>BrownHairedGirl: remove navbox {{Tamil Nadu}}, which doesn't link here

2021-04-29T19:56:02Z

remove navbox {{Tamil Nadu}}, which doesn't link here

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{{Use dmy dates|date=July 2020}}
{{Use Indian English|date=July 2020}}
[[File:St Thomas Mount.jpg|thumb]]
{{Coord|12.99506|80.19955|region:IN-TN|display=title}}
{{Location map
| India Chennai
| lat = 12.99506
| long = 80.19955
| locator_position = right
| caption = Location of Charnockite, St. Thomas Mount in Chennai
}}
'''Charnockite, St. Thomas Mount''', located to the south of the [[Chennai]] city, in [[Pallavaram]] suburb, [[Tamil Nadu]], is a characteristically profuse exposure of [[quartz]]–[[feldspar]]–[[hypersthene]] rock, illustrated by occurrence of two [[pyroxene]] [[facies]] [[metamorphism]].<ref name=Port>{{cite web|url=http://www.portal.gsi.gov.in/portal/page?_pageid=127,529399&_dad=portal&_schema=PORTAL&linkId=1074|title=Charnockite, St. Thomas Mount|publisher=Geological Survey of India|access-date=2009-02-02|archive-url=https://web.archive.org/web/20110721161438/http://www.portal.gsi.gov.in/portal/page?_pageid=127,529399&_dad=portal&_schema=PORTAL&linkId=1074|archive-date=2011-07-21|url-status=dead}}</ref><ref name= GSI>{{cite book |title=National Geological Monuments, Peninsular Gneiss|pages=85–89|publisher=Geological Survey of India,27,Jawaharlal Nehru Road, Kolkatta-700016|year=2001|url=http://www.vedamsbooks.com/no24484.htm}}</ref>

The name "Charnockite, St. Thomas Mount" originated from the use of the rocks quarried from a central band in the [[St.Thomas Mount]] for the [[tombstone]] of [[Job Charnock]], the founder of [[Kolkata]] in 1679. Several incidents in Charnock's life are linked to [[Charnockite]] rock, Chennai city (formerly [[Madras]]) and the St. Thomas Mount.<ref name=Port/><ref name= GSI/><ref name=nair>{{cite web|url=http://www.hindu.com/thehindu/mp/2002/05/27/stories/2002052700190300.htm|archive-url=https://web.archive.org/web/20031019210133/http://www.hindu.com/thehindu/mp/2002/05/27/stories/2002052700190300.htm|url-status=dead|archive-date=2003-10-19|title=A memorial at The Mount|date= 2007-05-27|work=[[The Hindu]]|access-date = 2009-02-01}}</ref>

==Geography and topography==
[[File:Charnockite Rock at st. Thomas Mount.JPG|left|thumb|200px|Charnockite rock exposure band quarried from here for the tomb of Job Charnock]]
Charnockite rock series is an ancient formation, similar to [[granite]], which has intruded into igneous rocks.<ref>{{Cite book|title=Precambrian Geology and Metamorphic Petrology: , Beijing|last=Proceedings of the 30th International Geological Congress|first=China, 4–14 August 1996|publisher=VSP|year=1998|location=China|pages=354}}</ref> It is found not only in St. Thomas Mount but also extends south of the [[Chingleput]] in Tamil Nadu. It is also traced to the [[Nilgiri hills]] with southern trend extending to the [[Malabar district]], and former feudal states of [[Cochin]] and [[Travancore]], princely towns in [[Kerala]]. It rises further above the [[sea level]] to form the great mass of [[Sri Lanka]] ([[Ceylon]]). The massive formations are more in the form of [[plateau]] (some of them at elevations between {{convert|6000|ft|m|abbr=on|1}} and {{convert|7000|ft|m|abbr=on|1}}) that facilitates formation of lakes.<ref>{{cite book|url=https://books.google.com/books?id=m0WzU2jXXfMC&q=Charnockite+at+St.+Thomas+Mount&pg=PA59|title = The Madras Presidency with Mysore, Coorg, and the Associated States|author= Edgar Thurston|pages = 322–330|access-date=2009-02-03|publisher = Asian Educational Services|year=2005|isbn = 9788120617162}}</ref>

