is a specific kind of: geologic time, geological time.

is a broader term that covers: glacial epoch, glacial period, ice age.

instances of which are: Age of Man, Quaternary, Quaternary period | Tertiary, Tertiary period | Cretaceous, Cretaceous period | Jurassic, Jurassic period | Triassic, Triassic period | Permian, Permian period | Carboniferous, Carboniferous period | Pennsylvanian, Pennsylvanian period, Upper Carboniferous, Upper Carboniferous period | Lower Carboniferous, Lower Carboniferous period, Missippian period, Mississippian | Age of Fishes, Devonian, Devonian period | Silurian, Silurian period | Ordovician, Ordovician period | Cambrian, Cambrian period ... show more.

has as a part: epoch.

is a part of: era, geological era.