Maria Anjos Ribeiro

Maria Anjos Ribeiro
University of Porto | UP · Departamento de Geociências, Ambiente e Ordenamento do Território

PhD

About

122
Publications
45,577
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
604
Citations
Additional affiliations
August 2007 - present
University of Porto Faculty of Sciences
Position
  • Professor (Associate)

Publications

Publications (122)
Article
Full-text available
The target of this study was the tungsten Regoufe mine, whose exploitation stopped in the 1970s. When the mine closed, an unacceptable legacy constituted of mining waste tailings and the ruins of infrastructure was left behind. This work assessed the soil, plants, and water contamination in the mining area; namely their content in potentially toxic...
Conference Paper
Full-text available
Most of the lithic tools made during Prehistory in the Iberian Peninsula are mainly composed of three main siliceous rock types: chert, quartzite, and quartz. While the methodologies for the characterization and provenance of raw materials made on chert (and obsidian) have been developed with well-established and widely used protocols, the same doe...
Article
Full-text available
A R T I C L E I N F O Keywords: Lithium pegmatite Metasomatism Geochemical halo Lithogeochemistry Psammitic and pelitic metasediments Geochemical exploration A B S T R A C T Fluid-assisted mass transfer and re-equilibration of mineral phases are common consequences of metasomatism associated with igneous intrusions. The addition and/or removal of c...
Article
Full-text available
Reflectance spectroscopy has been used to identify several deposit types. However, applications concerning lithium (Li)-pegmatites are still scarce. Reflectance spectroscopic studies complemented by microscopic and geochemical studies were employed in the Fregeneda–Almendra (Spain–Portugal) pegmatite field to analyze the spectral behavior of Li-min...
Article
Full-text available
The existence of diagnostic features in the visible and infrared regions makes it possible to use reflectance spectra not only to identify mineral assemblages but also for calibration and classification of satellite images, considering lithological and/or mineral mapping. For this purpose, a consistent spectral library with the target spectra of mi...
Conference Paper
Full-text available
The Central Iberian Zone (CIZ) and Galicia-Trás-os-Montes Zone (GTMZ) contain several important Li-mineralizations. A multivariate statistical approach, including correlation, cluster, and principal component analysis, was employed to define geochemical pathfinders for Li exploration. A total of 66 geochemical analyses of Li-bearing pegmatites and...
Article
The Esmolfe–Matança ilmenite-type granite is analyzed using petrography, microstructures, anisotropy of magnetic susceptibility and microfracturing. The granite occurs in two separated bodies outcropping in distinct villages, Esmolfe and Matança, which are located in the termination of the Juzbado-Penalva do Castelo (JPCSZ) and Dúrico-Beirão (DBSZ)...
Conference Paper
Full-text available
Porphyroblasts can give significant insights about the tectonometamorphic history of a region. Metapelite samples from the Almendra (Vila Nova de Foz Côa) region were investigated and the associated microstructures documented allowing to conclude that biotite porhyroblastesis was pre-to sin-a later deformation phase (probably D 3). Smaller, mimetic...
Chapter
Full-text available
This chapter aims to identify, characterize and locate the main facts/events related to orogenesis in the Iberian Peninsula. Its succession in space and time determines the geodynamic environment of the broader geological phenomenon corresponding to the Variscan cycle. In this sense, this section comprises two parts: I—The Iberian orogenic magmatis...
Conference Paper
Full-text available
The mechanisms involved in alkali-aggregate reaction and the characteristics of reactivity of some aggregates are not completely understood, although tens of thousands of mortar and concrete prisms have been tested in the laboratory and field exposure sites have been installed in a number of countries. Aggregates are the least well understood compo...
Conference Paper
Full-text available
The reactive forms of silica present in an aggregate depend on the origin and geological history of the rocks. The detection of specific reactive silica must be focused on characteristics such as the identification of polymorphs, the quantification of microcrystalline to cryptocrystalline quartz, and/or on the deformation manifestations for each ag...
Article
Full-text available
Resumo: O granito de Bagunte, varisco sintectónico relativamente a D3, corresponde a uma das facies do Maciço da Póvoa de Varzim-Porto, que aflora no bordo NW da Zona Centro Ibérica (ZCI). É um corpo alongado de direção NNW-SSE tendo como encaixante, micaxistos estaurolíticos, rochas gnaisso-migmatíticas e metassedimentos do Grupo do Douro (Complex...
Conference Paper
Full-text available
Satellite Data and Digital Elevation Models (DEM) have been widely used in several scientific domains and it can provide information on lineaments from either anthropogenic or natural sources. Geologically, they can be fault zones, geological contacts, shear zones, joints, fold axis, and others. This work follows the automatic lineament extraction...
