Geologia e Petrologia da suíte alcalina de Bom Repouso, MG

Rosa, Pedro Augusto da Silva

doi:10.11606/d.44.2012.tde-11112013-133338

Cited by 4 publications

(14 citation statements)

References 62 publications

(120 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The geological map in Figure 1 was compiled from: Leite et al (2004), Valeriano et al (2011), Alves et al (2015), Cioffi et al (2015) and Janasi et al (2015) for regional basement; Riccomini (1989), Meisling & Cob (2001) and Zalán & Oliveira (2005) for Cenozoic tectonic; and Almeida (1983Almeida ( , 1991, Schobbenhaus et al (1984), Motoki (1986), Bellieni et al (1990), Ferrari (2001), Chiessi (2004), Trouw et al (2007), Brotzu et al (2007), Heilbron et al (2007), Azzone et al (2009), Enrich et al (2009), Guarino et al (2011) and Rosa (2012) for alkaline provinces and massifs.…”

Section: Methodsmentioning

confidence: 99%

“…Magmatism in the IAM (71.3 to 67.5 Ma, Rosa 2017) followed a regional uplift that took place from 90 to 75 Ma and was over before tectonic collapse and development of the Continental Rift of Southeastern Brazil 55 to 40 Ma ago (Riccomini 1989, Zalán & Oliveira 2005, Cogné et al 2011, 2012, Engelmann de Oliveira et al 2016, Salgado et al 2016. The massif is adjacent to Resende Basin and was emplaced near the Queluz Accommodation Zone, which separates Paraíba do Sul Rift into two different tectonic patterns (Zalán & Oliveira 2005).…”

Section: Geological Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

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

Rosa

Ruberti

2018

Braz. J. Geol.

Self Cite

View full text Add to dashboard Cite

The Itatiaia Alkaline Massif comprises some of the largest meso-cenozoic alkaline igneous occurrences in Brazil, covering over 215 km 2 between the states of Minas Gerais and Rio de Janeiro. It appears as an elongated, 30-km long and 4.5-11.5-km wide SE-NW-trending body emplaced along accommodation zones of the Continental Rift of Southern Brazil, intruding metapelites, orthogneiss and granites of the Brasília and Ribeira fold belts. New data and geological mapping suggest that the massif evolved from a migratory magmatic center manifested as ring structures and successive moon-shaped intrusions from SE to NW in three sectors of distinct lithological and geomorphological characteristics: Southeastern, Central and Northwestern. The lithological variants in the three sectors present themselves as discrete intrusive bodies, comprising feldspathoid-bearing and quartz-bearing syenites, porphyritic to breccioid trachytes, granite, monzonite, gabbro and trachybasalt, which can be grouped into 21 units. These rocks occur in five petrographical sets: plagioclase-free nepheline syenites, plagioclase-bearing nepheline syenite and pulaskites, nordmarkite-granite series, anti-rapakivi associations and basic rocks. Sin-to tardi-plutonic dykes of nephelinites, phonolites, trachytes and rhyolites are also present.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Geological Evolutionmentioning

confidence: 99%

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

Rosa

Ruberti

2018

Braz. J. Geol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The magmatic events dated~70-90 Ma [38,45] are the most abundant and widespread ones, assembling all the remaining Brazilian alkaline centers. They include rock bodies of agpaitic affinity, of which the Poços de Caldas [14,[58][59][60][61], Itatiaia [15,40,43], Passa Quatro [19,20], Bom Repouso [21], Monte de Trigo Island [25,62], Lages [63] and Búzios Island [64,65] suites are examples.…”

Section: Alkaline Magmatism In Southern Brazilian Platform: Background Informationmentioning

confidence: 99%

Agpaitic Alkaline Rocks in Southern Brazilian Platform: A Review

et al. 2021

View full text Add to dashboard Cite

General information is presented on ten agpaitic occurrences located in southern Brazil and at the border between Brazil and Paraguay. All the Brazilian agpaitic rocks are Late Cretaceous in age, whereas the Paraguayan ones are older than Early Triassic. The most significant occurrence is Poços de Caldas, the largest alkaline massif in South America. In general, these agpaitic rocks contain mineral assemblages that indicate presence of typical halogen-bearing Na–Ca–HFSE phases, eudialyte-, rinkite- and wöhlerite-group minerals being the most frequent ones. However, these associations are indeed more complex in terms of composition, with accessory phases in some cases consisting of various minerals, including U–Th oxides/silicates, Nb oxides, REE–Sr–Ba bearing carbonates–fluorocarbonates–phosphates–silicates and Zr–Na rich silicates. They usually form late magmatic stage to hydrothermal/deuteric assemblages linked with coarse and fine-grained, mainly silica-undersaturated evolved rocks. Data also indicate significant differences in type, amount and composition of agpaitic minerals in all investigated occurrences.

show abstract

“…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

“…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

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

Silva¹

View full text Add to dashboard Cite

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

show abstract

Geologia e Petrologia da suíte alcalina de Bom Repouso, MG

Cited by 4 publications

References 62 publications

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

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

Agpaitic Alkaline Rocks in Southern Brazilian Platform: A Review

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

Contact Info

Product

Resources

About