Ajay Kumar at 19:43, 30 August 2023

2023-08-30T19:43:49Z

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{{short description|Third stage of the Holocene Epoch}}
{{Use British English|date=January 2021}}
{{Use dmy dates|date=December 2022}}
{{about|the most recent stage of the Holocene epoch|the Indian state|Meghalaya}}
{{Infobox geologic timespan
| name = Meghalayan
| color = Meghalayan
| time_start = 0.0042
| time_end = 0
| image_map =
| caption_map =
| image_outcrop =
| caption_outcrop =
| image_art =
| caption_art =

| timeline = Holocene
| formerly_part_of =
| partially_contained_in =
| partially_contains =

| name_formality = Formal
| name_accept_date = 14 June 2018<ref name="FRS">{{cite journal |last1=Walker |first1=Mike |last2=Head |first2=Martin J. |last3=Berkelhammer |first3=Max |last4=Björck |first4=Svante |last5=Cheng |first5=Hai |last6=Cwynar |first6=Les |last7=Fisher |first7=David |last8=Gkinis |first8=Vasilios |last9=Long |first9=Anthony |last10=Lowe |first10=John |last11=Newnham |first11=Rewi |last12=Rasmussen |first12=Sune Olander |last13=Weiss |first13=Harvey |title=Formal ratification of the subdivision of the Holocene Series/ Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/subseries |journal=Episodes |publisher=Subcommission on Quaternary Stratigraphy (SQS) |date=1 December 2018 |volume=41 |issue=4 |pages=213–223 |doi=10.18814/epiiugs/2018/018016 |doi-access=free |url=https://stratigraphy.org/gssps/files/meghalayan.pdf |accessdate=28 August 2020}} ''This proposal on behalf of the SQS has been approved by the International Commission on Stratigraphy (ICS) and formally ratified by the Executive Committee of the International Union of Geological Sciences (IUGS)''.</ref><ref>{{cite journal |last1=Head |first1=Martin J. |title=Formal subdivision of the Quaternary System/Period: Present status and future directions |journal=Quaternary International |date=17 May 2019 |volume=500 |pages=32–51 |doi=10.1016/j.quaint.2019.05.018 |bibcode=2019QuInt.500...32H |doi-access= }}</ref>
| alternate_spellings =
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| nicknames =
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| 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 = [[4.2 kiloyear event]]
| lower_gssp_location = Mawmluh Cave, [[Meghalaya]], [[India]]
| lower_gssp_coords = {{Coord|25.2622|N|91.7150|E|display=inline}}
| lower_gssp_accept_date = 14 June 2018
| upper_boundary_def = Ongoing
| upper_gssp_location = N/A
| upper_gssp_accept_date = N/A

| o2 =
| co2 =
| temp =
| sea_level =
}}
{{Human history}}

The '''Meghalayan''' age is the name given in 2018, by the [[International Commission on Stratigraphy]], to the current age or latest [[age (geology)|geologic age]] – or uppermost [[stage (stratigraphy)|stage]] of the [[Quaternary]].<ref name="ICS">{{cite web |url=http://www.stratigraphy.org/ICSchart/ChronostratChart2020-01.pdf |last1=Cohen |first1=K. M. |last2=Finney |first2=S. C. |last3=Gibbard |first3=P. L. |last4=Fan |first4=J-X. |title=International Chronostratigraphic Chart |publisher=International Commission on Stratigraphy |date=January 2020 |access-date=8 January 2021}}</ref> It is also the upper, or latest, of three subdivisions of the [[Holocene]] [[Epoch (geology)|epoch]] or [[series (stratigraphy)|series]].<ref>{{cite web |url=https://www.indiatoday.in/india/story/meghalayan-age-what-the-world-was-like-when-it-began-1290138-2018-07-19 |last=Radha-Udayakumar |first=Ganesh |title=Scientists call our era the Meghalayan Age. Here's what the world was like when it began |work=India Today |publisher=Living Media India Limited |location=New Delhi |date=19 July 2018 |access-date=3 January 2021}}</ref><ref>{{Cite web|url=https://scroll.in/latest/887119/meghalayan-age-latest-phase-in-earths-history-named-after-indian-state-began-4200-years-ago|title='Meghalayan Age': Latest phase in Earth's history named after Indian state, began 4,200 years ago|website=Scroll.in}}</ref> This way of breaking down time is based only on geology; for example it is unrelated to the [[three age system]] of [[historical period]]s into which human development is sometimes divided.

