Clinopyroxene
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Geochemistry of basaltic flows from a basalt ring structure of the Serra Geral formation at Água Vermelha dam, Triângulo Mineiro, Brazil: implications for the magmatic evolution of the Paraná-Etendeka Province
ABSTRACT: The Serra Geral Formation belongs to the Paraná-Etendeka Magmatic Province (PEMP) and its geochemical and petrographic characteristics are not homogeneous. Many studies segment this group into six basaltic and two rhyolitic magma-types. It is believed that its extrusion occurred through crustal fissures in the Cretaceous, but some authors describe
Braz. J. Geol.. Publicado em: 2018-06
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2. Melanite-bearing nepheline syenite fragments and 40Ar/39Ar age of phlogopite megacrysts in conduit breccia from the Poços de Caldas Alkaline Massif (MG/SP), and implications
ABSTRACT: The Poços de Caldas Alkaline Massif, located in southeast Brazil, is composed of tinguaites, as well as phonolites and nepheline syenites (NeS), together with assorted pyroclastic rocks. The latter constitute deposits within the Vale do Quartel, and show fragments of alkaline rocks (NeS, tinguaites), basaltic and ultramafic volcanics/subvolvanics,
Braz. J. Geol.. Publicado em: 2018-06
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3. Upper Cretaceous weakly to strongly silica-undersaturated alkaline dike series of the Mantiqueira Range, Serra do Mar alkaline province: Crustal assimilation processes and mantle source signatures
ABSTRACT: Three series of alkaline dikes are characterized in a restricted area of the Mantiqueira Range: a weakly silica-undersaturated series (normative ne < 7), of potassic character, represented by basanite, tephrites, alkali basalts, basaltic trachyandesites, phonotephrites, tephriphonolites, and trachyandesites, an intermediate series (7 > normative ne
Braz. J. Geol.. Publicado em: 2018-06
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4. Geology, geochemistry and petrology of basalts from Paraná Continental Magmatic Province in the Araguari, Uberlândia, Uberaba and Sacramento regions, Minas Gerais state, Brazil
Abstract: This study covers the region between the cities of Sacramento and Araguari/Uberlândia (Minas Gerais State, Brazil), where basalt flows from the Paraná Continental Magmatic Province outcrop. The investigated rocks present tholeiitic signature, with high titanium content, and are classified as Pitanga magma-type. The preserved basalt thickness is b
Braz. J. Geol.. Publicado em: 22/02/2018
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5. The Buritizal meteorite: classification of a new Brazilian chondrite
Abstract On August 14, 1967, the reporter Saulo Gomes, working at TV Tupi, went to a small city in the State of São Paulo called Buritizal to investigate reports of a meteorite fall and write a newspaper report. He actually recovered three fragments of the meteorite at a small farm. In 2014, he donated one of the fragments to the Museu Nacional of the Unive
REM, Int. Eng. J.. Publicado em: 2017-06
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6. Paralavas in the Cretaceous Paraná volcanic province, Brazil - A genetic interpretation of the volcanic rocks containing phenocrysts and glass
ABSTRACT The occurrences of glassy rocks containing long and curved phenocrysts in the Paraná volcanic province, South America, are here interpreted as paralavas. The large number of thin (0.1-0.5 m) dikes and sills of glassy volcanic rocks with hopper, hollow or curved, large crystals of clinopyroxene (up to 10 cm), plagioclase (up to 1 cm), magnetite and
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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7. Geoquímica das rochas máficas toleíticas da suíte pós-colisional Paulo Lopes, Neoproterozóico do Sul do Brasil
The Paulo Lopes Suite (SPL), composed of the Paulo Lopes Granite (GPL), Garopaba Granitoids (GG) and Silveira Gabbro (GS), is an association of contemporaneous acid and basic rocks, comprising monzo and syenogranites associated to basic dikes, with abundant mafic microgranular enclaves, interpreted as co-mingling products. The contacts between the granitoids
Publicado em: 2010
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8. Geoquímica de Sills Basálticos da formação Serra Geral, sul do Brasil, com base em rocha total e micro-análise de minerais
O grande magmatismo intracontinental ocorrido a 133 Ma na Bacia do Paraná foi desenvolvido por um sistema fissural no qual a interação da Pluma Tristão da Cunha na base da litosfera (com ou sem contaminação crustal) gerou derrames, diques e sills no Brasil, nos Estados do RS, SC, PR, SP, MT, MS e GO, e em parte do Paraguai, Argentina e Uruguai. Na Form
Publicado em: 2010
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9. Petrogêneses do complexo vulcânico Yate (42, 30ºS), Andes do Sul, Chile / Petrogenesis of the Yate Volcanic Complex (42, 30ºS), Andes Southern, Chile
The Yate Volcanic Complex (CVY) is located in the Southern Volcanic Zone of the Chilean Andes, at 42°30S, comprising the Yate, Gualaihué and Hornopirén volcanoes. The Yate volcano is a major compound type in which effusive activity occurred since Upper Pleistocene (c. 122 ka) until Holocene. Hornopirén and Gualaihué are minor, and represent strombilian-
Publicado em: 2009
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10. Geology of high pressure granulites of Carvalhos Klippe, southern Brasília Belt / Geologia dos granulitos de alta pressão da Klippe Carvalhos, extensão sul da Faixa Brasília
At the top of Andrelândia Nappes System, southern border of São Francisco craton, occur nappes formed dominantly by metasedimentary rocks with subordinated metabasics and metaultramafics which record metamorphism of high pressure granulite facies in the Ediacaran. These nappes are Três Pontas - Varginha, Pouso Alto and Klippen Airuoca and Carvalhos. In Ca
Publicado em: 2009
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11. Mineralogia e petrologia de xenólitos mantélicos das regiões de Ubatuba (SP) e Monte Carmelo (MG): evidências de fusão parcial e metassomatismo no manto superior do sudeste do Brasil / Mineralogy and petrology of mantle xenoliths from Ubatuba (SP) and Monte Carmelo (MG): melting and metasomatism evidences in the upper mantle from southeast Brazil
Mineralogical and petrological studies were conducted in mantle xenoliths included in a kaersutite lamprophyre dyke from Ubatuba (SP) (Serra do Mar Igneous Province), and in the Limeira 1 Kimberlite (Monte Carmelo, MG; Alto Paranaíba Alkalic Province), using petrography and major and trace element geochemistry in minerals by electron microprobe and LA-ICPMS
Publicado em: 2009
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12. PETROGÊNESE DO COMPLEXO ACAIACA, MG
The Acaiaca Complex (AC) is composed of mainly granulite facies rocks distributed along the Acaiaca county and surroundings, east of the Quadrilátero Ferrífero. The present work aimed to investigate the lithological diversity of the AC with emphasis on the mineralogical, microstructural, geochemical and petrogenetic characterization. The lithostructural su
Publicado em: 2009