Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/220267 |
Resumo: | Mineralogical evolution of ophiolites is significant to understand paleo-oceanic crust and mantle requiring multi-proxy techniques to identify steps in the processes. We studied the Bossoroca ophiolite from the southern Brasiliano Orogen, a prime example of Tonian accretion to an oceanic island arc. Integration of field geology, aeromagnetometry, aerogamaspectrometry, electron microprobe analyses, and compositional maps of minerals led to the decoding of oceanic and continental processes. The ophiolite is highly magnetic and low-K and is positioned at the base of the superstructure. We studied amphibolite, tourmalinite, and chromite-talc-magnesite granofels from the ophiolite, Capivaras diorite from the Cambaí Complex infrastructure and one metavolcanoclastic rock from the Vacacaí Group superstructure. Honblende is zoned in all rock types. Low-Ti hornblende is compatible with medium-pressure metamorphism at 7 kbar. This M1 to M2 amphibolite facies resulted in the widespread association of olivine + talc in metaserpentinite. Dravite is similar to tourmaline from the Ibaré ophiolite. Andesine and oligoclase are dominant and albite minor. Cr-spinel in granofels recrystallized in greenschist facies; host rock originated by carbonatization of serpentinite formed in the oceanic crust along with chloritite and tourmalinite. Serpentinite rare earth elements (REE) suggest origin in depleted mantle peridotite. The ophiolite evolved in the Adamastor Ocean until incorporation into the island arc. |
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Massuda, Amanda JulianoHartmann, Léo AfraneoQueiroga, Gláucia NascimentoCastro, Marco Paulo deLeandro, Carolina GonçalvesSavian, Jairo Francisco2021-04-27T04:34:17Z20202317-4889http://hdl.handle.net/10183/220267001123516Mineralogical evolution of ophiolites is significant to understand paleo-oceanic crust and mantle requiring multi-proxy techniques to identify steps in the processes. We studied the Bossoroca ophiolite from the southern Brasiliano Orogen, a prime example of Tonian accretion to an oceanic island arc. Integration of field geology, aeromagnetometry, aerogamaspectrometry, electron microprobe analyses, and compositional maps of minerals led to the decoding of oceanic and continental processes. The ophiolite is highly magnetic and low-K and is positioned at the base of the superstructure. We studied amphibolite, tourmalinite, and chromite-talc-magnesite granofels from the ophiolite, Capivaras diorite from the Cambaí Complex infrastructure and one metavolcanoclastic rock from the Vacacaí Group superstructure. Honblende is zoned in all rock types. Low-Ti hornblende is compatible with medium-pressure metamorphism at 7 kbar. This M1 to M2 amphibolite facies resulted in the widespread association of olivine + talc in metaserpentinite. Dravite is similar to tourmaline from the Ibaré ophiolite. Andesine and oligoclase are dominant and albite minor. Cr-spinel in granofels recrystallized in greenschist facies; host rock originated by carbonatization of serpentinite formed in the oceanic crust along with chloritite and tourmalinite. Serpentinite rare earth elements (REE) suggest origin in depleted mantle peridotite. The ophiolite evolved in the Adamastor Ocean until incorporation into the island arc.application/pdfengBrazilian Journal of Geology. Sao Paulo, SP: Sociedade Brasileira de Geologia. Vol. 50, n. 4, (Nov. 2020), e20190120Geologia de campoAeromagnetometriaAerogamaespectrometriaSão Gabriel (RS)Chromite-talc-magnesite granofelsTourmaliniteMetasomatismAerogeophysicsMineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terraneinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/otherinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001123516.pdf.txt001123516.pdf.txtExtracted Texttext/plain0http://www.lume.ufrgs.br/bitstream/10183/220267/2/001123516.pdf.txtd41d8cd98f00b204e9800998ecf8427eMD52ORIGINAL001123516.pdfTexto completo (inglês)application/pdf14451782http://www.lume.ufrgs.br/bitstream/10183/220267/1/001123516.pdf4fa3ebdd9e38692d62053f5d16868a06MD5110183/2202672021-11-20 06:09:17.534284oai:www.lume.ufrgs.br:10183/220267Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2021-11-20T08:09:17Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
