Person: Muñoz Martín, Alfonso
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First Name
Alfonso
Last Name
Muñoz Martín
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Geodinámica Interna
Identifiers
7 results
Search Results
Now showing 1 - 7 of 7
Item Quantifying the erosional impact of a continental-scale drainage capture in the Duero Basin, northwest Iberia(Quaternary Research, 2018) Antón López, Loreto; Muñoz Martín, Alfonso; De Vicente Muñoz, GerardoFormerly closed drainage basins provide exceptional settings for quantifying fluvial incision and landscape dissection at different time scales. Endorheic basins trap all the sediment eroded within the watershed, which allows estimates of post–basin opening erosion patterns. The Duero Basin was a former closed basin and is presently drained by the Duero River into the Atlantic Ocean. During the Cenozoic, the basin experienced a long endorheic period, marked by the formation of continental carbonates and evaporites. The retrogressive erosion of the Atlantic drainage coming from the Portuguese coast subsequently captured the internal drainage, and significant fluvial dissection occurred. Presently, the basin contains a relatively well-preserved sedimentary fill. Gridding and surface fitting in this paper provide the first attempt to reconstruct the surface of the top of the former endorheic sedimentary sequence to quantify the erosional impact of the basin opening. At least 2251±524 km3 of sediment was removed from the formerly closed basin following the start of exorheism. This volume represents a mean basin-surface lowering of 65±13 m. Erosion estimates and landscape dissection patterns are consistent with geologic evidence of progressive establishment of an outward drainage system.Item Análisis de la estructura alpina de la corteza del centro de la Península Ibérica: Una sección Magneto-Telúrica a través del Sistema Central (Sierra de Gredos)(Geotemas, 2012) Pous, Jaume; Muñoz Martín, Alfonso; Olaiz Campos, Antonio José; Seillé, H.; De Vicente Muñoz, GerardoWe present a magnetotelluric profile across the Duero basin, the Central System and the Madrid basin, acquired in the framework of the TOPO-IBERIA project. The MT profile consists of 24 magnetotelluric sites over a 200 km, NS oriented profile. Five components were measured with periods ranging from 0.001 s to 500s. The dimensional analysis reveals a dominant E-W direction and 2D joint inversion of apparent resistivity, phases and tipper was carried out. The inverse resistivity model obtained has been compared with other geological and geophysical data, and it shows a resistive and homogeneous crust that extends towards the Duero basin. The main conductive anomalies are elongated and inclined bodies that are related with the main big–scale Alpine thrusts. Other superficial conductive bodies are related with the tertiary sedimentary basins. [RESUMEN]Este trabajo muestra un nuevo perfil magnetotelúrico (MT) a través del la cuenca del Duero, el Sistema central y la Cuenca de Madrid, adquirido dentro del proyecto TopoIberia. El Perfil MT consiste en 24 sondeos a lo largo de 200 km con una orientación NS. En cada sondeo se han medido cinco componentes con periodos de 0.001 a 500 s. El análisis dimensional revela una dirección dominante E-O y se ha realizado una inversión conjunta en 2D de las resistividades aparentes, fases y tipper. El modelo de resistividades obtenido ha sido comparado con otros datos geológicos y geofísicos, y muestra una estructura cortical homogénea y resistiva que se prolonga hacia la cuenca del Duero. En esta corteza aparecen cuerpos conductores inclinados y alargados en profundidad asociados a grandes cabalgamientos alpinos. Otros cuerpos conductores superficiales están claramente relacionados con las cuencas sedimentarias terciariasItem Análisis de la sensibilidad de las estimaciones de la profundidad del basamento en la cuenca de Madrid (España Central)(Geotemas, 2012) Olaiz Campos, Antonio José; Muñoz Martín, Alfonso; Gascone, L.; De Vicente Muñoz, Gerardo; Mantilla Pimiento, A.The Madrid basin, over 20.000 km2 , located in Central Spain. Its evolution is conditioned by basement uplifts (Central System and Toledo Mountains) during the Alpine orogeny. The Madrid basin is connected with the Loranca basin at its NE corner and with La Mancha basin to the south. Sediment thickness accumulated from Late Cretaceous to the Late Miocene, is about 3.000 m at Pradillo well, but from seismic interpretation, a depocenter associated to Central System South Thrust is inferred. For this study four different methodologies were used(“Euler Deconvolution”, “Source Parameter Imaging”, “Analytic Signal” and “Tilt Depth”), in order to obtain depth to basement estimations from aermagnetic data. These methods work for simplified