Repositório do LNEG
Repositório Científico do Laboratório Nacional de Energia e Geologia
Entradas recentes
Mineralogical and Geochemical Characterization of Geological Materials, 2nd Edition
Publication . Silva, Teresa; de Oliveira, Daniel Pipa Soares; Veiga, João Pedro
ABSTRACT: This Special Issue reinforces the strategic role of mineralogical and geochemical characterization in tackling key scientific challenges associated with mineral resources, providing essential insights into ore genesis, mineral processing, environmental performance, and the sustainable supply of raw materials. The topics demonstrate how advanced analytical techniques and multidisciplinary approaches are improving knowledge of geological materials and Earth processes while supporting sustainable resource management, environmental protection, and cultural heritage conservation. Studies on lithium-bearing pegmatites, mining waste, and abandoned mine sites showcase the manner in which detailed mineralogical and geochemical research is able to uncover new resource opportunities, promote circular economy practices, and support responsible resource recovery. Contributions also explore applications in geoheritage and heritage conservation, including the use of geopolymers as sustainable restoration materials and the assessment of natural stones for monument preservation. Furthermore, environmental studies address soil geochemistry, environmental monitoring, and occupational health through innovative mineral and particle characterization methods. Several papers showcase cutting-edge analytical tools, including Raman spectroscopy, SEM-EDS, LA-ICP-MS, and ToF-SIMS, highlighting advances in analytical accuracy, efficiency, and data interpretation. This reprint provides an important reference resource for researchers working across Earth and materials sciences.
National energy and material flows along the building supply chain in the EU
Publication . Barbosa, Juliana Pacheco; Simoes, Sofia; Jordao, Cristine; Mao, Ruichang; Aloini, Davide; Zerbino, Pierluigi; Mabroum, Safaa; Montalbano, Giammarco; Sameer, Husam; Dürr, Hans H.; Jerónimo, B.; Maçãs Lima, Ana Teresa
ABSTRACT: Construction activity is responsible for substantial greenhouse gas (GHG) emissions, but most of these reflect only a single stage of the building construction supply chain. Closing the gap, this work presents a cross-supply-chain perspective on annual material and energy consumption and GHG emissions for the sector on the European scale. These are estimated at the country level, disaggregated for raw material extraction, material manufacturing, demolition, and several intermediary transport stages. The study underscores cement, steel, flat glass, and ceramic bricks as manufactured materials; and sand, limestone, clay, iron ore, and coal as raw materials. Estimates consider both new construction and renovation, across varied typologies of residential and non-residential buildings. The results show that new construction & renovation of the building stock emits 235.31 Mt of CO2 annually, excluding energy consumption for building operations. These are associated with the consumption of circa 1 994.29 Mt raw and construction materials, and circa 1 990.27 PJ of final energy per year. These figures correspond to 4.33% of the total EU values (45 923 PJ). New building construction and renovation account for 63% of the materials used, while the material manufacturing stage accounts for 74% of the final energy consumption. By adopting a full supply chain perspective at the European level, we can support the development of holistic and more targeted public policies to decarbonize the sector.
Geomorphological and sedimentary evolution of the Southwestern sector of the Tagus river [Resumo]
Publication . Dias, Ruben; Ressurreição, Ricardo; Legoinha, Paulo
ABSTRACT: The present-day Tejo River flows within the Lower Tejo Basin, a Cenozoic tectonic depression formed during the Alpine orogeny at the end of the Cretaceous and during the Paleogene under a NNE–SSW compressional stress. Deformation intensified during the Miocene with NNW–SSE compressional stress, reactivating pre-existing faults that controlled the accommodation space and thickness of the basin’s sedimentary fill. Tectonic inversion led to the uplift of the Lusitanian Basin and the Central Cordillera, which supplied sediments laterally to the Tejo Basin. Sedimentation began in the Paleogene with the development of extensive alluvial fan systems, later evolving into fluvial environments. Throughout the Miocene, the southwestern sector of the basin experienced several marine incursions, leading to the formation of reefs and coastal swamp environments that extended inland to the Santarém–Lavre region. Eustatic fluctuations caused repeated shoreline advances and retreats, controlling the position of the fluvial system. The pre-Tejo River developed as an alluvial plain dominated by a meandering system. At the beginning of the Pliocene, the pre-Tejo was characterized by an extensive alluvial plain transporting and depositing mainly medium- to coarse-grained siliciclastic sands. The river likely received contributions from the Alvalade Basin fluvial system and discharged into an estuary north of the Grândola range. The southern margin of the river can be recognized near Melides. Pliocene dating from Galé beach (Melides) and the Setúbal Peninsula indicates ages of ≈ 4.5 Ma (Ressurreição, 2018) and 3.8 Ma (Azevedo, 2006), respectively, showing progressively younger deposits towards the north. These data suggest that during the Pliocene the river gradually migrated northward, eventually reaching the
Setúbal Peninsula. Clay deposits in the Pegões region, with considerable lateral extent and thickness, suggest proximity to the mouth of a major river system. During the Pleistocene, fluvial incision began and terrace levels formed as the valley progressively entrenched. The river continued to migrate northward and eventually established its outlet in the Gargalo do Tejo constriction, possibly due to tectonic activity along its fault and/or river capture. The main clay depocentre shifted to the Mar da Palha. Overall, during the Pliocene and Pleistocene, the estuarine sector of the Tejo fluvial system experienced a
progressive northward migration until it became entrenched and stabilized in its present position.
