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: | Brazilian Journal of Geology |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000400307 |
Resumo: | Abstract 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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Brazilian Journal of Geology |
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Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terraneBossoroca ophiolitechromite-talc-magnesite granofelstourmalinitemetasomatismaerogeophysicsAbstract 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.Sociedade Brasileira de Geologia2020-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000400307Brazilian Journal of Geology v.50 n.4 2020reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-4889202020190120info:eu-repo/semantics/openAccessMassuda,Amanda JulianoHartmann,Léo AfraneoQueiroga,Gláucia NascimentoCastro,Marco Paulo deLeandro,Carolina GonçalvesSavian,Jairo Franciscoeng2020-11-05T00:00:00Zoai:scielo:S2317-48892020000400307Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2020-11-05T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false |
dc.title.none.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 Bossoroca ophiolite 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 |
Bossoroca ophiolite chromite-talc-magnesite granofels tourmalinite metasomatism aerogeophysics |
topic |
Bossoroca ophiolite chromite-talc-magnesite granofels tourmalinite metasomatism aerogeophysics |
description |
Abstract 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.none.fl_str_mv |
2020-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000400307 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000400307 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2317-4889202020190120 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
dc.source.none.fl_str_mv |
Brazilian Journal of Geology v.50 n.4 2020 reponame:Brazilian Journal of Geology instname:Sociedade Brasileira de Geologia (SBGEO) instacron:SBGEO |
instname_str |
Sociedade Brasileira de Geologia (SBGEO) |
instacron_str |
SBGEO |
institution |
SBGEO |
reponame_str |
Brazilian Journal of Geology |
collection |
Brazilian Journal of Geology |
repository.name.fl_str_mv |
Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO) |
repository.mail.fl_str_mv |
sbgsede@sbgeo.org.br||claudio.riccomini@gmail.com |
_version_ |
1752122399406424064 |