Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da UERJ |
Texto Completo: | http://www.bdtd.uerj.br/handle/1/16859 |
Resumo: | The Morro de São João Alkaline Complex is located at Barra de São João, district of Casimiro de Abreu-RJ, eastern portion of the Rio de Janeiro state. It is composed of alkaline rocks, being the only one in the state where occurs the interaction of felsic, mafic and ultramafic rocks relating each other and exhibiting textures that results of interaction between felsic and mafic magmatic magmas. This work presents petrographic data including studies of textures of magmatic mixture and assimilation that are observed throughout the massif and lithogeochemical data to generate a detailed analysis of the petrogenetic processes and magmatic evolution that generated this massif. Petrographic characterization was based on detailed descriptions, in the macro and microscopic scales, added to elementary mineral chemistry with electron probe analysis on feldspar, amphibole, pyroxene and garnet crystals. The JEOL JXA-8230 electronic probe micro-analyzer was used for this analytical method. The lithogeochemistry was based on the analysis of the major and trace elements in a classificatory and discriminatory levels added to the geochemical modeling of trace elements to determine the percentage of fractional crystallization and magmatic mixture. The whole rock analysis of the major elements was done by the ICP-AES method and for the trace elements ICP-MS method. The main lithotypes mapped were classified as gabbro hornblende, syenite hornblende with nepheline, syenite, syenite with nepheline, nepheline syenite and phonolite. From these classifications, three facies were defined according to similar petrographic characteristics of the mapped lithotypes: Melanocratic Facies, represented by gabbro hornblende, Mesocratic Facies, syenite hornblende with nepheline and Leucocratic Facies, represented mainly by syenite nepheline. The main mineralogy consists in nepheline, alkaline feldspar (albite), plagioclase (bytownite), amphiboles (Fe-kaersutite, Fe-pargasite and sadanagaite), clinopyroxene, titanite, magnetite, garnet (grossular), apatite and zircon. With the exception of the aphanitics phonolites, all rocks in question are phaneritic, equigranular and medium granulometry. They are potassic, metaluminous and form two distinct geochemical series: the first one is silica-saturated with normative hyperistene + olivine and the second one is moderate to strongly silica-unsaturated with nepheline + diopside (sometimes olivine). The ratios CaO/Al2O3, (La/Zr)N and (Ti/Eu)N corroborate with the hypothesis that the mafic and ultramafic rocks of Morro de São João are products of a partial fusion of a metasomatized peridotitic mantle with CO2 rich fluids. Felsic rocks are interpreted as a pulse of a more evolved liquid. By means of the calculations of geochemical modeling of trace elements, the main hypothesis if that the Morro de São João Alkaline Complex is a result of an interaction between two magmatic chambers with different evolutionary histories. Both mafic and felsic rocks, including phonolites, contain signs of assimilation of the siliceous basement and of another alkaline rock with a distinct geochemical character. |
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Ferreira, Eliane Guedeshttp://lattes.cnpq.br/8937741128112930Santos, Anderson Costa doshttp://lattes.cnpq.br/4949133831525911Valente, Sérgio de CastroGeraldes, Mauro Cesarhttp://lattes.cnpq.br/7230698703442593Fagundes, Mariana Bessamariannafbessa@gmail.com2021-11-04T23:05:52Z2020-03-20FAGUNDES, Mariana Bessa. Caracterização Petrográfica e Geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ. 2020. 105 f. Dissertação (Mestrado em Geociências) – Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, 2020.http://www.bdtd.uerj.br/handle/1/16859The Morro de São João Alkaline Complex is located at Barra de São João, district of Casimiro de Abreu-RJ, eastern portion of the Rio de Janeiro state. It is composed of alkaline rocks, being the only one in the state where occurs the interaction of felsic, mafic and ultramafic rocks relating each other and exhibiting textures that results of interaction between felsic and mafic magmatic magmas. This work presents petrographic data including studies of textures of magmatic mixture and assimilation that are observed throughout the massif and lithogeochemical data to generate a detailed analysis of the petrogenetic processes and magmatic evolution that generated this massif. Petrographic characterization was based on detailed descriptions, in the macro and microscopic scales, added to elementary mineral chemistry with electron probe analysis on feldspar, amphibole, pyroxene and garnet crystals. The JEOL JXA-8230 electronic probe micro-analyzer was used for this analytical method. The lithogeochemistry was based on the analysis of the major and trace elements in a classificatory and discriminatory levels added to the geochemical modeling