Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications

Detalhes bibliográficos
Autor(a) principal: Siachoque Velandia, Astrid
Data de Publicação: 2020
Tipo de documento: Tese
Idioma: eng
Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
Texto Completo: https://www.teses.usp.br/teses/disponiveis/44/44143/tde-27012021-154920/
Resumo: A-type granites from the Graciosa Province in S-SE Brazil are broader grouped in two main petrographic associations: one alkaline including metaluminous and peralkaline alkali-feldspar granites and syenites, while the other aluminous is constituted by metaluminous to slightly peraluminous syeno- and monzo-granites. These granites are geochemically characterized by high iron and alkali contents and relative elevated abundances of LILEs, HFSEs, REEs and F. Moreover, they include a large variety of Fe- and HFSE-rich primary mafic silicate minerals as well as REE-rich magmatic and hydrothermal accessory minerals. This thesis studied main mafic silicates and accessory minerals in granites and greisens from the Mandira Granite Massif and the Desemborque and Papanduva Plutons in the province. Our results are grouped in four chapters and the main insights show that: 1) the Mandira Granite Massif contains magmatic calcic, sodic-calcic and sodic amphiboles and Al-rich annite as well as hydrothermal calcic and sodic amphiboles, annite, chlorite and stilpnomelane. The Mandira granites crystallized at 720- 750°C and 130-170 MPa (plagioclase-hornblende geothermobarometer) under relatively low to moderate fO2 conditions while during the late to post-magmatic evolution, the redox conditions indicate high oxidizing conditions and hydrothermal temperatures 250-272°C (chloritethermometry). 2) The Mandira and Papanduva peralkaline granites include late-magmatic and hydrothermal astrophyllite with relatively LILEs- and LREE-rich, the late-magmatic is more enriched in Zr-Nb than the hydrothermal which is more enriched in Ti. The last one was formed as result of the replacement of primary sodic amphiboles (in Mandira) and clinopyroxenes (in Papanduva). Accordingly, astrophyllite compositions offer additional information of redox conditions as well as magmatic and hydrothermal environments in peralkaline granitic systems. 3) In syenogranites and greisens from the Desemborque pluton we found the occurrence of columbite crystals characterized by predominant enrichment of HFSEs and HREEs which were formed from early to late post-magmatic stages. 4) Accessory minerals in the Desemborque rocks are magmatic zircon (syenogranites) and post-magmatic zircon, monazite, xenotime and fluorite (greisen), while in the Mandira granites are magmatic and post-magmatic zircon and fluorite and post-magmatic fluorides (fluocerite and gagarinite). In both occurrences, the postmagmatic phosphates and the fluorides were formed by several hydrothermal alterations of zircons due to post-magmatic fluids. In general, all zircons experienced post-magmatic alterations leading to progressive increase of HFSEs and REEs from primary to hydrothermal altered zircon. This hydrothermal activity was dating in monazite crystals from the Desemborque pluton given ages of 584 ± 3 Ma using the CHIME method. Highlighting, this thesis follows the magmatic, late magmatic and post-magmatic processes during the evolution of the Graciosa rocks which are registered in the mafic and accessory minerals studied here. In this sense the late to post-magmatic processes are associated with the circulation of hydrothermal HFSE- and F-rich fluids derived from the destabilization of magmatic minerals and subsequently promoted the significant enrichment of incompatible elements in the final evolutionary stages of the granitic systems.
