Recursos Minerais - RM
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Browsing Recursos Minerais - RM by Field of Science and Technology (FOS) "Ciências Naturais::Ciências da Terra e do Ambiente"
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- Age dependent variation of the magnetic fabric of dike swarms and implications for the volcanic structure of ocean islands: the example of the Maio Island, Cabo Verde archipelagoPublication . Moreira, Mário; Mata, João; Madeira, José; Represas, Patricia; Martins, SofiaABSTRACT: Magnetic fabric analysis of dikes is a powerful technique when assessing magma transfer processes. This study presents an integrated analysis combining magnetic susceptibility and anisotropy of magnetic susceptibility, magnetic mineralogy, geochemistry and new 40Ar/39 Ar dating of dikes intruding formations ranging from the Lower Cretaceous to the Miocene on the island of Maio, in the Cabo Verde archipelago. We show that the dikes, dated at ≈9.2 Ma, intruding the younger Miocene Casas Velhas formation, display a Ti-rich titanomagnetite composition, higher whole-rock TiO2 content and very high magnetic anisotropy. They are clearly distinguished from the dikes, ranging in age from ≈9.3 to 11.3 Ma, intruding older formations, which show a predominantly Ti-poor titanomagnetite composition with multiple magnetic phases, lower whole-rock TiO2 concentration, higher range of magnetic susceptibilities and very low anisotropy. Magnetic fabric is predominantly normal with no significant imbrication relative to the dike margins. Numerical analysis of fabric shows a dominant coaxiality between the magnetic lineation and the preferred orientation of opaques and phenocrystals suggesting that magnetic lineation is, therefore, the proxy of the magmatic flow axis orientation. Based on the orientation of the magnetic fabric, we infer that magmatic flow within the studied dikes is predominantly vertical. The differences observed between the younger dikes and all other dikes may be related to magma sourced from distinct magma chambers. One, probably shallow, underneath the Casas Velhas fm in the southwest of the island, which would explain the very high values of magnetic anisotropy and the inferred vertical flow, and another located in a central position in the island, responsible for the dikes intruding the older formations. The location of such magma reservoirs and the dikes ages suggest a hypothetical migration with age of the magmatic sources that fed the dikes from the central part of the island to the southwest region. The magnetic and mineralogical heterogeneities of the dikes intruding older Lower Cretaceous formations may also be a result of a wider age range of the intrusions.
- Chemical and Mineralogical Characterization ofWaste from Abandoned Copper and Manganese Mines in the Iberian Pyrite Belt, Portugal: A First Step Towards the Waste-to-Value Recycling ProcessPublication . de Oliveira, Daniel Pipa Soares; Silva, Teresa; Morais, Igor; Fernandes, JoãoABSTRACT: This study examines the chemical and mineralogical composition of waste materials from abandoned copper and manganese mines in the Iberian Pyrite Belt, Portugal, as a first step toward their potential recycling for critical and strategic raw materials (CRM and SRM). Using portable X-ray fluorescence (pXRF) and other analytical techniques, this research highlights the presence of valuable elements, including copper, manganese, and rare earth elements, in concentrations significantly above their crustal abundance. The findings underscore the dual potential of these wastes: as sources of secondary raw materials and for mitigating environmental hazards such as acid mine drainage (AMD). Recovered materials include chalcopyrite, pyrolusite, and rhodochrosite, with critical elements like cobalt, lithium, and tungsten identified. pXRF proved to be a reliable, cost effective tool for rapid field and laboratory analyses, demonstrating high precision and good correlation with standard laboratory methods. The study emphasizes the importance of characterizing historical mining waste to support a circular economy, reduce reliance on foreign material imports, and address environmental challenges. This approach aligns with the European Union’s Critical Raw Materials Act, promoting sustainable resource use and the recovery of strategic resources from historical mining sites.
- Ciencia ciudadana en el análisis de peligros geológicos en el Área Atlántica [Resumo]Publication . Montoya-Montes, Isabel; Galindo, Inés; Sanchez, Nieves; Jaud, Marion; Le Dantec, Nicolas; Pinto, Cláudia; Ferreira, M. A.; Parker, Kieran; Lemon, Kirstin; Rodrigues, Domingos; Quental, Lídia; Ramalho, Elsa; Gonçalves, Pedro; Cruz-Pérez, N.; Ortega, A.; Holohan, Eoghan; Correia, Vítor; Jeremias, Filipe Telmo; Gomes, Rui CarrilhoRESUMEN: La participación ciudadana constituye la piedra angular común de los cinco Observatorios piloto de peligros geológicos (movimientos en masa, terremotos, inundaciones fluviales y costeras, riesgos geotécnicos y erosión costera) implementados en cuatro países del Área Atlántica en el marco del proyecto AGEO INTERREG, con varias iniciativas de divulgación llevadas a cabo para mejorar la concienciación de los ciudadanos sobre los peligros geológicos. En este contexto, el logro notable de AGEO reside en el desarrollo de herramientas estandarizadas capaces de satisfacer las numerosas necesidades de estos pilotos, de modo que tanto los ciudadanos como los colaboradores expertos tengan acceso a canales de comunicación que les permitan informar sobre la ocurrencia de eventos de peligros geológicos. Además, la utilización de productos y servicios de emergencia del programa europeo Copernicus asume un papel importante en el establecimiento y funcionamiento de los Observatorios. Debido a su adaptabilidad en todo el variado espectro de pilotos de AGEO, estas herramientas prometen una integración perfecta en posibles futuros observatorios ciudadanos de riesgos geológicos y por tanto una contribución a la mejora de los sistemas de gestión de riesgos.
