Norian | |||||||||||||||||||||||
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Chronology | |||||||||||||||||||||||
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Etymology | |||||||||||||||||||||||
Name formality | Formal | ||||||||||||||||||||||
Usage information | |||||||||||||||||||||||
Celestial body | Earth | ||||||||||||||||||||||
Regional usage | Global (ICS) | ||||||||||||||||||||||
Time scale(s) used | ICS Time Scale | ||||||||||||||||||||||
Definition | |||||||||||||||||||||||
Chronological unit | Age | ||||||||||||||||||||||
Stratigraphic unit | Stage | ||||||||||||||||||||||
Time span formality | Formal | ||||||||||||||||||||||
Lower boundary definition | Not formally defined[6] | ||||||||||||||||||||||
Lower boundary definition candidates | Base of Stikinoceras kerri ammonoid zone and near FAD of Metapolygnathus echinatus within the M. communisti Conodont zones[6] | ||||||||||||||||||||||
Lower boundary GSSP candidate section(s) | |||||||||||||||||||||||
Upper boundary definition | Not formally defined[6] | ||||||||||||||||||||||
Upper boundary definition candidates |
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Upper boundary GSSP candidate section(s) |
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The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227.3 to 205.7 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.[8]
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