Meaning of Geological Age

What is Geological Age:

By “geological age” is meant a unit of time that serves to identify certain periods of conformation of the Earth.

The geological eras are part of the geochronological units, divided into epochs, periods, eras and eons according to the duration of each stage.

Thus, an aeon contains eras, eras contain periods, and periods contain epochs.

The older the periodization (be it eon, era, or period), the longer the span of time covered.

The best known geological eras are the closest to ours, and are part of the Phanerozoic eon. In turn, each of the eras contains different periods. Let’s see the periodization, ordered from the most recent to the oldest:

Geological eras in the Phanerozoic eon

cenozoic era

It is part of the Phanerozoic eon and spans from 65 million years to the present. It comprises the following subdivision:

mesozoic era

It spans between 248 and 65 million years. The periods that make it up are:

paleozoic era

It spans between 550 and 248 million years. It is made up of the following periods:

  • permian period
  • Carboniferous period.
  • Devonian period.
  • Silurian period.
  • Ordovician period.
  • Cambrian period.


The geological eras that are known today are part of the eons, and these in turn form supereons. The period known as Precambrian corresponds to the oldest supereon.

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The Precambrian goes back to the origin of the earth 4,500 million years ago and covers up to 500 million years ago. spans the eons archaic and proterozoic.

From most recent to oldest we can order them as follows according to geological eras:

neoproterozoic era

  • Ediacaran period.
  • cryogenic period.
  • Tonic period.

Mesoproterozoic era

  • Sthenic period.
  • ectatic period.
  • Calimic period.

paleoproterozoic era

  • Stater period.
  • Orosirian period.
  • Riacic period.
  • Sideric period.

The Precambrian also includes the Archaic eon, made up of the eras neoarchaic, mesoarchaic, paleoarchaic Y eoarchaic.