Metamorphism
Mostrando 25-36 de 40 artigos, teses e dissertações.
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25. 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
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26. ZEOLITE AND WOLASTONITE SYNTHESIS FROM RICE HULL ASH / "Síntese de Zeólitas e Wolastonita à partir da cinza da casca do arroz"
Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wolastonite (CaSiO3). The synthetic zeolites, has not similar structures in nature, an
Publicado em: 2006
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27. Genese dos depositos auriferos em metaconglomerados da formação moeda, Quadrilatero Ferrifero, MG : o papel do metamorfismo e associação com a materia carbonosa / Genesis of the metaconglomerate-hosted gold deposits of the moeda formation, Quadrilatero Ferrifero (State of Minas Gerais) : role of the metamorphism and the association with carbonaceous matter
The Quadrilátero Ferrífero has historically been one of the most important gold province in Brazil, with a significant number of productive greenstone-hosted lode gold deposits within the Rio das Velhas Supergroup together with those associated with the metasedimentary sequence of the Minas Supergroup. At the base of the Moeda formation, Minas Supergroup,
Publicado em: 2005
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28. Analise estrutural do Pluton Abancay e sua importancia na evolução tectonica da porção Sul de Abancay - Peru / Structural analysis of the Abancay Pluton and its importance in the tectonic evolution of the southern Abancay region - Peru
Este trabalho objetiva determinar o comportamento estrutural, assim como as características petrográficas, metamórfica e idade do Plúton Abancay. A área de estudo abrange aproximadamente 280 km2 e está localizada na parte central da Cordilheira Ocidental dos Andes Peruanos, Província de Abancay, sul do Perú. Geologicamente a área situa-se no extremo
Publicado em: 2005
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29. CaracterizaÃÃo geolÃgica da regiÃo situada entre as localidades de Paranatama e Currais Novos (PE), porÃÃo Centro-Norte do DomÃnio TectÃnico Pernambuco-Alagoas, ProvÃncia Borborema
This thesis presents the geological characteristics of an important region inserted in the Pernambuco-Alagoas Tectonic Domain (PEALTD), considered as an integrated part of a Neoproterozoic orogenic belt that borders the northern portion of the SÃo Francisco Craton. In this context, the main geological units that outcrop in the PEALTD are: 1) Paleoproterozoi
Publicado em: 2005
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30. Mid amphibolite facies metamorphism of harzburgites in the Neoproterozoic Cerro Mantiqueiras Ophiolite, southernmost Brazil
O estudo integrado de relações geológicas, micro-estruturais e composição química de minerais resultou na obtenção de informações muito valiosas sobre a evolução dos harzburgitos do Ofiolito Cerro Mantiqueiras, de idade Neoproterozóica. Este importante marcador geotectônico da evolução geológica do extremo sul do Escudo Brasileiro foi serpen
Anais da Academia Brasileira de Ciências. Publicado em: 2003-03
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31. Evolução geologica das rochas maficas e ultramaficas no Greenstone Belt Barbacena, região de Nazareno, MG
The study area is located at the southem border of the São Francisco Craton and shows plutonic, vo1canic and sedimentary rocks, of Archean to Mesoproterozoic age, reworked by later thermo-tectonic events. Two different groups of mafic and ultramafic rocks occur in this region. The first is a komatiite-tholeiite sequence belonging to the Barbacena Greenstone
Publicado em: 2002
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32. Ion microprobe (SHRIMP) dates complex granulite from Santa Catarina, southern Brazil
Complex polymetamorphic granulites have been dated in the Santa Catarina granulite complex of southern Brazil through SHRIMP study of zircon. This complex is dominated by intermediate-acid plutonic rocks and contains small volumes of mafic and ultramafic rocks, and minor quartzite and banded iron formation. Porphyroblasts of orthopyroxene, clinopyroxene and
Anais da Academia Brasileira de Ciências. Publicado em: 2000-12
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33. Evolução geologica dos terrenos de alto grau metamorfico da Faixa Ribeira na região de Juiz de Fora, Minas Gerais
The orthogneisses of the Ribeira Belt, in the Juiz de Fora area, were submitted to a sequence of geologic processes during times previous to Ett Brasiliano (tectono-thermal event), that generated this belt. The present study intends to recover and to reconstitute the geological evolution related to these processes. The units are distributed in two main tecto
Publicado em: 1999
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34. Caracterização tectono-metamorfica do deposito aurifero Ambrosio, Greenstone Belt do Rio Itapicuru - Bahia
The Ambrósio lode gold deposit, located in the northem sector ofthe lower Proterozoic (2.200 to 2.000 Ma) Rio Itapicuru greenstone belt, northeast Brazil, is enclosed within a narrow belt ofhighly deformed supracrustals, tightly squeezed between two syn-tectonic granitic batholiths (pedra Alta and Ambrósio domes). The deposit is hosted at the contact of am
Publicado em: 1996
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35. Estudos geoquimicos e isotopicos das mineralizações auriferas e rochas associadas da Região de Pontes e Lacerda (MT)
Geochemistry and isotope studies were carried out on the gold deposits of Pontes e Lacerda region (Mato Grosso state, Brazil) where rocks of the Aguapei and Rondoniense mobile belts (SW of Amazon Craton) occur. The stratigraphy of this part of Amazon Craton consists of the Pontes e Lacerda Metavulcano-sedimentar Sequence (PLMVSS), Santa Helena Granite-Gneiss
Publicado em: 1996
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36. Estudo lito-estrutural das mineralizações auriferas nos arredores de São Gonçalo do Sapucai - Campanha Minas Gerais / A litho-structural study of gold mineralization in the environs of São Gonçalo do Sapucai - Campanha, Minas Gerais
A detailed geological study around São Gonçalo do Sapucaí, Campanha and Monsenhor Paulo in southern Minas Gerais, has shown the area to be underlain by two distinct lithological units; one belonging to the Amparo Group - (X" basement gneisses; and the other to the supracrustals of the Andrelândia Group. The basement gneisses comprise hornblende tonalite
Publicado em: 1994