Archean Hear it!

Archean Definition

Ar·chean (är kē′ən)

adjective

designating or of the geologic eon characterized by the development of the first igneous and metamorphic rocks and the first marine microorganisms; Precambrian, esp. early Precambrian

Etymology: < Gr archaios, archaic

Archean Idioms

the Archean

the Archean Eon or its rocks