979 resultados para Geologia -- Mètodes estadístics
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Important deposits of Zn-Pb associated with the Vazante Group, and Au in Group Canastra occur in the Vazante-Paracatu region (MG). They are located in the Brasília Fold Belt, which was generated from a convergent tectonic in the Brasiliano cycle, forming a complex system of imbricated nappes and faults. This study aims to characterize stratigraphic, structural and metamorphic aspects of an area, located in the Salobo’s farm region. A geological mapping in 1:20,000 scale was executed in order to identify the outcropping lithotypes and to collect structural measures. Drill holes were described to support the surface data and samples were selected for the preparation of thin and polished sections. In this context, the occurrence of rock types and hydrothermal processes that had not been previously described were found, for example layers of phosphatic quartzite in the Serra do Poço Verde Formation (SPV), hydrothermal hematites from martitization magnetite in contact by detachment of the Serra do Garrote Formation and SPV in the Vazante Group and layers of microbanded iron formations in Paracatu Formation (Canastra Group). In the area, four deformational phases were recognized, occurring progressively, in which two of them are related to convergent tectonic, with the development of thrust faults, one is associated to tectonic escape and/or reactivation of basement faults and the last has a distensive character, representing the post-convergence relaxation. The metamorphism in the area was subgreenschist facies, reaching lower greenschist, with temperatures up to 350°C
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The granites Rondonianos, located in Rondônia Tin Pronvíncia, the southwestern portion of the Amazonian Craton, have great economic importance due to its large potential metallogenic. These granites stands out Intrusive Suite or Suite Granites Latest Rondônia Rondônia, with approximately 997-998 Ma (Bettencourt et al., 1997, 1999), for their tin mineralization having the largest reserves of this ore from Brazil. These tin mineralization in veins greissen are genetically related to these granites, deposits with different structural styles both within granitic plutons (endogreissen) as the host rocks (exogreissen). The western region of the Massif Caritianas has few published works, and the geology and potential econômicoão that were never fully known, now with the recovery of tin in the world market need new campaigns and prospective discoveries of new deposits
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The Pampo oil field is located in the southwest of the trend Badejo-Linguado-Pampo in an accumulation of single - mixed trap: structural-stratigraphic-diagenetic. Its main reservoir is a coquina shell of bivalves (the lowest) in the Lagoa Feia Group. During the rift phase, the Badejo-Linguado-Pampo trend´s accumulations evolve according to three tectono-stratigraphic cycles. The first two cycles are formed by siliciclastic rocks with fining up sequences and carbonates coquinas bivalves. The youngest cycle related to Alagoas age is a transgressive event represented by the presence of an evaporitic layer in the top (anhydrite). This study aims to characterize the reservoir Coqueiros Formation based on the analysis of 2D and 3D seismic data and well data-correlation profiles. The structural map of the top of coquinas reservoir indicates a curvilinear contour of Pampo Fault as described on the literature. This fault was interpreted on seismic data as a basement´s high, and it doesn´t show influence on the horizons above the top of Lagoa Feia Group. The Pampo fault is responsible for the division of the field into two blocks: the hanginwall in the West and the footwall to the East. This division is well marked on the reservoir´s isopach map where a greater thickness of reservoir is observed on the lower block. In the Southeast extreme of Badejo-Linguado-Pampo trend, on Pampo Field, the thick siliciclastic´s interval ends laterally to the basement, and its lower´s cycle forms a wedge, as consequence the carbonate-coquina overlaps directly the basement. Another implication of the higher and distal position of Pampo field is that the third cycle is absent, truncated by the unconformity pre-Macaé Group (Albian)
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The study area of the Guarda-Mor target (Israelândia-GO) contextualizes the terrains of the estaern portion of the Arenópolis Magmatic Arc, more accurately, the Neoproterozoic associations inserted in the field of the Jaupaci volcano-sedimentary sequence. The mapped area is located in the central-western of Goiás state. The presente paper has as main objective to characterize the structural, petrographic and litogeochemistry of the target rocks beyond to compare these factors with the Mina Bacilândia rocks (Fazenda Nova-GO) in order to assess the genetic similarity of volcano-sedimentary units and deposits associated. The Guarda-Mor target is represented by the Jaupaci metavolcanic rocks sequence presenting bimodal volcanism. This sequence consists in metafelsic rocks like sericite/muscovite quartz schist, phyllite and metarriolites and/or metariodacites with calc-alkaline geochemical signature and metamafic rocks with tholeiitic character formed by actinolite - chlorite schist and chlorite - quartz schist. Besides the package of supracrustal rocks also can be observed the occurrence of a local intrusion syn- to late - tectonic named Granito Subvulcânico. In the study area beyond the marked volcanism also seen an event of crustal melting granitogênese evidenced by the presence of 2 granites at the east and the west of the map, Granito Israelândia and Granito Iporá respectively. Structural analysis both at the macro and micro have identified 3 deformation phases. The types of rock on the region record features in the metamorphic facies top and down. These features were subdivided into 3 metamorphic areas: the east and West areas show thermal metamorphism due to intrusion of adjacente granites while the central domain displays features of regional metamorphism. Gold mineralization of the Guarda –Mor deposit target suggests a possible structural control beyond pronounced the hydrothermal alteration. The mineralization may also be...
