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Ediacaran and early-palaeozoic bimodal volcanism in the Ossa-Morena Zone, SW Ib...
Cachapuz, P.; Chichorro, Martim Afonso; Bento dos Santos, Telmo; Carvalho, D.; Linnemann, Ulf; Zieger-Hofmann, M.; Zieger, J.; Dantas, E.; Santos, R. V.ABSTRACT: This study focuses on bimodal meta-volcanic rocks present in the Iberian Massif, in the Evora-Aracena Metamorphic Belt of the Ossa-Morena Zone (OMZ), near the boundary with the South Portuguese Zone. New petrological, geochemical (whole-rock and Sr-Nd isotopes) and LA-ICP-MS U-Pb zircon geochronology data are presented to track the magmatic evolution of both felsic and mafic rocks and their respective...
Petrochronology of the metamorphic belt located west of the Porto-Tomar Shear Z...
Bento dos Santos, Telmo; Carvalho, Diogo; Damas, Elton; Webb, Laura; Chichorro, Martim; Moreira, Noel; Romão, JoséThe nature of the metamorphic belt located west of the Porto-Tomar Shear Zone (central-west Portugal) has been abundantly discussed in terms of its pre-Variscan paleogeography (Moreira et al., 2019; Bento dos Santos et al., 2023). However, not enough attention has been given to its metamorphic evolution during the Variscan Orogeny and ensuing deformation/metamorphic stages. In this work, we aim at providing qua...
Estudo geocronológico das unidades metassedimentares do soco Pré-Mesozoico a Oe...
Carvalho, Diogo; Bento dos Santos, Telmo; Chichorro, Martim; Cachapuz, Pedro; Solá, Rita; Dantas, Elton; Romão, José; Moreira, NoelTo the west of the Porto-Tomar Shear Zone, several pre-Mesozoic metasedimentary outcrops belonging to the basement of the Lusitanian Basin are poorly exposed. The traditional view suggests that these units belong to Ossa Morena Zone (OMZ), while more recent models propose the existence of the Finisterra Terrane (TF), considered exotic relative to the Iberian Massif (Moreira et al., 2019). To better constrain th...
Geochronological data for the Pre-Mesozoic basement located west of the Porto-T...
Bento dos Santos, Telmo; Chichorro, Martim; Carvalho, Diogo; Cachapuz, Pedro; Solá, Rita; Dantas, E.; Romão, José; Moreira, Noel; Dias da Silva, ÍcaroGeochronological data from the pre-Mesozoic basement of the Lusitanian Basement (West of the Porto-Tomar Fault) was obtained. Results show a predominant Cadomian/Pan-African and Eburnean inheritance/source, placing this sector as a peri-Gondwanan domain. However, two major differences can be seen in the data: samples with a clear absence in Mesoproterozoic ages vs. samples with a clear presence of these ages an...
Exhumation of a migmatite complex along a transpressive shear zone: inferences ...
Pereira, Inês; Dias, Rui; Bento dos Santos, Telmo; Mata, JoãoHigh-grade metamorphic rocks associated with S-type granites are recorded in the Central Iberian Zone, Iberian Variscides. Though most of these occur as inferred metamorphic core complexes affiliated with detachment faults, others, such as the Figueira de Castelo Rodrigo–Lumbrales Anatectic Complex, crop out between low-grade metamorphic rocks separated by steeply-dipping strike-slip shear zones, such as the Ju...
Complexo anatético de Figueira de Castelo Rodrigo - Lumbrales, Zona Centro Ibér...
Pereira, Inês; Bento dos Santos, Telmo; Mata, João; Dias, Rui; Calvo, R; Santos, RNa região de Figueira de Castelo Rodrigo – Lumbrales ocorrem espacialmente associadas rochas de alto grau metamórfico e diferentes tipos de granitóides. A análise geoquímica preliminar revela uma provável relação genética entre os migmatitos e alguns dos granitóides analisados que, nesta perspectiva, são considerados anatécticos e sin-orogénicos. No entanto na região ocorrem alguns granitóides sem aparente rela...
Zona de cisalhamento de Juzbado - Penalva do Castelo no sector de Figueira de C...
Pereira, Inês; Dias, Rui; Bento dos Santos, Telmo; Mata, JoãoA Zona de Cisalhamento Juzbado-Penalva do Castelo (Zona Centro Ibérica) separa unidades com distintas características estruturais, metamórficas e litoestratigráficas, revelando-se como um acidente tectónico de primeira ordem durante a evolução da Cadeia Varisca Ibérica. A realização de cartografia geológica e estrutural detalhada em sectores escolhidos e a sua extrapolação regional, colocou em evidência o carác...
Figueira de Castelo Rodrigo-Lumbrales anatectic complex (Central Iberian Zone):...
Pereira, Inês; Bento dos Santos, Telmo; Dias, Rui; Mata, JoãoIn the Central Iberian Zone (Iberian Massif) there is a significant change in the Variscan D1 trend from the dominant NW–SE to E–W (Marofa and Ahigal de los Aceiteros synclines). This change is due to the 65 to 100 km sinistral movement of the Juzbado–Penalva do Castelo shear zone (JPCSZ), a composite structure where several shear bands formed as a result of progressive deformation (Pereira et al., 2013). Despi...
Upper crustal structure of Madeira Island revealed from ambient noise tomography
Matos, Catarina; Silveira, Graça; Matias, Luís; Caldeira, Rita; Ribeiro, Maria Luísa; Dias, Nuno; Krüger, Frank; Bento dos Santos, TelmoWe present the first image of the Madeira upper crustal structure, using ambient seismic noise tomography. 16 months of ambient noise, recorded in a dense network of 26 seismometers deployed across Madeira, allowed reconstructing Rayleigh wave Green's functions between receivers. Dispersion analysis was performed in the short period band from 1.0 to 4.0 s. Group velocity measurements were regionalized to obtain...
Zona de cisalhamento de Juzbado-Penalva do Castelo no sector de Figueira de Cas...
Pereira, Inês; Dias, Rui; Bento dos Santos, Telmo; Mata, João