{{short description|Second age of the late Triassic}} {{Infobox geologic timespan | name = Norian | color = Norian | time_start = 227.3 | time_end = 205.7 | image_map =Mollweide Paleographic Map of Earth, 220 Ma (Norian Age).png | caption_map =A map of Earth as it appeared 220 million years ago | image_outcrop = | caption_outcrop = | image_art = | caption_art = <!--Chronology--> | timeline = Triassic | formerly_part_of = | partially_contained_in = | partially_contains = <!--Etymology--> | name_formality = Formal | name_accept_date = | alternate_spellings = | synonym1 = | synonym1_coined = | synonym2 = | synonym2_coined = | synonym3 = | synonym3_coined = | nicknames = | former_names = | proposed_names = <!--Usage Information--> | celestial_body = earth | usage = Global ([[International Commission on Stratigraphy|ICS]]) | timescales_used = ICS Time Scale | formerly_used_by = | not_used_by = <!--Definition--> | chrono_unit = Age | strat_unit = Stage | proposed_by = | type_section = | timespan_formality = Formal | lower_boundary_def = Not formally defined<ref name="GSSP Web">{{cite web|title=Global Boundary Stratotype Section and Point |url=https://stratigraphy.org/gssps/|publisher=International Commission of Stratigraphy |access-date=23 December 2020 }}</ref> | lower_def_candidates = Base of ''[[Stikinoceras|Stikinoceras kerri]]'' ammonoid zone and near [[First appearance datum|FAD]] of ''[[Metapolygnathus|Metapolygnathus echinatus]]'' within the ''[[Metapolygnathus|M. communisti]]'' [[Conodont]] zones<ref name="GSSP Web"/> | lower_gssp_candidates = * [[Black Bear Ridge]], [[British Columbia]], [[Canada]]<ref name="GSSP Web"/> * [[Pizzo Mondello]], [[Sicily]], [[Italy]]<ref name="GSSP Web"/> | upper_boundary_def = Not formally defined<ref name="GSSP Web"/> | upper_def_candidates = * FAD of the Conodont ''[[Misikella|Misikella posthernsteini]]'' * Near FAD of the [[Ammonite]] [[genus]] ''[[Cochloceras]]''<ref name="GSSP Web"/> * Near FAD of the Conodont ''[[Epigondolella|Epigondolella mosheri]]''<ref name="GSSP Web"/> * Near FAD of the [[Radiolaria]]n ''[[Proparvicingula|Proparvicingula moniliformis]]''<ref name="GSSP Web"/> | upper_gssp_candidates = * [[Steinbergkogel]], [[Austria]]<ref name="GSSP Web"/> * [[Pignola-Abriola]], Italy<ref>{{Cite journal|last1=Rigo|first1=Manuel|last2=Bertinelli|first2=Angela|last3=Concheri|first3=Giuseppe|last4=Gattolin|first4=Giovanni|last5=Godfrey|first5=Linda|last6=Katz|first6=Miriam E.|last7=Maron|first7=Matteo|last8=Mietto|first8=Paolo|last9=Muttoni|first9=Giovanni|last10=Sprovieri|first10=Mario|last11=Stellin|first11=Fabio; Mariachiara, Zaffani|date=2016|title=The Pignola-Abriola section (southern Apennines, Italy): a new GSSP candidate for the base of the Rhaetian Stage|url=https://www.researchgate.net/publication/281461104|journal=Lethaia|language=en|volume=49|issue=3|pages=287–306|doi=10.1111/let.12145|bibcode=2016Letha..49..287R |issn=1502-3931|hdl=11577/3157425|hdl-access=free}}</ref> * [[Turkey]]<ref name="GSSP Web"/> * British Columbia, Canada<ref name="GSSP Web"/> <!--Atmospheric and Climatic Data--> | o2 = | co2 = | temp = | sea_level = }}
The '''Norian''' is a division of the [[Triassic]] [[geological period|Period]]. It has the rank of an [[age (geology)|age]] ([[geochronology]]) or [[stage (stratigraphy)|stage]] ([[chronostratigraphy]]). It lasted from 227.3 to {{Period start|Rhaetian}} [[Mya (unit)|million years ago]]. It was preceded by the [[Carnian]] and succeeded by the [[Rhaetian]].<ref name=TimeScale>{{Cite web |url=https://stratigraphy.org/ICSchart/ChronostratChart2024-12.pdf |title=ICS - Chart/Time Scale |access-date=2025-01-14 |archive-date=2025-01-01 |archive-url=https://web.archive.org/web/20250101170925/https://stratigraphy.org/ICSchart/ChronostratChart2024-12.pdf}}</ref>
==Stratigraphic definitions== [[File:Otisk stopy ceskeho dinosaura.jpg|thumb|Cast of a tridactyl footprint of a theropod dinosaur from the Norian of the [[Czech Republic]]]] The Norian was named after the [[Noric Alps]] in [[Austria]]. The stage was introduced into scientific literature by Austrian geologist [[Johann August Georg Edmund Mojsisovics von Mojsvar|Edmund Mojsisovics von Mojsvar]] in 1869.
