Ajay Kumar at 03:25, 30 August 2023

2023-08-30T03:25:13Z

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{{short description|Stage of the Pleistocene Epoch}}
{{Infobox geologic timespan
| name = Chibanian
| color = Chibanian
| time_start = 0.774
| time_end = 0.129
| image_map =
| caption_map =
| image_outcrop =
| caption_outcrop =
| image_art =
| caption_art =

| timeline = Quaternary
| formerly_part_of =
| partially_contained_in =
| partially_contains =

| name_formality = Formal
| name_accept_date = January 2020
| alternate_spellings =
| synonym1 = Middle Pleistocene
| synonym1_coined =
| synonym2 = Ionian
| synonym2_coined =
| synonym3 =
| synonym3_coined =
| nicknames =
| former_names =
| proposed_names =

| celestial_body = earth
| usage = Global ([[International Commission on Stratigraphy|ICS]])
| timescales_used = ICS Time Scale
| formerly_used_by =
| not_used_by =

| chrono_unit = Age
| strat_unit = Stage
| proposed_by =
| type_section =
| timespan_formality = Formal
| lower_boundary_def = 1.1 m below the directional midpoint of the [[Brunhes-Matuyama]] magnetic reversal
| lower_gssp_location = [[Chiba, Chiba|Chiba]], [[Japan]]
| lower_gssp_coords = {{Coord|35.2943|N|140.1465|E|display=inline}}
| lower_gssp_accept_date = January 2020<ref>{{cite web|title=Global Boundary Stratotype Section and Point |url=https://stratigraphy.org/gssps/ |publisher=International Commission of Stratigraphy |access-date=26 December 2020}}</ref>
| upper_boundary_def = Not formally defined
| upper_def_candidates = Marine Isotope Substage 5e
| upper_gssp_candidates = None

| o2 =
| co2 =
| temp =
| sea_level =
}}
The '''Chibanian''', widely known as the '''Middle Pleistocene''', is an [[Age (geology)|age]] in the international [[geologic timescale]] or a [[Stage (stratigraphy)|stage]] in [[chronostratigraphy]], being a division of the [[Pleistocene]] Epoch within the ongoing [[Quaternary]] Period.<ref name="Eos_30Jan20">{{cite web |url=https://eos.org/articles/japan-puts-its-mark-on-geologic-time-with-the-chibanian-age |title=Japan Puts Its Mark on Geologic Time with the Chibanian Age |publisher=[[American Geophysical Union]] |work=Eos – Earth & Space Science News |date=30 January 2020 |access-date=31 January 2020 |author=Hornyak, Tim}}</ref> The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770 [[annum|Ma]] (770,000 years ago) and 0.126 Ma (126,000 years ago), also expressed as 770–126 ka. It includes the transition in [[palaeoanthropology]] from the [[Lower Paleolithic|Lower]] to the [[Middle Paleolithic]] over 300 ka.

The Chibanian is preceded by the [[Calabrian (stage)|Calabrian]] and succeeded by the proposed [[Tarantian]].<ref name="ICC2">{{cite web |url=http://www.stratigraphy.org/ICSchart/ChronostratChart2020-01.pdf |title=International Chronostratigraphic Chart |publisher=International Commission on Stratigraphy |last1=Cohen |first1=K. M. |last2=Finney |first2=S. C. |last3=Gibbard |first3=P. L. |last4=Fan |first4=J.-X. |date=January 2020 |access-date=23 February 2020}}</ref> The beginning of the Chibanian is the [[Brunhes–Matuyama reversal]], when the Earth's magnetic field last underwent reversal.<ref>{{cite book |editor2-last=Ogg |editor2-first=James G. |editor3-last=Smith |editor3-first=Alan G. |editor-last=Gradstein |editor-first=Felix M. |title=A Geological Time Scale 2004 |url=https://archive.org/details/geologictimescal2004grad |url-access=limited |date=2004 |publisher=Cambridge University Press |location=Cambridge |isbn=9780521786737 |page=[https://archive.org/details/geologictimescal2004grad/page/n49 28] |edition=3rd}}</ref> It ends with the onset of the [[Eemian]] interglacial period ([[Marine Isotope Stage 5]]).<ref name="Eemian">{{cite journal |title=Eemian interglacial reconstructed from a Greenland folded ice core |journal=Nature |volume=493 |issue=7433 |pages=489–494 |year=2013 |author=D. Dahl-Jensen & others |bibcode=2013Natur.493..489N |url=http://nora.nerc.ac.uk/id/eprint/500331/1/2012-07-09846-NEEM_revised.pdf |doi=10.1038/nature11789 |pmid=23344358|s2cid=4420908}}</ref>

The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the [[International Union of Geological Sciences]] (IUGS). While the three lowest ages of the Pleistocene, the [[Gelasian]], Calabrian and Chibanian have been officially defined, the [[Late Pleistocene]] has yet to be formally defined, along with consideration of a proposed [[Anthropocene]] sub-division of the [[Holocene]].<ref name="Gibbard">{{cite journal |url=https://www.sciencedirect.com/science/article/abs/pii/S1068797115000747 |title=The Quaternary System/Period and its major sub-divisions |author=P. L. Gibbard |journal=Russian Geology and Geophysics |publisher=Elsevier BV |series=Special Issue: Topical Problems of Stratigraphy and Evolution of the Biosphere |volume=56 |issue=4 |pages=686–688 |date=17 April 2015 |doi=10.1016/j.rgg.2015.03.015 |bibcode=2015RuGG...56..686G |access-date=13 November 2019}}</ref>

