EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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3 resultados
Resultados da Pesquisa
Item Genesis of clayey bodies in Quadrilátero Ferrífero, Minas Gerais, Brazil.(2004) Santos, Marcelo Cabral; Varajão, Angélica Fortes Drummond Chicarino; Yvon, JacquesThis work deals with macromorphological, mineralogical, micromorphological and geochemical studies in clayey bodies from Quadrilátero Ferrı́fero in order to define their genesis and formation conditions in this geologic province from Minas Gerais State. Methodologies, based on the description of outcrops and drill cores, using X-ray diffraction (XRD), differential and gravimetric thermal analyses (DTA-TG), scanning electron microscopy (SEM), optical analysis of thin sections and chemical analyses allowed for the definition of two different genetic types of clayey bodies. One type, SET 1, occurs upon saprolitic material from Paleoproterozoic rocks in unconformity contact. It is constituted, from the base to the top, by four facies: nodular, ferruginous kaolinitic, mottled kaolinitic, and massive kaolinitic. The origin of this set is related to the deposition of lateritic materials by gravitational process. The faciological differentiation of this set is related to the syn-depositional process and postdepositional mechanisms of ferruginization and deferruginization. The second type, SET 2, is composed by an ilmenitic–kaolinitic tabular facies in discordant relationships with the saprolite material from Paleoproterozoic rocks. The origin of this second set is related to “in situ” alteration of intrusive rocks of acidic composition.Item Geochemical evolution of the capim river kaolin, northern Brazil.(2006) Sousa, Daniel José Lima de; Varajão, Angélica Fortes Drummond Chicarino; Yvon, JacquesThe Capim River kaolin, located in the eastern Brazilian Amazon, constitutes one of the most important kaolin deposits in the world. Known for its high whiteness, its noble application is in the paper industry. Studies were carried out on samples from the six facies of the deposit (sand kaolin, soft kaolin, lower transition facies, ferruginous crust, upper transition facies and flint kaolin) in order to trace its geochemical evolution. The kaolin developed at the expense of Cretaceous sandy–clayey sediments of the Ipixuna Formation. Intense lateritic processes characterized by ferruginization and deferruginization mechanisms led to the distinction of the different facies.Item Geochemistry of a sedimentary lateritic kaolin deposit in Quadrilátero Ferrífero, Brazil.(2006) Santos, Maria do Carmo; Varajão, Angélica Fortes Drummond Chicarino; Yvon, JacquesThe present study deals with the mineralogy and geochemistry of the clayey facies of the Água Limpa kaolin deposit, situated in the Moeda Syncline, Quadrilátero Ferrífero, Minas Gerais, Brazil. Kaolinite, quartz, oxides and iron hydroxides (hematite and goethite) represent the mineral assembly of the five facies of the deposit. White mica, rutile, anatase and gibbsite are heterogeneously distributed along the profile. Despite the variable behavior of the chemical elements along the profile, the geochemical patterns for major and rare earth elements enable to define the filiations generated by the laterization process that affected the sediments.