age

1. Any one of the named epochs in the history of the earth marked by specific phases of physical conditions or organic evolution, such as the Age of Mammals. 2. One of the smaller subdivisions of the epoch as geologic time, corresponding to the stage or the formation, such as the Lockport Age in the Niagara Epoch.

Related terms:

• geologic age
• Old Age
• age of phase inequality
• absolute age
• relative age
• age determination
• radiometric age
• The Age of Acrogens
• Azoic Age
• Glacial Epoch