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- Cristalografia na GeologiaPublication . Figueiredo, M. Ondina
- Contributo para a identificação dos processos responsáveis pela composição das águas termais da Região de LisboaPublication . Policarpo, A.; Marrero Diaz, Rayco; Carvalho, M.R.; Carvalho, J. M.
- Matérias primas críticas para a Europa : o caso do rénioPublication . Figueiredo, M. Ondina
- Tectonic and neotectonic implications of a new basement map of the Lower Tagus Valley, PortugalPublication . Carvalho, João; Rabeh, Taha; Dias, Rui; Dias, Ruben Pereira; Pinto, Carlos C.; Oliveira, José Tomás; Cunha, Teresa Arriaga; Borges, José FernandoIn this paper we present a new basement (defined here as Paleozoic, Precambrian and Mesozoic igneous rocks) map of the Lower Tagus Valley area. This map is a contribution to the understanding of the structural evolution of the top of the basement in the Lower Tagus Valley area during the Mesozoic and Cenozoic Eras. The map was produced using aeromagnetic, well, seismic reflection and geological outcrop data. It shows unprecedented details of the geometry of the basement rock's surface with higher resolution and covers a larger area than the previous basement map of the study area. In spite of an estimated average error of 200 m in depth and an horizontal resolution of 4 km, our map not only reproduces with accuracy several well known basement structures but it also emphasizes previously unknown features. Major basement faults were inferred from large depth variations at the top of the basement, magnetic 2D Euler deconvolution and horizontal gradient analysis and are compatible with surface geological structures, well data and hydrogeological information. Implications to the geodynamic evolution of the SW European Variscides and consequences to Meso-Cenozoic tectonics are discussed. The correlation of the basement structures with instrumental seismicity is carried out and their neotectonic activity is discussed on the basis of existing geological outcrop data.
- Contributo para a identificação dos processos responsáveis pela composição das águas termais da Região de LisboaPublication . Policarpo, A.; Marrero Diaz, Rayco; Carvalho, M.R.; Carvalho, J. M.
- Diagnosis of pathologies in ancient (seventeenth-eighteenth centuries) decorative blue-and-white ceramic tiles : Green stains in the glazes of a panel depicting Lisbon prior to the 1755 earthquakePublication . Silva, Teresa; Figueiredo, M. Ondina; Barreiros, M. Alexandra; Prudêncio, Maria IsabelDecorative panels of ceramic glazed tiles comprise a valuable cultural heritage in Mediterranean countries. Their preservation requires the development of a systematic scientific approach. Exposure to an open-air environment allows for a large span of deterioration effects. Successfully overcoming these effects demands a careful identification of involved degradation processes. Among these, the development of micro-organisms and concomitant glaze surface staining is a very common effect observed in panels manufactured centuries ago. This paper describes a study on the nature of green stains appearing at the surface of blue-and-white tile glazes from a large decorative panel with more than one thousand tiles, called Vista de Lisboa that depicts the city before the destruction caused by the 1755 earthquake. The characterization of green-stained blue-and-white tile glazes was performed using non-destructive X-ray techniques (diffraction and fluorescence spectrometry) by directly irradiating the surface of small tile fragments, complemented by a destructive scanning electron microscopy (SEM) observation of one fragment. Despite the green staining, analytical X-ray data showed that no deterioration had occurred irrespective of the blue or white color, while complementary SEM-EDX data provided chemical evidence of microorganism colonization at the stained glaze surface.