162 research outputs found

    Petrografía y aspectos geoquímicos de los enclaves microgranudos de Cangas de Morrazo - Moaña (prov. de Pontevedra)

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    [Resumen] En este trabajo se estudian y describen las particularidades mineralógicas, petrograficas y químicas encaminadas a la correcta caracterización y clasificación del "pasillo de enclaves" de Cangas de Morrazo - Moaña (Ria de Vigo). Desde el punto de vista petrografico y químico aparecen tres tipos diferentes de enclaves asociados a rocas básicas y granitos biotíticos, todas ellas emplazadas en las denominadas granodioritas precoces de Galicia. Los enclaves son fundamentalmente rocas tonalíticas y granodioríticas cuyas diferencias esenciales parecen estribar en un grado de hibridación progresivo entre magma ácido y magma básico[Abstract] This paper deals with the petrographical and geochemical characteristics of the enclaves situated near the estuary of Vigo, between the localities of Cangas de Morrazo and Moaña (Pontevedra, NW of Spain). Enclaves are associated to basic rocks and al1 of them are placed into older hercynian granodiorites of Galicia. There are essentially three types of enclaves ranging from tonalites to granodiorites The difference-between them can be explained by the progressive grade of basic and acid magma hybridatio

    U-Pb dating of Ordovician felsic volcanism in the Schistose Domain of the Galicia-Trás-os-Montes Zone near Cabo Ortegal (NW Spain)

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    The northern termination of the Schistose Domain of the Galicia-Trás-os-Montes Zone is a tectonic slice named the Rio Baio Thrust Sheet, which is sandwiched between the Cabo Ortegal Complex and the Ollo de Sapo Domain of the Central-Iberian Zone. The Rio Baio Thrust Sheet is formed by two volcanosedimentary series, the Loiba and the Queiroga Series. The Loiba Series contains calc-alkaline dacite and rhyolite, while the overlying Queiroga Series has alkaline rhyolite. These series were considered to be in stratigraphically upwards continuity and believed to be Silurian in age. U-Pb dating of an alkaline rhyolite in the Queiroga Series provides an Arenig age of 475 ± 2 Ma. This age makes the Queiroga Series the oldest known stratigraphic unit in the Schistose Domain of the Galicia-Trás-os-Montes Zone, impeding correlation between the lithostratigraphic sequences of Ortegal and Central Galicia. As well as providing evidence of an unforeseen structural complexity within the Rio Baio Sheet, the new data supports the notion that the Schistose Domain is not parautochtonous, but a separate lithotectonic unit in thrust contact with the underlying Central-Iberian Zone

    Origin and provenance of igneous clasts from late Palaeozoic conglomerate formations (Del Ratón and El Planchón) in the Andean Precordillera of San Juan, Argentina