of trace elements to determine the percentage of fractional crystallization and magmatic mixture. The whole rock analysis of the major elements was done by the ICP-AES method and for the trace elements ICP-MS method. The main lithotypes mapped were classified as gabbro hornblende, syenite hornblende with nepheline, syenite, syenite with nepheline, nepheline syenite and phonolite. From these classifications, three facies were defined according to similar petrographic characteristics of the mapped lithotypes: Melanocratic Facies, represented by gabbro hornblende, Mesocratic Facies, syenite hornblende with nepheline and Leucocratic Facies, represented mainly by syenite nepheline. The main mineralogy consists in nepheline, alkaline feldspar (albite), plagioclase (bytownite), amphiboles (Fe-kaersutite, Fe-pargasite and sadanagaite), clinopyroxene, titanite, magnetite, garnet (grossular), apatite and zircon. With the exception of the aphanitics phonolites, all rocks in question are phaneritic, equigranular and medium granulometry. They are potassic, metaluminous and form two distinct geochemical series: the first one is silica-saturated with normative hyperistene + olivine and the second one is moderate to strongly silica-unsaturated with nepheline + diopside (sometimes olivine). The ratios CaO/Al2O3, (La/Zr)N and (Ti/Eu)N corroborate with the hypothesis that the mafic and ultramafic rocks of Morro de São João are products of a partial fusion of a metasomatized peridotitic mantle with CO2 rich fluids. Felsic rocks are interpreted as a pulse of a more evolved liquid. By means of the calculations of geochemical modeling of trace elements, the main hypothesis if that the Morro de São João Alkaline Complex is a result of an interaction between two magmatic chambers with different evolutionary histories. Both mafic and felsic rocks, including phonolites, contain signs of assimilation of the siliceous basement and of another alkaline rock with a distinct geochemical character.O Complexo Alcalino do Morro de São João, situado no distrito de Barra de São João, Casimiro de Abreu-RJ, porção leste do estado do Rio de Janeiro é composto por rochas alcalinas, sendo o único no estado que possui ocorrência de rochas félsicas, máficas e ultramáficas relacionando-se entre si exibindo texturas que evidenciam interação entre líquidos magmáticos félsicos e máficos. No presente trabalho são apresentados dados petrográficos incluindo estudo de texturas de mistura magmática e assimilação observadas ao longo do maciço e dados litogeoquímicos com intuito de gerar uma análise detalhada dos processos petrogenéticos e evolução magmática que geraram esse corpo rochoso. As tipificações petrográficas basearam-se nas descrições detalhadas nas escalas macro e microscópica somadas à química mineral elementar com análises de microssonda eletrônica em cristais de feldspato, anfibólio, piroxênio e granada. Para este método analítico foi utilizado o micro-analisador de sonda eletrônica JEOL JXA-8230. A litogeoquímica baseou-se nas análises dos elementos maiores e traços a níveis classificatórios e discriminatórios somadas à modelagem geoquímica de elementos traços para determinação do percentual de cristalização fracionada e mistura magmática. A análise de rocha total dos elementos maiores deu-se pelo método ICP-AES e para os elementos-traço ICP-MS. Os litotipos principais mapeados foram classificados como hornblenda gabro, hornblenda sienito com nefelina, sienito, sienito com nefelina, nefelina sienito e fonolito. A partir dessas classificações, foram definidas três fácies segundo características petrográficas similares dos litotipos mapeados. São elas: Fácies Melanocrática, representada pelo hornblenda gabro, Fácies Mesocrática, hornblenda sienito com nefelina e Fácies Leucocrática, representada principalmente, pelo nefelina sienito. A mineralogia principal encontrada nessas rochas consiste em nefelina, feldspato alcalino (albita), plagioclásio (bytownita), anfibólios (Fe-kaersutita, Fe-pargasita e sadanagaíta), clinopiroxênio, titanita, magnetita, ocorrência de granada (grossulária), apatita e zircão. Com exceção do fonolito afaníticos, as rochas em questão são faneríticas, equigranulares e de granulometria média. São rochas potássicas, metaluminosas e foram duas séries geoquímicas distintas. Uma saturada em sílica com hiperstênio + olivina normativos e uma segunda moderada a fortemente a insaturada em sílica com nefelina + diopsídio (por vezes olivina) normativos. As razões CaO/Al2O3, (La/Zr)N e (Ti/Eu)N corroboram com a hipótese de que as rochas máficas e ultramáficas do Morro de São João serem produtos de uma fusão parcial de um manto peridotítico metassomatizado com fluidos ricos em CO2. Já as rochas félsicas são interpretadas como um pulso de um líquido mais evoluído. Com os cálculos de modelagem geoquímica de elementos-traço, chegou-se a hipótese principal de que o Complexo Alcalino do Morro de São João é o resultado de uma interação entre duas câmaras magmáticas com histórias