Geologic era

A geologic era is the second largest unit of time for the geologic time scale (Figure 1). Geologic eras are also referred to as "erathems" (the chronostratigraphic name) or simply "eras". Eras tend to be a few hundred million of years in length. Eras are subsections of longer eons and consist of groups of shorter periods. Era names typically end in the suffix "-ozoic". [1]

Currently the eras are:[1]

Figure 1. The ICS Chronostratigraphic Chart[2]

For Further Reading


  1. 1.0 1.1 International Commission on Stratigraphy."Chapter 9. Chronostratigraphic units" Accessed Nov.12, 2018 [Online]. Available:
  2. International Commission on Stratigraphy."International Chronostratigraphic Chart v2018" Accessed Nov.8, 2018 [Online]. Available:

Authors and Editors

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