Conference Paper
Full-text available
Nos arredores do Porto, no setor NW da faixa magmato-metamórfica Porto-Viseu estão caraterizadas rochas gnaisso-migmatíticas, nomeadamente no Complexo Migmatítico do Mindelo (CMM) e nos Migmatitos de Lavadores-Madalena (MLM), englobados em diferentes unidades geotectónicas do Maciço Ibérico. Estes complexos apresentam bastante similaridade litológi...
Conference Paper
Full-text available
Calc-silicate and amphibolitic nodules occur in the gneiss-migmatitic outcrops in the coastal zone of Vila Nova de Gaia, Madalena. The calc-silicate nodules present a zonal structure and are texturally uniform, whereas the amphibolitic nodules have more diverse textures. The amphibolitic nodules are very similar, in the lithological and petrographi...
Conference Paper
Full-text available
In this work we give a contribution to the petrographic, mineralogical and geochemical study of calc-silicate and quartz-phyllite lithologies of Bateiras Formation. It was observed in the majority of the studied samples epidote minerals and chlorite resulting of chloritization of biotite. When the biotite is present it has a poikilitic texture and...
Code
Full-text available
In the NW sector of the Porto-Viseu Metamorphic Belt migmatites associated with granites are intrusive in metasedimentary rocks of the Schist-Greywacke Complex. West of Porto Granite outcrops the Fânzeres Granite, a granitoid of peculiar sigmoidal geometry, cartographed as an alkaline gneissic granite rich in garnet, limited at west and east by two...
Conference Paper
Full-text available
Resumo: O complexo migmatítico do Pedregal e o Complexo Anatéctico de Figueira de Castelo Rodrigo-Lumbrales (CAFCR-L) são áreas onde afloram rochas migmatíticas associadas a granitos de tipo-S, sin-orogénicos, estando estes separados de rochas de baixo grau metamórfico do Supergrupo Dúrico-Beirão por zonas de cisalhamento. Embora este seja um impor...
Conference Paper
Full-text available
Resumo Foram analisadas, para isótopos de Sr e Nd, cinco amostras de metassedimentos pertencentes ao Complexo Xisto-Grauváquico (CXG), ou Supergrupo Dúrico-Beirão, de idade ante-ordovícica, mais precisamente ediacarana. Quatro das amostras são de litologias pertencentes ao Grupo das Beiras do CXG, tendo sido colhidas na área de Sarnadas do Ródão, r...
Conference Paper
Full-text available
The NW sector of Porto-Viseu metamorphic belt, in the western border of Central Iberian Zone (CIZ), is characterised by the confluence of two major variscan shear zones: the Douro-Beira shear zone (DBSZ) and the Porto-Tomar shear zone (PTSZ). This later structure is a major geotectonic alignment from which different models of tectonic evolution hav...
Chapter
Sedimentary rocks form from deposition and consolidation of older rock and mineral materials near or at the Earth’s surface in atmosphere or underwater, normally deposited in horizontal layers. The composing materials may have different sources: (1) lithic or mineral detritus from natural breakdown of pre-existing rocks (igneous, sedimentary or met...
Chapter
Metamorphic rocks form from prograde or retrograde recrystallization of igneous, sedimentary, or metamorphic precursor rocks, variously changing mineral content, structure, and texture/fabric. Metamorphic rocks may be formed from shallow depth near the Earth’s surface to great depth down in the mantle. Weathering and alteration at (near) surface co...
Book
This RILEM AAR 1.2 Atlas is complementary to the petrographic method described in RILEM AAR 1.1. It is designed and intended to assist in the identification of alkali-reactive rock types in concrete aggregate by thin-section petrography. Additional issues include: • optical thin-section petrography conforming to RILEM AAR 1.1 is considered the pri...
Chapter
Igneous rocks form from cooling and solidification of molten rock, either from magma within the Earth’s crust (plutonic rocks), or from lava extruded on to the Earth’s surface in the atmosphere or underwater (volcanic rocks).
Conference Paper
Full-text available
Two samples of "skarn", respectively from Riba d'Alva and Tabuaço were studied, with the purpose of making a petrographic comparison. This study was performed using petrographic microscope and the electron microscope scanning. Both samples are from the “Complexo Xisto.-Grauváquico – Grupo do Douro”. The mineralogical composition identified in the "...
Conference Paper
Full-text available
Resumo Apresentam-se e discutem-se os resultados obtidos na caraterização de rochas xistosas de duas áreas: Estrada Nacional 17 (EN17), em Coimbra, e Vila Velha de Ródão. A caraterização foi adaptada ao tipo de amostras tendo sido realizados ensaios de propriedades índice e a determinação de propriedades mecânicas e de durabilidade. Os resultados m...
