View source for Calabrian stage

{{short description|Subdivision of the Pleistocene Epoch}}
{{Infobox geologic timespan
| name                         = Calabrian
| color                        = Calabrian
| time_start                   = 1.80
| time_end                     = 0.774
| image_map                    =
| caption_map                  =
| image_outcrop                =
| caption_outcrop              =
| image_art                    =
| caption_art                  =
<!--Chronology-->  
| timeline                     = Quaternary
| 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           = Approximately 8 m after the end of magnetic polarity [[chronozone]] C2n (Olduvai)
| lower_gssp_location          = Vrica Section, [[Calabria]], Italy
| lower_gssp_coords            = {{Coord|39.0385|N|17.1348|E|display=inline}}
| lower_gssp_accept_date       = 5 December 2011 (as base of Calabrian)<ref>{{cite journal |last1=Cita |first1=Maria |last2=Gibbard |first2=Philip |last3=Head |first3=Martin |title=Formal ratification of the GSSP for the base of the Calabrian Stage (second stage of the Pleistocene Series, Quaternary System) |journal=Episodes |date=September 2012 |volume=35 |issue=3 |pages=388–397 |doi=10.18814/epiiugs/2012/v35i3/001 |url=https://www.researchgate.net/publication/258882567 |access-date=26 December 2020|doi-access=free |hdl=10261/250367 |hdl-access=free }}</ref>
| upper_boundary_def           = 1.1 m below the directional midpoint of the [[Brunhes-Matuyama]] magnetic reversal
| upper_gssp_location          = [[Chiba, Chiba|Chiba]], [[Japan]]
| upper_gssp_coords            = {{Coord|35.2943|N|140.1465|E|display=inline}}
| upper_gssp_accept_date       = 2020<ref>{{cite web|title=Global Boundary Stratotype Section and Point |url=https://stratigraphy.org/gssps/ |publisher=International Commission of Stratigraphy |accessdate=26 December 2020 }}</ref>
<!--Atmospheric and Climatic Data-->
| o2                           =
| co2                          =
| temp                         =
| sea_level                    =
}}

'''Calabrian''' is a subdivision of the [[Pleistocene]] [[epoch (geology)|Epoch]] of the [[geologic time scale]], defined as 1.8 Ma—774,000 years ago ± 5,000 years, a period of ~{{Mya|1.8-0.774|million years}}.

The end of the stage is defined by the last [[geomagnetic reversal|magnetic pole reversal]] (781 ± 5 Ka) and plunge into an ice age and global drying possibly colder and drier than the late Miocene ([[Messinian]]) through early Pliocene ([[Zanclean]]) cold period.<ref>A chronology of Pliocene sea-level fluctuations, U.S. Atlantic Coastal Plain: Quaternary Science Reviews, v. 10, p. 163–174.</ref> Originally the Calabrian was a European [[faunal stage]] primarily based on mollusk fossils.  It has become the second geologic age in the Early Pleistocene.  

==History of the definition of the Calabrian==
Because sea shells are much more abundant as fossils, 19th- and early-20th-century geo-scientists used the plentiful and well-differentiable [[Mollusca]] (mollusks) and [[Brachiopod]]s to identify [[Stratigraphy|stratigraphic]] boundaries. Thus the Calabrian was originally defined as an assemblage of mollusk fossils, most brachiopods being extinct by then.  Efforts were then made to find the best representation of that assemblage in a [[stratigraphic section]]. By 1948 scientists used the initial appearance of cool-water (northern) invertebrate faunas in [[Mediterranean]] marine sediments as the beginning marker for the Calabrian. The 18th International Geological Congress in London (1948) placed the base of the Pleistocene at the base of the marine strata of the Calabrian Faunal Stage and denominated a [[Global Boundary Stratotype Section and Point|type section]] in [[Mezzogiorno|southern Italy]].  However, it was discovered that the original type section was discontinuous at that point and that the base of the Calabrian Stage as defined by fauna assemblages extended to earlier levels within the Pleistocene. A new type section was chosen, several miles from the original one, at Vrica, 4&nbsp;km south of [[Crotone]] in [[Calabria]], southern Italy. Analysis of [[strontium]] and [[oxygen]] [[isotope]]s as well as of [[plankton]]ic [[foraminifera]] has confirmed the viability of the current type section.  The 27th International Geological Congress in Moscow in 1984 formally ratified the type section.  The starting date was originally thought to be about 1.65 million years ago, but has been recalculated as 1.806 Mya.<ref name="GeoW1">{{GeoWhen|Early_Pleistocene}}</ref>

==Present formal definition==
The Global Boundary Stratotype Section and Point, [[GSSP]], for the former<ref>In 2009 the [[Gelasian]] was included within the Pleistocene, making the Calabrian the second stage in the Pleistocene. {{Cite journal|first1=Philip L.|last1=Gibbard|first2=Martin J.|last2=Head|first3=Michael J. C.|last3=Walker|s2cid=54629809|year=2009|title=Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma|journal=Journal of Quaternary Science|volume=25|issue=2|page=96|doi=10.1002/jqs.1338|doi-access=free}} [http://onlinelibrary.wiley.com/doi/10.1002/jqs.1338/abstract abstract]</ref> start of the Pleistocene is in a reference section at Vrica, 4&nbsp;km south of [[Crotone]] in Calabria, [[Southern Italy]], a location whose exact dating has recently been confirmed by analysis of strontium and oxygen isotopes as well as by planktonic foraminifera.<ref name="Lourens">Lourens, L., Hilgen, F., Shackleton, N.J., Laskar, J., Wilson, D., (2004) “The Neogene Period”. In: Gradstein, F., Ogg, J., Smith, A.G. (Eds.), Geologic Time Scale Cambridge University Press, Cambridge;</ref>

The beginning of the Calabrian hence is defined as:  Just above top of magnetic polarity chronozone C2n (Olduvai) and the extinction level of [[calcareous nannofossils|calcareous nannofossil]] ''[[Discoaster]] brouweri'' (base Zone CN13).  Above the boundary are the lowest occurrence of calcareous nannofossil medium ''[[Gephyrocapsa]] spp.'' and the extinction level of the planktonic foraminifer ''[[Globigerinoides]] extremus''.<ref name="GeoW1"/>

The end of the Calabrian is defined as the [[Brunhes–Matuyama reversal|Brunhes–Matuyama magnetic reversal]] event.<ref name="Lourens"/><ref>{{Cite journal|author=Cita, Maria Bianca|authorlink=Maria Bianca Cita|year=2008|title=The Calabrian stage redefined|journal=Episodes|volume=31|issue=4|pages=408&ndash;419|display-authors=etal|doi=10.18814/epiiugs/2008/v31i4/006|doi-access=free}}</ref>

==See also==
*[[Eburonian]]
*[[Villafranchian]]

==Notes==
<!--<nowiki> 
See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref> and </ref> tags.
</nowiki>-->
{{Reflist}}

== References ==
* {{GeoWhen|Early_Pleistocene}}

{{Quaternary Footer}}
{{Geological history|p|c}}

{{coord|39|02|19|N|17|08|06|E|source:kolossus-frwiki|display=title}}

{{DEFAULTSORT:Calabrian (Stage)}}
[[Category:Calabrian (stage)| ]]
[[Category:Pleistocene geochronology]]
[[Category:Geological ages]]
[[Category:Pleistocene Europe]]
[[Category:Quaternary geochronology]]