Archean

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Related to Archaen: archaean, Proterozoic

Archean

[är′kē·ən]
(geology)
A term, meaning ancient, which has been applied to the oldest rocks of the Precambrian; as more physical measurements of geologic time are made, the usage is changing; the term Early Precambrian is preferred.
References in periodicals archive ?
The pegmatites of Chitral, Dir and Gilgit are part of Afghan Archaen syste and can be a rich source of lithium bearing and precious and semiprecious minerals.
In early Archaen rocks, gold is found in horizons of iron-bearing formations, mainly in silicate and sulphide facies.
Bedrock consisting of Archaen sedimentary and igneous rocks underlies the area of the fourth anomaly.