Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting
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=S2317-48892020000300300 |
Resumo: | Abstract Field, petrological and LA-ICP-MS U-Pb geochronological data of metavolcanic rocks were used to interpret the petrological processes and to propose the tectonic setting for the Mundo Novo greenstone belt (MNGB) in the eastern São Francisco Craton. The metavolcanic rocks studied are metakomatiite, eastern and western metabasalts, and metadacite with subordinate metarhyolite, which host ocean floor hydrothermal alteration zones and are covered by ocean floor lithological associations composed of chemical metasedimentary rocks. Fractional crystallization and heterogeneous intraoceanic contaminations explain the mineralogical differences between the two metabasalts and the high (La/Yb)N ratio values of metakomatiite and metadacite. The metakomatiite and the eastern and western metabasalts feature a vector from the MORB-OIB array to the volcanic arc array in the Nb/Yb-Th/Yb diagram, similar to the Archean intraoceanic arc-basin systems. The geochemical pattern of the eastern and western metabasalts in the Zr-Zr/Y diagram suggests volcanism in nearby island arc and back-arc basin settings, respectively. The 2595 ± 21 Ma U-Pb zircon crystallization age of the metadacite allowed the determination of the timing of volcanism in the MNGB. Therefore, an intraoceanic provenance in an arc-basin system is proposed for the MNGB in the Neoarchean, which was later compressed between cratonic blocks during the Rhyacian-Orosirian event. |
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Brazilian Journal of Geology |
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Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic settingMundo Novo greenstone beltmetavolcanic rockpetrologygeochronologyintraoceanic arc-basin systemAbstract Field, petrological and LA-ICP-MS U-Pb geochronological data of metavolcanic rocks were used to interpret the petrological processes and to propose the tectonic setting for the Mundo Novo greenstone belt (MNGB) in the eastern São Francisco Craton. The metavolcanic rocks studied are metakomatiite, eastern and western metabasalts, and metadacite with subordinate metarhyolite, which host ocean floor hydrothermal alteration zones and are covered by ocean floor lithological associations composed of chemical metasedimentary rocks. Fractional crystallization and heterogeneous intraoceanic contaminations explain the mineralogical differences between the two metabasalts and the high (La/Yb)N ratio values of metakomatiite and metadacite. The metakomatiite and the eastern and western metabasalts feature a vector from the MORB-OIB array to the volcanic arc array in the Nb/Yb-Th/Yb diagram, similar to the Archean intraoceanic arc-basin systems. The geochemical pattern of the eastern and western metabasalts in the Zr-Zr/Y diagram suggests volcanism in nearby island arc and back-arc basin settings, respectively. The 2595 ± 21 Ma U-Pb zircon crystallization age of the metadacite allowed the determination of the timing of volcanism in the MNGB. Therefore, an intraoceanic provenance in an arc-basin system is proposed for the MNGB in the Neoarchean, which was later compressed between cratonic blocks during the Rhyacian-Orosirian event.Sociedade Brasileira de Geologia2020-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300300Brazilian Journal of Geology v.50 n.3 2020reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-4889202020190041info:eu-repo/semantics/openAccessSpreafico,Ricardo RamosBarbosa,Johildo Salomão FigueiredoMoraes,Antônio Marcos Vitória deSouza Júnior,Francisco Dias deeng2020-07-03T00:00:00Zoai:scielo:S2317-48892020000300300Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2020-07-03T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false |
dc.title.none.fl_str_mv |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
title |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
spellingShingle |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting Spreafico,Ricardo Ramos Mundo Novo greenstone belt metavolcanic rock petrology geochronology intraoceanic arc-basin system |
title_short |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
title_full |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
title_fullStr |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
title_full_unstemmed |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
title_sort |
Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting |
author |
Spreafico,Ricardo Ramos |
author_facet |
Spreafico,Ricardo Ramos Barbosa,Johildo Salomão Figueiredo Moraes,Antônio Marcos Vitória de Souza Júnior,Francisco Dias de |
author_role |
author |
author2 |
Barbosa,Johildo Salomão Figueiredo Moraes,Antônio Marcos Vitória de Souza Júnior,Francisco Dias de |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Spreafico,Ricardo Ramos Barbosa,Johildo Salomão Figueiredo Moraes,Antônio Marcos Vitória de Souza Júnior,Francisco Dias de |
dc.subject.por.fl_str_mv |
Mundo Novo greenstone belt metavolcanic rock petrology geochronology intraoceanic arc-basin system |
topic |
Mundo Novo greenstone belt metavolcanic rock petrology geochronology intraoceanic arc-basin system |
description |
Abstract Field, petrological and LA-ICP-MS U-Pb geochronological data of metavolcanic rocks were used to interpret the petrological processes and to propose the tectonic setting for the Mundo Novo greenstone belt (MNGB) in the eastern São Francisco Craton. The metavolcanic rocks studied are metakomatiite, eastern and western metabasalts, and metadacite with subordinate metarhyolite, which host ocean floor hydrothermal alteration zones and are covered by ocean floor lithological associations composed of chemical metasedimentary rocks. Fractional crystallization and heterogeneous intraoceanic contaminations explain the mineralogical differences between the two metabasalts and the high (La/Yb)N ratio values of metakomatiite and metadacite. The metakomatiite and the eastern and western metabasalts feature a vector from the MORB-OIB array to the volcanic arc array in the Nb/Yb-Th/Yb diagram, similar to the Archean intraoceanic arc-basin systems. The geochemical pattern of the eastern and western metabasalts in the Zr-Zr/Y diagram suggests volcanism in nearby island arc and back-arc basin settings, respectively. The 2595 ± 21 Ma U-Pb zircon crystallization age of the metadacite allowed the determination of the timing of volcanism in the MNGB. Therefore, an intraoceanic provenance in an arc-basin system is proposed for the MNGB in the Neoarchean, which was later compressed between cratonic blocks during the Rhyacian-Orosirian event. |
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=S2317-48892020000300300 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300300 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2317-4889202020190041 |
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.3 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_ |
1752122399370772480 |