ERA


Meaning of ERA in English

n.

Very long span of geologic time; in formal usage, a portion of geologic time of the second-greatest magnitude (eons are longer).

Three eras are recognized: Paleozoic , Mesozoic , and Cenozoic . Because of the difficulties involved in establishing accurate chronologies, the Precambrian , or earliest, eras are classified independently. An era is composed of one or more geologic periods .

Britannica Concise Encyclopedia.      Краткая энциклопедия Британика.