A reconstruction of the Earth's continents during the middle Neoarchean, c. 2.65 Ga.
Proposed redefinition(s)2780–2420 Ma
Gradstein et al., 2012
Proposed subdivisionsMethanian Period, 2780–2630 Ma

Gradstein et al., 2012
Siderian Period, 2630–2420

Gradstein et al., 2012
Name formalityFormal
Alternate spelling(s)Neoarchaean
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Chronological unitEra
Stratigraphic unitErathem
Time span formalityFormal
Lower boundary definitionDefined Chronometrically
Lower GSSA ratified1991[citation needed]
Upper boundary definitionDefined Chronometrically
Upper GSSA ratified1991[citation needed]

The Neoarchean (/ˌn.ɑːrˈkən/ NEE-oh-ar-KEE-ən; also spelled Neoarchaean) is the last geologic era in the Archean Eon that spans from 2800 to 2500 million years ago—the period being defined chronometrically and not referencing a specific level in a rock section on Earth. The era is marked by major developments in complex life and continental formation.

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