evolutivas distintas. Tanto as rochas máficas e félsicas, incluindo os fonolitos, contém indícios de assimilação, tanto da encaixante silicática, quanto de uma outra rocha alcalina com um caráter geoquímico distinto.Submitted by Fernanda Maria CTC/C (fernandalobo@uerj.br) on 2021-11-04T23:05:52Z No. of bitstreams: 1 Dissertação - Mariana Bessa Fagundes - 2020 - Completa.pdf: 3123830 bytes, checksum: 358792c345e289768d7dc230e9062992 (MD5)Made available in DSpace on 2021-11-04T23:05:52Z (GMT). No. of bitstreams: 1 Dissertação - Mariana Bessa Fagundes - 2020 - Completa.pdf: 3123830 bytes, checksum: 358792c345e289768d7dc230e9062992 (MD5) Previous issue date: 2020-03-20Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro - FAPERJapplication/pdfporUniversidade do Estado do Rio de JaneiroPrograma de Pós-Graduação em GeociênciasUERJBrasilCentro de Tecnologia e Ciências::Faculdade de GeologiaAlkaline MagmatismCrustal AssimilationMagmatic MixtureMagmatismo alcalinoAssimilação crustalMistura magmáticaMagmatismo – Barra de São João (Casimiro de Abreu, RJ)Petrologia – Barra de São João (Casimiro de Abreu, RJ)Geoquímica – Barra de São João (Casimiro de Abreu, RJ)CIENCIAS EXATAS E DA TERRA::GEOCIENCIASCaracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJPetrographic and Geochemical Characterization of Morro de São João Alkaline Complex, Casimiro de Abreu-RJinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UERJinstname:Universidade do Estado do Rio de Janeiro (UERJ)instacron:UERJORIGINALDissertação - Mariana Bessa Fagundes - 2020 - Completa.pdfDissertação - Mariana Bessa Fagundes - 2020 - Completa.pdfapplication/pdf3123830http://www.bdtd.uerj.br/bitstream/1/16859/2/Disserta%C3%A7%C3%A3o+-+Mariana+Bessa+Fagundes+-+2020+-+Completa.pdf358792c345e289768d7dc230e9062992MD52LICENSElicense.txtlicense.txttext/plain; charset=utf-82123http://www.bdtd.uerj.br/bitstream/1/16859/1/license.txte5502652da718045d7fcd832b79fca29MD511/168592024-02-27 15:43:47.846oai:www.bdtd.uerj.br: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Biblioteca Digital de Teses e Dissertaçõeshttp://www.bdtd.uerj.br/PUBhttps://www.bdtd.uerj.br:8443/oai/requestbdtd.suporte@uerj.bropendoar:29032024-02-27T18:43:47Biblioteca Digital de Teses e Dissertações da UERJ - Universidade do Estado do Rio de Janeiro (UERJ)false |
dc.title.por.fl_str_mv |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
dc.title.alternative.eng.fl_str_mv |
Petrographic and Geochemical Characterization of Morro de São João Alkaline Complex, Casimiro de Abreu-RJ |
title |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
spellingShingle |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ Fagundes, Mariana Bessa Alkaline Magmatism Crustal Assimilation Magmatic Mixture Magmatismo alcalino Assimilação crustal Mistura magmática Magmatismo – Barra de São João (Casimiro de Abreu, RJ) Petrologia – Barra de São João (Casimiro de Abreu, RJ) Geoquímica – Barra de São João (Casimiro de Abreu, RJ) CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS |
title_short |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
title_full |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
title_fullStr |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
title_full_unstemmed |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
title_sort |
Caracterização petrográfica e geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ |
author |
Fagundes, Mariana Bessa |
author_facet |
Fagundes, Mariana Bessa mariannafbessa@gmail.com |
author_role |
author |
author2 |
mariannafbessa@gmail.com |
author2_role |
author |
dc.contributor.advisor1.fl_str_mv |
Ferreira, Eliane Guedes |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/8937741128112930 |
dc.contributor.advisor-co1.fl_str_mv |
Santos, Anderson Costa dos |
dc.contributor.advisor-co1Lattes.fl_str_mv |
http://lattes.cnpq.br/4949133831525911 |
dc.contributor.referee1.fl_str_mv |
Valente, Sérgio de Castro |
dc.contributor.referee2.fl_str_mv |
Geraldes, Mauro Cesar |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/7230698703442593 |
dc.contributor.author.fl_str_mv |
Fagundes, Mariana Bessa mariannafbessa@gmail.com |
contributor_str_mv |
Ferreira, Eliane Guedes Santos, Anderson Costa dos Valente, Sérgio de Castro Geraldes, Mauro Cesar |
dc.subject.eng.fl_str_mv |
Alkaline Magmatism Crustal Assimilation Magmatic Mixture |
topic |
Alkaline Magmatism Crustal Assimilation Magmatic Mixture Magmatismo alcalino Assimilação crustal Mistura magmática Magmatismo – Barra de São João (Casimiro de Abreu, RJ) Petrologia – Barra de São João (Casimiro de Abreu, RJ) Geoquímica – Barra de São João (Casimiro de Abreu, RJ) CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS |
dc.subject.por.fl_str_mv |
Magmatismo alcalino Assimilação crustal Mistura magmática Magmatismo – Barra de São João (Casimiro de Abreu, RJ) Petrologia – Barra de São João (Casimiro de Abreu, RJ) Geoquímica – Barra de São João (Casimiro de Abreu, RJ) |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS |
