Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India
Integrated structural, petrological and geochronological study on a suite of granulites from the central part of the Eastern Ghats Belt (EGB), India unveils polyphase tectonothermal evolution. We document (a) M1 ultrahigh temperature (UHT) metamorphism (~1000°C at 6.5-8.5kbar) on an anticlockwise P-...
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ftindianacasci:oai:repository.ias.ac.in:76390 2023-05-15T13:32:12+02:00 Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath 2011-06 http://repository.ias.ac.in/76390/ http://onlinelibrary.wiley.com/doi/10.1002/gj.1246/abstract unknown John Wiley and Sons Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath (2011) Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India Geological Journal, 46 (2-3). pp. 217-239. ISSN 0072-1050 QE Geology Article PeerReviewed 2011 ftindianacasci 2013-01-20T12:58:32Z Integrated structural, petrological and geochronological study on a suite of granulites from the central part of the Eastern Ghats Belt (EGB), India unveils polyphase tectonothermal evolution. We document (a) M1 ultrahigh temperature (UHT) metamorphism (~1000°C at 6.5-8.5kbar) on an anticlockwise P-T trajectory simultaneously with early deformations D 1 -D 2 involving partial melting, (b) cooling down to ~ 800°C, 6 kbar that produced a variety of coronae/symplectites (M 1R ), (c) an unrelated compressional orogeny (D 3 ) that produced deep crustal shears and mylonitic foliation (S 3m ) at low angles to D 1 -D 2 structures and was associated with slight loading, and possible partial melt extraction under granulite facies condition (M 2 ~7 kbar, 850°C), and (d) localized retrogression (M 3 ) in the presence of melt accompanying D 4 deformation. This is the first record of the prograde P-T path of the superimposed granulite facies metamorphism in the EGB. U-Pb SHRIMP data of zircon preserves an inherited grain domain of ca. 1700Ma ( 207 Pb- 206 Pb age) that traces back the history of EGB with a lineage of the Mesoproterozoic supercontinent, Columbia. The UHT metamorphosed (peak M 1 at ca. 1000Ma) and subsequently cooled crustal segment (M1R) was subjected to strong tectonothermal reworking (M 2 ) along a clockwise P-T path at 953+6Ma (concordia age) that partially exhumed the rocks to mid-crustal levels. A later fluid-induced retrogressive event vis-à-vis melt crystallization occurred at ca. 900Ma ( 207 Pb- 206 Pb age). The post-peak evolution reveals striking similarities with those recorded in the rocks of the Rayner Complex of east Antarctica, thereby strengthening the notion of Indo-Antarctic correlation as part of Rodinia. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Indian Academy of Sciences: Publication of Fellows Antarctic East Antarctica Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
institution |
Open Polar |
collection |
Indian Academy of Sciences: Publication of Fellows |
op_collection_id |
ftindianacasci |
language |
unknown |
topic |
QE Geology |
spellingShingle |
QE Geology Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
topic_facet |
QE Geology |
description |
Integrated structural, petrological and geochronological study on a suite of granulites from the central part of the Eastern Ghats Belt (EGB), India unveils polyphase tectonothermal evolution. We document (a) M1 ultrahigh temperature (UHT) metamorphism (~1000°C at 6.5-8.5kbar) on an anticlockwise P-T trajectory simultaneously with early deformations D 1 -D 2 involving partial melting, (b) cooling down to ~ 800°C, 6 kbar that produced a variety of coronae/symplectites (M 1R ), (c) an unrelated compressional orogeny (D 3 ) that produced deep crustal shears and mylonitic foliation (S 3m ) at low angles to D 1 -D 2 structures and was associated with slight loading, and possible partial melt extraction under granulite facies condition (M 2 ~7 kbar, 850°C), and (d) localized retrogression (M 3 ) in the presence of melt accompanying D 4 deformation. This is the first record of the prograde P-T path of the superimposed granulite facies metamorphism in the EGB. U-Pb SHRIMP data of zircon preserves an inherited grain domain of ca. 1700Ma ( 207 Pb- 206 Pb age) that traces back the history of EGB with a lineage of the Mesoproterozoic supercontinent, Columbia. The UHT metamorphosed (peak M 1 at ca. 1000Ma) and subsequently cooled crustal segment (M1R) was subjected to strong tectonothermal reworking (M 2 ) along a clockwise P-T path at 953+6Ma (concordia age) that partially exhumed the rocks to mid-crustal levels. A later fluid-induced retrogressive event vis-à-vis melt crystallization occurred at ca. 900Ma ( 207 Pb- 206 Pb age). The post-peak evolution reveals striking similarities with those recorded in the rocks of the Rayner Complex of east Antarctica, thereby strengthening the notion of Indo-Antarctic correlation as part of Rodinia. |
format |
Article in Journal/Newspaper |
author |
Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath |
author_facet |
Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath |
author_sort |
Das, Kaushik |
title |
Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
title_short |
Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
title_full |
Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
title_fullStr |
Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
title_full_unstemmed |
Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India |
title_sort |
multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 ma (zircon u-pb shrimp) compressional reworking of uht aluminous granulites from the eastern ghats belt, india |
publisher |
John Wiley and Sons |
publishDate |
2011 |
url |
http://repository.ias.ac.in/76390/ http://onlinelibrary.wiley.com/doi/10.1002/gj.1246/abstract |
long_lat |
ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
geographic |
Antarctic East Antarctica Rayner |
geographic_facet |
Antarctic East Antarctica Rayner |
genre |
Antarc* Antarctic Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica |
op_relation |
Das, Kaushik Bose, Sankar Karmakar, Subrata Dunkley, Daniel J. Dasgupta, Somnath (2011) Multiple tectonometamorphic imprints in the lower crust: first evidence of ca. 950 Ma (zircon U-Pb SHRIMP) compressional reworking of UHT aluminous granulites from the Eastern Ghats Belt, India Geological Journal, 46 (2-3). pp. 217-239. ISSN 0072-1050 |
_version_ |
1766024954089832448 |