Basalts
Mostrando 13-24 de 55 artigos, teses e dissertações.
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13. Os Depósitos de Cu-Au-Mo do tipo pórfiro de Bajo de La Alumbrera e Água Rica, Argentina : considerações genéticas sobre formação e fonte de minério
The world-class deposits of Bajo de la Alumbrera and Agua Rica in NW Argentina, are of the Cu-Au-Mo porphyry type (although Agua Rica has some epithermal characteristics). Both deposits are closely related to the activities and formation processes of the Miocene Farallón Negro Volcanic Complex. They are also controlled by the Tucuman Transfer Zone, which is
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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14. Petrologia, caracterização geológica, geoquímica e geocronológica do magmatismo pré, sin e pós-colisional presente no Complexo Metamórfico Brusque nas regiões de Itapema e Botuverá, Santa Catarina, Brasil
Este trabalho objetiva a caracterização petrológica, geoquímica, geocronológica e metamórfica das rochas ortoderivadas pertencentes ao Complexo Metamórfico Brusque em duas regiões: Itapema e Botuverá, Santa Catarina, Brasil. Dos litotipos, destacam-se as exposições de rochas metamáficas e metaultramáficas, ocorrentes em ambas regiões. Em Itapem
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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15. Structural constraints on Paraná basalt volcanism and their implications on agate geode mineralization (Salto do Jacuí, RS, Brazil)
The Paraná-Etendeka Continental Flood Basalt province hosts world-class agate and amethyst geode deposits in Rio Grande do Sul (Brazil; Serra Geral Fm.). Salto do Jacuí Mining District (Rio Grande do Sul, Brasil) has different types of agate geode hosted in vesicular basalt. A series of structural features has recently been investigated in the Salto do Jac
Publicado em: 2010
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16. 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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17. 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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18. 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
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19. DETERMINAÇÃO DE ELEMENTOS MENORES E TRAÇO EM ROCHAS POR LA-ICPMS: PROGRESSOS NA UTILIZAÇÃO DE VIDROS BORATOS COMO ALVOS / DETERMINATION OF MINOR AND TRACE ELEMENTS IN ROCK SAMPLES BY LA-ICPMS: PROGRESS IN THE UTILIZATION OF BORATE GLASSES AS TARGETS
The present master dissertation is a continuation of a research study developed by Leite (2006) aiming at the multielemental analysis of rock samples (basalts, obsidians and shale) by inductively coupled plasma mass spectrometry (ICPMS), in combination with laser ablation (LA) and using borate glass as analytical targets. As in the former work, the experimen
Publicado em: 2009
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20. 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
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21. Contribuição ao estudo dos métodos de ensaio na avaliação das reações álcali-agregado em concretos. / Contribution to the study of test methods in assessing alkali-aggregate reactions in concrete.
Many concrete structures have been suffering from alkali-aggregate reactions (AAR) since the last decades in Brazil and around the world. The reactions generate expansions that could compromise the strength of a concrete structure as well as its performance in service and its durability. Nowadays, it is completely possible to detect AAR in the field, but rep
Publicado em: 2008
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22. Geoquímica de rocha total, geocronologia de u-pb e geologia isotópica de sm-nd das rochas ortognáissicas e unidades litológicas associadas da região ipameri - Catalão (Goiás)
The part of the southern Brasília Belt, Tocantins Province, exposed in central Brazil, comprises metasedimentary rocks, metavolcano-sedimentary sequences, amphibolites and intrusive granites, and a large orthogneiss belt. These units are tectonically imbricated, and vary in metamorphic grade from lower greenschist to amphibolite facies, characterized by a 7
Publicado em: 2008
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23. A história do intemperismo na Província Borborema Oriental, Nordeste do Brasil: implicações paleoclimáticas e tectônicas
Until some years ago, weathering geochronology was primarily based on the K-Ar and 40Ar/39Ar dating of supergene minerals. Recent advances in the analysis of supergene goethite by the (U-Th)/He method expanded the number of suitable minerals for such purpose, as well as the time of application for weathering geochronology. This study represents the first sys
Publicado em: 2008
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24. Reavaliação do contexto tectonico dos basaltos do greenstone belt do Rio Itapicuru (Bahia), com base na geoquimica de elementos-traço / Tectonic setting of basalts from the Rio Itapicuru greenstone belt revisited (Bahia, Bazil) by trace-element geochemistry
The Paleoproterozoic Rio Itapicuru Greenstone Belt, situated in the Serrinha Block - northeast São Francisco Craton, has a sequence of basaltic rocks whose tectonic setting is under discussion, i.e whether a back arc setting or intracontinental rift. The basalt geochemistry was revisited on the basis of incompatible trace elements data, such as high field s
Publicado em: 2007