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    Late Palaeozoic conglomerate formations (Del Ratón and El Planchón) from the Andean Precordillera (Argentina) were studied to unravel their age, composition and provenance. The conglomerates from the Del Ratón Formation are formed by igneous clasts of acid, intermediate and basic compositions (volcanic and plutonic). Laser Ablation (ICP-MS) zircon U-Pb study has yielded an age of 348±2 Ma (late Tournaisian) for the crystallization of a granitic clast, interpreted as a maximum deposition age for the Del Ratón Formation. Geochemistry of these clasts (high LILE/HFSE and La/Yb ratios, negative Nb-Ta anomalies) suggests a calc-alkaline batholithic source, probably located along the Andean Frontal Cordillera currently to the west, where similar calc-alkaline igneous rocks have been described. The El Planchón Formation overlies the Del Ratón Formation and, in the studied conglomerates, there are only igneous clasts of mafic composition (volcanic/subvolcanic). These mafic clasts have a very similar petrography and geochemistry to the Late Ordovician mafic igneous rocks of the Western Precordillera (low LILE/HFSE and La/Yb ratios, no negative Nb-Ta anomalies). Therefore we suggest that the El Planchón conglomerate clasts were probably delivered mainly from northern sources within the Precordillera terrane. This change in clast provenance is tentatively related to a shift in mountain uplift from the Frontal Cordillera (in the west) to the Precordillera (in the east) after the early Visean.Las formaciones conglomeráticas del Paleozoico superior (Del Ratón y El Planchón) de la Precordillera Andina (Argentina) fueron es­tudiadas con el fin de determinar su edad, composición y procedencia. Los conglomerados de la Formación Del Ratón están constituidos por clastos de rocas ígneas (volcánicas y plutónicas) ácidas, intermedias y básicas. Un estudio en circones con espectrometría de masas con plasma acoplado por inducción con ablación láser (LA-ICP-MS) proporciona una edad de 348±2 Ma (Tournaisiense superior) para la cristalización de un clasto granítico, que interpretamos como la máxima edad del depósito de la Formación Del Ratón. La geoquímica de los clastos (altas relaciones LILE/HFSE y La/Yb, anomalías negativas de Nb-Ta) sugiere que probablemente derivan de batolitos calcoal­calinos descritos en algunos sectores de la Cordillera Frontal Andina localizada actualmente al oeste. La Formación El Planchón se super­pone a la Formación Del Ratón y los clastos estudiados en los conglomerados de esta formación son únicamente de rocas ígneas básicas (subvolcánicas/volcánicas). Estos clastos tienen una petrografía y geoquímica similar a las rocas ígneas máficas del Ordovícico Superior de la Precordillera Occidental (bajas relaciones LILE/HFSE y La/Yb, ausencia de anomalías negativas en Nb-Ta). Por ello nosotros suge­rimos que los clastos de los conglomerados de la Formación El Planchón proceden de materiales localizados al norte dentro de la propia Precordillera. Este cambio en la procedencia de los clastos es tentativamente relacionado con una transferencia de la deformación desde la Cordillera Frontal (al oeste) a la Precordillera (al este), provocando el levantamiento de la Precordillera a partir del Viseense inferior

    Metavolcanic rocks from schistose domain of Galicia-Tras-os-Montes: petrography, geochemistry and tectonic environment (Galice, NW. Spain)

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    [Resumen] Se estudia el vulcanismo intercalado en los grupos litoestratigráficos inferiores que integran el Dominio Esquistoso de Galicia Tras-os-Montes (DEGTM) denominados de muro a techo Santabaía, Nogueira y Paraño. El grupo de LalínForcarei que completa la secuencia no será tratado en este trabajo. La edad de estos grupos debe comprender desde el Precámbrico hasta el Devónico Inf. Los tres grupos tiene un cierto carácter vulcanosedimentario, más marcado en el grupo de Santabaía que en los dos grupos superiores. Se encuentran en ellos diferentes niveles volcánicos y vulcanosedimentarios de espesor y continuidad lateral variables, correspondientes a neises microporfídicos de dos micas y ortoneises biotíticos, además de algún nivel de riolitas y tranquitas presentes hacia la parte alta del grupo de Paraño. Geoquímicamente se caracteriza por ser un vulcanismo ácido de naturaleza calcoalcalina en el que predominan los términos riolíticos y iodacíticos de alto contenido en K, posiblemente originado en la zona externa de un margen continental pasivo existente durante el Ordovícico-Silúrico en el NO. de la Península, en el que tendrían lugar diferentes episodios o etapas de aportes volcánicos alternando con etapas más largas de sedimentación detrítica.[Abstract] The Vulcanism interbedded in the lower litostratigraphic groups of the DEGTM is studied. Those gruoups are known as Santabaia, Nogueira and Paraño from bo~tom to top; The sequence is completed with the Lalín-Forcarei group that is not studied in this paper. The age of the whole sequence is probably, from Precambrian to lower Devonian. The three groups show volcano-sedimentary features which are dominant in the Santabaia group. Several volcanic and volcano-sedimentary levels with different thickness and extension are found; these correspond to two mica microporfidic gneisses and biotitic ortogneisses and seldom ryolites and trachites in the uppermost pan of the Paraño group. Geochemically correspond to acid calcoalcaline vulcanites with ryolites and K rich ryodacites as main types. These rocks are possibily related to an external area of a continental margin which existed during Ordovician-Silurian time in the NW of the Iberian Peninsula. Several volcanic stages would alternate with sedimentation in this geotectonic environment

    Datación U-Pb del volcanismo Siluro-Ordovícico del Sinforme de Verín (Orense, Dominio Esquistoso, Zona de Galicia-Trás-os-Montes)

