Time-space distribution of silicic plutonism in a gneiss dome of the Iberian Variscan Belt: The Évora Massif (Ossa-Morena Zone, Portugal)

In the Iberian Variscan Belt, polyphasic deformation has been recognized as comprising an early phase of crustal thickening, followed by an intermediate phase of crustal extension and doming, and a later phase of shortening. The Évora Massif is a gneiss dome of the westernmost domains of the Ossa-Morena Zone (SW Iberia), which provides a remarkable insight into the late Paleozoic deep crustal structure of the Variscan continental crust of northern Gondwana. In this study, we bring new structural and geochronological U-Pb data for the northern hanging-wall of the Évora Massif. We describe the existence of low-dipping D2 extensional shear zones associated with Buchan-type metamorphism (M2); this enables three tectono-metamorphic units to be distinguished: the Lower Gneiss Unit, the Intermediate Schist Unit, and the Upper Slate Unit. D2-M2 structures experienced sub- horizontal shortening (D3) and were transposed by low-plunging folding, thrusting and strike-slip faulting. Zircon grains extracted from Pavia quartz-feldspathic gneiss of the Lower Gneiss Unit yielded a crystallization age of ca. 521 Ma (Cambrian Stage 2–3), which establishes a correlation with tectono-metamorphic units of the footwall and southern hanging-wall of the Évora Massif. U-Pb zircon dating of Divôr foliated quartz-diorite (339 ± 7 Ma), Malarranha weakly foliated biotite-rich granite (322 ± 3 Ma), and undeformed porphyritic granite of the Pavia pluton (314 ± 4 Ma) constrain the timing of emplacement of granitic magmas synchro- nously with doming. Carboniferous magmatism initiated with doming (ME1 - ca. 343–335 Ma), continued through D2-M2 (ME2 - ca. 328–319 Ma), and lasted until the waning stage of crustal extension (ME3 - ca. 317–313 Ma). The Évora Massif gneiss dome probably formed as result of the combined effect of gravitational collapse of the thickened crust and buoyancy-driven gravitational instability developed in the partially molten continental crust influenced by the transfer of heat from rising mantle-derived (i.e. dioritic-gabbroic) magmas rocks found in the footwall of the Évora Massif

Age of the basement beneath the Mesozoic Lusitanian Basin revealed by granitic xenoliths from the Papôa volcanic breccia (West Iberia)

The dyke of the Papôa volcanic breccia cross-cutting the Lower Jurassic sequence of the Lusitanian Basin (West Iberia) contains granitic xenoliths. In this study, for the first time, U-Th-Pb zircon analysis of two xenoliths yielded 298 ± 4 Ma for biotite granite and of 292 ± 2 Ma for two-mica granite, indicating that the pre-Mesozoic basement of the Lusitanian Basin includes Permian intrusions. These ages are close within the margin of error of the age of the Late Carboniferous granites of the Berlengas isle that with the Late Devonian high-grade metamorphic rocks of the Farilhões isles, located northwest of the study area, which form the pre-Mesozoic basement of the Lusitanian Basin. These new geochronological findings enable it to be established that Permo-Carboniferous magmatism lasted at least 13 Ma, in this region of the Appalachian-Variscan belt. Furthermore, a comparison with available data from Paleozoic tectonic units of the Appalachian-Variscan belt located both in the Iberian Massif and outside it enables the suggestion to be made that the Lusitanian Basin (Peniche) most probably rests on the South Portuguese Zone, which may also be correlated with the Rhenohercynian Zone present in southwest England, and the Meguma terrane of Nova Scotia

Age of the basement beneath the Mesozoic Lusitanian Basin revealed by granitic xenoliths from the Papôa volcanic breccia (West Iberia)

The dyke of the Papôa volcanic breccia cross-cutting the Lower Jurassic sequence of the Lusitanian Basin (West Iberia) contains granitic xenoliths. In this study, for the first time, U-Th-Pb zircon analysis of two xenoliths yielded 298±4Ma for biotite granite and of 292±2Ma for two-mica granite, indicating that the pre-Mesozoic basement of the Lusitanian Basin includes Permian intrusions. These ages are close within the margin of error of the age of the Late Carboniferous granites of the Berlengas isle that with the Late Devonian high-grade metamorphic rocks of the Farilhões isles, located northwest of the study area, which form the pre-Mesozoic basement of the Lusitanian Basin. These new geochronological findings enable it to be established that Permo-Carboniferous magmatism lasted at least 13Ma, in this region of the Appalachian-Variscan belt. Furthermore, a comparison with available data from Paleozoic tectonic units of the Appalachian-Variscan belt located both in the Iberian Massif and outside it enables the suggestion to be made that the Lusitanian Basin (Peniche) most probably rests on the South Portuguese Zone, which may also be correlated with the Rhenohercynian Zone present in southwest England, and the Meguma terrane of Nova Scotia

From reading literature in secondary school to its learning assessment in the 12th year national exam

