Norian

Norian
Norian
Chronology
←	Permian-Triassic extinction event
←	Smithian–Spathian boundary event
←	Carnian pluvial episode
←	Full recovery of woody trees
←	Coals return
←	Scleractinian; corals & calcified sponges
←	Triassic–Jurassic extinction event
←	Manicouagan impact
	Subdivision of the Triassic according to the ICS, as of 2021.; Vertical axis scale: millions of years ago.;
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
Lower boundary definition candidates	Base of Stikinoceras kerri ammonoid zone and near FAD of Metapolygnathus echinatus within the M. communisti Conodont zones
Lower boundary GSSP candidate section(s)	Black Bear Ridge, British Columbia, Canada; Pizzo Mondello, Sicily, Italy;
Upper boundary definition	Not formally defined
Upper boundary definition candidates	FAD of the Conodont Misikella posthernsteini; Near FAD of the Ammonite genus Cochloceras; Near FAD of the Conodont Epigondolella mosheri; Near FAD of the Radiolarian Proparvicingula moniliformis;
Upper boundary GSSP candidate section(s)	Steinbergkogel, Austria; Pignola-Abriola, Italy; Turkey; British Columbia, Canada;

The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to 208.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.