Browsing by Author "Díez-Montes, Alejandro"
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- Dados geocronológicos para o soco pré-Mesozoico localizado a Oeste da Falha Porto-Tomar: implicações geodinâmicasPublication . Santos, Telmo M. Bento Dos; Chichorro, Martim; Carvalho, D.; Cachapuz, P.; Solá, A. Rita; Dantas, E.; Romão, José; Moreira, Noel; Silva, I. Dias da; Clavijo, E.; Díez-Montes, Alejandro; Valverde-Vaquero, Pablo; Santos, R. V.; Linnemann, UlfSUMMARY: Geochronological 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 and Silurian-Devonian ages. If the former show clear signs of affinity with the Ossa-Morena Zone, the latter are similar to the South Portuguese Zone, being one of the samples, probably deposited in the Middle-Upper Devonian, interpreted as having a mixed source.
- Estimativas geotermobarométricas e percursos P-T de migmatitos dos Farilhões, Arquipélago das Berlengas, Oeste de Portugal = Geothermobarometric estimates and P-T paths for migmatites from Farilhões Islands, Berlengas Archipelago, W PortugalPublication . Bento dos Santos, Telmo; Ribeiro, Maria Luísa; González-Clavijo, Emilio J.; Díez-Montes, Alejandro; Solá, A. Rita
- Geochronology and P-T-t paths of the Berlengas Archipelago rocks, W Portugal [Abstract]Publication . Valverde-Vaquero, Pablo; Bento dos Santos, Telmo; González-Clavijo, Emilio J.; Díez-Montes, Alejandro; Ribeiro, Maria Luísa; Solá, A. Rita
- Introduction and geological setting of the Iberian Pyrite BeltPublication . Inverno, Carlos; Díez-Montes, Alejandro; Rosa, C.; García-Crespo, J.; Matos, João Xavier; García-Lobón, J. L.; Carvalho, João; Bellido Mulas, Félix; Castelo-Branco, José Mário; Ayala, C.; Batista, Maria Joao; Rubio, F.; Granado, Isabel; Tornos, F.; Oliveira, José Tomás; Rey, C.; Araújo, Vítor; Sánchez-García, Teresa; Pereira, Zélia; Represas, Patricia; Solá, A. Rita; Sousa, Pedro
- A new approach to palynostratigraphy of the middle late Famennian Gafo Formation, southern sector of the Pulo do Lobo Domain, SW Iberia (Portugal and Spain)Publication . Mendes, Márcia; Pereira, Zélia; Vaz, Nuno; Díez-Montes, Alejandro; Matos, João Xavier; Albardeiro, Luís; Fernandes, Paulo; Jorge, Raul CG Santos; Chew, DavidABSTRACT: New palynological results from the Gafo Formation (southern sector of the Pulo do Lobo Domain, South Portuguese Zone) are integrated with recently studied sections and drillholes from the Portuguese and Spanish sectors. A total of 44 samples were studied, 27 of which were positive for palynomorph taxonomy. This research revealed well preserved palynological assemblages, including 73 spore species allocated to 28 genera, four acritarch genera, three prasinophyte algae genera plus common chitinozoan remains. Some additional forms were retained under open nomenclature. From this, the first complete age determination for the Gafo Formation in Portugal and Spain was achieved, indicating a middle Famennian (Grandispora gracilis–Grandispora famenensis, GF Biozone) to a late Famennian (Grandispora echinata, VH Biozone) age. A greywacke sample from the same Gafo Formation was dated by U–Pb zircon geochronology and a maximum depositional age of 369 ± 2.5 Ma was obtained. A correlation between these palynological and U–Pb zircon data and the palynoflora assemblages of previous authors was made, as well as with the ages of felsic volcanic rocks found intercalated in the Gafo Formation, confirming the complex stratigraphy of Pulo do Lobo Domain. The results are consistent with stratigraphic mapping and structural interpretations, allowing a middle–late Famennian age (GF and VH Biozone) to be assigned to the Gafo Formation sedimentary rocks. This work has also contributed to a reinterpretation of Gafo Formation depositional facies correlatives (e.g. the Santa Barbara Group in Spain) as being the same lithological unit.