The Meghalayan begins 4,200 years [[Before Present|BP]] ({{circa}} 2251 BCE or 7750 [[Holocene calendar|HE]]),<ref name=":0">{{cite web |url=https://www.bbc.com/news/science-environment-44868527 |title=Welcome to the Meghalayan Age – a new phase in history |publisher=BBC |author=Jonathan Amos |date=18 July 2018 |access-date=19 July 2018}}</ref> leaving room for the possible introduction of the [[Anthropocene]].<ref>{{cite web |author= International Commission on Stratigraphy |title= Collapse of civilizations worldwide defines youngest unit of the Geologic Time Scale |url= http://www.stratigraphy.org/index.php/ics-news-and-meetings/119-collapse-of-civilizations-worldwide-defines-youngest-unit-of-the-geologic-time-scale |website= News and Meetings |access-date=15 July 2018}}</ref><ref name=irving>{{cite web |url=https://newatlas.com/new-geological-age-declared-meghalayan/55532/ |title=Time for the Meghalayan: A new geological age has officially been declared |author=Michael Irving |date=19 July 2018 |access-date=19 July 2018 |url-status=dead |archive-url=https://web.archive.org/web/20180715004024/https://stratigraphy.org/index.php/ics-news-and-meetings/119-collapse-of-civilizations-worldwide-defines-youngest-unit-of-the-geologic-time-scale |archive-date=15 July 2018}}</ref> Helama & Oinonen (2019) dated the start of the Meghalayan to 2190-1990 BCE.<ref>{{Cite journal|date=15 June 2019|title=Exact dating of the Meghalayan lower boundary based on high-latitude tree-ring isotope chronology|url=https://www.sciencedirect.com/science/article/abs/pii/S0277379118310345|journal=Quaternary Science Reviews|language=en|volume=214|pages=178–184|doi=10.1016/j.quascirev.2019.04.013|issn=0277-3791|hdl=10138/330959|hdl-access=free|last1=Helama |first1=Samuli |last2=Oinonen |first2=Markku |bibcode=2019QSRv..214..178H |s2cid=150012152 }}</ref> The age began with a [[4.2-kiloyear event|200-year drought that impacted human civilizations]] in the [[Eastern Mediterranean]], [[History of Mesopotamia|Mesopotamia]], the [[Indus Valley Civilisation|Indus Valley]] and the [[Yangtze civilization|Yangtze River Valley]].<ref name=":0" /> "The fact that the beginning of this age coincides with a cultural shift caused by a global climate event makes it unique," according to Stanley Finney, Secretary General of the [[International Union of Geological Sciences]].<ref name=irving/>

==Origins==

This age is named after the [[Northeast India|Northeast Indian]] [[States and union territories of India|state]] of [[Meghalaya]], where the stalagmite was found that is used to mark out its years.

The [[International Commission on Stratigraphy]] officially ratified this age in June 2018, along with the earlier [[Greenlandian]] and [[Northgrippian]] ages/stages.<ref name=ics/> Its [[Global Boundary Stratotype Section and Point]] (GSSP) is a Krem Mawmluh Cave [[Speleothem|formation]] in [[Meghalaya]].<ref name=ics>{{cite web |author= International Commission on Stratigraphy |title= ICS chart containing the Quaternary and Cambrian GSSPs and new stages (v 2018/07) is now released! |url= http://www.stratigraphy.org/index.php/ics-news-and-meetings/120-ics-chart-containing-the-quaternary-gssps-and-new-stages-v-2018-07-is-now-released |access-date=15 July 2018|url-status=dead|archive-url=https://web.archive.org/web/20200219122950/http://www.stratigraphy.org/index.php/ics-news-and-meetings/120-ics-chart-containing-the-quaternary-gssps-and-new-stages-v-2018-07-is-now-released|archive-date=19 February 2020}}</ref> Mawmluh cave is one of the longest and deepest caves in India, and conditions there were suitable for preserving chemical signs of the transition in ages.<ref>{{Cite news|url=https://www.hindustantimes.com/science/meghalayan-age-makes-the-state-a-part-of-geologic-history/story-bvbKrd33IXgMD1o6BaSjmM.html|title='Meghalayan Age' makes the state a part of geologic history|date=18 July 2018|work=Hindustan Times|access-date=26 July 2018|language=en}}</ref> The global auxiliary stratotype is an [[ice core]] from [[Mount Logan]] in Canada.<ref>{{Cite web|url=https://www.qpg.geog.cam.ac.uk/news/formalsubdivisionoftheholoceneseriesgeogr18.pdf|title=Formal subdivision of the Holocene Series/Epoch}}</ref>

===IUGS geological heritage site===
In respect of the Mawmluh Cave site being the "GSSP of the youngest unit of the geologic time scale associated with dramatic climate changes with implications on human civilisation" the [[International Union of Geological Sciences]] (IUGS) included the GSSP of the Meghalayan Stage in the Mawmluh Cave in its assemblage of 100 "geological heritage sites" around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as "a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with a substantial contribution to the development of geological sciences through history."<ref>{{cite web |title=The First 100 IUGS Geological Heritage Sites |url=https://iugs-geoheritage.org/videos-pdfs/iugs_first_100_book_v2.pdf |website=IUGS International Commission on Geoheritage |publisher=IUGS |access-date=10 November 2022}}</ref>

== See also ==
* [[Geologic time scale]]
* [[4.2-kiloyear event]]

==References==
{{Reflist}}

==External links==
* [https://ghkclass.com/ghkC.html?Meghalayan Chronostratigraphy benchmarks]
*[https://www.youtube.com/watch?v=SZVe-i1fwPs&t=334s Meghalayan Age in details]

{{Holocene footer}}
{{Geological history|p|m}}

[[Category:3rd millennium BC]]
[[Category:Cenozoic|*01]]
[[Category:First 100 IUGS Geological Heritage Sites]]
[[Category:Geological epochs]]
[[Category:Holocene|*]]
[[Category:Quaternary geochronology|*03]]
[[Category:Quaternary|*]]

Meghalayan - Revision history

Ajay Kumar at 19:43, 30 August 2023