title |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
spellingShingle |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane Massuda, Amanda Juliano Geologia de campo Aeromagnetometria Aerogamaespectrometria São Gabriel (RS) Chromite-talc-magnesite granofels Tourmalinite Metasomatism Aerogeophysics |
title_short |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
title_full |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
title_fullStr |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
title_full_unstemmed |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
title_sort |
Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane |
author |
Massuda, Amanda Juliano |
author_facet |
Massuda, Amanda Juliano Hartmann, Léo Afraneo Queiroga, Gláucia Nascimento Castro, Marco Paulo de Leandro, Carolina Gonçalves Savian, Jairo Francisco |
author_role |
author |
author2 |
Hartmann, Léo Afraneo Queiroga, Gláucia Nascimento Castro, Marco Paulo de Leandro, Carolina Gonçalves Savian, Jairo Francisco |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Massuda, Amanda Juliano Hartmann, Léo Afraneo Queiroga, Gláucia Nascimento Castro, Marco Paulo de Leandro, Carolina Gonçalves Savian, Jairo Francisco |
dc.subject.por.fl_str_mv |
Geologia de campo Aeromagnetometria Aerogamaespectrometria São Gabriel (RS) |
topic |
Geologia de campo Aeromagnetometria Aerogamaespectrometria São Gabriel (RS) Chromite-talc-magnesite granofels Tourmalinite Metasomatism Aerogeophysics |
dc.subject.eng.fl_str_mv |
Chromite-talc-magnesite granofels Tourmalinite Metasomatism Aerogeophysics |
description |
Mineralogical evolution of ophiolites is significant to understand paleo-oceanic crust and mantle requiring multi-proxy techniques to identify steps in the processes. We studied the Bossoroca ophiolite from the southern Brasiliano Orogen, a prime example of Tonian accretion to an oceanic island arc. Integration of field geology, aeromagnetometry, aerogamaspectrometry, electron microprobe analyses, and compositional maps of minerals led to the decoding of oceanic and continental processes. The ophiolite is highly magnetic and low-K and is positioned at the base of the superstructure. We studied amphibolite, tourmalinite, and chromite-talc-magnesite granofels from the ophiolite, Capivaras diorite from the Cambaí Complex infrastructure and one metavolcanoclastic rock from the Vacacaí Group superstructure. Honblende is zoned in all rock types. Low-Ti hornblende is compatible with medium-pressure metamorphism at 7 kbar. This M1 to M2 amphibolite facies resulted in the widespread association of olivine + talc in metaserpentinite. Dravite is similar to tourmaline from the Ibaré ophiolite. Andesine and oligoclase are dominant and albite minor. Cr-spinel in granofels recrystallized in greenschist facies; host rock originated by carbonatization of serpentinite formed in the oceanic crust along with chloritite and tourmalinite. Serpentinite rare earth elements (REE) suggest origin in depleted mantle peridotite. The ophiolite evolved in the Adamastor Ocean until incorporation into the island arc. |
publishDate |
2020 |
dc.date.issued.fl_str_mv |
2020 |
dc.date.accessioned.fl_str_mv |
2021-04-27T04:34:17Z |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/other |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/220267 |
dc.identifier.issn.pt_BR.fl_str_mv |
2317-4889 |
dc.identifier.nrb.pt_BR.fl_str_mv |
001123516 |
identifier_str_mv |
2317-4889 001123516 |
url |
http://hdl.handle.net/10183/220267 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Brazilian Journal of Geology. Sao Paulo, SP: Sociedade Brasileira de Geologia. Vol. 50, n. 4, (Nov. 2020), e20190120 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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