1,584 research outputs found

    Sedimentología del mioceno de la ciudad autónoma de Melilla

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    En este trabajo se describen la estratigrafía y las facies de los materiales miocenos del territorio de la Ciudad Autónoma de Melilla y se realiza una correlación con las diferentes unidades cronoestratigráficas descritas en la cuenca que permite asignar una edad más precisa a estos materiales. Se definen tres nuevas unidades estratigráficas. La unidad carbonática inferior consta de dos subunidades. La subunidad inferior arrecifal está formada casi exclusivamente por colonias de corales de tipo Porites ( boundstones ), con facies bien desarrolladas de núcleo y talud arrecifal. Estas facies arrecifales son muy similares a las descritas en los arrecifes coralinos típicos del Messiniense. Adaptándose a las bioconstrucciones arrecifales se dispone una subunidad carbonática bioclástica compuesta principalmente por calizas ( grainstones-packstones ) de moluscos y algas rojas. La estratificación de esta subunidad exhibe diferentes grupos de clinoformas que indican una progradación hacia el O de esta plataforma bioclástica. Por encima se dispone la unidad detrítica intermedia, que está constituida por areniscas y limos de color amarillo depositados en un ambiente deltaico progradante que rellena la paleotopografía dejada por la unidad subyacente. La unidad carbonática superior se dispone sobre las dos anteriores y está constituida por capas de calizas oolíticas ( packstones/ grainstones ) y por niveles estromatolíticos ( boundstones ) depositados en un ambiente de plataforma somera. Hacia el SO, la serie miocena pasa lateralmente a los sedimentos volcanoclásticos pertenecientes al cercano complejo volcánico del Gourougou. La similitud entre las facies de las tres unidades estratigráficas definidas en este trabajo y las de las unidades cronoestratigráficas descritas en la Cuenca de Melilla permite asignar una edad Messiniense para toda la serie terciaria del territorio de Melilla.Peer ReviewedPostprint (published version

    Conglomerats, gresos, argiles i calcàries de Montgat

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    Inventari d'espais d'interès geològic a Catalunya. Generalitat de Catalunya. Departament de Medi Ambient i Habitatge. Direcció General del Medi NaturalPostprint (published version

    Estratigrafía y petrología del subsuelo recuaternario del sector sw de la depresión de Barcelona (cadenas costeras catalanas, ne de Iberia)

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    [email protected] numerosas obras de Ingeniería Civil que se han realizado en los últimos años en la depresión de Barcelona (ampliación del aeropuerto, ampliación del metro y AVE fundamentalmente) han permitido recabar mucha información sobre el subsuelo de esta área. En este trabajo se caracterizan las distintas unidades de subsuelo precuaternarias que aparecen en los numerosos sondeos realizados recientemente en la zona SW de la depresión de Barcelona. Se ha identificado un sustrato triásico formado por areniscas del Buntsandstein y dos unidades de edad Miocena, una basal de carácter continental y otra superior depositada en un ambiente marino. Todas estas unidades fueron fracturadas debido a una tectónica extensiva y, posteriormente, fueron fosilizadas en primer lugar por los sedimentos del Plioceno, que recubren la superficie de erosión messiniense, y finalmente, por el Cuaternario. El análisis de las distintas unidades permite obtener datos sobre la evolución paleogeográfica y tectónica de la depresión de Barcelona durante el Mioceno y el Plioceno.Current building of civil Engineering infrastructures in the Barcelona plain and Llobregat delta (mainly metro and airport extension and high speed train) is providing new geological subsurface data to build better geologic models and understand the basin evolution. This work focuses on the pre-Quaternary units observed in cores. Based on petrographic analyses combined when it was possible with paleontological studies, we identified the lower Triassic Buntsandstein sandstone facies and Miocene continental and marine facies which appear compartmentalized due to extensive deformation. After this extensive episode, Pliocene and Quaternary sediments, which were deposited after the development of successive erosive surfaces, overlay the Triassic and Miocene units. The identification of these units enabled one to improve the interpretation of the tectonic and paleogeographic evolution of the Barcelona plain

    Estratigrafía y petrología del subsuelo precuaternario del sector SW de la depresión de Barcelona (Cadenas Costeras Catalanas, NE de Iberia)

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    Las numerosas obras de Ingeniería Civil que se han realizado en los últimos años en la depresión de Barcelona (ampliación del aeropuerto, ampliación del metro y AVE fundamentalmente) han permitido recabar mucha información sobre el subsuelo de esta área. En este trabajo se caracterizan las distintas unidades de subsuelo precuaternarias que aparecen en los numerosos sondeos realizados recientemente en la zona SW de la depresión de Barcelona. Se ha identificado un sustrato triásico formado por areniscas del Buntsandstein y dos unidades de edad Miocena, una basal de carácter continental y otra superior depositada en un ambiente marino. Todas estas unidades fueron fracturadas debido a una tectónica extensiva y, posteriormente, fueron fosilizadas en primer lugar por los sedimentos del Plioceno, que recubren la superficie de erosión messiniense, y finalmente, por el Cuaternario. El análisis de las distintas unidades permite obtener datos sobre la evolución paleogeográfica y tectónica de la depresión de Barcelona durante el Mioceno y el Plioceno.Peer ReviewedPostprint (published version

