Basalts
Mostrando 1-12 de 55 artigos, teses e dissertações.
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1. The Barreiro suite in the central Ribeira Belt (SE-Brazil): a late Tonian tholeiitic intraplate magmatic event in the distal passive margin of the São Francisco Paleocontinent
Abstract New geochemical, U-Pb, Lu-Hf and Sr-Nd data from the Barreiro Suite metabasites in comparison with enclaves within the distal Andrelândia Group and the orthogranulites of the Juiz de Fora Complex are presented. Geochemical data suggest intraplate setting, with high and low-TiO 2 , TDM Nd ages between 1.80 and 1.41 Ga, negative ΕNd t and ( 87 Sr/ 8
Braz. J. Geol.. Publicado em: 20/05/2019
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2. 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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3. 2D magnetometric modeling of a basic-intermediate intrusion geometry: geophysical and geological approaches applied to the Limeira intrusion, Paraná Magmatic Province (SP, Brazil)
ABSTRACT: The Limeira Intrusion is an occurrence related to the Mesozoic continental flood basalts of Paraná Magmatic Province, cropping out at the eastern São Paulo state. It is made up of basic-intermediate rocks with a great diversity of structures, textures and modal compositions, related to specific evolutionary process in a magma chamber. Previous ge
Braz. J. Geol.. Publicado em: 2018-06
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4. 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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5. 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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6. 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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7. Pb isotope geochemistry and reappraisal of Sr-Nd isotopes of the Cerro Morado basic magmatism (Ischigualasto-Villa Union Triassic basin, NW Argentina): Implications for the mantle sources
ABSTRACT: Sr-Nd-Pb isotopic signatures were determined for silica-undersaturated hypabyssal alkaline basic rocks of the Los Baldecitos Formation in the Cerro Morado area, situated in the Ischigualasto - Vale de la Luna Provincial Park (northernmost San Juan Province, Argentina). The basic rocks show slight variations of the Sr-Nd-Pb isotopes and similar beha
Braz. J. Geol.. Publicado em: 2018-01
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8. Petrography and geochemistry of the Pedra Dourada Granulite, southeastern Minas Gerais, Brazil
Abstract The Pedra Dourada Granulite (PDG) occurs at the southeastern portion of the Araçuaí Belt, north of the town of Ponte Nova. It comprises bodies up to 45 km2 inserted into amphibolite-facies gneisses of the Mantiqueira Complex. Motivated by the discrepancy of metamorphic grade with surrounding rocks, this paper presents results of the petrographic a
REM, Int. Eng. J.. Publicado em: 2016-12
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9. Caracterização geológico-geotécnica de diferentes litotipos basálticos: basalto denso, basalto vesículo-amigdaloidal e brecha basáltica / Geological-geotechnical characterization of different basaltics lithotypes: dense basalt, vesicular-amygdaloidal basalt and basaltic breccia
Esta dissertação apresenta a caracterização geológico-geotécnica de diferentes litotipos basálticos, abrangendo basaltos densos, basaltos vesículo-amigdaloidais e brecha basáltica. Estes materiais são oriundos de quatro derrames basálticos pertencentes à Formação Serra Geral, região da barragem de Itaipu. Para a caracterização foram realizad
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/04/2012
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10. Petrologia e geocronologia do complexo máfico-ultramáfico trincheira, sudoeste do cráton amazônico: implicações tectônicas do mesoproterozóico
The tectonic framework of the ultramafic-mafic rocks of the southwestern Amazon Craton is generally little known. Most of work this cratonic portion is focused on the geochronological studies of granitoids, so that little is known about the origin and tectonic significance of these rocks. In this context, this study contributes to the knowledge of the tecton
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012
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11. Prospecção geoquímica: estaurolita, ilmenita e magnetita como minerais traçadores para depósitos do tipo VMS / Chemistry prospection: staurolite, ilmenite, magnetite guide minerals for VMS deposits
The Itutinga region was studied for BP mineration in 80s , where they found sulphide mineralization in lenses (Zn-Cu-Ag-Fe) associated with komatiitic peridotite rocks and tholeitic basalts (amphibolites) of greenstone belts, near of Fazenda São Jerônimo. With this information in the literature the propose is study the staurolite, magnetite and ilmenite fo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/09/2011
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12. Tipologia e origem das fraturas sub-horizontais em basaltos da Formação Serra Geral, Brasil / Typology and origin of subhorizontal fractures in basalts of Serra Geral Formation, Brzil
Nos derrames basálticos da Formação Serra Geral são reconhecidas numerosas ocorrências de fraturas sub-horizontais de grande continuidade lateral. Tais fraturas, de até centenas de metros de extensão, foram consideradas estruturas típicas em derrames e constituem importantes descontinuidades na estabilidade de obras de engenharia e como rotas de perc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/04/2011