Nepheline syenites to syenites and granitic rocks of the Itatiaia Alkaline Massif, Southeastern Brazil: new geological insights into a migratory ring Complex

Rosa, Pedro Augusto da Silva; Ruberti, Excelso

doi:10.1590/2317-4889201820170092

Cited by 27 publications

(21 citation statements)

References 67 publications

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“…Brechas magmáticas, estruturas anelares e minerais exóticos são característicos a tais litotipos félsicos (Alves et al, 1992;Brotzu et al, 1989Brotzu et al, , 1992Brotzu et al, , 1997Brotzu et al, , 2005Atencio et al, 1999;Enrich et al, 2005Enrich et al, , 2009Marins, 2012;Lopes, 2015;Melluso et al, 2017;Rosa, 2012Rosa, , 2017Rosa & Ruberti, 2018).…”

Section: Rochas Alcalinas Cretáceas Da Serra Da Mantiqueira Pasmunclassified

“…No entanto, rochas máfica-ultramáficas cumuláticas constitiuem predominantemente o maciço Ponte Nova, que merece destaque, pois é uma exceção na PASM (Azzone, 2008;Azzone et al, 2009aAzzone et al, , 2009bAzzone et al, , 2016 Vinagre et al, 2014b). Fácies máfica-ultramáficas alcalinas são encontradas, volumetricamente restritas, em alguns corpos intrusivos félsicos da PASM (Bellieni et al, 1990;Enrich et al, 2005Enrich et al, , 2009Brotzu et al, 2007;Rosa & Ruberti, 2018).…”

Section: Rochas Alcalinas Cretáceas Da Serra Da Mantiqueira Pasmunclassified

“…No sistema nefelina-diopsídio-sílica (NaAlSiO 4 -CaMgSi 2 O 6 -SiO 2 ) em pressão atmosférica de Schairer & Yoder (1960) Ambos os trends alcalinos (fracamente e fortemente insaturados em sílica) são observados nos enxames de diques cretácicos da serra da Mantiqueira (Brotzu et al, 1989(Brotzu et al, , 1997(Brotzu et al, , 2005Thompson et al, 1998, Marins, 2012, Lopes, 2015Rosa & Ruberti, 2018), sendo um terceiro proposto por Azzone et al (2018), observando os valores intermediários de nefelina normativa (7<Ne<13) entre os membros das duas séries. Adiconalmente, rochas alcalinas miaskíticas e agpaíticas são encontradas em Morro Redondo, Passa Quatro e Ponte Nova (Brotzu et al, 1989(Brotzu et al, , 1992(Brotzu et al, , 2005Marins, 2012;Lopes, 2015;Azzone et al, 2018).…”

Section: Contexto Magmático Dos Diques Da Serra Da Mantiqueiraunclassified

“…Adiconalmente, rochas alcalinas miaskíticas e agpaíticas são encontradas em Morro Redondo, Passa Quatro e Ponte Nova (Brotzu et al, 1989(Brotzu et al, , 1992(Brotzu et al, , 2005Marins, 2012;Lopes, 2015;Azzone et al, 2018). Já rochas predominantemente miaskíticas ou predominantemente agpaíticas estão restritas a Itatiaia e Bom Repouso respectivamente (Brotzu et al, 1997(Brotzu et al, , 2005Marins, 2012;Rosa, 2012;Rosa & Ruberti, 2018).…”

Section: Contexto Magmático Dos Diques Da Serra Da Mantiqueiraunclassified

“…Nos diques alcalinos da Mantiqueira, o processo de cristalização fracionada parece ser o principal responsável pela evolução da série fortemente insaturada em sílica miaskítica (Marins, 2012;Rosa & Ruberti, 2018). No entanto, esse processo é ineficaz para a geração de fonolitos agpaíticos em ambos os trends e pela hipótese de origem primária, o processo de mistura de magmas nefelinítico/basaltíco alcalino com fonolítico/traquítico não explica a assinatura química dos litotipos composicionalmente intermediários a tais membros em ambas as séries (Marins, 2012;Lopes, 2015).…”

Section: Contexto Magmático Dos Diques Da Serra Da Mantiqueiraunclassified

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Antecristais e xenocristais máficos em diques ultrabá¡sicos de tendência alcalina da Serra da Mantiqueira (SP)