==History==
[[File:St Thomas Church on the Mount.JPG|thumb|left|200px|Peaceful little [[Portuguese people|Portuguese]] chapel of [[Thomas the Apostle|St. Thomas]] who was martyred on top of the mount made up of Charnockite rock formations]]
One of the earliest memorials in Chennai is the peaceful little [[Portuguese people|Portuguese]] chapel on top of the hill (a flight of 132 steps leads to the summit) and built at the site where [[Doubting Thomas]], the [[Apostle (Christian)|Apostle]] of India, was martyred in 72 A.D. and thereafter the hill has been famously known as the [[St. Thomas Mount]].<ref name=nair/><ref>{{cite web|url=http://www.whereincity.com/india/tamilnadu/chennai.php|title =Chennai – Little mount & Mount of St. Thomas|access-date=2009-02-03}}</ref>

The earliest recorded history related to the Charnockite is of an announcement made in 1892 by [[Thomas Oldham]] of the [[Geological Survey of India]], of the occurrence of hypersthene granite in [[South India]]. In 1893, Dr T.H.Holland, the then Chief of the Geological Survey of India reported that the Hypderstehene granites found in Madras (Chennai) was associated with large masses of [[norite]]. It was also noted that the same type of stone was used for the tombstone of Job Charnock and that it was extracted from the neighbourhood of St Thomas Mount.<ref name= GSI/>
Following the above finding, in 1893, Holland, had read a paper at the Asiatic Society of Bengal titled "The [[Petrology]] of Job Charnock's Tombstone" and suggested that the rock which was of a new type be named as the ‘Charnockite rock’ in honour of the founder of Calcutta who had become the unaware means of bringing this rock to Calcutta. Thus, 200 years after his death the rock from Pallavaram (suburb of Chennai) was named Charnockite.<ref name=nair/>

Recent studies in 1950 by Pascoe suggest that the material used in Charnock's tombstone was quarried from a central band in the St. Thomas Mount.<ref name= GSI/>

In 1975, the [[Geological Survey of India]] declared the monument "Charnockite, St. Thomas Mount" in memory of Job Charnock for whom the stone from this hill, (which was then called the Pallavaram [[Gneiss]]) was shipped to [[Calcutta]] for building his [[tomb]]. Since then "Charnockite" is also prefixed with the famous "St. Thomas Mount".<ref name= GSI/>

Job Charnock, a servant and administrator of the [[English East India Company]], is credited for founding the city of Calcutta in 1686, 50 years after the city of Madras was founded.<ref name=nair/>
[[File:Picture of Baptisaml Font of Charnockite.jpg|thumb|right|200px|[[Baptismal Font]] at St. Mary's Church at [[Fort St. George]] in Chennai with a plaque behind it that corroborates the history]]
Several incidents of Charnock's association with Madras and the St. Thomas Mount have been cited. In 1655, he arrived in Madras and proceeded to [[Bengal]] where he was to serve in Cossim Bazar. Subsequently, he went to [[Patna]] (1657), in [[Bihar]] and in 1686 he became the Agent of the Company. He fled to Madras in 1689 as he was thrown out by the local [[Muslim]] rulers during the Anglo–Moghal war. He was given protection by Governor Elihu Yale at Madras for 18 months and who also supported him fully to return to [[Bengal]]. This subsequently resulted in establishing [[Calcutta|Kolkatta]] in 1690 by Job Charnock. He rescued an Indian women from [[Bihar]], who was about to commit [[Sati (practice)|Sati]] on the [[funeral]] [[pyre]] of her husband, by gallantly blazing with guns, and later married her and renamed her as Maria. They had one son (who predeceased them) and three daughters –Mary, Elizabeth and Catherine – who married men of the reputed John Company Establishment in Bengal –. They were baptized on 19 August 1689 in front the Baptismal Font (picture of the Font and the plaque in the gallery testifies the dates) of black Pallavaram granite that existed on the Mount since 1680 (but shifted to the [[St. Mary's Church (Fort St. George)|St Mary's Church]] at [[Fort St. George]] in 1885).<ref name=nair/><ref>{{cite web|url=http://www.wmcarey.edu/carey/wmward/Misc%20html/jobcharnock.html|title=Job Charnock|access-date=2009-02-02}}</ref><ref>{{cite book |last=Islam |first=Sirajul |year=2012 |chapter=Charnock, Job |chapter-url=http://en.banglapedia.org/index.php?title=Charnock,_Job |editor1-last=Islam |editor1-first=Sirajul |editor1-link=Sirajul Islam |editor2-last=Jamal |editor2-first=Ahmed A. |title=Banglapedia: National Encyclopedia of Bangladesh |edition=Second |publisher=[[Asiatic Society of Bangladesh]]}}</ref>

