1,409 research outputs found

    Características del emplazamiento, Petrología y Geoquímica de Espessartitas en el Plutón de la Maladeta: estudio preliminar

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    [Resumen] Los diques de lamprófidos espessartíticos son frecuentes en el plutón circunscrito de La Maladeta (Pirineos Centrales, Huesca-Lérida). Su emplazamiento, se produjo bajo unas condiciones confinadas y con un control estructural, afectando a todos los litotipos plutónicos (Cuarzo-Gabros, Granodioritas, Tonalitas y Sienogranitos) y, también a las etapas filonianas ácidas (Aplita y Pegmatitas). La composición mineral (con destacado contenido en anfíboles de composición hornblenda pargasítica) y la Geoquímica, definen una afinidad calco-alcalina cuya signatura en elementos mayores y trazas, es bastante análoga a la óbtenida en lamprófidos similares, emplazados en macizos granodioríticos. Esta afinidad presenta una relación genética con la granodiorita, como término volumétricamente más representativo del Macizo.[Abstract] Lamprophyric dykes (Spessartites) are frequent in the Maladeta circumscribe plutonic massif (Central Pyrenees, Huesca-Lérida). The setting of these dykes, under confinant strains and with a structural control, affected to á1l the plutonic rocktypes (Quanz-Gabbros, Granodiorites, Tonalites and Syenogranites) and to the acid dykes (Aplites and Pegmatites) too. The mineral (with high contents in Pargasitic-Hornblende amphiboles) and geochemical compositions, define a calc-alkaline affinity, very similar (Major and trace elements) to that of analogue lan prophyres, set in Granodioritic massifs. This affinity shows a genetic relation with the Granodiorite, as volumetrically most representative rock-type in the massif

    Petrology of the Maladeta granitoids ln the Tahüll-Lago Negro sector (Lérida)

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    [Resumen] El Macizo plutónico de La Maladeta (Huesca-Lérida) corresponde, en su sector central (Tahül1-lago Negro), a un plutón circunscrito, cuyo carácter polifásico, está representado por los cuatro pulsos siguientes: a) los Cuarzo-Gabros, ubicados en su extremo sur, b) las Granodioritas que, con contenidos variables en anfíbol y biotita, comprenden, en conjunto, el volumen dominante y el pulso más representativo, c) las tonalitas con alto contenido en biotita y, por último, d) los sienogranitos (de dos micas) situados en su zona más central. La composición modal y, en especial, el análisis químico de las fases minerales principales (piroxeno, anfíbol, plagioclasa, biotita, moscovita y feldespato) corroboran una evolución magmática gradual, desde las composiciones más indiferenciadas (Cuarzo-Gabros) hasta las más tardías (Sienogranitos). Se observa una buena correspondencia entre la evolución petrologica (a nivel espacia!) y la de composición mineral, obtenidas por nosotros, con la secuencia de edades radiométicas (Rb/ Sr y U/Pb) determinadas por MICHARD-VITRAC, A. el al, (1980). Esta zonación tiene, a su vez, una muy buena correspondencia con las pautas de evolución geoquímica (elementos mayores y trazas) obtenidas en estudios preliminares (ARRANZ, E., 1991; ARRANZ, E. el al., 1991 a, by c).[Abstract] The Maladeta plutonic Massif (Huesca-Lérida) corresponds, in its central area (Tahül1-Lago Negro), to a circumscribed pluton wich, with multiepisodic character, is represented by the fol1owing four pulses: a) the Quartz-Gabbros, located in its southern extreme brim, b) the Granodiorites that, with variable amount in amphibole and biotite, consist, as a whole, the dominant volume and the most representative pulse, c) the biotite-rich Tonalites and, lastly, d) the syenogranites (with two micas), located in its centermost point. The modal composition and, special1y, the chemical analysis in main mineral phases (pyroxene, amphibole, plagioclase, biotite, muscovite, and feldspar), confirm a gradual magmatic evolution, from' a more indifferentiate composition (Quartz-Gabbross) to the latest (Syenogranites). There exists a good correspondence between the petrological and mineralogical composition, obtained by us, with the sequence of radiometric dates (Rb/Sr and U/Pb) analysed by MICHARD-VITRAC el al., (1980). The petrological zonation has, in turn, a very good correspondence with the pattern of magmatic evolution (major and trace elements) obtained in preliminary studies (ARRANZ, E., 1991; ARRANZ, E. el al., 1991 a, b y c)

