Classification Issues
Instead of being based on stratigraphy as all other geological ages are, the beginning of the Archean eon is defined chronometrically. The lower boundary (starting point) of 3.8 billion years has not been officially recognized by the International Commission on Stratigraphy.
The Archean customarily starts at 3.8 Ga—at the end of the Hadean Eon. In older literature, the Hadean is included as part of the Archean. The name comes from the ancient Greek Αρχή (Arkhē), meaning "beginning, origin".
Read more about this topic: Archean
Famous quotes containing the word issues:
“To make life more bearable and pleasant for everybody, choose the issues that are significant enough to fight over, and ignore or use distraction for those you can let slide that day. Picking your battles will eliminate a number of conflicts, and yet will still leave you feeling in control.”
—Lawrence Balter (20th century)