==Geology==
The constituents of the rock suggests of its origin in particularly dry and high temperature conditions which is deduced to have an important bearing in explicating prehistoric crustal development of the earth.<ref name=Port/><ref name=GSI/>
From the time Holland, named the rock as Charnockite, its characteristics have been extensively studied by several researches in [[Earth Science]]s over the [[century]]. An analysis of three charnockites in the region, extending from St. Thomas Mount – [[Pallavaram]] –[[Tambaram]], south of the city of Chennai, carried out on the compositional characteristics of coexisting [[orthopyroxene]], [[garnet]] and [[biotite]] has established several [[petrographic]] varieties within the charnockites–[[enderbite]]s such as the [[granulite]]s and [[gneisses]] corresponding to [[adamellite]], [[monzonite]], granite and others.<ref>{{cite journal|title= Phase relations in three charnockites from Pallavaram-Tambaram|author=S. K. Sen|author2=J. R. Sahu |date =2004-12-10|doi=10.1007/BF00385780|bibcode=1970CoMP...27..239S|volume=27|issue= 3|journal=Contributions to Mineralogy and Petrology|pages=239–243|s2cid=129633348}}</ref>
Another study on the general characteristics of the rocks of this series has recorded that the rocks are in general bluish gray or darkish in colour and extremely fresh in appearance with an even grained granular structure. The mineral composition shows an unvarying presence of [[pleochroic]] [[rhombus|rhombic]] [[pyroxene]]. The other femic minerals noted are [[augite]] and [[hornblende]] with minute grains of opaque [[iron ore]]s and these minerals have been noted to cluster together. Plagioclase [[feldspars]], [[alkali]] [[feldspars]] and quartz are the [[sialic]] minerals present in this series of rocks.<ref>{{cite web|url=http://www.ias.ac.in/jarch/proca/26/00000258.pdf |title=studies in Charnockites from St. Thomas Mount, Madras, Part II|access-date=2009-02-03|author= Rajagopalan|publisher= Geology Department, Andhra University|date=1947-02-14}}</ref>
[[File:Chranockite exposure at Pallavaram quarry.JPG|thumb|right|200px|Charnockite rock quarry at Pallavaram]]
In order to determine the geological age of the charnockitic region of the Pallavaram area in the Madras (Chennai) Block, [[palaeomagnetic]] investigations were carried out at 12 sites, which suggested an age of magnetization in the Pallavaram charnockites as 2600 [[Mya (unit)|Ma]] while in the St. Thomas Mount the period of emplacement was assessed as 1650 [[Mya (unit)|Ma]] ([[Mesoproterozoic]]). There was a further inference that the Madras block granulites indicated [[crust (geology)|crust]]al evolution similar to those in the [[Eastern Ghats]] belt with identical palaeopoles from both the areas. The study also noted that "pressure, temperature and the chemical potential of water were constant for assemblages separated by large distances."<ref>{{cite journal|title= A palaeomagnetic study of charnockites from Madras Block, Southern Granulite Terrain|author=V.S. Poornachandra Rao|author2=J. Mallikharjuna Rao|date=2005-04-11|doi=10.1016/j.gr.2005.11.015|volume=10|issue= 1–2|journal=Gondwana Research|pages=57–65|bibcode=2006GondR..10...57P}}</ref>

