Eoarchean

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Eoarchean era v • d • e
Geologic timescale of the Precambrian
(millions of years ago)
(expand)

The Eoarchean (pronounced /ˌiːoʊɑrˈkiːən/, also spelled Eoarchaean) is an era in the geologic timescale lasting from 3800 Ma to 3600 Ma (million years ago). It is the first part of the Archaean Eon, preceded by the Hadean eon. In chronostratigraphy, its zone rank is an erathem.

The International Commission on Stratigraphy does not recognize the lower boundary of the era nor the preceding Hadean Eon.

The Eoarchean was followed by the Paleoarchean era.

The name comes from two Greek words: eos (dawn) and archios (ancient). The first supercontinent Vaalbara appeared around the end of this period around 3600 ma.

Also the oldest rock formation on earth the Isua greenstone belt also appeared during the Eoarchean around 3.8 Billion years ago.