Conference Paper
Full-text available
Resumo Neste trabalho são apresentados os resultados isotópicos Sr-Nd do Granito do Pedregal e das rochas gnaisso-migmatíticas associadas, aflorantes na Zona Centro-Ibérica noroeste de Portugal, no bordo oriental do maciço granítico sin-orogénico do Porto. O granito do Pedregal é um pequeno corpo alongado na direcção NW-SE, intrusivo em micaxistos...
Conference Paper
Full-text available
Alkali-silica reaction is a mechanism of deterioration of concrete structures which is associated with the composition of the rocks used as aggregates. The assessment of aggregates to evaluate their potential reactivity to alkalis is made both by visual methods and laboratory expansion tests. There are a number of national standards regarding the p...
Chapter
Full-text available
The study of metasedimentary rocks using laboratory test methods is presented. Field work revealed a highly weathered yellowish metasedimentary quartz-pelitic rock characterized by very close discontinuities. The Schmidt hardness values obtained at an excavated slope were low. The rock mass was studied in depth for the excavation of a tunnel with t...
Conference Paper
Full-text available
The action of the geodynamic agents (external and/or internal), or even the human activities, can cause changes in the structure of a slope that may result in an imbalance between the internal and the external forces acting on the ground. The aim of this study is the analysis of the stability of a natural rock slope located along the Távora river,...
Article
Full-text available
The synorogenic Variscan granite-migmatite complex in study outcrops in the Central Iberian Zone, northern Portugal. The Pedregal granite dated of 311±5 Ma has an NW-SE elongated shape and is intrusive in staurolite-micaschist and banded gneiss-migmatite rocks, with local igneous breccias along the contact. This granite is a fine to medium-grained...
Article
Full-text available
The results obtained in the characterization of schist rocks from two distant areas in Portugal are presented: black shales of the road EN17 in Coimbra and phyllites of Vila Velha de Ródão (VVR). At EN17 the shale is exposed on excavation slopes, while in VVR the phyllites belong to a rock mass where an underground excavation is planned. The charac...
Article
Full-text available
This work aims to describe the petrography and to report some chemical data of white micas observed in samples from the Serra da Quinta (Sobreira-Paredes) gold-bearing system, located at East of Porto, Northwestern Portugal, in the Central Iberian Zone. The petrographic studies reveal the occurrence of distinct generations of white micas and quartz...
Article
Full-text available
The Pedregal granite outcrops in the Central Iberian Zone, northern Portugal, in the eastern border of a synorogenic variscan granite-migmatite complex sub-concordant with the regional metamorphic structures. It is a granitoid (ca. 3 km2) with an elongated NW-SE shape intruded in staurolite-micaschist and banded gneiss-migmatite rocks, with local i...
Article
Full-text available
O maciço granito pós-tectónico de Lavadores-Madalena, ocorre num sector chave da evolução geodinâmica varisca da Zona de Cisalhamento Porto-Tomar. Dados cartográficos, estruturais e de fabric magnético indicam que os granitos do maciço exibem uma fluência magmática condicionada pela convergência de estruturas de orientação NNW-SSE a N-S com estrutu...
Article
The aim of this study is the analysis of the stability of a natural rock slope located along the Távora river, NW of the village of Távora. The geological mapping of the area and the use of the stereonet to determine the main sets of joints were the starting points for the performed analysis, followed by the kinematic analysis. It was complemented...
Article
Full-text available
The application of petrographic techniques to concrete started at the XIX century and it has been developed since then becoming an indispensable tool in the assessment of the potential reactivity of aggregates and in the detection of deterioration signs in concrete structures. The chemical reactions of internal origin, with expansive nature, partic...
Article
Full-text available
The Santa Eulália Plutonic Complex (SEPC), located in the Ossa Morena Zone (south Portugal), is composed of a medium- to coarse-grained pink granite (G0-type) and a central grey medium-grained biotite granite (G1-type). Available Rb-Sr data indicates an age of 290 Ma. An emplacement model for the SEPC is proposed, taking into account magnetic fabri...
Conference Paper
Full-text available
The gneiss-migmatitic rocks that crop out in the Madalena coast, in Vila Nova de Gaia, are part of a metamorphic belt, adjacent to the sin-tectonic massif of Porto in its western edge, and which was later intruded by the post-tectonic granite of Lavadores. A lithological and petrographic study of the metatexite and diatexite rocks was performed. Th...
Article
Full-text available
The Mindelo Migmatitic Complex crops out in the coastal zone north of Porto (Portugal) and consists of a set of migmatitic and granitic lithologies. Field relationships, petrography, geochemistry and isotopic signature of the various lithologies allow inferring the sequence of anatectic processes that resulted in their characteristic lithological h...
