The stage is the fundamental chronostratigraphic unit.
Stages/ages are formally defined following the indications of the ICS (International Commission on Stratigraphy). More specifically, stages/ages are defined by the GSSP of their base, their top being defined by the GSSP of the overlying stage/age.
A list of stages/ages may be found here.
Interdisciplinary Links in Citizendium
- Earth science
- Age (geology)
- Geologic time scale
- Geologic ages of earth history