    Composition and barometric implications of the amphiboles from the Maladeta plutonic complex (Central Pyrenees, Huesca-Lérida)

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    [Abstract] The composition of the amphiboles in basic rocks (gabbros and diorites), granodiorites, monzogranites with minor amphibole and mafic microgranular enclaves from the Maladetta massif, corresponds to calcic terms (magnesioHornblende, actinolitic hornblende and actinolite), with reduced values ofAl tot• The main substitutional types are edenite, pargasite and Ti-Tschermakite, with other minor types, generating compositions with an AIIV excess. The application of three of the proposed calibrations for the Altot in Horblende geobarometer, gives anomalously low pressure values for the cristallyzation of the plutonic rock-types, suggesting that the amphibole crystals were formed below 2 Kbar of pressure, and in a continous way to subsolidus conditions,probably at the same time as AI-saturating phases formed

    The development of a resource-efficient photovoltaic system

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    This paper presents the measures taken in the demonstration of the photovoltaic case study developed within the European project ‘Towards zero waste in industrial networks’ (Zerowin), integrating the D4R (Design for recycling, repair, refurbishment and reuse) criteria at both system and industrial network level. The demonstration is divided into three phases. The first phase concerns the development of a D4R photovoltaic concept, the second phase focused on the development of a specific component of photovoltaic systems and the third phase was the demonstration of the D4R design in two complete photovoltaic systems (grid-connected and stand-alone). This paper includes a description of the installed photovoltaic systems, including a brief summary at component level of the lithium ion battery system and the D4R power conditioning system developed for the pilot installations. Additionally, industrial symbioses within the network associated with the photovoltaic systems and the production model for the network are described

    Application of a Neural Network classifier for the generation of clean Small Magellanic Cloud stellar samples

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    Context. Previous attempts to separate Small Magellanic Cloud (SMC) stars from the Milky Way (MW) foreground stars are based only on the proper motions of the stars. Aims. In this paper we develop a statistical classification technique to effectively separate the SMC stars from the MW stars using a wider set of Gaia data. We aim to reduce the possible contamination from MW stars compared to previous strategies. Methods. The new strategy is based on neural network classifier, applied to the bulk of the Gaia DR3 data. We produce three samples of stars flagged as SMC members, with varying levels of completeness and purity, obtained by application of this classifier. Using different test samples we validate these classification results and we compare them with the results of the selection technique employed in the Gaia Collaboration papers, which was based solely on the proper motions. Results. The contamination of MW in each of the three SMC samples is estimated to be in the 10-40%; the "best case" in this range is obtained for bright stars (G > 16), which belong to the Vlos sub-samples, and the "worst case" for the full SMC sample determined by using very stringent criteria based on StarHorse distances. A further check based on the comparison with a nearby area with uniform sky density indicates that the global contamination in our samples is probably close to the low end of the range, around 10%. Conclusions. We provide three selections of SMC star samples with different degrees of purity and completeness, for which we estimate a low contamination level and have successfully validated using SMC RR Lyrae, SMC Cepheids and SMC/MW StarHorse samples.Comment: arXiv admin note: substantial text overlap with arXiv:2210.0172

    A feature-rich transmission spectrum for WASP-127b

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    WASP-127b is one of the lowest density planets discovered to date. With a sub-Saturn mass (Mp=0.18±0.02MJM_{\rm p}=0.18 \pm 0.02 M_J) and super-Jupiter radius (Rp=1.37±0.04RJR_{\rm p}= 1.37 \pm 0.04 R_J), it orbits a bright G5 star, which is about to leave the main-sequence. We aim to explore WASP-127b's atmosphere in order to retrieve its main atmospheric components, and to find hints for its intriguing inflation and evolutionary history. We used the ALFOSC spectrograph at the NOT telescope to observe a low resolution (R∼330R\sim330, seeing limited) long-slit spectroscopic time series during a planetary transit, and present here the first transmission spectrum for WASP-127b. We find the presence of a strong Rayleigh slope at blue wavelengths and a hint of Na absorption, although the quality of the data does not allow us to claim a detection. At redder wavelengths the absorption features of TiO and VO are the best explanation to fit the data. Although higher signal-to-noise ratio observations are needed to conclusively confirm the absorption features, WASP-127b seems to posses a cloud-free atmosphere and is one of the best targets to perform further characterization studies in the near future.Comment: Accepted for Publication A&A Letters, May 22nd, 201
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