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spelling Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implicationsnão disponívelA-type Graciosa ProvinceAccessory mineralsEPMA and LAICPMSGranites and greisensGranitos e greisensMafic silicate mineralsMinerais acessóriosMinerais silicáticos máficosProcessos de alteração tarde a hidrotermalProvíncia Graciosa tipo AA-type granites from the Graciosa Province in S-SE Brazil are broader grouped in two main petrographic associations: one alkaline including metaluminous and peralkaline alkali-feldspar granites and syenites, while the other aluminous is constituted by metaluminous to slightly peraluminous syeno- and monzo-granites. These granites are geochemically characterized by high iron and alkali contents and relative elevated abundances of LILEs, HFSEs, REEs and F. Moreover, they include a large variety of Fe- and HFSE-rich primary mafic silicate minerals as well as REE-rich magmatic and hydrothermal accessory minerals. This thesis studied main mafic silicates and accessory minerals in granites and greisens from the Mandira Granite Massif and the Desemborque and Papanduva Plutons in the province. Our results are grouped in four chapters and the main insights show that: 1) the Mandira Granite Massif contains magmatic calcic, sodic-calcic and sodic amphiboles and Al-rich annite as well as hydrothermal calcic and sodic amphiboles, annite, chlorite and stilpnomelane. The Mandira granites crystallized at 720- 750°C and 130-170 MPa (plagioclase-hornblende geothermobarometer) under relatively low to moderate fO2 conditions while during the late to post-magmatic evolution, the redox conditions indicate high oxidizing conditions and hydrothermal temperatures 250-272°C (chloritethermometry). 2) The Mandira and Papanduva peralkaline granites include late-magmatic and hydrothermal astrophyllite with relatively LILEs- and LREE-rich, the late-magmatic is more enriched in Zr-Nb than the hydrothermal which is more enriched in Ti. The last one was formed as result of the replacement of primary sodic amphiboles (in Mandira) and clinopyroxenes (in Papanduva). Accordingly, astrophyllite compositions offer additional information of redox conditions as well as magmatic and hydrothermal environments in peralkaline granitic systems. 3) In syenogranites and greisens from the Desemborque pluton we found the occurrence of columbite crystals characterized by predominant enrichment of HFSEs and HREEs which were formed from early to late post-magmatic stages. 4) Accessory minerals in the Desemborque rocks are magmatic zircon (syenogranites) and post-magmatic zircon, monazite, xenotime and fluorite (greisen), while in the Mandira granites are magmatic and post-magmatic zircon and fluorite and post-magmatic fluorides (fluocerite and gagarinite). In both occurrences, the postmagmatic phosphates and the fluorides were formed by several hydrothermal alterations of zircons due to post-magmatic fluids. In general, all zircons experienced post-magmatic alterations leading to progressive increase of HFSEs and REEs from primary to hydrothermal altered zircon. This hydrothermal activity was dating in monazite crystals from the Desemborque pluton given ages of 584 ± 3 Ma using the CHIME method. Highlighting, this thesis follows the magmatic, late magmatic and post-magmatic processes during the evolution of the Graciosa rocks which are registered in the mafic and accessory minerals studied here. In this sense the late to post-magmatic processes are associated with the circulation of hydrothermal HFSE- and F-rich fluids derived from the destabilization of magmatic minerals and subsequently promoted the significant enrichment of incompatible elements in the final evolutionary stages of the granitic systems.Os granitos tipo A da Província Graciosa no S-SE Brasil são agrupados em duas associações petrográficas principais: uma alcalina incluindo sienitos e álcali feldspato granitos metaluminosos e peralcalinos, enquanto a outra é aluminosa, a qual é constituída por sienogranitos e monzogranitos metaluminosos a ligeiramente peraluminosos. Esses granitos são geoquímicamente caracterizados por altos teores de ferro e álcalis e abundâncias relativamente elevadas de LILE, HFSE, REE e F, além disso, eles incluem uma grande variedade de minerais máficos primários ricos em Fe e HFSE, bem como minerais acessórios magmáticos e posmagmáticos ricos em REE. Nesta tese, foram estudados os principais silicatos máficos e minerais acessórios em granitos e greisens do Maciço Granítico Mandira e dos plutons Desemborque e Papanduva dentro da província. Nossos resultados estão agrupados em quatro capítulos e as principais contribuições mostram que: 1) o Maciço Granitico Mandira contém anfibólios cálcicos, sódico-cálcicos e sódicos e annita rica em Al magmáticos, bem como anfibólios sódicos, annita, clorita e estilpnomelano pos-magmáticos. Os granitos de Mandira se cristalizaram a 720-750 °C e 130-170 MPa (geotermobarômetro de plagioclásio-hornblenda) sob condições relativamente baixas a moderadas de fO2, enquanto durante a evolução tardi a pós-magmática, as condições redox indicam condições mais oxidantes e temperaturas hidrotermais na faixa de 250-272 ° C (termometria por clorita). 