Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Geologic periods are one subdivision of geologic time enabling cross-referencing rocks and geologic events from place to place. These periods form elements of a hierarchy e.g., eons, eras, periods, epochs and ages.
Related terms
Geologic Time Scale: A system of chronological dating that relates geological strata to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events in geologic history.
The branch of geology concerned with the order and relative position of strata and their relationship to the geological time scale.
Plate Tectonics: The theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates that move slowly over the underlying mantle. This movement can influence climate change which can lead to new geologic periods.