3,220 research outputs found

    Terremotos y montañas

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    3-D modelling of a fossil tufa outcrop. The example of La Peña del Manto (Soria, Spain)

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    [EN]Classical studies of tufas lack quantitative outcrop descriptions and facies models, and normally do not integrate data from subsurface in the stratigraphic and evolutive analysis. This paper describes themethodology followed to construct one of the first digital outcrop models of fossil tufas. This model incorporates 3-D lines and surfaces obtained from a terrestrial laser scanner, electric resistivity tomography (ERT) profiles, and stratigraphic and sedimentologic data from 18 measured sections. This study has identified seven sedimentary units (from SU-1 to SU-7) which are composed of tufa carbonates (SU-1; 3; 5; 6) and clastics (SU-2; 4; 7). Facies identified occur in different proportions: phytoherm limestones of bryophytes represent 43% of tufa volume, bioclastic limestones 20%, phytoherm limestones of stems 12%, oncolitic limestones 8%, and clastics 15%. Three main architectural elements have been identified: 1) Steeply dipping strata dominated by phytoherm limestones of bryophytes; 2) gently dipping strata dominated by phytoherm limestones of stems; and 3) horizontal strata dominated by bioclastic and oncoid limestones. The alternation of tufa growth and clastic input stages is interpreted as the result of climatic changes during Mid–Late Pleistocene.18.KA4A-463 A.C.01, Universidad de Salamanca CGL2014-54818-P of the Ministerio de Economía y Competitividad (MINECO)

    Geomorphic and Stratigraphic evidence of Quaternary diapiric activity enhanced by fluvial incision. Navarrés salt wall and graben system, SE Spain

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    The structural and stratigraphic geological features associated with salt structures have received extensive attention fromgeologists. However, there is limited work on the geomorphic and Quaternary record of diapiric activity despite its practical implications (e.g., salt and hydrocarbon extraction, geostorage activities). Thiswork analyses the Quaternary geomorphic and stratigraphic evidence of diapiric activity in the Navarrés saltwall (SE Spain), developed along the axis of a Neogene graben. This salt system is located in a region characterized by a peculiar network of orthogonal grabens that control the configuration and evolution of the drainage network. The protruding salt walls are spatially associated with the erosionally unloaded and deeply entrenched graben sections situated close to the regional base level. Evidence of recent/current activity in the Navarrés salt wall include: (1) internally drained areas in a marginal withdrawal basin with long-sustained aggradation; (2) distorted drainage network (defeated and deflected streams,wind gaps, knickpoints, changes in fluvial style), which changed froman initial axial longitudinal pattern to a longitudinal marginal distribution at the flanks of the saltwall; (3) development of diapiric fault scarps at the edge of the saltwall; (4) tilted fluvial terraces dipping away fromthe salt wall andwith localized sediment thickening. The available data indicate along-strike variability in deformation style and longterm vertical deformation rates. These range from ≤0.09mm/yr, to significantly higher values (N0.2-0.4 mm/yr) in the section where the salt wall displays a more prominent relief and is affected by deep fluvial entrenchment. The regional analysis and the characterization of the Navarrés salt wall suggest that Quaternary diapirism in the region is enhanced by erosional unloading related to fluvial entrenchment,which expands fromthe regional base level through the upstream propagation of an incision wave