description |
The Morro de São João Alkaline Complex is located at Barra de São João, district of Casimiro de Abreu-RJ, eastern portion of the Rio de Janeiro state. It is composed of alkaline rocks, being the only one in the state where occurs the interaction of felsic, mafic and ultramafic rocks relating each other and exhibiting textures that results of interaction between felsic and mafic magmatic magmas. This work presents petrographic data including studies of textures of magmatic mixture and assimilation that are observed throughout the massif and lithogeochemical data to generate a detailed analysis of the petrogenetic processes and magmatic evolution that generated this massif. Petrographic characterization was based on detailed descriptions, in the macro and microscopic scales, added to elementary mineral chemistry with electron probe analysis on feldspar, amphibole, pyroxene and garnet crystals. The JEOL JXA-8230 electronic probe micro-analyzer was used for this analytical method. The lithogeochemistry was based on the analysis of the major and trace elements in a classificatory and discriminatory levels added to the geochemical modeling of trace elements to determine the percentage of fractional crystallization and magmatic mixture. The whole rock analysis of the major elements was done by the ICP-AES method and for the trace elements ICP-MS method. The main lithotypes mapped were classified as gabbro hornblende, syenite hornblende with nepheline, syenite, syenite with nepheline, nepheline syenite and phonolite. From these classifications, three facies were defined according to similar petrographic characteristics of the mapped lithotypes: Melanocratic Facies, represented by gabbro hornblende, Mesocratic Facies, syenite hornblende with nepheline and Leucocratic Facies, represented mainly by syenite nepheline. The main mineralogy consists in nepheline, alkaline feldspar (albite), plagioclase (bytownite), amphiboles (Fe-kaersutite, Fe-pargasite and sadanagaite), clinopyroxene, titanite, magnetite, garnet (grossular), apatite and zircon. With the exception of the aphanitics phonolites, all rocks in question are phaneritic, equigranular and medium granulometry. They are potassic, metaluminous and form two distinct geochemical series: the first one is silica-saturated with normative hyperistene + olivine and the second one is moderate to strongly silica-unsaturated with nepheline + diopside (sometimes olivine). The ratios CaO/Al2O3, (La/Zr)N and (Ti/Eu)N corroborate with the hypothesis that the mafic and ultramafic rocks of Morro de São João are products of a partial fusion of a metasomatized peridotitic mantle with CO2 rich fluids. Felsic rocks are interpreted as a pulse of a more evolved liquid. By means of the calculations of geochemical modeling of trace elements, the main hypothesis if that the Morro de São João Alkaline Complex is a result of an interaction between two magmatic chambers with different evolutionary histories. Both mafic and felsic rocks, including phonolites, contain signs of assimilation of the siliceous basement and of another alkaline rock with a distinct geochemical character. |
publishDate |
2020 |
dc.date.issued.fl_str_mv |
2020-03-20 |
dc.date.accessioned.fl_str_mv |
2021-11-04T23:05:52Z |
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.citation.fl_str_mv |
FAGUNDES, Mariana Bessa. Caracterização Petrográfica e Geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ. 2020. 105 f. Dissertação (Mestrado em Geociências) – Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, 2020. |
dc.identifier.uri.fl_str_mv |
http://www.bdtd.uerj.br/handle/1/16859 |
identifier_str_mv |
FAGUNDES, Mariana Bessa. Caracterização Petrográfica e Geoquímica do Complexo Alcalino do Morro de São João, Casimiro de Abreu-RJ. 2020. 105 f. Dissertação (Mestrado em Geociências) – Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, 2020. |
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http://www.bdtd.uerj.br/handle/1/16859 |
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por |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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Universidade do Estado do Rio de Janeiro |
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Programa de Pós-Graduação em Geociências |
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UERJ |
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Brasil |
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Centro de Tecnologia e Ciências::Faculdade de Geologia |
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Universidade do Estado do Rio de Janeiro |
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Biblioteca Digital de Teses e Dissertações da UERJ |
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Biblioteca Digital de Teses e Dissertações da UERJ - Universidade do Estado do Rio de Janeiro (UERJ) |
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bdtd.suporte@uerj.br |
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