakmarian290.1
AsselianAsselianBursumian †293.52
Kuzel297.7
CarboniferousPennsylvanianGzhelianMapingian †Virgilian298.9
StephanianStephanian C300.3 *
Stephanian B300.9 *
Stephanian A301.4 *
KasimovianMissourian303.7
Cantabrian305 *
Desmoinesian305.9 *
Moscovian307
WestphalianWestphalian D307.4 *
Westphalian C309.8
Atokan312.7 *
Westphalian B314.6
Bashkirian315.2
Westphalian A317 *
Morrowan318.4 *
NamurianYeadonian318.8 *
Marsdenian320.2 *
Kinderscoutian321.5 *
Alportian322 *
Chokierian323.1 *
MississippianSerpukhovianChesterian323.2
Arnsbergian324 *
Pendleian327.4 *
ViseanWarnantianBrigantian †330.9
Meramecian335.8 *
LivianAsbian †336.3 *
MoliniacianHolkerian †/Arundian/Chadian340.2 *
Osagean343.1 *
TournaisianIvorian346.7
Kinderhookian351.9 *
Hastarian353.7 *
DevonianLate DevonianFamennianWocklum/Dasberg/Hemberg/Nehden358.9
FrasnianAdorf372.2
Middle DevonianGivetianSrbskoGivetian382.7
EifelianChotecEifelian387.7
Early DevonianEmsianDaleje/ZlichovianEmsian393.3
PragianPragianSiegen407.6
LochkovianLochkovianGedinnine410.8
SilurianPridoliOhesaare419.2
Kaugetuma421.7 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianRootsikula427.4
Jaagarahu429.2 *
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 *
Tremadocian477.7
Varangu481.3 *
Pakerort482.2 *
CambrianFurongianStage 10485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangian497
Drumian500.5
Wuliuan504.5
Series 2Stage 4509
Stage 3514
TerreneuvianStage 2521
Fortunian529
ProterozoicNeoproterozoicEdiacaranVendian538.8
Cryogenian635
Tonian720
Karatau800
MesoproterozoicStenian1000
Yurmatian1100
Ectasian1200
Burzyan1375
1400