Wiktionary
geologic era
n. (context geology Paleontology English) A subdivision of geologic time that divides an eon into smaller timeframes.
Usage examples of "geologic era".
If this huge arena did not have extremes of weather, a single footprint on that sand might last a geologic era.
You then had to launch it, set it on its way and wait anywhere from a decade to a geologic era for it to reach a nearby star.