View source for Stenian

{{short description|Third and last period of the Mesoproterozoic Era}}
{{Infobox geologic timespan
| name                         = Stenian
| color                        = Stenian
| top_bar                      = all time
| time_start                   = 1200
| time_end                     = 1000
| image_map                    = 1040 Ma paleoglobe.png
| caption_map                  = Paleoglobe of Earth during the late Stenian, c. 1040 Ma{{citation needed|reason=Description on Wikimedia Commons page is "own work" with no cited sources|date=June 2024}}
| image_outcrop                =
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<!--Chronology-->  
| timeline                     = Stenian
<!--Etymology-->
| name_formality               = Formal
| name_accept_date             =
| alternate_spellings          =
| synonym1                     =
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| synonym2                     =
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<!--Usage Information--> 
| celestial_body               = earth
| usage                        = Global ([[International Commission on Stratigraphy|ICS]])
| timescales_used              = ICS Time Scale
<!--Definition-->
| chrono_unit                  = Period
| strat_unit                   = System
| proposed_by                  =
| timespan_formality           = Formal
| lower_boundary_def           = Defined chronometrically
| lower_gssa_accept_date       = 1991<ref name=Plumb1991>{{cite journal |last=Plumb |first=K. A. |date=June 1, 1991 |title=New Precambrian time scale |journal=Episodes |doi=10.18814/epiiugs/1991/v14i2/005 |volume=14 |issue=2 |pages=139–140|doi-access=free }}</ref>
| upper_boundary_def           = Defined chronometrically
| upper_gssa_accept_date       = 1991<ref name=Plumb1991/>
<!--Atmospheric and Climatic Data-->
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The '''Stenian Period''' ({{IPAc-en|'|s|t|i:|n|i|.|@|n}} {{respell|STEE|nee|ən}}, from {{langx|grc|στενός|stenós}}, meaning "narrow") is the final [[geologic period]] in the [[Mesoproterozoic]] [[era (geology)|Era]] and lasted from {{Period start|Stenian}} [[annum|Mya]] to {{Period start|Tonian}} Mya (million years ago). Instead of being based on [[stratigraphy]], these dates are defined [[Absolute dating|chronometrically]]. The name derives from narrow [[Metamorphic rock|polymetamorphic]] belts formed over this period. It is preceded by the [[Ectasian]] Period and followed by the [[Neoproterozoic]] era and the [[Tonian]] period.

The [[supercontinent]] [[Rodinia]] assembled during the Stenian. It would last into the Tonian period before breaking up in the [[Cryogenian]].

This period includes the formation of the [[Midcontinent Rift System|Keweenawan Rift]] at about 1100 Mya.<ref>{{cite web|url=http://deepblue.lib.umich.edu/bitstream/2027.42/28843/1/0000678.pdf|title=Organic geochemical study of mineralization in the Keweenawan Nonesuch Formation at White Pine, Michigan|publisher=University of Michigan|access-date=28 September 2011}}</ref>

Fossils of the oldest known sexually reproducing organism, ''[[Bangiomorpha pubescens]]'', first appeared in the Stenian.<ref name="Gibson2017">{{cite journal|doi=10.1130/G39829.1|title=Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis|journal=Geology|volume=46|issue=2|pages=135–138|year=2017|last1=Gibson|first1=Timothy M|last2=Shih|first2=Patrick M|last3=Cumming|first3=Vivien M|last4=Fischer|first4=Woodward W|last5=Crockford|first5=Peter W|last6=Hodgskiss|first6=Malcolm S.W|last7=Wörndle|first7=Sarah|last8=Creaser|first8=Robert A|last9=Rainbird|first9=Robert H|last10=Skulski|first10=Thomas M|last11=Halverson|first11=Galen P|url=https://authors.library.caltech.edu/83811/3/2018030.pdf}}</ref>

==See also==
*{{annotated link|Boring Billion}}
*{{annotated link|Riphean (stage)}}

==Notes==
{{Reflist}}

== References ==
*{{cite web | title=Stenian Period | work=GeoWhen Database | url=http://www.stratigraphy.org/geowhen/stages/Stenian.html | access-date=January 5, 2006 |archive-url = https://web.archive.org/web/20060512164255/http://www.stratigraphy.org/geowhen/stages/Stenian.html <!-- Bot retrieved archive --> |archive-date = May 12, 2006}}
*{{cite journal | author=James G. Ogg | title=Status on Divisions of the International Geologic Time Scale | journal=Lethaia | year=2004 | volume=37 | issue= 2| pages=183–199 | doi=10.1080/00241160410006492 }}

{{Proterozoic footer}}
{{Geological history of Earth}}

[[Category:Mesoproterozoic|*]]
[[Category:Geological periods]]
[[Category:Proterozoic geochronology]]

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