    Stratigraphy and petrology af the miocene Montjuïc delta (Barcelona, Spain)

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    The Neogene rift in the Catalan Coastal Ranges, which is located in the NE part of the Eastern Iberian Margin, corresponds to a system of grabens formed at the north-western edge of the Valencia Trough. In the central part of the Catalan Coastal Ranges are the Vallès - Penedès half-graben in the onshore and the Barcelona half-graben in the offshore, which are separated by the Garraf and the Collserola-Montnegre horsts. Montjuïc hill is a tilted block, which is located to the S of the Barcelona city, between the Collserola-Montnegre horst and the Barcelona half-graben . The Middle Miocene section of Montjuïc is constituted by an alternation of conglomerate, sandstone, mudstone and marlstone beds. The Montjuïc section was divided into four lithostratigraphic units from base to top: (1) The Morrot conglomerate and sandstone Unit, interpreted as delta plain deposits; (2) the Castell conglomerate, sandstone and mudstone Unit considered as proximal delta front deposits; (3) the Miramar marlstone Unit attributed to prodelta deposits; and (4) the Mirador conglomerate, sandstone and mudstone Unit interpreted as delta front deposits. As regards the foraminifera association, the Miocene of Montjuïc may be attributed to the N9-N10 zones of Blow, indicating a Serravallian age. The palaeobotanical record suggests that the climate during the deposition of the Miocene of Montjuïc was temperate-warm and humid. The sandstones and conglomerates are litharenites and lithorudites; they show variable amounts of matrix and are well cemented. The main framework components are quartz, rock fragments and K-feldspar. The Collserola mountain, where Palaeozoic materials crop out is the deduced source area. Montjuïc sandstones are characterized by an early silicic cementation consisting of K-feldspar overgrowths, quartz overgrowths, mesoquartz intergranular cement and a microquartz transformation of a former detrital matrix. A surface cementation is considered for these cements in the absence of compaction and the geological setting.Peer ReviewedPostprint (published version

    The building stone of the Roman city of Lixus (NW Morocco): provenance, petrography and petrophysical characterization

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    The characterization of building materials is a key tool to assess deterioration processes and improve potential restoration works of archaeological sites. The aim of this paper is to identify and characterize most important building stone used in the construction of the Roman city of Lixus (Larache, Morocco) by means of petrographic and petrophysical techniques. Based on the visual analysis of the monuments, three major building stones (i.e. lithotypes) have been identified: i) Oligocene sandstones, ii) Quaternary sandstones and iii) Quaternary conglomerates. Based on the analysis of the regional geology and exploitation marks, these three lithotypes have been recognised to crop out in the surroundings of Lixus and the quarries, presumably Roman in origin, recognized. The Oligocene sandstone is the primary building stone in Lixus as it forms and crops out extensively in the Tchemmis hill, at top of which the city is settled. The Quaternary sandstones and conglomerates, which represent nearshore deposits and eolianites, crop out along the Atlantic coast where they form part of the cliffs next to Larache. Petrographic results indicate that lithotypes differ notably in grain size, ratio of detrital to allochemical components, and the configuration of their porous system. Mechanical analysis show that the Oligocene sandstones are more resistant to compression than the Quaternary sandstones and conglomerates, the latter exhibiting relatively low compressive strength. The Oligocene sandstones, which display scarce porosity and permeability, show a hydric behaviour characterized by a very low degree of absorbing and desorbing water, likely resulting from a poor connectivity of the pore network. Contrary to the latter lithotype, the Quaternary sandstones, which exhibit very high porosity and permeability, display a hydric behaviour characterized by high degree of both absorbing and desorbing water. This is attributed to the low degree of cementation compared to porosity of this lithotype and the excellent connectivity of the porous network. Finally, the accelerated artificial aging test of the Oligocene and Quaternary sandstones do not show a significant weight loss after the accelerated artificial aging test, indicating that both are slightly affected by salt crystallization and presumably ice as well. Results indicate that the relatively fine state of conservation of the building rocks of Lixus is linked to intrinsic factors as mineralogy and petrophysical characteristics together with the favourable effect of the climatic condition of the study area.Peer ReviewedPostprint (published version

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    Measurement of electroweak WZ boson production and search for new physics in WZ + two jets events in pp collisions at √s=13TeV

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    A measurement of WZ electroweak (EW) vector boson scattering is presented. The measurement is performed in the leptonic decay modes WZ→ℓνℓ′ℓ′, where ℓ,ℓ′=e,μ. The analysis is based on a data sample of proton-proton collisions at √s=13 TeV at the LHC collected with the CMS detector and corresponding to an integrated luminosity of 35.9 fb−1. The WZ plus two jet production cross section is measured in fiducial regions with enhanced contributions from EW production and found to be consistent with standard model predictions. The EW WZ production in association with two jets is measured with an observed (expected) significance of 2.2 (2.5) standard deviations. Constraints on charged Higgs boson production and on anomalous quartic gauge couplings in terms of dimension-eight effective field theory operators are also presented
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