Article
Full-text available
The Santa Eulália Plutonic Complex (SEPC) is a late-Variscan granitic body located in the northern part of the Ossa Morena Zone, a inner zone of the Variscan Iberian Massif. The SEPC host rocks are composed of meta-igneous and metasedimentary units, from Upper Proterozoic to Paleozoic ages, with a NW-SE structure, cross cutted by the SEPC. The SEPC...
Article
Full-text available
The petrogenetic characterization of anatectic granites in Variscan Orogen and their spatial association with gneissic-migmatite thermal domes has been advocated and demonstrated in a more integrated way combining geological, geochemical, isotopic and geochronological data. Migmatitic rocks associated with the “Granito do Porto” are referred since...
Article
Full-text available
The Pedregal granite is exposed in the Central Iberian Zone, northern Portugal, in the eastern border of a synorogenic variscan granite-migmatite complex which includes the Porto granite, subconcordant with the regional structures. It is a small body with an elongated NW-SE shape, intruded in staurolite-micaschist and banded gneiss-migmatite rocks,...
Article
Full-text available
Mindelo Migmatitic Complex outcrops in the coastal-zone, north of Porto. This complex consists on a set of diverse lithologies including metasedimentary, migmatitic and granitic rocks, and pegmatite veins. Field relationships, petrography, geochemistry and isotopic signature of these lithologies allow inferring the sequence of anatectic processes t...
Article
Full-text available
O extremo NW da cintura metamórfica Porto-Viseu é caracterizado por magmatismo sin-tectónico e pós-tectónico, associado a rochas migmatíticas e a uma zonalidade metamórfica condensada variando progressivamente da zona da clorite até à zona da silimanite. A presença de estaurolite e a ausência de cordierite nas paragéneses metamórficas exclui condiç...
Article
Full-text available
Resolving time differences between successive magmatic pulses in granitoid plutons is often a difficult task. High-precision ages, obtained by U-Pb SHRIMP in Lavadores granite, provide evidence that the crystallization of this granite happened at 294±3 Ma which is more precise that a previous age obtained by conventional U–Pb method on multigrain z...
Article
Full-text available
Resumo: O extremo NW da cintura metamórfica Porto-Viseu é caracterizado por magmatismo sin-tectónico e pós-tectónico, associado a rochas migmatíticas e a uma zonalidade metamórfica condensada variando progressivamente da zona da clorite até à zona da silimanite. A presença de estaurolite e a ausência de cordierite nas paragéneses metamórficas exclu...
Article
Full-text available
Modern day Portland-cement concrete was for decades considered to be a long lasting material, until in the 1940s it was recognised that concrete could deteriorate as the result of chemical reactions between Portland cement and some components of the aggregates. Research has been undertaken since then in order to find the best test methods for ident...
Article
Full-text available
The Pedregal granite is exposed in the Central Iberian Zone, northern Portugal, in the eastern border of a synorogenic variscan granite-migmatite complex which includes the Porto granite, subconcordant with the regional structures. It is a small body with an elongated NW-SE shape, intruded in staurolite-micaschist and banded gneiss-migmatite rocks,...
Article
Full-text available
The NW of the Porto-Viseu metamorphic belt is characterized by syn-tectonic and post-tectonic magmatism, associated with migmatites. The surrounding metasedimentary rocks show narrow and progressive metamorphic zoning ranging from chlorite to sillimanite zone. The metamorphic paragenesis with staurolite and without cordierite exclude barometric con...
Conference Paper
Full-text available
Este estudo tem como objetivo a análise estrutural dos afloramentos presentes nas rochas encaixantes do bordo SW do maciço de Lavadores onde afloram rochas migmatíticas de natureza diatexítica e metatexítica, nas quais o maciço granítico pós-tectónico de Lavadores é intrusivo. Na análise estrutural das litologias fez-se um estudo preliminar utiliza...
Conference Paper
Full-text available
The Pedregal granite is exposed in the Central Iberian Zone, northern Portugal, in the eastern border of a synorogenic variscan granite-migmatite complex sub-concordant with the regional structures. It is a small body (ca 3km 2) with an elongated NW-SE shape, that intruded in staurolite-micaschist and banded gneiss-migmatite rocks, with local igneo...
Article
Full-text available
A monitoring system has been detecting progressive displacements in Fagilde dam, completed in 1984. Site inspection revealed the existence of random cracking, surface discoloration, and superficial dissolution of cement in the spillway surfaces and in the upstream face of the dam. The macroscopic signs of deterioration, which could be due to differ...