Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil

Detalhes bibliográficos
Autor(a) principal: Dias,Tatiana Gonçalves
Data de Publicação: 2016
Outros Autores: Caxito,Fabrício de Andrade, Pedrosa-Soares,Antônio Carlos, Stevenson,Ross, Dussin,Ivo, Silva,Luiz Carlos da, Alkmim,Fernando, Pimentel,Márcio
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=S2317-48892016000200199
Resumo: ABSTRACT: The Jequitinhonha Complex of the northeastern Araçuaí orogen is an extensive sedimentary unit metamorphosed in the amphibolite-granulite facies transition around 580-545 Ma. The unit consists of Al-rich (kinzigitic) paragneisses with decametric intercalations of graphite gneisses and quartzites, and centimetric to metric lenses of calcsilicate rocks. A new detrital zircon U-Pb age spectrum is reported for a sample of quartzite, and whole-rock geochemical (major and trace elements, 9 samples) and Sm-Nd isotope data (10 samples) for Jequitinhonha Complex paragneiss. Together with published data these show that: (1) the geochemistry of paragneiss samples of the Jequitinhonha Complex are similar to those of passive margin sedimentary protoliths; (2) detrital zircon data yield U-Pb age populations between ca. 0.9 and 2.5 Ga; and (3) Sm-Nd TDM model ages range from 1.6 to 1.8 Ga and εNd(575 Ma) around -7.5. The data reveal a mixture of Cryogenian to Mesoproterozoic rift-related igneous rocks with the Palaeoproterozoic-Archaean basement rocks of the São Francisco-Congo palaeocontinent as the main source areas, and also support the correlation between the Jequitinhonha Complex and the passive margin units of the upper Macaúbas Group, constituting the precursor basin of the orogen. Our results, with the absence of ophiolites in the Jequitinhonha Complex, reinforce the interpretation that the São Francisco-Congo palaeocontinent was not divided to the north of the focused region, suggesting an ensialic termination of a gulf during the Neoproterozoic.
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spelling Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern BrazilKinzigite gneissJequitinhonha ComplexAraçuaí OrogenWest GondwanaABSTRACT: The Jequitinhonha Complex of the northeastern Araçuaí orogen is an extensive sedimentary unit metamorphosed in the amphibolite-granulite facies transition around 580-545 Ma. The unit consists of Al-rich (kinzigitic) paragneisses with decametric intercalations of graphite gneisses and quartzites, and centimetric to metric lenses of calcsilicate rocks. A new detrital zircon U-Pb age spectrum is reported for a sample of quartzite, and whole-rock geochemical (major and trace elements, 9 samples) and Sm-Nd isotope data (10 samples) for Jequitinhonha Complex paragneiss. Together with published data these show that: (1) the geochemistry of paragneiss samples of the Jequitinhonha Complex are similar to those of passive margin sedimentary protoliths; (2) detrital zircon data yield U-Pb age populations between ca. 0.9 and 2.5 Ga; and (3) Sm-Nd TDM model ages range from 1.6 to 1.8 Ga and εNd(575 Ma) around -7.5. The data reveal a mixture of Cryogenian to Mesoproterozoic rift-related igneous rocks with the Palaeoproterozoic-Archaean basement rocks of the São Francisco-Congo palaeocontinent as the main source areas, and also support the correlation between the Jequitinhonha Complex and the passive margin units of the upper Macaúbas Group, constituting the precursor basin of the orogen. Our results, with the absence of ophiolites in the Jequitinhonha Complex, reinforce the interpretation that the São Francisco-Congo palaeocontinent was not divided to the north of the focused region, suggesting an ensialic termination of a gulf during the Neoproterozoic.Sociedade Brasileira de Geologia2016-06-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892016000200199Brazilian Journal of Geology v.46 n.2 2016reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-4889201620160012info:eu-repo/semantics/openAccessDias,Tatiana GonçalvesCaxito,Fabrício de AndradePedrosa-Soares,Antônio CarlosStevenson,RossDussin,IvoSilva,Luiz Carlos daAlkmim,FernandoPimentel,Márcioeng2016-08-03T00:00:00Zoai:scielo:S2317-48892016000200199Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2016-08-03T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false
dc.title.none.fl_str_mv Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
title Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
spellingShingle Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
Dias,Tatiana Gonçalves
Kinzigite gneiss
Jequitinhonha Complex
Araçuaí Orogen
West Gondwana
title_short Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
title_full Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
title_fullStr Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
title_full_unstemmed Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
title_sort Age, provenance and tectonic setting of the high-grade Jequitinhonha Complex, Araçuaí Orogen, eastern Brazil
author Dias,Tatiana Gonçalves
author_facet Dias,Tatiana Gonçalves
Caxito,Fabrício de Andrade
Pedrosa-Soares,Antônio Carlos
Stevenson,Ross
Dussin,Ivo
Silva,Luiz Carlos da
Alkmim,Fernando
Pimentel,Márcio
author_role author
author2 Caxito,Fabrício de Andrade
Pedrosa-Soares,Antônio Carlos
Stevenson,Ross
Dussin,Ivo
Silva,Luiz Carlos da
Alkmim,Fernando
Pimentel,Márcio
author2_role author
author
author
author
author
author
author
dc.contributor.author.fl_str_mv Dias,Tatiana Gonçalves
Caxito,Fabrício de Andrade
Pedrosa-Soares,Antônio Carlos
Stevenson,Ross
Dussin,Ivo
Silva,Luiz Carlos da
Alkmim,Fernando
Pimentel,Márcio
dc.subject.por.fl_str_mv Kinzigite gneiss
Jequitinhonha Complex
Araçuaí Orogen
West Gondwana
topic Kinzigite gneiss
Jequitinhonha Complex
Araçuaí Orogen
West Gondwana
description ABSTRACT: The Jequitinhonha Complex of the northeastern Araçuaí orogen is an extensive sedimentary unit metamorphosed in the amphibolite-granulite facies transition around 580-545 Ma. The unit consists of Al-rich (kinzigitic) paragneisses with decametric intercalations of graphite gneisses and quartzites, and centimetric to metric lenses of calcsilicate rocks. A new detrital zircon U-Pb age spectrum is reported for a sample of quartzite, and whole-rock geochemical (major and trace elements, 9 samples) and Sm-Nd isotope data (10 samples) for Jequitinhonha Complex paragneiss. Together with published data these show that: (1) the geochemistry of paragneiss samples of the Jequitinhonha Complex are similar to those of passive margin sedimentary protoliths; (2) detrital zircon data yield U-Pb age populations between ca. 0.9 and 2.5 Ga; and (3) Sm-Nd TDM model ages range from 1.6 to 1.8 Ga and εNd(575 Ma) around -7.5. The data reveal a mixture of Cryogenian to Mesoproterozoic rift-related igneous rocks with the Palaeoproterozoic-Archaean basement rocks of the São Francisco-Congo palaeocontinent as the main source areas, and also support the correlation between the Jequitinhonha Complex and the passive margin units of the upper Macaúbas Group, constituting the precursor basin of the orogen. Our results, with the absence of ophiolites in the Jequitinhonha Complex, reinforce the interpretation that the São Francisco-Congo palaeocontinent was not divided to the north of the focused region, suggesting an ensialic termination of a gulf during the Neoproterozoic.
publishDate 2016
dc.date.none.fl_str_mv 2016-06-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892016000200199
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892016000200199
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/2317-4889201620160012
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.46 n.2 2016
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
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