Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica
Sixty-three internally consistent geothermobarometers for mineral equilibria involving sapphirine (2:2:1 and 7:9:3), pyrope, cordierite, enstatite, Mg-tschermak orthopyroxene, quartz, spinel and sillimanite have been calibrated in the MAS system. The updated thermodynamic data of these minerals are...
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Indian Academy of Sciences
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ftindianacasci:oai:repository.ias.ac.in:18752 2023-05-15T13:22:48+02:00 Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica Lal, R. K. 1997-09 application/pdf http://repository.ias.ac.in/18752/ http://repository.ias.ac.in/18752/1/314.pdf http://www.ias.ac.in/j_archive/epsci/106/2/91-113/viewpage.html unknown Indian Academy of Sciences http://repository.ias.ac.in/18752/1/314.pdf Lal, R. K. (1997) Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al2O3-SiO2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica Proceedings of the Indian Academy of Sciences - Earth and Planetary Sciences, 106 (3). pp. 91-113. ISSN 0253-4126 QE Geology Article PeerReviewed 1997 ftindianacasci 2013-01-20T10:17:11Z Sixty-three internally consistent geothermobarometers for mineral equilibria involving sapphirine (2:2:1 and 7:9:3), pyrope, cordierite, enstatite, Mg-tschermak orthopyroxene, quartz, spinel and sillimanite have been calibrated in the MAS system. The updated thermodynamic data of these minerals are consistent, within limits of error, with highP-T experiments on several mineral equilibria and calorimetric data. TheP-T conditions of the granulite facies metamorphism, spanning a range of 700 to more than 1000°C and 4 to more than 10 kbar, can be estimated simultaneously from these geothermobarometers andP-T-t trajectories can be deduced from the reaction coronas well preserved in these rocks because of the refractory nature of aluminous phases. The geothermobarometers have been applied to sapphirine-spinel granulites of Eastern Ghats and Enderby Land. TheP-T conditions of metamorphism (a-prograde/thermal peak and b-retrograde isothermal/isobaric decompression/cooling) estimated for these granulites are: (1) Eastern Ghats (Visakhapatnam): Paderu- (a) 900°C/8.3kbar, (b-1) 900°C/6.8kbar and (b-2) 740°C/5.4 kbar; Anantgiri- (a) prograde anticlockwise 930°C/6.2 kbar and (b) 870°C/6.8 kbar, 820°C/6.1 kbar; Anakapalle- (b) 845°C/8.5-6.2 kbar; and Araku- (b) 840°C/6.2 kbar to 795°C/5.9 kbar. Enderby Land (Napier complex): Spot height 945, Tula Mts.- (a) 970°C/9.1 ± 0.6 kbar, isobaric cooling (b) 885°C/ 7.75 kbar, isothermal decompression (b) 880°C/6.85 kbar; Mt. Hardy, Tula Mts.- (b) 885°C/6.75 kbar; Mt. Riiser-Larsen, Amundsen bay- (a) 1000°C/7.0 kbar prograde anticlockwise; Mt. Sones- (b) 920°C/ 6.8 kbar; Forefinger Point, SW Enderby Land- (b) 840°C/6.7 kbar, 810°C/6.5 kbar and 775°C/5.0 kbar. The estimatedP-T andP-T-t are mostly consistent with those inferred from the granulites of these areas. Article in Journal/Newspaper Amundsen Bay Antarc* Antarctica Enderby Land Indian Academy of Sciences: Publication of Fellows Amundsen Bay ENVELOPE(50.000,50.000,-66.917,-66.917) Forefinger Point ENVELOPE(48.067,48.067,-67.617,-67.617) Napier ENVELOPE(-58.440,-58.440,-62.167,-62.167) Riiser-Larsen ENVELOPE(50.667,50.667,-66.783,-66.783) Tula ENVELOPE(-65.650,-65.650,-65.517,-65.517) |
institution |
Open Polar |
collection |
Indian Academy of Sciences: Publication of Fellows |
op_collection_id |
ftindianacasci |
language |
unknown |
topic |
QE Geology |
spellingShingle |
QE Geology Lal, R. K. Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
topic_facet |
QE Geology |
description |