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Eight Mesoproterozoic granite suites are recognized in the Rondônia Tin Province, called Serra da Providência Intrusive Suite (1606-1532 Ma), Rio Crespo Intrusive Suite (1500 Ma), St. Anthony Intrusive Suite (1406 Ma), Teotonio Intrusive Suite (1387 Ma ), Santa Clara Intrusive Suite (1082-1074 Ma) and Younger Granites of Rondônia Intrusive Suite (998-974 Ma), represent successive magmatic type A (anorogenic) and the intra-plate basement rocks intruded in the metamorphic complex named Jamari separated into two distinct lithologic associations, a ortogneiss (U-Pb from 1.76 to 1.73 Ga) and a paragneiss (1675 + / - 12 Ma). Tin mineralization are widely found in the Tin Province and are associated with granitic intrusions known Mesoproterozoic more closely with the last two magmatic events, represented by the Santa Clara and Younger Granites of Rondônia. The tin mineralization are of primary and secondary, with the primary form deposits of different structural styles and is presented in the form of endo-or exogreisens, veins, stockworks and pegmatites. The secondary mineralization are related to natural processes of weathering and erosion of primary rocks, leading to placer deposits classified as colluvial, eluvial and colluvial-alluvial. The Target Alvo Sol Nascente is located in the central-eastern Rondônia Tin Province and has basement rocks of the metamorphic-magmatic region represented by Jamari Complex intrusive suites and Sierra Providence and Rio Crespo. The last tectonic event spa in the area was responsible for the intrusion of Younger Granites of Rondônia (São Carlos and Caripuanã Massifis). The anomalous levels of tin, sufficient to operate (Mina Rising Sun), indicate that there was possibly mineralization event, evidenced by pegmatite veins well defined, easily found relatively close to mine. Plaque deposits associated with Quaternary sedimentary sequences can also be observed
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Pós-graduação em Matemática em Rede Nacional - IBILCE
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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O estágio pedagógico proporciona uma oportunidade de crescimento pessoal e profissional, sendo uma etapa fundamental para a formação de um professor. O presente relatório, realizado no âmbito do Mestrado em Ensino da Biologia e da Geologia no 3º Ciclo do Ensino Básico e no Ensino Secundário, descreve o estágio pedagógico concretizado na Escola Secundária Jaime Moniz, no ano letivo de 2012/2013. O relatório teve por objetivo descrever, analisar e refletir sobre todas as atividades realizadas, as práticas vividas e as competências adquiridas e desenvolvidas ao longo da Prática de Ensino Supervisionada. Este relatório é uma síntese das atividades desenvolvidas nos seguintes domínios: Prática de Ensino Supervisionada, Atividades de Integração no Meio Escolar, Atividades de Intervenção na Comunidade Escolar e Atividades de Natureza Científico-Pedagógica. O trabalho desenvolvido ao longo do estágio e durante a escrita do relatório revelou-se um tempo importante para vivenciar e refletir a realidade do quotidiano da profissão professor e para compreender os desafios da mesma. Das várias componentes do estágio, destacou-se a prática letiva, porque foi em torno dela que decorreu o estágio, tendo o professor estagiário, através da mesma, tido a oportunidade de evoluir pessoal e profissionalmente. As atividades e as reflexões realizadas permitiram adquirir conhecimentos e competências imprescindíveis para um profissional do ensino e contribuíram para a formação integral do professor estagiário.
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A área de Potiraguá, no sul do Estado da Bahia, é constituída geologicamente por rochas metamórficas pré-cambrianas de pelo menos três idades diferentes. Os granulitos da parte oriental, representados localmente por associações ácidas e intermediárias (enderbitos), são orientados segundo N-NE, com fortes mergulhos para W. Essas rochas têm idades superiores a 2,5 bilhões de anos. Aos granulitos parecem associados migmatitos e gnaisses que ocorrem em torno de Potiraguá. Na parte ocidental, quartzitos, quartzo-muscovita-xistos e gnaisses cataclásticos formam uma seqüência mais nova, que foi correlacionada às rochas do embasamento sul do Grupo Rio Pardo, datadas do Pré-Cambriano Superior. Ao sul da área, rochas carbonáticas fracamente metamórficas foram assumidas do Grupo Rio Pardo, cujo metamorfismo ocorreu a 470 milhões de anos. Anortositos formam um maciço alongado de direção N-S, encaixado em rochas granulíticas. São compostos principalmente de andesina-labradorita, augita, hiperstênio e olivina, apresentando todas as características dos anortositos que formam intrusões independentes em terrenos pré-cambrianos de diversas partes do mundo. Não foram encontradas evidências que pudessem relacionar os anortositos às rochas da série charnoquítica (granulitos). Três maciços alcalinos foram delimitados, alinhando-se na direção N-NW. A idade das rochas alcalinas de Potiraguá foi determinada, sendo da ordem de 765 milhões de anos, bastante mais antiga em relação as outras províncias alcalinas brasileiras. Petrograficamente, foram determinadas rochas da família dos nefelina-sienitos, com tipos de transição para os litchfielditos. Em muitos casos, sodalita substitui completamente a nefelina, formando os sodalita-sienitos. Pertita constituída de microclina e albita, nefelina, cancrinita, biotita, anfibólio e sodalita são os minerais mais difundidos nas rochas da área, enquanto esfeno é, sem dúvida, o mais importante dos minerais acessórios. As determinações químicas mostraram que são rochas pobres em sílica, cálcio e magnésio e ricas em sódio e potássio, tendo um caráter atlântico forte. Alguns diagramas de variação apontaram resultados em grande parte concordantes com uma origem a partir da cristalização de um magma basáltico, não existindo, entretanto, qualquer outra prova de que este tenha sido o processo genético envolvido. Sienitos e quartzo-sienitos ocorrem próximos às rochas alcalinas, havendo notável concordância estrutural entre os quartzo-sienitos da Serra das Araras e os nefelina-sienitos, tendo sido sugerido um relacionamento genético.