- Construction raw materials in Timor Leste and sustainable developmentPublication . Carvalho, Jorge; Lisboa, JoseABSTRACT: Timor Leste is the newest and one of the poorer nations in the world. One of its main challenges that could lead to poverty reduction is the reconstruction and maintenance of the infrastructures that were almost completely destroyed after its independence referendum. To achieve this, there is an imperative need for construction raw materials in a country where the extractive industry is scarce and artisanal. Available geological studies deal with the island’s geology and tectonic evolution or its oil and gas potentialities. Very few broach other geological resources. A general study of the country’s territory demonstrates that Timor Leste possesses large resources in clays, limestones and sand and gravel, which can support small- to large-scale raw material extractive industries. Some selected areas have been the target of more detailed study: Venilale and Aileu, with resources for structural ceramics and whiteware respectively, and Beheda, where a crinoid-rich limestone crops out, with potential for usage as ornamental stone. These resources are suitable for non-sophisticated small-scale mining operations that should be able to accomplish environmental and social liabilities. No public policy exists for the management of these mineral resources, which is essential for the sustainable development of Timor Leste.
- Decision criteria for the exploration of ornamental-stone deposits: Application to the marbles of the Portuguese Estremoz AnticlinePublication . Falé, Patrícia; Carvalho, Jorge; Henriques, Paulo; Luís, GabrielABSTRACT: Ornamental stones are almost ready-made raw materials with a high economic value for the building-construction industry. The discovery of new near-surface deposits, the very low exploitation efficiency, the huge amounts of wastes produced, and the land-use accessibility conditions are the main challenges that the extractive industry for this mineral resource is facing nowadays. Research on advanced geological exploration tools and methodologies is needed to reply to those challenges. During the process of geological ornamental-stone deposits exploration, the unique and decisive criteria that should be considered are its dimensions, homogeneity, and fracturing state. Lithostructural geological mapping and in situ fracturing surveys are the basic indispensable tools for their field assessment. By applying these criteria and tools to a marble-rich area in the Portuguese Estremoz Anticline and a step-by-step numerical evaluation of the qualitative geological parameters, the delimitation of the best target areas for exploitation or environmental rehabilitation has been effectively mapped.
- Exposure to ionizing radiation and dangerous substances inside buildings related to construction productsPublication . Carvalho, F.P.; Paiva, J.V.; Carvalho, Jorge; Batista, Maria JoaoABSTRACT: The use of many materials of geological origin and recycled materials in the construction of buildings faces an increasing demand and stricter regulation for quality control. Construction products are requested to meet safety standards including those for radon exhalation and gamma radiation emission, amongst other dangerous substances, because if unchecked they could deteriorate the quality and safety of the indoor environment. Construction products shall pass testing for radioactivity in order to meet those standards and to maintain a high ranking position in the international markets.
- GeologiaPublication . Carvalho, Jorge; Henriques, PauloRESUMO: Portugal, na sua área continental, é formado por três grandes unidades geológicas: o Maciço Antigo, as Orlas Meso-Cenozóicas e as Bacias do Tejo e do Sado. No esboço geológico de Portugal continental apresentado na Figura 2.1, as formações geológicas são escalonadas, de modo simplificado, quanto à sua idade relativa. O Maciço Antigo ocupa cerca de dois terços do território e corresponde a parte de um antigo soco que compreende, essencialmente, séries dominantemente xistentas Pré-Câmbricas e Paleozóicas, estas de idades compreendidas entre o Câmbrico e o Pérmico e em algumas das quais se geraram massas de mármores. Encontra-se localmente coberto por depósitos detríticos discordantes de idade Terciária (ou Cenozóica) e Quaternária, cuja espessura não ultrapassa os 200-300 metros. As séries xistentas do Maciço Antigo foram intruídas, durante fases de intenso magmatismo relacionadas com as orogenias hercínica e alpina, por massas de rochas ígneas de natureza diversa, predominando os granitos. As Orlas sedimentares Meso-Cenozóicas formaram-se, a partir do Pérmico, nas margens continentais a Oeste e a Sul da Península Ibérica, estando relacionadas com os fenómenos tectónicos distensivos que deram lugar à abertura do Oceano Atlântico. Incluem os Períodos Triássico, Jurássico e Cretácico da Era Mesozóica, durante a qual, com relevo para o Jurássico, teve lugar a formação de espessas séries de calcários. Durante o Terciário (ou Cenozóico) a sedimentação foi essencialmente de natureza arenosa e argilosa. Destacam-se as Bacias do Tejo e do Sado que resultaram da instalação de dois importantes golfos subdividindo a Orla Meso-Cenozóica Ocidental durante o Terciário. Funcionaram como zonas de subsidência onde se depositaram espessas sequências de sedimentos de natureza detrítica, com um máximo de 1400 m na Bacia do Tejo. Aí predominam níveis arenosos, mais ou menos grosseiros, com intercalações conglomeráticas e argilosas, e calcários lacustres.