2) Nos granitos peralcalinos do Mandira e Papanduva, há astrofilita tardi a pos-magmatica, e ambas são relativamente ricas em LILE e LREE; no entanto, a tardi-magmática é mais enriquecida em Zr-Nb do que a posmagmática, que é mais enriquecida Ti. Esta última foi formada como resultado da substituição de anfibólios sódicos primários (em Mandira) e clinopiroxênios (em Papanduva). Consequentemente, as composições de astrofilita oferecem informações adicionais sobre condições redox, bem como ambientes magmáticos e hidrotermais em sistemas graníticos peralcalinos. 3) Nos sienogranitos e greisens do plúton Desemborque incluem-se cristales de columbita caracterizados por enriquecimento predominante de HFSE e HREE, que são formados desde os estágios hidrotermais precoces até tardios. 4) Os minerais acessórios nas rochas do plúton Desemborque são zircão magmático (sienogranitos) e zircão, monazita, xenotima e fluorita hidrotermais (greisen), enquanto nos granitos de Mandira são zircão e fluorita magmáticos e fluorita e fluoretos pos-magmáticos (fluocerita e gagarinita). Em ambas ocorrências, os fosfatos e os fluoretos pos-magmáticos foram formados por várias alterações hidrotermais no zircão devido a fluidos pós-magmáticos. Em geral, todos os tipos de zircão sofreram alterações pós-magmáticas, levando a um aumento progressivo de HFSE e REE desde o zircão alterado primário para o hidrotermal. Esta atividade hidrotermal foi datada pela ocorrência de monazita nas rochas do Desemborque com uma idade de 584 ± 3 Ma, usando o método CHIME. Destaca-se que esta tese descreveu os processos magmáticos, tardemagmáticos e hidrotermais durante a evolução das rochas da Graciosa, que estão registrados nos minerais máficos e acessórios estudados aqui. Nesse sentido, os processos tardios a hidrotermais estão associados à circulação de fluidos pós-magmáticos ricos em HFSE e F, os quais são derivados da desestabilização de minerais magmáticos e subsequentemente promoveram um enriquecimento significativo dos elementos incompatíveis nos estágios evolutivos finais do sistema granítico.Biblioteca Digitais de Teses e Dissertações da USPVlach, Silvio Roberto FariasSiachoque Velandia, Astrid 2020-04-24info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfhttps://www.teses.usp.br/teses/disponiveis/44/44143/tde-27012021-154920/reponame:Biblioteca Digital de Teses e Dissertações da USPinstname:Universidade de São Paulo (USP)instacron:USPLiberar o conteúdo para acesso público.info:eu-repo/semantics/openAccesseng2021-02-01T21:54:02Zoai:teses.usp.br:tde-27012021-154920Biblioteca Digital de Teses e Dissertaçõeshttp://www.teses.usp.br/PUBhttp://www.teses.usp.br/cgi-bin/mtd2br.plvirginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.bropendoar:27212021-02-01T21:54:02Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false
dc.title.none.fl_str_mv Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
não disponível
title Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
spellingShingle Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
Siachoque Velandia, Astrid
A-type Graciosa Province
Accessory minerals
EPMA and LAICPMS
Granites and greisens
Granitos e greisens
Mafic silicate minerals
Minerais acessórios
Minerais silicáticos máficos
Processos de alteração tarde a hidrotermal
Província Graciosa tipo A
title_short Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
title_full Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
title_fullStr Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
title_full_unstemmed Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
title_sort Main mafic and accessory mineralogy in granites and greisens from selected occurrences in the A-type Graciosa Province, S-SE Brazil, and petrological implications
author Siachoque Velandia, Astrid
author_facet Siachoque Velandia, Astrid
author_role author
dc.contributor.none.fl_str_mv Vlach, Silvio Roberto Farias
dc.contributor.author.fl_str_mv Siachoque Velandia, Astrid
dc.subject.por.fl_str_mv A-type Graciosa Province
Accessory minerals
EPMA and LAICPMS
Granites and greisens
Granitos e greisens
Mafic silicate minerals
Minerais acessórios
Minerais silicáticos máficos
Processos de alteração tarde a hidrotermal
Província Graciosa tipo A
topic A-type Graciosa Province
Accessory minerals
EPMA and LAICPMS
Granites and greisens
Granitos e greisens
Mafic silicate minerals
Minerais acessórios
Minerais silicáticos máficos
