Ordovician of North America

The interval definitions in this timescale are derived from the following sources:

  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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 14 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 6005 collections

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International Chronostratigraphic TimescaleOrdovician of North AmericaCambrian of BritainCambrian of Australia
OrdovicianLate OrdovicianHirnantianCincinnatianGamachian443.8
Katian445.2
Richmondian446 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Sandbian453
Turinian453.7 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †470
Tulean473.9 *
Tremadocian477.7
Stairsian480.3 *
SkullrockianDemingian †482 *
CambrianFurongianStage 10MerionethDolgellian/TrempealeauanDatsonian485.4
Payntonian486.8 *
487.5
Festiniogian489.2 *
JiangshanianIverian489.5
Maentwrogian493.1 *
PaibianIdamean494
MiaolingianGuzhangianSt DavidsMindyallan497
Boomerangian499
DrumianUndillan500.5
Floran503
WuliuanTempletonian504.5
Ordian507.8 *
Series 2Stage 4Caerfai509
510.8 *
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8