- The Geological Survey Organisations in delivering Critical Raw Materials autonomy through a Geological Service for EuropePublication . Hollis, Julie; Albert, Capucine; Bertrand, Guillaume; Cabidoche, Marina; de Oliveira, Daniel Pipa Soares; Dobnikar, Meta; Teran, Klemen; Tulstrup, JørgenABSTRACT: Europe’s dependence on foreign-sourced critical raw materials poses a significant threat to its strategic autonomy and competitiveness. In this paper, we examine the historical significance of mining in Europe, the current geopolitical complexities surrounding critical raw materials supply, and recent EU policy initiatives aimed at bolstering domestic critical raw materials production and processing and building resilient supply chains. We highlight the crucial role of National Geological Survey Organisations in delivering knowledge of Europe’s critical raw materials potential, as well as contributing to international partnerships through technical engagement and geoscientific diplomacy. National Geological Survey Organisations collect and compile data on mineral resources, often serving as a primary resource for national and regional decision-making. This work is now crucial at EU level, with National Geological Survey Organisations mandated under the EU Critical Raw Materials Act to deliver National Exploration Programs to promote exploration investment through technical de-risking, and to coordinate efforts and geoscientific data and knowledge management at pan-European level. The National Geological Survey Organisations already share knowledge and best practices on European mineral resources through EuroGeoSurveys. Future efforts to secure European critical raw materials resilience will be served through their shared vision of a Geological Service for Europe.
- Ordenamento do Território e Desenvolvimento Sustentável da Indústria ExtractivaPublication . Carvalho, Jorge; Martins, Luís PlácidoRESUMO: Os conceitos de organização e desenvolvimento territorial enquanto função do estado tiveram origem na comunicação do ministro francês Claudius Petit, “Pur un plan national d’aménagement du territoire”, em 1950 (in C. ALVERGNE et P. MUSSO, 2003) em que este defendeu uma repartição da população francesa em função dos recursos naturais e das diferentes actividades económicas, procurando assegurar um maior equilíbrio entre cidade/campo e litoral/interior, ao mesmo tempo que a preservação do meio ambiente não seria esquecida. Esta procura de racionalidade no uso do território tem sofrido diversas evoluções consoante é abordado como um objectivo a atingir ou como um conjunto de processos instrumentais integrados para a organização do espaço físico. Hoje em dia o Ordenamento do Território anda a par, de modo indissociável, com os conceitos e políticas de desenvolvimento sustentável na procura das melhores soluções que possam conduzir a uma eficaz e rentável ocupação do território sem degradar as condições ambientais nem comprometer o seu uso futuro. O espaço territorial é, em si mesmo, um recurso.
- Ranked Mappable Criteria for Magmatic Units: Systematization of the Ossa-Morena Zone Rift-Related Alkaline BodiesPublication . Roseiro, José; Moreira, Noel; de Oliveira, Daniel Pipa Soares; Silva, Marcelo; Eguiluz, Luis; Nogueira, PedroABSTRACT: The Ossa-Morena Zone (SW Iberian Massif) hosts the largest set of Cambro-Ordovician alkaline magmatic plutons related to the Palaeozoic rifting of the northern Gondwana margin so far described. An organized framework for their classification at different scales is proposed through data-driven ranks based on their distinctive petrological features relative to other rift-related magmatic rocks found throughout western Europe. The classification method aims to enhance geological mapping at different scales, regional- and continental-scale correlations, and, as such, facilitate the petrogenetic interpretation of this magmatism. The hierarchical scheme, from highest to lowest rank, is as follows: rank-1 (supersuite) assembles rocks that have distinctive characteristics from other magmatic units emplaced in the same magmatic event; rank-2 (suite) categorizes the units based on their major textural features, indicating if the body is plutonic, sub-volcanic, or a strongly deformed magmatic-derived unit; rank-3 (subsuite) clusters according to their spatial arrangement (magmatic centres) or association to larger structures (e.g., shear zones or alignments); rank-4, the fundamental mapping unit, characterizes the lithotype (alkaline granite, alkaline gabbro, syenite, albitite, etc.) by considering higher ranks (alkalinity and textural aspects); rank-5 characterizes the geometry of individual plutons (with several intrusions) or swarms; rank-6 (smallest mappable unit) corresponds to each intrusion or individual body from a swarm. Although this classification scheme is currently presented solely for the Ossa-Morena Zone, the scheme can be easily extended to incorporate other co-magmatic alkaline bodies, such as those in the NW Iberian allochthonous units or other peri-Gondwanan zones or massifs, in order to facilitate regional correlations of the rift-related magmatism.