Processos de alteração tarde a hidrotermal
Província Graciosa tipo A
description A-type granites from the Graciosa Province in S-SE Brazil are broader grouped in two main petrographic associations: one alkaline including metaluminous and peralkaline alkali-feldspar granites and syenites, while the other aluminous is constituted by metaluminous to slightly peraluminous syeno- and monzo-granites. These granites are geochemically characterized by high iron and alkali contents and relative elevated abundances of LILEs, HFSEs, REEs and F. Moreover, they include a large variety of Fe- and HFSE-rich primary mafic silicate minerals as well as REE-rich magmatic and hydrothermal accessory minerals. This thesis studied main mafic silicates and accessory minerals in granites and greisens from the Mandira Granite Massif and the Desemborque and Papanduva Plutons in the province. Our results are grouped in four chapters and the main insights show that: 1) the Mandira Granite Massif contains magmatic calcic, sodic-calcic and sodic amphiboles and Al-rich annite as well as hydrothermal calcic and sodic amphiboles, annite, chlorite and stilpnomelane. The Mandira granites crystallized at 720- 750°C and 130-170 MPa (plagioclase-hornblende geothermobarometer) under relatively low to moderate fO2 conditions while during the late to post-magmatic evolution, the redox conditions indicate high oxidizing conditions and hydrothermal temperatures 250-272°C (chloritethermometry). 2) The Mandira and Papanduva peralkaline granites include late-magmatic and hydrothermal astrophyllite with relatively LILEs- and LREE-rich, the late-magmatic is more enriched in Zr-Nb than the hydrothermal which is more enriched in Ti. The last one was formed as result of the replacement of primary sodic amphiboles (in Mandira) and clinopyroxenes (in Papanduva). Accordingly, astrophyllite compositions offer additional information of redox conditions as well as magmatic and hydrothermal environments in peralkaline granitic systems. 3) In syenogranites and greisens from the Desemborque pluton we found the occurrence of columbite crystals characterized by predominant enrichment of HFSEs and HREEs which were formed from early to late post-magmatic stages. 4) Accessory minerals in the Desemborque rocks are magmatic zircon (syenogranites) and post-magmatic zircon, monazite, xenotime and fluorite (greisen), while in the Mandira granites are magmatic and post-magmatic zircon and fluorite and post-magmatic fluorides (fluocerite and gagarinite). In both occurrences, the postmagmatic phosphates and the fluorides were formed by several hydrothermal alterations of zircons due to post-magmatic fluids. In general, all zircons experienced post-magmatic alterations leading to progressive increase of HFSEs and REEs from primary to hydrothermal altered zircon. This hydrothermal activity was dating in monazite crystals from the Desemborque pluton given ages of 584 ± 3 Ma using the CHIME method. Highlighting, this thesis follows the magmatic, late magmatic and post-magmatic processes during the evolution of the Graciosa rocks which are registered in the mafic and accessory minerals studied here. In this sense the late to post-magmatic processes are associated with the circulation of hydrothermal HFSE- and F-rich fluids derived from the destabilization of magmatic minerals and subsequently promoted the significant enrichment of incompatible elements in the final evolutionary stages of the granitic systems.
publishDate 2020
dc.date.none.fl_str_mv 2020-04-24
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://www.teses.usp.br/teses/disponiveis/44/44143/tde-27012021-154920/
url https://www.teses.usp.br/teses/disponiveis/44/44143/tde-27012021-154920/
dc.language.iso.fl_str_mv eng
language eng
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dc.rights.driver.fl_str_mv Liberar o conteúdo para acesso público.
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Liberar o conteúdo para acesso público.
eu_rights_str_mv openAccess
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dc.publisher.none.fl_str_mv Biblioteca Digitais de Teses e Dissertações da USP
publisher.none.fl_str_mv Biblioteca Digitais de Teses e Dissertações da USP
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reponame:Biblioteca Digital de Teses e Dissertações da USP
instname:Universidade de São Paulo (USP)
instacron:USP
instname_str Universidade de São Paulo (USP)
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institution USP
reponame_str Biblioteca Digital de Teses e Dissertações da USP
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repository.name.fl_str_mv Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)
repository.mail.fl_str_mv virginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.br
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