Era and Geologic time

Era noun - A major division of geological time; an era is usually divided into two or more periods.

Geologic time and era are semantically related. In some cases you can use "Geologic time" instead a noun "Era".

Geologic time noun - The time of the physical formation and development of the earth (especially prior to human history).

Era and geologic time are semantically related. Sometimes you can replace term "Era" with "Geologic time", this terms are similar.