    Models of coupled smooth muscleand endothelial cells

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    Impaired mass transfer characteristics of blood borne vasoactive species such as ATP in regions such as an arterial bifurcation have been hypothesized as a prospective mechanism in the aetiology of atherosclerotic lesions. Arterial endothelial (EC) and smooth muscle cells (SMC) respond differentially to altered local hemodynamics and produce coordinated macro-scale responses via intercellular communication. Using a computationally designed arterial segment comprising large populations of mathematically modelled coupled ECs & SMCs, we investigate their response to spatial gradients of blood borne agonist concentrations and the effect of micro-scale driven perturbation on the macro-scale. Altering homocellular (between same cell type) and heterocellular (between different cell types) intercellular coupling we simulated four cases of normal and pathological arterial segments experiencing an identical gradient in the concentration of the agonist. Results show that the heterocellular calcium (Ca2+) coupling between ECs and SMCs is important in eliciting a rapid response when the vessel segment is stimulated by the agonist gradient. In the absence of heterocellular coupling, homocellular Ca2+ coupling between smooth muscle cells is necessary for propagation of Ca2+ waves from downstream to upstream cells axially. Desynchronized intracellular Ca2+ oscillations in coupled smooth muscle cells are mandatory for this propagation. Upon decoupling the heterocellular membrane potential, the arterial segment looses the inhibitory effect of endothelial cells on the Ca2+ dynamics of underlying smooth muscle cells. The full system comprising hundreds of thousands of coupled nonlinear ordinary differential equations simulated on the massively parallel Blue Gene architecture. The use of massively parallel computational architectures shows the capability of this approach to address macro-scale phenomena driven by elementary micro-scale components of the system

    Efecto de compuestos fenólicos presentes en extractos de plantas argentinas en el crecimiento miceliar del fitopatógeno Botrytis cinerea Pers

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    The polyphagous plant pathogen Botrytis cinerea has the ability of growing fast under several conditions, and producing grey moulds in different plant tissues. Because of its adaptive plasticity, resistant strains have made difficult their chemical control. Therefore, new strategies of management and the use of natural compounds could be important control alternatives. The aim of this work was to study the potential value of four Argentine native plant extracts and some of its phenolic compounds as biodrugs on B. cinerea. Aqueous plant extracts of Larrea divaricata, Prosopis strombulifera, Tessaria absinthioides and Schinus molle var. areira, were used. The capability to inhibit the mycelial growth was studied using either the crude plant extract or same its most important, detected phenolic compounds. Phenolic compounds were analyzed by Capillary Zone Electrophoresis (CZE) with UV detection, and then statistically analyzed by Principal Component Analysis to correlate them and their biological activity against the fungus. Prosopis strombulifera and T. absinthioides extracts did not inhibit mycelial growth while S. molle stimulated it. Larrea divaricata demonstrated inhibition above 50% at plant extracts concentrations of 100 mg/mL.Fil: Hapon, María Vanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Boiteux, Joana Jaqueline. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Fernández, M. A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Lucero, G.. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Silva, María Fernanda. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Pizzuolo, Pablo Humberto. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentin

    Caracterización de depósitos carbonáticos ligados a paleosurgencias en el sector de Batallones-Malcovadeso (Neógeno de la Cuenca de Madrid)

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    En la zona de canteras de Valdeinfierno, en el sector de Batallones-Malcovadeso, parte centro-meridional de la Cuenca de Madrid, se ha reconocido una serie de depósitos carbonáticos que presentan geometría dómica y estructura interna columnar. Dentro de estos depósitos de carbonato se distinguen dos unidades. La inferior (U2) es mayoritariamente dolomítica y de estructura brechoide, y petrográficamente consiste en dolomicritas con cemento calcítico. La superior (U3) está formada tanto por dolomita como por calcita, y se caracteriza por el desarrollo de morfologías columnares de aspecto travertínico. Petrográficamente, los depósitos de esta unidad consisten en caliza con texturas alveolar y biogénica. Entre las columnas de carbonato se distinguen abundantes masas arcillosas. Hacia la base de estas unidades carbonáticas se sitúa una unidad detrítica (U1), formada por arenas feldespáticas y a su techo se dispone un conjunto lutítico con alguna intercalación carbonática de composición dolomítica (Unidad U4) y, por encima de estas lutitas, un conjunto calizo (Unidad U5). Las arcillas presentes en la unidad U3 tienen una composición (sepiolita > esmectita trioctaédrica ± illita) netamente diferente a las de la unidad U4 (esmectita dioctaédrica > illita ± caolinita). La composición isotópica de los carbonatos de las unidades U2 y U3, así como de los niveles carbonatados de la unidad U4, es bastante similar en el caso de la dolomita, con valores δ13C que oscilan entre –6,21 y –7,78‰ y entre –3,23 y –4,05‰ para el δ18O. Por otro lado, desde un punto de vista de su composición isotópica, se diferencian los carbonatos de la unidad 4 y del techo de la unidad 2, exclusivamente calcíticos, en los que los valores de δ13C oscilan entre –8,07 y –11,75‰, y los de δ18O entre –5,27 y –7,35‰. La calcita existente en los niveles dolomíticos presenta valores intermedios entre los dos grupos anteriores. Los rasgos de la sucesión sedimentaria y los resultados analíticos obtenidos indican una fase de expansión lacustre en la zona estudiada con un cambio en la química de las aguas, todo ello favorecido por la entrada de aguas subterráneas a través de surgencias.Este trabajo se ha realizado dentro del Proyecto de investigación CGL2005-03900/BTE financiado por el Ministerio de Educación y Ciencia.Peer reviewe