source geometries, estimating depths as a good starting point for a structural interpretation. In Madrid Basin, this knowledge is important due to the geothermal and hydrological potential of the basin, as well as for CO2 storage. [RESUMEN]La cuenca de Madrid, con un área aproximada de 20.000 km2, se extiende en la zona central de la Península Ibérica. Su evolución está condicionada por el levantamiento del Sistema Central y de los Montes de Toledo durante la orogenia Alpina. La cuenca de Madrid está conectada con las cuencas de Loranca, en su límite NE, y de La Mancha por el sur. El espesor de sedimentos, con registro continuo desde el Cretácico Superior hasta el Mioceno Superior, alcanza los 3000 m en el pozo Pradillo, aunque de la interpretación sísmica se obtiene un depocentro, de mayor profundidad, adosado al cabalgamiento del Borde Sur del Sistema Central . En este trabajo se han seguido distintas metodologías para estimar la profundidad del basamento, a partir de datos aeromagnéticos. Los distintos métodos (“Deconvolucion de Euler”, “Source Parameter Imaging”, “Analytic Signal” y “Tilt Depth”) tienen en común que asumen geometrías sencillas, pero los resultados obtenidos resultan de gran interés para la interpretación estructural del basamento. En el caso de la cuenca de Madrid, este conocimiento es muy importante dado su potencial geotérmico e hidrogeológico, así como un posible uso como almacenamiento geológico.Item Structural Achitecture of the Madrid Basin from 3D Gravity Inversion(Conference Paper. 77th EAGE Conference & Exhibition 2015, 2015) Olaiz, A.J.; Mantilla Pimiento, A.; Muñoz Martín, Alfonso; De Vicente Muñoz, GerardoThe Madrid Basin is an intraplate Cenozoic basin located in the central area of the Iberian Peninsula. Basement is characterized by a wide range of lithologies, from meta-sediments to granites. Sedimentary section is associated with a carbonatic platform in Cretaceous time and with continental environments during Tertiary. During the second half of the last century 2D seismic data was acquired and some wells were drilled by several oil & gas companies. Due to the lack of refraction seismic, the geometry of the Moho is not very well-known in the area. This study presents the results of the 3D gravity inversion performed mainly to determine the configuration of the Moho. Also, the geometry of basement has been refined after the inversion. The initial model was constrained by surface geology, 2D seismic and well data. The final 3D model shows significant density variations within the basement and the presence of an intra-basement structure in the Central Iberian System.Item Using river long profiles and geomorphic indices to evaluate the geomorphological signature of continental scale drainage capture, Duero basin (NW Iberia)(Geomorphology, 2013) Antón López, Loreto; De Vicente Muñoz, Gerardo; Muñoz Martín, Alfonso; Stokes, MartinWell-constrained case studies of transient landscape responses are needed to improve our understanding of erosion processes associated with drainage captures. The Duero basin is an excellent location for such a study because the landscape is currently undergoing pronounced geomorphological changes resulting from the opening of a former closed drainage. The present-day continental interior basin (N50,000 km2) drains to the Atlantic Ocean via the Duero River, but during the Cenozoic the basin experienced a long endorheic period marked by the formation of evaporites. Currently, the entire continental interior is an area of relative tectonic quiescence, characterised by a relict low-relief upland topography (Meseta). Systematic variations in lithology and a well-constrained tectonic setting throughout the basin and adjacent areas allow for the comparison of channel morphology between the Cenozoic Duero basin and its western fringe. To explore the signal of transient geomorphic response to capture and opening of the former endorheic basin, the main channel and 24 tributaries were analysed in terms of their longitudinal profiles and the application of geomorphic indices (concavity index [Ci], valley floorwidth-to-height ratio [Vf], and stream-length gradient index [SL]). The analysis reveals two zones with distinctive morphologies: (1) an upper reach domain consisting of broad flat valleys and low-gradient streams where concave longitudinal profiles dominate and (2) a middle reach domain characterised by steep, deeply incised canyons where a convex long profile dominates marking a major kinckzone. The quantitative information on channel shapes and long profile geometries allows the interpretation of these patterns in terms of driving forces for fluvial landscape development. Large-scale morphometric analysis highlights the transient response of the entire basin to a capture-related base