Silva¹

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Lopes, J.C.S., 2018, Mafic antecrysts and xenocrysts in alkaline ultrabasic dykes of the Mantiqueira range (SP) [Master's Thesis], São Paulo, Instituto de Geociências, Universidade de São Paulo, 186p. Weakly to strongly silica-undersaturated mafic alkaline dike series occur nearby Santo Antonio do Pinhal (SP) and Campos do Jordão (SP) in a restricted area of the Mantiqueira range, SE Brazil. These are intrusive in the Precambrian crystalline basement (south of the Brasília orogen) and in the Ponte Nova mafic-ultramafic alkaline massif. These are Cretaceous rocks and are grouped as part of the Serra do Mar alkaline province. In the majority, the dikes are classified as alkaline basalts and alkaline lamprophyres. Are porphyritic, with the macrocryst population having clinopyroxene and olivine as main phases. Subordinatedly, kaersutite, and occasionally, phlogopite, enstatite, magnetite, spinel and plagioclase were found. These macrocrysts present desequilibrium textures, such as sieve and embayment, combined with complex zoning styles, which indicate a open-system magmatic evolution. The study involves: (1) detailed petrographic analyses by optical microscopy and scanning electron microscopy, (2) quantitative punctual analyses of major and minor elements by electron microprobe and trace element by laser ablation -inductively coupled plasma mass espectrometry (LA-ICP-MS) in different horizons of the main macrocrystic phases, and (3) whole-rock geochemistry by X-ray fluorescence and ICP-MS. These determinations were collected focusing in the determination of the genesis of each population of zoned crystals. From the obtained compositions, mass balance calculations were done to exclude the macrocryst influence in the bulk compositions of the bodies and to have a compositional estimative of the melts, represented by the fine-grained to aphanitic matrices of these rocks. The crystalline zones of macrocrysts in equilibrium with the calculated melts were defined using the Mg-Fe exchange equilibrium constant between minerals and liquid, -.The equilibrium relationships allowed the designation genetic meanings to the the crystalline zones, being these classified as xenocrysts, antecrysts and phenocrysts. The first two types (in textural and chemical disequilibrium with the matrices) were captured and/or recycled from an early magmatic environment, allowing to access the former magmatic processes during the

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Section: Rochas Alcalinas Cretáceas Da Serra Da Mantiqueira Pasmunclassified

Section: Contexto Magmático Dos Diques Da Serra Da Mantiqueiraunclassified

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Antecristais e xenocristais máficos em diques ultrabá¡sicos de tendência alcalina da Serra da Mantiqueira (SP)

Silva¹

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Criteria for Assessing Geological Sites in National Parks: a Study in the Itatiaia National Park, Brazil

2021

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Interest in geoconservation has been growing since the 1990s and, therefore, several actions have been taken to integrate geoheritage in scientific research, public policies and nature conservation. In this context, the International Union for Conservation of Nature (IUCN) has included many initiatives to integrate geodiversity and geoheritage in a broader nature concept in its agenda. In Brazil, the protected areas follow IUCN's guidelines. Thus, this study aimed to map the distribution of geoconservation research in Brazilian National Parks and to discuss the criteria and procedures applied in the inventory of geological sites in the Itatiaia National Park that can be adapted to other Brazilian protected areas. The applied methods were carried out based on the literature review, geoprocessing techniques and application of criteria and parameters to ensure the proper assessment of geological sites. The results show that geoconservation research in national parks has been growing over the years, and the geosites located in them may compound a potential list to be included in the Brazilian geoheritage inventory. Furthermore, the application of pre-established criteria in the selection of geological sites made the qualitative process more transparent, and the identification of additional values showed to be a useful tool to help park managers to integrate geological sites in the management process. Therefore, the criteria and parameters applied in this paper may be replicated in existing Brazilian National Parks and should be considered when assessing potential areas for establishing new protected areas.

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South Atlantic Ocean

Mohriak

Almeida

Gordon

2022

Meso-Cenozoic Brazilian Offshore Magmatism

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Nepheline syenites to syenites and granitic rocks of the Itatiaia Alkaline Massif, Southeastern Brazil: new geological insights into a migratory ring Complex

Cited by 27 publications

References 67 publications

Antecristais e xenocristais máficos em diques ultrabá¡sicos de tendência alcalina da Serra da Mantiqueira (SP)

Antecristais e xenocristais máficos em diques ultrabá¡sicos de tendência alcalina da Serra da Mantiqueira (SP)

Criteria for Assessing Geological Sites in National Parks: a Study in the Itatiaia National Park, Brazil

South Atlantic Ocean

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