==Definition process==
The [[International Union of Geological Sciences]] (IUGS) had previously proposed replacement of the Middle Pleistocene by an Ionian Age based on strata found in Italy. In November 2017, however, the Chibanian (based on strata at a site in [[Chiba Prefecture]], Japan) replaced the Ionian as the Subcommission on Quaternary Stratigraphy's preferred GSSP proposal for the age that should replace the Middle Pleistocene sub-epoch.<ref name="Chiba1">{{cite web |url=https://www.japantimes.co.jp/news/2017/11/14/national/science-health/japan-based-name-chibanian-set-represent-geologic-age-last-magnetic-shift |title=Japan-based name 'Chibanian' set to represent geologic age of last magnetic shift |publisher=The Japan Times |date=14 November 2017 |access-date=13 November 2019}}</ref> The "Chibanian" name was ratified by the IUGS in January 2020.<ref name="Eos_30Jan20"/>

==Palaeoanthropology==
The Chibanian includes the transition in [[palaeoanthropology]] from the [[Lower Paleolithic|Lower]] to the [[Middle Paleolithic]]: i.e., the emergence of ''[[Homo sapiens sapiens]]'' between 300 ka and 400 ka.<ref>{{cite journal |title=The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age |journal=Nature |volume=546 |issue=7657 |pages=293–296 |date=8 June 2017 |author=D. Richter & others|doi=10.1038/nature22335 |pmid=28593967 |bibcode=2017Natur.546..293R |s2cid=205255853}}.</ref> The oldest known human DNA dates to the Middle Pleistocene, around 430,000 years ago. This is the oldest found, {{As of|2016|lc=y}}.<ref name="DNA">{{cite news |url=https://www.sciencealert.com/the-oldest-human-genome-ever-has-been-sequenced-and-it-could-rewrite-human-history |last=Crew |first=Bec |title=The Oldest Human Genome Ever Has Been Sequenced, And It Could Rewrite Our History |work=ScienceAlert |date=15 March 2016 |access-date=5 June 2019}}</ref>

==Chronology==
{{see|Timeline of glaciation}}
{{see|Marine isotope stages|Last Glacial Period}}
{{see|Brunhes–Matuyama reversal}}
{|class="wikitable"
!Age
!paleoclimate
!glaciation
!palaeoanthropology
|-
|790–761 ka|| MIS 19|| [[Gunz glaciation|Günz (Elbe) glaciation]] || [[Peking Man]] (''[[Homo erectus]]'')
|-
|761–712 ka|| MIS 18
|-
|712–676 ka|| MIS 17
|-
|676–621 ka||MIS 16
|-
|621–563 ka|| MIS 15 ||[[Gunz-Haslach interglacial]]|| [[Mauer 1|Heidelberg Man]] (''[[Homo heidelbergensis]]''), [[Bodo cranium]]
|-
|563–524 ka|| MIS 14
|-
|524–474 ka|| [[MIS13|MIS 13]]||end of [[Cromerian Stage|Cromerian (Günz-Mindel) interglacial]] || [[Boxgrove Man]] (''[[Homo heidelbergensis]]'')
|-
|474–424 ka|| MIS 12 || [[Anglian (stage)|Anglian Stage]] in Britain; [[Haslach glaciation]]|| [[Tautavel Man]] (''[[Homo erectus]]'')
|-
|424–374 ka|| [[Marine Isotope Stage 11|MIS 11]] ||[[Hoxnian Stage|Hoxnian]] (Britain), [[Yarmouthian (stage)|Yarmouthian]] (North America)|| [[Swanscombe Man]] (''[[Homo heidelbergensis]]'')
|-
|374–337 ka|| MIS 10 ||[[Mindel glaciation]], [[Elster glaciation]], [[Riss glaciation]]
|-
|337–300 ka|| [[MIS 9]] ||Purfleet Interglacial in Britain || [[Mousterian]]
|-
|300–243 ka|| MIS 8|| ||[[Irhoud 1]] (''[[Homo sapiens]]''); [[Middle Paleolithic]]; [[Haplogroup A (Y-DNA)]]
|-
|243–191 ka|| MIS 7 || Aveley Interglacial in Britain || [[Galilee Man]]; [[Haua Fteah]]
|-
|191–130 ka|| MIS 6 || [[Illinoian (stage)|Illinoian Stage]] || [[Herto Man]] (''[[Homo sapiens]]''); [[Macro-haplogroup L (mtDNA)]]; [[Mousterian]]
|-
|130–123 ka|| [[MIS 5]]e || peak of [[Eemian]] interglacial sub-stage, or Ipswichian in Britain||[[Klasies River Caves]]; [[Sangoan]]
|-
|}

==See also==
* [[Mid-Pleistocene Transition]]
* [[100,000-year problem]]
* [[Pleistocene megafauna]]

== References ==
{{Reflist}}

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

[[Category:Middle Pleistocene| ]]
[[Category:Pleistocene|*02]]
[[Category:Geological ages]]
[[Category:Pleistocene geochronology]]
[[Category:Cenozoic geochronology]]

Chibanian - Revision history

Ajay Kumar at 03:25, 30 August 2023