    3D Modelling of archaeoseismic damage in the Roman site of Baelo Claudia (Gibraltar Arc, south Spain)

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    This study deals with the morphometric characterization and quantification of earthquake damage in the ancient Roman city of Baelo Claudia in South Spain (Gibraltar Arc) by means of the use of 3D modelling from drone imagery. Baelo Claudia is a world-renowned archaeological site recording recurrent earthquake destruction during the first and third centuries AD. The first earthquake destroyed the lower littoral zone of the city, allowing its reconstruction from the year c. 60–70 CE, but the second earthquake in 365–390 CE led to the complete destruction of the renewed city and its eventual abandonment. This second earthquake imprinted important deformations in the main monumental zone of the city, including the basilica temples, macellum, city walls, aqueducts and funerary monuments, as well as in the main paved zones of the city. This is the case for the Forum, Decumanus and Cardos, which show a variety of folds, pop-up structures, conjugate fractures and impact marks susceptible to be measured in a 3D format. The current study presents detailed (up to 3 mm/pixel) surface models of iconic monuments within the city. The 3D models were obtained by means of serial orthophotos taken with a UAV Mavic Pro 2 (DJI) Drone device equipped with a 20 mpx camera and a 1” CMOS sensor. Each individual image was captured in a geo-referenced jpg format and processed with the Agisoft Metashape Professional software®. Depending on the measured monument, the final images consisted of 250 to 700 photographs clustered by 50,000 to 150,000 tie points. In all studied items (Decumanus, city walls and bath dish), we follow the same workflow of analysis: (1) alignment of photos with support points; (2) building a dense cloud of points; (3) creation of the surface texture; (4) creation of the Digital Elevation Model (DEM); (5) creation of the orthomosaic; and finally, (6) the building of the high-quality 3D tiled surface models. The obtained models allow the geometric quantification of earthquake deformations (displacements, amplitudes, orientation, etc.) in a GIS-based 3D environment suitable to quantify oriented damage of seismic origin. In a complementary way, these 3D models deserve to be considered for their potential role as digital seismoscopes of ancient archaeological sites and/or heritage building

    Structure and kinematics of the Ayora-Cofrentes Diapir (eastern Betics). Role of basement faulting in the salt and suprasalt deformation of the Mesozoic cover

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    The Ayora-Cofrentes Diapir is a 34 km long N-trending salt wall cutting the Valencian Domain that is made by Middle to Upper Triassic salt. On both sides, it is flanked by parallel half grabens offsetting the subtabular strata of the Jurassic to Cretaceous suprasalt carbonate successions. Based on detailed geological mapping and cross-sections, one of them supported by a new magnetotelluric profile, this study analyses the structure and kinematics of this salt wall with the purpose of establishing the role played by the subsalt structure in its development; and, thus, help in the interpretation of diapirs currently incorporated in fold and thrust belts. In this regard, the study evidences the presence of a subsalt basement fault (the Ayora Fault), active as extensional during the Early Jurassic, and reactivated with a reverse throw sometime between the latest Cretaceous and middle Miocene. Both motions are older than the salt wall growth (middle-late Miocene). This strongly suggest that the Ayora-Cofrentes Diapir was not triggered by the vertical motion of the underlying Ayora basement fault but by thin-skinned processes for which this pre-existing basement fault appears to have played a crucial role as salt/suprasal strain localizer
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