Basaltic Rocks
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Geochemistry, metamorphic evolution and tectonic significance of metabasites from Caçapava do Sul, southern Brazil
Abstract This paper proposes the generation and closure of a proto-ocean and formation of an island arc in the Neoproterozoic Passo Feio Metamorphic Complex (PFMC), Caçapava do Sul region, southern Brazil. The PFMC, São Gabriel Terrane, consists of a Neoproterozoic supracrustal metavolcano-sedimentary sequence intruded by the Caçapava Granite. The study u
Braz. J. Geol.. Publicado em: 29/04/2019
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2. 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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3. 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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4. 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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5. 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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6. CaracterizaÃÃo da cobertura superficial em encosta na Bacia do Rio das Pombas, Guarapuava â PR: bases para entendimento da gÃnese erosiva em tÃneis / Characterization of hillside superficial covering at the basin of Rio das Pombas, Guarapuava, Paranà state: basis for understading of tunnel erosion genesis
On the Guarapuava Plateau/Palmas, in a low slope hillside of superficial covering from basaltic origins, on the right bank of the Rio das Pombas, Paranà state, processes of tunnel erosion (pipes) were identified. These are subsuperficial erosion processes with typical features, such as subsidence of the tunnel roof and rebate structures, which tend to evolv
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/07/2011
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7. Geoquímica de rochas metabasálticas da mina da Palma, Bloco São Gabriel, escudo sul-rio-grandense: um possível platô oceânico
The Mina da Palma oceanic plateau is described for the first time in the São Gabriel Block, southern Brazilian Shield. It is composed mostly of metabasalts, marbles and metachert. Two deformational events are recognized in the Palma region, thrust faulting followed by dextral subvertical shearing. The rocks were metamorphosed in the greenschist facies, as s
Publicado em: 2010
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8. Áreas fontes dos minerais pesados e sua distribuição sobre a plataforma continental sul-brasileira, uruguaia e norte-argentina
The heavy mineral fraction of sedimentary rocks and sediments can provide important information about provenance in sedimentary basins studies because some minerals or group of minerals can be traced to a source rock or terrain of specific composition. This work is a provenance study based on heavy mineral analyses of samples collected on the Rio Grande do S
Publicado em: 2010
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9. Rock mass characterization of Morro Grande PCH using the RMR system / Compartimentação de maciços rochosos para projetos básicos de PCH´s usando o sistema RMR: aplicação no projeto básico da PCH Morro Grande - RS
The opening of the electric production sector in Brazil causes an increase amount of Small Hydroelectric Power Station - PCHs - project. The necessaries geological-geotechnical studies for this kind of construction had to be adapted to this new sector necessity, without quality losses. This research aim was the improvement of the geological-geotechnical stud
Publicado em: 2009
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10. CompreensÃo da evoluÃÃo das encostas do mÃdio vale do rio Marrecas (planalto basÃltico - SW PR) atravÃs da caracterizaÃÃo de depÃsitos de colÃvio / Understanding the evolution of hilllside middle river valley Teal (plateau basalt - SW PR) through the characterization of colluvial deposits
The object of this research is to understand the evolution of the slopes of the middle valley of Marrecas River, established in basaltic rocks, located in southwestern of Paranà state, through the characterization of two colluvial deposits. Colluviums deposits are set on the slopes of the urban area in Francisco BeltrÃo, one of them located in the Hill of
Publicado em: 2009
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11. Estratigrafia e petrogênese das sequências vulcânicas paleoproterozóicas na região de São Félix do Xingu (PA), Província Mineral de Carajás / Stratigraphy and petrogenesis of the paleoproterozoic volcanic sequences in the São Félix do Xingu (PA) region, Carajás Mineral Province
Near the São Félix do Xingu city, centersouth portion of the Pará state, in the context of the Carajás Mineral Province, occur extensive Paleoproterozoic volcanoplutonism (1.88 1.87 Ga) exceptionally well-preserved and grouped in the Sobreiro and Santa Rosa formations. These suites are generically correlated to Uatumã Supergroup volcanoplutonism, a magm
Publicado em: 2009
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12. Petrologia da sucessão magmática do Arquipélago de Abrolhos
The Magmatic Succession of Abrolhoss Archipelago is composed by four units: Olivine-Plagioclase Basalt (b1), Pyroxene-Plagioclase-Olivine Basalt (b2), Pyroxene-Plagioclase Basalt (b3) and Cumulado (b4). The units are not stratigraphically correlated. They are stacked from the basis to the top in units: b1, b2, b3 and b4. The units of the magmatic succession
Publicado em: 2008