Sixty-three internally consistent geothermobarometers for mineral equilibria involving sapphirine (2:2:1 and 7:9:3), pyrope, cordierite, enstatite, Mg-tschermak orthopyroxene, quartz, spinel and sillimanite have been calibrated in the MAS system. The updated thermodynamic data of these minerals are consistent, within limits of error, with highP-T experiments on several mineral equilibria and calorimetric data. TheP-T conditions of the granulite facies metamorphism, spanning a range of 700 to more than 1000°C and 4 to more than 10 kbar, can be estimated simultaneously from these geothermobarometers andP-T-t trajectories can be deduced from the reaction coronas well preserved in these rocks because of the refractory nature of aluminous phases. The geothermobarometers have been applied to sapphirine-spinel granulites of Eastern Ghats and Enderby Land. TheP-T conditions of metamorphism (a-prograde/thermal peak and b-retrograde isothermal/isobaric decompression/cooling) estimated for these granulites are: (1) Eastern Ghats (Visakhapatnam): Paderu- (a) 900°C/8.3kbar, (b-1) 900°C/6.8kbar and (b-2) 740°C/5.4 kbar; Anantgiri- (a) prograde anticlockwise 930°C/6.2 kbar and (b) 870°C/6.8 kbar, 820°C/6.1 kbar; Anakapalle- (b) 845°C/8.5-6.2 kbar; and Araku- (b) 840°C/6.2 kbar to 795°C/5.9 kbar. Enderby Land (Napier complex): Spot height 945, Tula Mts.- (a) 970°C/9.1 ± 0.6 kbar, isobaric cooling (b) 885°C/ 7.75 kbar, isothermal decompression (b) 880°C/6.85 kbar; Mt. Hardy, Tula Mts.- (b) 885°C/6.75 kbar; Mt. Riiser-Larsen, Amundsen bay- (a) 1000°C/7.0 kbar prograde anticlockwise; Mt. Sones- (b) 920°C/ 6.8 kbar; Forefinger Point, SW Enderby Land- (b) 840°C/6.7 kbar, 810°C/6.5 kbar and 775°C/5.0 kbar. The estimatedP-T andP-T-t are mostly consistent with those inferred from the granulites of these areas. |
format |
Article in Journal/Newspaper |
author |
Lal, R. K. |
author_facet |
Lal, R. K. |
author_sort |
Lal, R. K. |
title |
Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
title_short |
Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
title_full |
Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
title_fullStr |
Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
title_full_unstemmed |
Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al 2 O 3 -SiO 2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica |
title_sort |
internally consistent calibrations for geothermobarometry of high-grade mg-al rich rocks in the system mgo-al 2 o 3 -sio 2 and their application to sapphirine-spinel granulites of eastern ghats, india and enderby land, antarctica |
publisher |
Indian Academy of Sciences |
publishDate |
1997 |
url |
http://repository.ias.ac.in/18752/ http://repository.ias.ac.in/18752/1/314.pdf http://www.ias.ac.in/j_archive/epsci/106/2/91-113/viewpage.html |
long_lat |
ENVELOPE(50.000,50.000,-66.917,-66.917) ENVELOPE(48.067,48.067,-67.617,-67.617) ENVELOPE(-58.440,-58.440,-62.167,-62.167) ENVELOPE(50.667,50.667,-66.783,-66.783) ENVELOPE(-65.650,-65.650,-65.517,-65.517) |
geographic |
Amundsen Bay Forefinger Point Napier Riiser-Larsen Tula |
geographic_facet |
Amundsen Bay Forefinger Point Napier Riiser-Larsen Tula |
genre |
Amundsen Bay Antarc* Antarctica Enderby Land |
genre_facet |
Amundsen Bay Antarc* Antarctica Enderby Land |
op_relation |
http://repository.ias.ac.in/18752/1/314.pdf Lal, R. K. (1997) Internally consistent calibrations for geothermobarometry of high-grade Mg-Al rich rocks in the system MgO-Al2O3-SiO2 and their application to sapphirine-spinel granulites of Eastern Ghats, India and Enderby Land, Antarctica Proceedings of the Indian Academy of Sciences - Earth and Planetary Sciences, 106 (3). pp. 91-113. ISSN 0253-4126 |
_version_ |
1766367024377757696 |