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    El Grupo Paraño constituye la parte más alta de la estratigrafía del Dominio Esquistoso de Galicia-Trásos- Montes y está expuesto en el núcleo de la Sinforma de Verín. Como al resto del dominio, a este grupo se le ha atribuido una edad Silúrica. Con el fin de comprobar su edad se ha datado por el método U-Pb en circón una traquita félsica, de afinidades alcalinas, que ha proporcionado una edad Siluro- Ordovícica de 439,6+/-5 Ma. Esta edad demuestra que la estratigrafia del Dominio Esquistoso es más compleja de lo que se suponía, e invalida la correlación entre las rocas volcánicas en Galicia Central y las riolitas alcalinas de la Serie de Queiroga en la zona de Cabo Ortegal, datadas con una edad de 475 Ma por el método U-P

    Simultaneous Culture and Biomachining of Copper in MAC Medium: A Comparison between Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans

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    Biomachining will not be considered as a full-scale manufacturing technology until a stable, controlled, and continuous metal removal rate (MRR) is achieved. In this research work, a novel strategy that could promote its industrial implementation, namely simultaneous bacterial growth and machining of copper contained in oxygen-free copper (OFC) workpieces, was investigated. This proposal has the major advantage of being a single-stage process, thereby reducing total operating times and becoming more economical in comparison with conventional biomachining (downtime due to bacterial growth would disappear). The study was carried out using mesophilic (Acidithiobacillus ferrooxidans) and thermophilic (Sulfobacillus thermosulfidooxidans) extremophile bacteria in order to prevent the progressive decrease in the amount of metal removed per unit time. A constant MRR of 43 mg h-1 was achieved with A. ferrooxidans in the simultaneous process. Despite the accomplishment of a constant MRR, this value is lower than the maximum MRR obtained in conventional biomachining (109 mg h-1), probably due to the inability of ferric ions to come into contact with the metallic surface. With regard to the culture period in MAC medium, S. thermosulfidooxidans showed a slower growth rate (0.11 h-1) and lower ferrous ion oxidation level (0.12 g Fe2+ L-1 h-1) than A. ferrooxidans (0.17 h-1 and 0.22 g Fe2+ L-1 h-1, respectively) under optimal pH (1.5) and Fe2+ concentration (6 g L-1) conditions.Fil: Diaz Tena, E.. Universidad del País Vasco; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Gallastegui, G.. Universidad del País Vasco; EspañaFil: Hipperdinger, Marcela Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Donati, Edgardo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Rojo, N.. Universidad del País Vasco; EspañaFil: Santaolalla, A.. Universidad del País Vasco; EspañaFil: Ramirez, M.. Universidad del País Vasco; EspañaFil: Barona, A.. Universidad de Cádiz; EspañaFil: Elías, A.. Universidad del Pais Vasco - Euskal Herriko Unibertsitatea, Campus Bizkaia

    U-Pb dating of Ordovician felsic volcanism in the Schistose Domain of the Galicia-Trás-os-Montes Zone near Cabo Ortegal (NW Spain)

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    The northern termination of the Schistose Domain of the Galicia-Trás-os-Montes Zone is a tectonic slice named the Rio Baio Thrust Sheet, which is sandwiched between the Cabo Ortegal Complex and the Ollo de Sapo Domain of the Central-Iberian Zone. The Rio Baio Thrust Sheet is formed by two volcanosedimentary series, the Loiba and the Queiroga Series. The Loiba Series contains calc-alkaline dacite and rhyolite, while the overlying Queiroga Series has alkaline rhyolite. These series were considered to be in stratigraphically upwards continuity and believed to be Silurian in age. U-Pb dating of an alkaline rhyolite in the Queiroga Series provides an Arenig age of 475 ± 2 Ma. This age makes the Queiroga Series the oldest known stratigraphic unit in the Schistose Domain of the Galicia-Trás-os-Montes Zone, impeding correlation between the lithostratigraphic sequences of Ortegal and Central Galicia. As well as providing evidence of an unforeseen structural complexity within the Rio Baio Sheet, the new data supports the notion that the Schistose Domain is not parautochtonous, but a separate lithotectonic unit in thrust contact with the underlying Central-Iberian Zone

    Late Pleistocene climate of the northern Iberian Peninsula: New insights from palaeoglaciers at Fuentes Carrionas (Cantabrian Mountains)

