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Mesoarchean

The Mesoarchean ( , also spelled Mesoarchaean) is a geologic era in the Archean Eon, spanning , which contains the first evidence of modern-style plate subduction and expansion of microbial life. The era is defined chronometrically and is not referenced to a specific level in a rock section on Earth.

Key facts

Geologic timespan.name: Mesoarchean
Geologic timespan.color: Mesoarchean
Geologic timespan.top_bar: all time
Geologic timespan.timeline: Mesoarchean
Geologic timespan.proposed_boundaries1: 3490–2780 Ma
Geologic timespan.proposed_boundaries1_ref: Gradstein et al., 2012
Geologic timespan.proposed_subdivision1: Vaalbaran Period, 3490–3020 Ma
Geologic timespan.proposed_subdivision1_coined: Gradstein et al., 2012
Geologic timespan.proposed_subdivision2: Pongolan Period, 3020–2780 Ma
Geologic timespan.proposed_subdivision2_coined: Gradstein et al., 2012
Geologic timespan.name_formality: Formal
Geologic timespan.alternate_spellings: Mesoarchaean
Geologic timespan.celestial_body: earth
Geologic timespan.usage: Global (ICS)
Geologic timespan.timescales_used: ICS Time Scale
Geologic timespan.chrono_unit: Era
Geologic timespan.strat_unit: Erathem
Geologic timespan.timespan_formality: Formal

via Wikipedia infobox

Article

6 sections

Contents

Tectonics
Environmental conditions
Early microbial life
See also
References
External links

== Tectonics == The Mesoarchean era is thought to be the birthplace of modern-style plate subduction, based on geologic evidence from the Pilbara Craton in western Australia. A convergent margin with a modern-style oceanic arc existed at the boundary between West and East Pilbara approximately 3.12 Ga. By 2.97 Ga, the West Pilbara Terrane converged with and accreted onto the East Pilbara Terrane. A supercontinent, Vaalbara, may have existed in the Mesoarchean.