Literature plays a core role in the class of Portuguese Language, a specialised context for teaching literacy competencies. This text reports a study about knowledge and skills privileged in literary texts’ reading in national exams. A document analysis of seventeen exams of Portuguese, used by the Ministry of Education between 1996 and 2012, was conducted to identify the “reading objects” chosen for the exams, the text structures that were the focus of the questions and the reading operations requested. The results show that besides the central role of the national literary canon in the assessment, contemporary poetry texts are the preferred “reading objects”. This allows the conclusion that questions about literary contents aim to evaluate student’s critical thinking regarding works by canonical authors. The study also showed that reading literature is perceived as the act of understanding and (re)constructing the meanings of a text by an active and competent reader.La literatura juega un papel central en la clase de Lengua Portuguesa, como contexto especializado para la enseñanza y el aprendizaje de competencias de alfabetización. Este texto reporta un estudio sobre el conocimiento y las habilidades privilegiadas en los exámenes nacionales externos. Un análisis de diecisiete exámenes de Portugués, del Ministerio de Educación entre 1996 y 2012, ha identificado “objetos de lectura” elegidos, estructuras textuales enfocadas por las preguntas y operaciones de lectura requeridas. Los resultados revelan el papel central del canon literario nacional en la evaluación y que los textos poéticos contemporáneos son los “objetos de lectura” preferidos. Se concluye que las preguntas sobre contenidos literarios se plantean evaluar el pensamiento crítico del estudiante con respecto a las obras de autores canónicos y que la lectura se percibe como el acto de comprender y (re)construir los significados de un texto por un lector activo y competente.La littérature joue un rôle central dans la classe de Langue Portugaise, un contexte spécialisé pour l’enseignement des compétences en littératie. Ce texte présente une étude sur les connaissances et compétences privilégiées dans la lecture de textes littéraires aux examens nationaux. Une analyse de dix-sept examens de Portugais, utilisés par le Ministère de l’Éducation entre 1996 et 2012, a été menée afin d’identifier “objets de lecture” choisis pour les examens, structures de texte au centre des questions et opérations de lecture demandées. Les résultats montrent que, outre le rôle central du canon littéraire dans l’évaluation, textes de poésie contemporaine sont les “objets de lecture” préférés. Cela permet la conclusion que les questions concernant le contenu littéraire visent à évaluer la pensée critique de l’élève concernant les œuvres d’auteurs canoniques. L’étude a également montré que la lecture littéraire est perçue comme (re)construction de la signification d’un texte par un lecteur compétent.CIED - UMinhoinfo:eu-repo/semantics/publishedVersio

Revisiting the Ediacaran-Cambrian boundary in the Ossa-Morena Zone (SW Iberia)

Some of the best outcrops of Iberia to study the Ediacaran-Cambrian boundary are located in the Ossa- Morena Zone. In the Crato-Campo Maior region (SW Iberia, Portugal), this stratigraphic boundary is marked by an angular unconformity (Gonçalves, 1971). The Ediacaran sedimentary rocks of the Série Negra Group (maximum depositional age of c. 545 Ma; Linnemann et al., 2008) are overlain by Early Cambrian strata. A folded foliation has been recognized in the Ediacaran metagreywackes, metapelites, black metachert, marbles and metabasic rocks (Pereira & Silva, 2002). This deformation event is previous to the intrusion of c. 526-525 Ma granitic rocks (Barquete and Barreiros plutons; Pereira et al., 2011; Sánchez-García et al., 2013), and is not represented in the unconformable overlying Early Cambrian strata including sandstone (maximum depositional age of c. 532 Ma; Pereira et al., 2011). At the base of the lower Cambrian stratigraphic section there is the Freixo-Segóvia volcanosedimentary complex consisting of felsic tuff interbedded with conglo-merate and rhyolitic-dacitic lava flow (Pereira et al., 2006). The conglomerate is composed of pebbles of volcanic rock (basalt, rhyolite, dacite and mafic and felsic tuff), granitic rocks, chert, quartzite, arkosic sandstone, greywacke and shale in a tuffaceous sandy matrix. This volcano-sedimentary complex is overlain by a sequence of sandstone and shale passing vertically to limestone beds which have been attributed to the lower Cambrian (Pereira et al., 2006) (see Fig. 12). An ongoing research project intends to date the volcanic rocks of the volcano-sedimentary complex using U-Pb zircon geochronology. The absolute dates determined from these volcanic rocks will provide the time framework for the calibration of the existing stratigraphic scheme based on regional correlation

Aplicação do algoritmo LEGAL/SPRING na cobertura florestal do município de Ivorá/RS nos anos de 2011 e 2012.

Neste trabalho, foram utilizadas técnicas de sensoriamento remoto a fim de analisar a distribuição dos recursos florestais do Município de Ivorá, RS, enfocando sua evolução, para, com isso, manejar a área do município visando a sustentabilidades de suas atividades. A área de estudo é caracterizada pelos biomas Mata Atlântica e Pampa, característicos do Estado do Rio Grande do Sul, e tem sua economia fortemente baseada na pecuária e agricultura. Para a realização do trabalho, foram utilizados dados temporais do satélite RapidEye, sensor Reis, datados de 2011 e 2012. Foi criado um banco de dados, que foi usado para: testar variadas composições e contrastes; definir as legendas das categorias de uso e cobertura da terra; realizar testes de segmentação, classificação das imagens e elaborar uma programação em Linguagem Espacial para Geoprocessamento Algébrico (LEGAL) (CÂMARA, 1995); e elaborar os mapas temáticos. A classificação supervisionada das imagens revelou que a classe de uso do solo ?Floresta? foi predominante no município em 2011 e 2012, quando representou um quarto da sua área total. Conclui-se que, por meio da análise LEGAL, houve aumento da expansão florestal em detrimento do desmatamento, o que evidencia a importância da análise de uso do solo para a adequação e o planejamento ambiental do município

Diluted manganese on the bond-centered site in germanium

The functional properties of Mn-doped Ge depend to large extent on the lattice location of the Mn impurities. Here, we present a lattice location study of implanted diluted Mn by means of electron emission channeling. Surprisingly, in addition to the expected substitutional lattice position, a large fraction of the Mn impurities occupies the bond-centered site. Corroborated by ab initio calculations, the bond-centered Mn is related to Mn-vacancy complexes. These unexpected results call for a reassessment of the theoretical studies on the electrical and magnetic behavior of Mn-doped Ge, hereby including the possible role of Mn-vacancy complexes