Revealing the link between A-type granites and hottest melts from residual metasedimentary crust
Among S-, I-, and A-type granites, the latter are the most debated in terms of origin, and metasedimentary crust is usually discarded as a potential source. Here we tackle this issue by adopting an in-source perspective, rather than focusing on the final product (granite), documenting the occurrence...
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Online Access: | https://hdl.handle.net/11391/1567423 https://doi.org/10.1130/G51097.1 |
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ftuniperugiairis:oai:research.unipg.it:11391/1567423 2024-04-14T08:03:02+00:00 Revealing the link between A-type granites and hottest melts from residual metasedimentary crust Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. 2023 https://hdl.handle.net/11391/1567423 https://doi.org/10.1130/G51097.1 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:001091244000009 volume:51 issue:9 firstpage:845 lastpage:849 numberofpages:5 journal:GEOLOGY https://hdl.handle.net/11391/1567423 doi:10.1130/G51097.1 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85168083147 info:eu-repo/semantics/article 2023 ftuniperugiairis https://doi.org/10.1130/G51097.1 2024-03-21T15:42:29Z Among S-, I-, and A-type granites, the latter are the most debated in terms of origin, and metasedimentary crust is usually discarded as a potential source. Here we tackle this issue by adopting an in-source perspective, rather than focusing on the final product (granite), documenting the occurrence of pristine melt inclusions (MIs) in garnet from residual metapelitic ultrahightemperature (UHT) granulite from East Antarctica. Coexistence of sapphirine + quartz, phase equilibria calculations, and Zr-in-rutile thermometry indicate that MIs trapped UHT melts formed at peak conditions (930-1000 degrees C) from a residual metapelitic source. MIs are granitic with weakly peraluminous to weakly peralkaline affinity, ferroan character, high alkali contents, high K/Na and Ga/Al, and low Ca, Ba, Sr, and H2O concentrations. These features and geochemical modeling indicate that MIs represent primary melts for high-SiO2 A-type granites. Therefore, MIs reveal the missing link between A-type granites and the hottest metasedimentary crust. Voluminous amounts of slightly peraluminous, high-SiO2 A-type granites can be produced in large, residual UHT terranes such as those of eastern Gondwana. Our results provide a wider view of processes responsible for granite formation and show that a larger variety of granites must be considered in models of the effects of UHT anatexis on crustal differentiation. Article in Journal/Newspaper Antarc* Antarctica East Antarctica IRIS Università degli Studi di Perugia East Antarctica Geology 51 9 845 849 |
institution |
Open Polar |
collection |
IRIS Università degli Studi di Perugia |
op_collection_id |
ftuniperugiairis |
language |
English |
description |
Among S-, I-, and A-type granites, the latter are the most debated in terms of origin, and metasedimentary crust is usually discarded as a potential source. Here we tackle this issue by adopting an in-source perspective, rather than focusing on the final product (granite), documenting the occurrence of pristine melt inclusions (MIs) in garnet from residual metapelitic ultrahightemperature (UHT) granulite from East Antarctica. Coexistence of sapphirine + quartz, phase equilibria calculations, and Zr-in-rutile thermometry indicate that MIs trapped UHT melts formed at peak conditions (930-1000 degrees C) from a residual metapelitic source. MIs are granitic with weakly peraluminous to weakly peralkaline affinity, ferroan character, high alkali contents, high K/Na and Ga/Al, and low Ca, Ba, Sr, and H2O concentrations. These features and geochemical modeling indicate that MIs represent primary melts for high-SiO2 A-type granites. Therefore, MIs reveal the missing link between A-type granites and the hottest metasedimentary crust. Voluminous amounts of slightly peraluminous, high-SiO2 A-type granites can be produced in large, residual UHT terranes such as those of eastern Gondwana. Our results provide a wider view of processes responsible for granite formation and show that a larger variety of granites must be considered in models of the effects of UHT anatexis on crustal differentiation. |
author2 |
Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. |
format |
Article in Journal/Newspaper |
author |
Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. |
spellingShingle |
Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
author_facet |
Carvalho, B. B. Bartoli, O. Cesare, B. Satish-Kumar, M. Petrelli, M. Kawakami, T. Hokada, T. Gilio, M. |
author_sort |
Carvalho, B. B. |
title |
Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
title_short |
Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
title_full |
Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
title_fullStr |
Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
title_full_unstemmed |
Revealing the link between A-type granites and hottest melts from residual metasedimentary crust |
title_sort |
revealing the link between a-type granites and hottest melts from residual metasedimentary crust |
publishDate |
2023 |
url |
https://hdl.handle.net/11391/1567423 https://doi.org/10.1130/G51097.1 |
geographic |
East Antarctica |
geographic_facet |
East Antarctica |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:001091244000009 volume:51 issue:9 firstpage:845 lastpage:849 numberofpages:5 journal:GEOLOGY https://hdl.handle.net/11391/1567423 doi:10.1130/G51097.1 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85168083147 |
op_doi |
https://doi.org/10.1130/G51097.1 |
container_title |
Geology |
container_volume |
51 |
container_issue |
9 |
container_start_page |
845 |
op_container_end_page |
849 |
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1796297865575792640 |