Neoarchean

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
EtymologyName formalityFormalAlternate spelling(s)NeoarchaeanUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEraStratigraphic unitErathemTime span formalityFormalLower boundary definitionDefined ChronometricallyLower GSSA ratifiedNot formally definedUpper boundary definitionDefined ChronometricallyUpper GSSA ratified1990

The Neoarchean ( ; also spelled Neoarchaean) is the last geologicera 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.