level lowering and illustrates the importance of drainage captures as potential internal drivers of landscape modification and topographic adjustments. Furthermore, the Duero basin case study also emphasises that well-constrained bedrock geology and tectonic patterns are essential to avoid misinterpretation of geomorphic indexes.Item Mapa de esfuerzos activos en línea de la Península Ibérica a partir de Mecanismos Focales calculados desde el Tensor de Momento Sísmico(Geotemas, 2012) Muñoz Martín, Alfonso; De Vicente Muñoz, Gerardo; Olaiz Campos, Antonio José; Antón López, Loreto; Vegas, Ramón; Granja Bruña, José LuisThis work shows a new on-line stress map for Iberian Peninsula obtained from the inversion of earthquakes focal mechanisms calculated with the centroid moment tensor. An amount of 299 focal mechanisms have been selected with several quality criteria from different catalogues (CMT Harvard, ETH, Med-Net, I.G.N. and I.A.G.) from 1973 to January 2012. Values for the maximum horizontal stress and the shape factor of the ellipsoid (horizontal/vertical stress) have been calculated following De Vicente et al. (2008).. The local results have been interpolated to a 10’ regular grid in which the relation between tectonic horizontal stress and vertical load has been taken into account. The final map shows a good correlation with the primary tectonic forces generated in the plate boundaries and the local perturbations related with main crustal heterogeneities. Both the maps and data are free for download from http://www.ucm.es/info/lta/lta.html Applied Tectonophysics Group WebSite). [RESUMEN]Este trabajo muestra el nuevo mapa en línea de esfuerzos activos para la Península Ibérica obtenido a partir de la inversión de mecanismos focales de terremotos (MF) calculados con Tensor de Momento Sísmico (TMS). Un total de 299 MF han sido seleccionados con varios criterios de calidad de diferentes catálogos (CMT Harvard, ETH, Med-Net, I.G.N. e I.A.G.), para un periodo comprendido entre 1973 y enero de 2012 y profundidades menores de 60 km. Los valores de la dirección de máximo acortamiento horizontal (Dey) y el factor de forma (carga horizontal/vertical) han sido calculados siguiendo a De Vicente et al. (2008). Los resultados obtenidos se han interpolado a una malla regular de 10’, teniendo en cuenta las orientaciones de las componentes horizontales de esfuerzo, y el factor de forma. Los mapas finales muestran una buena correlación con indicadores geológicos y cinemáticos. Las orientaciones de los esfuerzos horizontales se relacionan con las fuerzas primarias provenientes de los límites de placas, y con perturbaciones locales relacionadas con heterogeneidades de primer orden a nivel cortical. Tanto los mapas, como los datos procesados son accesibles a través de la Web del Grupo de Tectonofísica Aplicada de la UCM http://www.ucm.es/info/lta/lta.html.Item The Spanish-Portuguese Central System: An Example of Intense Intraplate Deformation and Strain Partitioning(Tectonics, 2018) De Vicente Muñoz, Gerardo; Cunha, P.P.; Muñoz Martín, Alfonso; Cloetingh, S.A.P.L.; Olaiz Campos, Antonio José; Vegas, RamónThe intraplate deformation of Iberia during the Cenozoic produced a series of ranges and deformation belts with a wide variety of structural trends. The Spanish-Portuguese Central System is the most prominent feature crossing over the whole of central Iberia. It is a large thick-skinned crustal pop-up with NE-SW to E-W thrusts. However, the 500-km-long left-lateral strike-slip Messejana-Plasencia fault, also NE-SW oriented, bends these thrusts to produce NE-SW local paleostresses close to the fault, which seems to be consistent with a common deformational arrangement. This is also supported by the similar sedimentary infilling characteristics found in the surrounding Cenozoic basins. The moment of the maximum intraplate deformation is registered at the same time in all these basins during the upper Priabonian-lower Chattian. As there are two possible sources for the intraplate compressive stresses, the Pyrenean (N-S shortening) orogen to the north and the Betic (NW-SE shortening) orogen to the south, neither can simply explain both simultaneous movements (NE-SW strike-slip and NE-SW thrusting). The deduced age of the main deformation indicates a Pyrenean origin. In contrast, the concept of strain partitioning between the two types of faults gives as a result an overall north trending compression. Existing data do not support crustal detachment from the Betics neither from the Pyrenees but are consistent with a crustal uplift related to lithospheric folding. The subsequent Betic-related stress field only slightly reworked previously Pyrenean-related structures, except for the Portuguese sector, where tectonic activity occurred mainly in the Upper Miocene.