The Norian Stage begins at the base of the [[ammonite]] [[biozone]]s of ''[[Klamathites|Klamathites macrolobatus]]'' and ''[[Stikinoceras|Stikinoceras kerri]]'', and at the base of the [[conodont]] biozones of ''[[Metapolygnathus|Metapolygnathus communisti]]'' and ''[[Metapolygnathus|Metapolygnathus primitius]]''. A global reference profile for the base (a [[GSSP]]) had in 2009 not yet been appointed.
The top of the Norian (the base of the Rhaetian) is at the first appearance of ammonite species ''[[Cochloceras|Cochloceras amoenum]]''. The base of the Rheatian is also close to the first appearance of conodont species ''[[Misikella|Misikella spp.]]'' and ''[[Epigondolella|Epigondolella mosheri]]'' and the [[radiolaria|radiolarid]] species ''[[Proparvicingula|Proparvicingula moniliformis]]''.
In the [[Tethys Ocean|Tethys domain]], the Norian Stage contains six ammonite biozones: *zone of ''[[Halorites|Halorites macer]]'' *zone of ''[[Himavatites|Himavatites hogarti]]'' *zone of ''[[Cyrtopleurites|Cyrtopleurites bicrenatus]]'' *zone of ''[[Juvavites|Juvavites magnus]]'' *zone of ''[[Malayites|Malayites paulckei]]'' *zone of ''[[Guembelites|Guembelites jandianus]]''
=== Subages === The Norian is divided into three global subages or substages:
* '''Lacian''' (lower Norian) * '''Alaunian''' (middle Norian) * '''Sevatian''' (upper Norian)
Many older studies considered the Rhaetian to be the uppermost substage of the Norian, though it has subsequently been raised to its own stage.
The [[Revueltian]] [[Triassic land vertebrate faunachrons|land-vertebrate faunachron]] (LVF) corresponds to part of the Norian (215–207 Ma), and it is probable that the [[Otischalkian]] and [[Adamanian]] LVFs (227–215 Ma) are also early-middle Norian in age.<ref name=":8">{{Citation |last1=Martz |first1=J. W. |title=Revised Formulation of the Late Triassic Land Vertebrate "Faunachrons" of Western North America: Recommendations for Codifying Nascent Systems of Vertebrate Biochronology |date=2017-01-01 |work=Terrestrial Depositional Systems |pages=39–125 |editor-last=Zeigler |editor-first=Kate E. |url=https://www.sciencedirect.com/science/article/pii/B9780128032435000029 |access-date=2022-08-28 |publisher=Elsevier |language=en |isbn=978-0-12-803243-5 |last2=Parker |first2=W. G. |editor2-last=Parker |editor2-first=William G.}}</ref>
== Notable formations ==
* [[Calcare di Zorzino]] (Italy) * [[Caturrita Formation]] ([[Rio Grande do Sul]], Brazil) * [[Chinle Formation]] (Arizona and New Mexico, USA) * [[Cow Branch Formation]] (North Carolina and Virginia, USA) * [[Dockum Group]] (Carnian – Norian) (Texas and New Mexico, USA) * [[Dolomia di Forni]] (Italy) * [[Ischigualasto Formation]] (Carnian – Norian) (Argentina) * [[Los Colorados Formation]] (Argentina) * [[Stubensandstein]] (Germany) * [[Trossingen Formation]] (Norian – Rhaetian) (Switzerland and Germany)
== References ==
===Notes=== {{reflist}}
===Literature=== *{{aut|Brack, P.; Rieber, H.; Nicora, A. & Mundil, R.}}; '''2005''': ''The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale'', Episodes '''28(4)''', pp. 233–244. *{{aut|Gradstein, F.M.; Ogg, J.G. & Smith, A.G.}}; '''2004''': ''A Geologic Time Scale 2004'', [[Cambridge University Press]]. *{{aut|[[Zofia Kielan-Jaworowska|Kielan-Jaworowska, Z.]]; Cifelli, R. L.; Luo, Zhe-Xi}}; '''2004''': ''Mammals from the Age of Dinosaurs'', [[Columbia University Press]]. *{{aut|Martz, J.W.}}; '''2008''': ''Lithostratigraphy, chemostratigraphy, and vertebrate biostratigraphy of the Dockum Group (Upper Triassic), of southern Garza County, West Texas'', Doctoral Dissertation, Texas Tech.
==External links== *[http://www.stratigraphy.org/bak/geowhen/stages/Norian.html GeoWhen Database - Norian] *[http://stratigraphy.science.purdue.edu/charts/Timeslices/7_Upper_Trias.pdf Upper Triassic timescale], at the website of the subcommission for stratigraphic information of the ICS *Norges Network of offshore records of geology and stratigraphy: ''Stratigraphic charts for the Triassic'', [https://web.archive.org/web/20060518100851/http://norges.uio.no/timescale/Late_Triassic.pdf] and [https://web.archive.org/web/20051109154300/http://norges.uio.no/timescale/Fig16.1_Tri_colA.pdf]
{{Triassic Footer}} {{Geological history|p|m}}
[[Category:Norian| ]] [[Category:Late Triassic|*02]] [[Category:Geological ages]] [[Category:Triassic geochronology]]