- Programa de cartografia transfronteiriça do LNEG-IGME na Zona Sul Portuguesa nas escalas 1/200 000 e 1/400 000. Um contributo para a estratigrafia do SW IbéricoPublication . Matos, João Xavier; Díez-Montes, Alejandro; Dias, Ruben Pereira; Pereira, Zélia; Machado, Susana; Solá, A. Rita; Carmona, J.J. Huerta; Ressurreição, Ricardo; Albardeiro, Luís; Mendes, Márcia; Morais, Igor; González-Clavijo, Emilio J.; Gonçalves, Pedro; Santos, Sara; de Oliveira, Daniel Pipa Soares; Salgueiro, Rute; Henriques, S.B.A.; Oliveira, José Tomás; Fernandes, Paulo; Inverno, Carlos; Lopez, M. T.SUMMARY: The South Portuguese Zone (SPZ) 1/200 000 and 1/400 000 scale maps and stratigraphic program in SW Iberia is presented by a LNEG-IGME consortium and funded by GEO_FPI/Interreg-POCTEP. The 1/200 000 mapped area corresponds to the border area and is based on previous work (Folha 8 and Sevilla-Puebla de Guzmán maps). The 1/400 000 map covered a larger area, from Lisbon to Seville. The following domains of SPZ were considered: Pulo do Lobo (early Frasnian-late Famennian), Iberian Pyrite Belt (late Famennian-late Visean) and Baixo Alentejo Flysch Group (late Visean-late Moscovian). The maps include the Mesozoic Algarve basin and the Cenozoic Guadalquivir/Algarve basins. Field surveys were done using standard stratigraphic and GIS database methodologies. Palynological studies of Paleozoic metasedimentary rocks and U/Pb zircon geochronology of plutonic and volcanic rocks were essential to refine and update the Paleozoic stratigraphy. The new data allowed new knowledge and the validation of the geological models.
- Proyecto GEO_FPI, cartografía de la Zona Surportuguesa (ZSP). Datos preliminares de un estudio geocronológico U-PbPublication . Díez-Montes, Alejandro; Matos, João Xavier; Valverde-Vaquero, Pablo; Solá, A. Rita; Beranoaguirre, Aratz; Albardeiro, Luis; Salgueiro, Rute; Morais, Igor; Montero, P.; López, M. T.RESUMEN: La ZSP es la unidad geotectónica más al suroeste del Orógeno Varisco y se consideran los siguientes dominios: Pulo do Lobo (Frasniense inferior y Fameniense superior), Faja Pirítica Ibérica (Givetiense-Viseense superior), Grupo Flysch Baixo Alen tejo (Viseense superior-Moscoviense superior) y Grupo Suroeste (Estruniense-Bashkiriense medio). En el proyecto GEO_FPI se ha prestado especial atención a la Faja Pirítica Ibérica, ya que es una de las provincias metalogenéticas más importantes del mundo, con depósitos de sulfuros masivos (VHMS) e importantes recursos de Cu, Zn, Pb, Ag, Au, Sn, In, Se, Ge. Se ha realizado un trabajo de campo en común en la región fronteriza de España y Portugal para permitir una mejor inte gración y correlación de los datos geológicos y cartográficos. Además, se han seleccionado 31 afloramientos donde se han recogido muestras para realizar un estudio de geocronología de U-Pb en circón. Los datos de edad obtenidos son importantes para restringir las estructuras geológicas de la Faja Pirítica Ibérica que albergan la mineralización masiva de sulfuros y, por otra parte, mejoran la visión geotectónica de toda la ZSP
- The Berlengas Archipelago granitoids within the frame of the Variscan Orogeny, W Portugal : new data and insightsPublication . Valverde-Vaquero, Pablo; Bento dos Santos, Telmo; González Clavijo, Emilio José; Díez-Montes, Alejandro; Ribeiro, Maria Luísa; Solá, A. Rita; Silva, I. Dias da