Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica
In this paper, we compare the petrological histories of the Kemp Land Coast (east Antarctica), and Gokavaram area (Eastern Ghats), that were supposed to have been juxtaposed. The area around Gokavaram is dominated by different varieties of paragneisses (pelitic, quartzofeldspathic, and calcareous co...
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ftindianacasci:oai:repository.ias.ac.in:67390 2023-05-15T13:46:14+02:00 Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato 1999-04 http://repository.ias.ac.in/67390/ http://www.sciencedirect.com/science/article/pii/S1342937X05701477 unknown Elsevier Science Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato (1999) Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica Gondwana Research, 2 (2). pp. 227-236. ISSN 1342-937X QE Geology Article PeerReviewed 1999 ftindianacasci 2013-01-20T12:34:17Z In this paper, we compare the petrological histories of the Kemp Land Coast (east Antarctica), and Gokavaram area (Eastern Ghats), that were supposed to have been juxtaposed. The area around Gokavaram is dominated by different varieties of paragneisses (pelitic, quartzofeldspathic, and calcareous composition) with relatively minor amounts of orthogneisses (mafic, enderbitic, and granitic composition). The rocks were involved in three major phases of deformation, and were finally affected by localised shear movement. On the basis of reaction textures, well preserved in high Mg-Al granulites, and calc-silicate granulites, and geothermobarometric data we deduce a polymetamorphic evolution of the rocks. Following an early M 1 metamorphism culminating at 9.2-9.4 kbar, > 950 °C, the rocks cooled nearly isobarically down to 850 °C. During a subsequent M 2 metamorphism, near isothermal decompression to 5-6 kbar occurred. This was followed by near isobaric cooling down to 600-650 °C. M 3 is a weak amphibolite facies overprint, largely restricted to late shears, which involved hydration as well. Available radiometric data from this area can be interpreted in terms of partial resetting of U-Pb systematics in older sphenes due to M 3 metamorphism at ca. 550 Ma. Despite the absence of sufficient isotopic data on the Eastern Ghats granulites, we document a remarkable similarity in the petrological history of the two supposedly erstwhile neighbours. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Kemp Land Indian Academy of Sciences: Publication of Fellows East Antarctica Kemp Land ENVELOPE(57.500,57.500,-67.500,-67.500) |
institution |
Open Polar |
collection |
Indian Academy of Sciences: Publication of Fellows |
op_collection_id |
ftindianacasci |
language |
unknown |
topic |
QE Geology |
spellingShingle |
QE Geology Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
topic_facet |
QE Geology |
description |
In this paper, we compare the petrological histories of the Kemp Land Coast (east Antarctica), and Gokavaram area (Eastern Ghats), that were supposed to have been juxtaposed. The area around Gokavaram is dominated by different varieties of paragneisses (pelitic, quartzofeldspathic, and calcareous composition) with relatively minor amounts of orthogneisses (mafic, enderbitic, and granitic composition). The rocks were involved in three major phases of deformation, and were finally affected by localised shear movement. On the basis of reaction textures, well preserved in high Mg-Al granulites, and calc-silicate granulites, and geothermobarometric data we deduce a polymetamorphic evolution of the rocks. Following an early M 1 metamorphism culminating at 9.2-9.4 kbar, > 950 °C, the rocks cooled nearly isobarically down to 850 °C. During a subsequent M 2 metamorphism, near isothermal decompression to 5-6 kbar occurred. This was followed by near isobaric cooling down to 600-650 °C. M 3 is a weak amphibolite facies overprint, largely restricted to late shears, which involved hydration as well. Available radiometric data from this area can be interpreted in terms of partial resetting of U-Pb systematics in older sphenes due to M 3 metamorphism at ca. 550 Ma. Despite the absence of sufficient isotopic data on the Eastern Ghats granulites, we document a remarkable similarity in the petrological history of the two supposedly erstwhile neighbours. |
format |
Article in Journal/Newspaper |
author |
Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato |
author_facet |
Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato |
author_sort |
Dasgupta, Somnath |
title |
Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
title_short |
Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
title_full |
Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
title_fullStr |
Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
title_full_unstemmed |
Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica |
title_sort |
evidence of superposed metamorphism from the gokavaram area, eastern ghats belt, and its relation with the kemp land coast, east antarctica |
publisher |
Elsevier Science |
publishDate |
1999 |
url |
http://repository.ias.ac.in/67390/ http://www.sciencedirect.com/science/article/pii/S1342937X05701477 |
long_lat |
ENVELOPE(57.500,57.500,-67.500,-67.500) |
geographic |
East Antarctica Kemp Land |
geographic_facet |
East Antarctica Kemp Land |
genre |
Antarc* Antarctica East Antarctica Kemp Land |
genre_facet |
Antarc* Antarctica East Antarctica Kemp Land |
op_relation |
Dasgupta, Somnath Sengupta, Pulak Pal, Supratim Fukuoka, Masato (1999) Evidence of superposed metamorphism from the Gokavaram area, Eastern Ghats Belt, and its relation with the Kemp Land Coast, East Antarctica Gondwana Research, 2 (2). pp. 227-236. ISSN 1342-937X |
_version_ |
1766238738404343808 |