geochronological unit
time interval of geologic time scale
age
Subdivision of geological time; shorter than an epoch and larger than a chron
epoch
Subdivision of geological time; shorter than a period and longer than an age
period
subdivision of geological time; shorter than an era and longer than an epoch
moment
formal geochronological unit
eon
subdivision of geological time; short than a supereon and longer than an era
era
subdivision of geological time; shorter than an eon and longer than a period