New 87Sr/86Sr constraints on the marine Miocene of the Lower Tagus Basin and the Alentejo Coastal Plain (Portugal) [Resumo]
Publication . Ressurreição, Ricardo; Legoinha, Paulo; Dias, Ruben; Horta Pacheco dos Santos, José Francisco; Monteiro Ribeiro, Sara; Patinha, Carla
ABSTRACT: Sedimentation in the Lower Tagus Basin was strongly controlled by eustatic oscillations, with several marine incursions during the Miocene. Previous studies, based on biostratigraphic and isotopic data, identified ten depositional sequences in the southwestern sector of the basin that correlate with thirdorder eustatic cycles. Some of these transgressions reached considerable amplitudes, with marine influence extending up to ~80 km inland under the present-day configuration of the territory. Preliminary results of 87Sr/86Sr isotopic dating from oyster shells collected in the Lower Tagus Basin (LTB) and the Alentejo Coastal Plain (ACP) are presented (figure 1). At Vila Nova da Rainha, a 15.69 Ma age (correlating with Langhian, V-b unit at Lisbon) anchors the marine-influenced base of the local succession, exposing a ~5 Ma hiatus between these levels and the overlying sands with Hipparion (Vallesian, MN 9). This age corroborates previous bio-chronostratigraphic assignments. Marine and marginal-marine sediments crop out along the eastern margin of the LTB and in the ACP. In the Alcácer
do Sal region and along the Melides–Sines coast, these deposits are assigned to the Alcácer do Sal Formation (upper Serravallian–lower Tortonian). However, further north, as far as Lavre (Montemor-o-Novo), geological mapping attributes them to a broader interval corresponding to the Vindobonian (Langhian–Tortonian). Oyster shells collected at two sites along the Marateca stream (Monte da Moinhola and Monte Novo) and at Melides yielded ages of 11.13 Ma, 11.03–7.32 Ma and 8.58 Ma. These values indicate Tortonian deposition and are consistent with the Alcácer do Sal Formation, suggesting that marine Miocene deposits cropping out as far north as Lavre may belong to this unit, representing one of the most landward-penetrating Miocene transgressions. At the base of the sea cliff at Galé beach (Melides), calcareous sandstones and sands with marine fauna have been mapped as part of the Alcácer do Sal Formation. However, 87Sr/86Sr dating of oyster shells yielded ages between 6.79 and 5.80 Ma, indicating Messinian deposition. These sediments can therefore be correlated with the Esbarrondadoiro Formation, a Messinian marine unit of the Alvalade Basin whose connection with the coastal area had not previously been unequivocally identified. This study contributes to the understanding of the marine Miocene of southwestern Portugal and has implications for paleogeographic reconstruction and geological mapping.
O controlo estrutural da Serra de Grândola [Resumo]
Publication . Ressurreição, Ricardo; Dias, Ruben; Cabral, João; Represas, Patricia; Carvalho, João
ABSTRACT: Essencialmente desenvolvida nos terrenos paleozóicos da Zona Sul Portuguesa (ZSP), a serra de Grândola constitui um grande bloco de geometria grosseiramente triangular basculado para SE, com altitude máxima (325 m) situada próximo da sua extremidade NW. Destaca-se da bacia de Alvalade, a N, e da planície litoral, a W, através de vertentes escarpadas de direcção WNW-ESE e N-S, respectivamente, passando em continuidade à superfície da bacia de Alvalade a SE. A vertente setentrional corresponde à escarpa da falha de Grândola, estrutura relevante na evolução cenozóica regional com sucessivos levantamentos do bloco S desde o Paleogénico. Ao longo de todo este bordo, o Cenozóico cobre em “onlap” as rochas da ZSP, desconhecendo-se contactos por falha à superfície. O seu traçado cartográfico é maioritariamente inferido. Existem evidências de deformação indicadas por fracturação e basculamento em afloramento, lineamentos gravimétricos importantes, sísmica de reflexão e sondagens. Estes dados, a par da evolução do campo de tensões cenozóico e enquadramento regional, sugerem que a falha de Grândola tem tido um comportamento predominante em desligamento direito face à compressão alpina. A vertente ocidental da serra é mais irregular, tendo direcção N-S, grosso modo. É parcialmente talhada em rochas mesozóicas do sector emerso da bacia do Alentejo, que se encontram basculadas para W e localmente muito fracturadas. A passagem da ZSP para a planície litoral coincide em alguns locais com a presença de
falhas a que se associam pequenas escarpas, encontrando-se a deformação distribuída por um conjunto de estruturas de onde se destaca a falha de Deixa-o-Resto (NNE-SSW), de cinemática esquerda e inversa. A orientação de várias falhas, mais ou menos coincidente com os principais limites da serra, sugere que esta é um relevo controlado por sistemas conjugados de fracturas, paralelos aos bordos setentrional e ocidental, actuando com componente de movimentação direita no bordo
setentrional e esquerda no bordo ocidental. Admite-se a existência de uma componente de deformação flexural da crusta acompanhando o deslocamento do bloco da serra de Grândola ao longo das zonas de falha, contribuindo para um empolamento da superfície topográfica, com máximo encurtamento junto à intersecção das duas famílias direccionais de fracturação. A falha de Grândola corresponderá assim a uma “tear fault”, delimitando a N a deformação vertical associada ao
empolamento flexural, e acomodando o deslocamento para NW do bloco correspondente à serra através de movimentação horizontal direita (figura 1).