geologic age

1. Any great time period in the earth’s history marked by special phases of physical conditions or organic development. 2. A formal geologic unit of time that corresponds to a stage. 3. An informal geologic time unit that corresponds to any stratigraphic unit.

Related terms:

• age
• Old Age
• Age of Man
• geologic time scale
• geologic province
• geologic time
• Age of Mammals
• Age of Fishes
• Little Ice Age
• geologic log