Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path
Calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica, exhibit a sequence of reaction textures that have been used to elucidate their retrograde P–T path. The highest temperature recorded in the calc‐silicates is represented by the wollastonite‐ and scapolite‐bearing assembl...
Published in: | Journal of Metamorphic Geology |
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crwiley:10.1111/j.1525-1314.1991.tb00524.x 2023-12-03T10:12:54+01:00 Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path MOTOYOSHI, Y. THOST, D. E. HENSEN, B. J. 1991 http://dx.doi.org/10.1111/j.1525-1314.1991.tb00524.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1991.tb00524.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1991.tb00524.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Metamorphic Geology volume 9, issue 3, page 293-300 ISSN 0263-4929 1525-1314 Geochemistry and Petrology Geology journal-article 1991 crwiley https://doi.org/10.1111/j.1525-1314.1991.tb00524.x 2023-11-09T13:46:29Z Calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica, exhibit a sequence of reaction textures that have been used to elucidate their retrograde P–T path. The highest temperature recorded in the calc‐silicates is represented by the wollastonite‐ and scapolite‐bearing assemblages which yield at least 760°C at 6 kbar based on experimental results. The calc‐silicates have partially re‐equilibrated at lower temperatures (down to 450°C) as evidenced by the successive reactions: (1) wollastonite + scapolite + calcite = garnet + CO 2 , (2) wollastonite + CO 2 = calcite + quartz, (3) wollastonite + plagioclase = garnet + quartz, (4) scapolite = plagioclase + calcite + quartz, (5) garnet + CO 2 + H 2 O = epidote + calcite + quartz, and (6) clinopyroxene + CO 2 + H 2 O = tremolite + calcite + quartz. The reaction sequence observed indicates that a CO 2 was relatively low in the wollastonite‐bearing rocks during peak metamorphic conditions, and may have been further lowered by local infiltration of H 2 O from the surrounding migmatitic gneisses on cooling. Fluid activities in the Bolingen calc‐silicates were probably locally variable during the granulite facies metamorphism, and large‐scale CO 2 advection did not occur. A retrograde P–T path, from the sillimanite stability field ( c. 760°C at 6 kbar) into the andalusite stability field ( c. 450°C at <3 kbar), is suggested by the occurrence of secondary andalusite in an adjacent cordierite–sillimanite gneiss in which sillimanite occurs as inclusions in cordierite. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Prydz Bay Wiley Online Library (via Crossref) East Antarctica Prydz Bay Bolingen Islands ENVELOPE(75.696,75.696,-69.532,-69.532) Journal of Metamorphic Geology 9 3 293 300 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Geochemistry and Petrology Geology |
spellingShingle |
Geochemistry and Petrology Geology MOTOYOSHI, Y. THOST, D. E. HENSEN, B. J. Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
topic_facet |
Geochemistry and Petrology Geology |
description |
Calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica, exhibit a sequence of reaction textures that have been used to elucidate their retrograde P–T path. The highest temperature recorded in the calc‐silicates is represented by the wollastonite‐ and scapolite‐bearing assemblages which yield at least 760°C at 6 kbar based on experimental results. The calc‐silicates have partially re‐equilibrated at lower temperatures (down to 450°C) as evidenced by the successive reactions: (1) wollastonite + scapolite + calcite = garnet + CO 2 , (2) wollastonite + CO 2 = calcite + quartz, (3) wollastonite + plagioclase = garnet + quartz, (4) scapolite = plagioclase + calcite + quartz, (5) garnet + CO 2 + H 2 O = epidote + calcite + quartz, and (6) clinopyroxene + CO 2 + H 2 O = tremolite + calcite + quartz. The reaction sequence observed indicates that a CO 2 was relatively low in the wollastonite‐bearing rocks during peak metamorphic conditions, and may have been further lowered by local infiltration of H 2 O from the surrounding migmatitic gneisses on cooling. Fluid activities in the Bolingen calc‐silicates were probably locally variable during the granulite facies metamorphism, and large‐scale CO 2 advection did not occur. A retrograde P–T path, from the sillimanite stability field ( c. 760°C at 6 kbar) into the andalusite stability field ( c. 450°C at <3 kbar), is suggested by the occurrence of secondary andalusite in an adjacent cordierite–sillimanite gneiss in which sillimanite occurs as inclusions in cordierite. |
format |
Article in Journal/Newspaper |
author |
MOTOYOSHI, Y. THOST, D. E. HENSEN, B. J. |
author_facet |
MOTOYOSHI, Y. THOST, D. E. HENSEN, B. J. |
author_sort |
MOTOYOSHI, Y. |
title |
Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
title_short |
Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
title_full |
Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
title_fullStr |
Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
title_full_unstemmed |
Reaction textures in calc‐silicate granulites from the Bolingen Islands, Prydz Bay, East Antarctica: implications for the retrograde P–T path |
title_sort |
reaction textures in calc‐silicate granulites from the bolingen islands, prydz bay, east antarctica: implications for the retrograde p–t path |
publisher |
Wiley |
publishDate |
1991 |
url |
http://dx.doi.org/10.1111/j.1525-1314.1991.tb00524.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1991.tb00524.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1991.tb00524.x |
long_lat |
ENVELOPE(75.696,75.696,-69.532,-69.532) |
geographic |
East Antarctica Prydz Bay Bolingen Islands |
geographic_facet |
East Antarctica Prydz Bay Bolingen Islands |
genre |
Antarc* Antarctica East Antarctica Prydz Bay |
genre_facet |
Antarc* Antarctica East Antarctica Prydz Bay |
op_source |
Journal of Metamorphic Geology volume 9, issue 3, page 293-300 ISSN 0263-4929 1525-1314 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1525-1314.1991.tb00524.x |
container_title |
Journal of Metamorphic Geology |
container_volume |
9 |
container_issue |
3 |
container_start_page |
293 |
op_container_end_page |
300 |
_version_ |
1784259533771636736 |