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    Producción CientíficaNew Be dates for glacial landforms in the Fuentes Carrionas area (Cantabrian Mountains, nothern Spain) are presented. Mapped and dated landforms in Fuentes Carrionas made possible a palaeoglacier reconstruction for four glacial stages. Results were compared to other nearby palaeoenvironmental proxies, so a final approximation on the mean annual temperature and annual precipitation that caused the four glacial advance stages is proposed. Glaciers reached their maximum extension at 36 ka, in a cold and dry environment. A second advance stage took place between 18.5 and 19.5 ka, during the Last Glacial Maximum (LGM), when glaciers advanced in a wet environment, with positive rainfall anomalies. A third glacial advance was dated during the Oldest Dryas, in which climate shifted to extremely cold and dry conditions. Finally, a last stage has been identified and proposed to the Younger Dryas, in which precipitation anomalies are negligible. Our results confirm some of the previously made palaeoglacial and palaeoenvironmental inferences for the Iberian Peninsula, as well as provide Q4 valuable and accurate anomalies, which are useful for climate modelling.Ministerio de Economía, Industria y Competitividad (project CGL2015-68144-R

    Osteogenic differentiation of human dental pulp stem cells in decellularised adipose tissue solid foams

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    3D cell culture systems based on biological scaffold materials obtainable from both animal and human tissues constitute very interesting tools for cell therapy and personalised medicine applications. The white adipose tissue (AT) extracellular matrix (ECM) is a very promising biomaterial for tissue engineering due to its easy accessibility, malleability and proven biological activity. In the present study, human dental pulp stem cells (hDPSCs) were combined in vitro with ECM scaffolds from porcine and human decellularised adipose tissues (pDAT, hDAT) processed as 3D solid foams, to investigate their effects on the osteogenic differentiation capacity and bone matrix production of hDPSCs, compared to single-protein-based 3D solid foams of collagen type I and conventional 2D tissue-culture-treated polystyrene plates. pDAT solid foams supported the osteogenic differentiation of hDPSCs to similar levels to collagen type I, as assessed by alkaline phosphatase and alizarin red stainings, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and osteocalcin/bone gamma-carboxyglutamate protein (BGLAP) immunostaining. Interestingly, hDAT solid foams showed a markedly lower capacity to sustain hDPSC osteogenic differentiation and matrix calcification and a higher capacity to support adipogenesis, as assessed by RT-qPCR and oil red O staining. White ATs from both human and porcine origins are relatively abundant and available sources of raw material to obtain high quality ECM-derived biomedical products. These biomaterials could have promising applications in tissue engineering and personalised clinical therapy for the healing and regeneration of lesions involving not only a loss of calcified bone but also its associated soft non-calcified tissues.This research was supported by the Basque Government (ELKARTEK program PLAKA KK2019-00093; to NB), MICINN retos I+D+i (PID2019- 104766RB-C21, to JRP) and UPV/EHU (PPGA20/22; to FU, GI). The authors would like to thank the staff members of the SGIKER services of the UPV/EHU: Lipidomic service (Beatriz Abad) and Analytical Microscopy (Ricardo Andrade, Alejandro Díez-Torre and Irene Fernández) for their technical assistance

    Topo-Iberia Project: CGPS crustal velocity field in the Iberian Peninsula and Morocco

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    A new continuous GPS network was installed under the umbrella of a research project called 'Geociencias en Iberia: Estudios integrados de topografı´a y evolución 4D (Topo-Iberia)', to improve understanding of kinematic behavior of the Iberian Peninsula region. Here we present a velocity field based on the analysis of the 4 years of data from 25 stations constituting the network, which were analyzed by three different analysis groups contributing to the project. Different geodetic software packages (GIPSY-OASIS, Bernese and GAMIT) as well as different approaches were used to estimate rates of present day crustal deformation in the Iberian Peninsula and Morocco. In order to ensure the consistency of the velocity fields determined by the three groups, the velocities obtained by each analysis center were transformed into a common Eurasia Reference Frame. After that, the strain rate field was calculated. The results put in evidence more prominent residual motions in Morocco and southernmost part of the Iberian Peninsula. In particular, the dilatation and shear strain rates reach their maximum values in the Central Betics and northern Alboran Sea. A small region of high shear strain rate is observed in the east-central part of the peninsula and another deformation focus is located around the Strait of Gibraltar and the Gulf of Cadiz
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