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Webster 1913 Edition

Archaean

Ar-chæ′an

,
Adj.
[Gr.
ἀρχαῖοσ
ancient, fr.
ἀρχή
beginning.]
Ancient; pertaining to the earliest period in geological history.

Ar-chæ′an

,
Noun.
(Geol.)
The earliest period in geological period, extending up to the Lower Silurian. It includes an Azoic age, previous to the appearance of life, and an Eozoic age, including the earliest forms of life.
☞ This is equivalent to the formerly accepted term Azoic, and to the Eozoic of Dawson.

Definition 2024

Archaean

Archaean

See also: archaean and Archæan

English

Alternative forms

Adjective

Archaean ‎(not comparable)

  1. (geology) of, or relating to the geologic eon from about 3,800 to 2,500 million years ago; comprises the Eoarchean, Paleoarchean, Mesoarchean and Neoarchean eras; marked by an atmosphere with little oxygen, the formation of the first continents and oceans and the emergence of simple life

Translations

Proper noun

Archaean

  1. (geology) The eon from 2,500 Ma to 4,000 Ma.

Hypernyms

Hyponyms

  • (eon 2,500-4,000 Ma): Eoarchaean, Paleoarchaean, Mesoarchaean, Neoarchaean

Coordinate terms

Translations

See also

  • Appendix:Geologic timescale

External links

archaean

archaean

See also: Archaean and Archæan

English

Noun

archaean ‎(plural archaeans)

  1. (biology) Any organism of the domain Archaea

Translations

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