===Trivia===
[[File:Oscar wilde in dublin.jpg|thumb|left|200px|Statue of [[Oscar Wilde]] in different types of rocks and minerals including Charnockite from [[India]] which forms the shoes and the socks]]
An interesting [[Oscar Wilde]] memorial monument erected in the year 2000 on the centenary of his death, seen in [[Merrion Square]], [[Dublin]], [[Ireland]] opposite to his childhood house, is reclining on a 35-ton boulder of quartz from the [[Wicklow Mountains]], [[Ireland]]. The statue (pictured) is splendidly sculpted out of semi–precious stones with [[blue]] [[pearl]]granite trousers ([[Larvikite]] known as blue granite from the western shores of [[Oslo Fjord]] in [[Norway]], [[jacket]] of [[Nephrite]] [[jade]] [originally a {{convert|980|kg|lb}} block from the [[Yukon]]], Canada, the red [[cuff]]s and [[collar (clothing)|collar]] made of [[Thulite]] from [[Norway]], [[shoes]] and [[socks]] made of black charnockite [[granite]] from [[India]] and holding a [[green]] [[carnation]] to his breast.<ref>{{cite book|url=https://books.google.com/books?id=TCuErjM2hM8C&q=Statue+of+Oscar+Wilde+at+Merrion+square,+Dublin&pg=PA64|title= Dublin Handbook|access-date=2009-03-17|author=Sean Sheehan|author2=Patricia Levy|publisher=Footprint Travel Guides|page=64|isbn=978-1-900949-98-9 |year=2001}}</ref><ref>{{cite web|url=http://www.literarytraveler.com/ireland_tours/ireland_tours_oscar.aspx|title=Ireland Tours - Oscar Wilde in Dublin: "Townspeople commonly allude to the statue of Oscar Wilde as "The Queer with the Leer"|access-date=2009-03-17|url-status=dead|archive-url=https://web.archive.org/web/20080513135635/http://www.literarytraveler.com/ireland_tours/ireland_tours_oscar.aspx|archive-date=2008-05-13}}</ref><ref>{{cite web|url=https://www.flickr.com/photos/xandershaw/2656429976/page2/|title= Statue of Oscar Wilde|access-date= 2008-02-28|author=Danny Osbourne}}</ref><ref>{{cite journal|title = The Oscar Wilde sculpture|author= Chris Stillman|date=2001-12-24|pages= 72–75|doi=10.1046/j.1365-2451.1999.1502008.x|volume=15|issue = 2|journal=Geology Today}}</ref>

==Access==
{{Further|Chennai}}{{Further|St.Thomas Mount}}
The charnockite rocks at St. Thomas Mount (about {{convert|60|m|ft|abbr=on|1}} high above ground) is located in the southern part of Chennai city. Chennai, as the capital of Tamil Nadu, is very well connected by [[road]], [[Rail transport|rail]], [[sea]] and [[air]] with rest of the country and the world. The Chennai International Airport is {{convert|3|km|mi|abbr=on|1}} away from the Mount. Within the city, it is in the neighborhood of [[Guindy]], {{convert|9.7|mi|km|abbr=on|1}} from Fort St. George, {{convert|4|mi|km|abbr=on|1}} from South west of Santhome-de-Meliyapore (burial ground of St. Thomas), and close to the flying range. Chennai Suburban Railway South line has a railway station at St. Thomas, {{convert|18|km|mi|abbr=on|1}} from starting point.<ref name= GSI/><ref>{{cite web|url=http://www.stthoma.com/archae_littlemount.html |title=Archeology, Little mount |access-date=2009-02-02 |publisher=St. Thoma.com |archive-url=https://web.archive.org/web/20080822064126/http://www.stthoma.com/archae_littlemount.html |archive-date=2008-08-22 |url-status=dead }}</ref>

==Gallery==
<gallery>
File:Charnockite dykes Jibbeheia.JPG|Typical Charnockite dykes
File:Plaque on Baptismal Font at Mary's Church at Fort st. George.JPG|Plaque behind the Baptismal Font in St. Mary's Church in Chennai gives history of the Font and Job Charnock
File:Charnockite exposure below the St. Thomas Hill.JPG|Rock quarry at [[St Thomas Mount]]
File:Charnockite exposure in St. Thomas Mount.JPG|A Closer view of Charnockite from St. Thomas Mount
</gallery>

==See also==
* [[St. Thomas Mount]]
* [[Charnockite]]s
* [[Job Charnock]]

==References==
{{commons category}}
{{reflist}}

[[Category:Geology of India]]
[[Category:Kanchipuram district]]
[[Category:National Geological Monuments in India]]

Charnockite, St. Thomas Mount - Revision history

>BrownHairedGirl: remove navbox {{Tamil Nadu}}, which doesn't link here