An eonothem is a chronostratigraphic unit of geologic time more commonly referred to as an "eon" or "geologic eon", its geochronologic name equivalent.[1] Please refer to Geologic eon or Geologic time scale for more information.

Chronostratigraphic/geochronologic name reference chart.[1]
Rank of Time Unit Chronostratigraphic Name Geochronologic Name
1 - Longest Eonothem Eon
2 Erathem Era
3 System Period
4 Series Epoch
5 - Shortest Stage Age

For Further Reading


  1. 1.0 1.1 International Commission on Stratigraphy."Chapter 9. Chronostratigraphic units" Accessed Nov.12, 2018 [Online]. Available: http://www.stratigraphy.org/upload/bak/chron.htm

Authors and Editors

Ashley Sheardown, Jason Donev
Last updated: January 4, 2019
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