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
14 results
Search Results
Now showing 1 - 10 of 14
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 A multi-isotopic approach to investigate the influence of land use on nitrate removal in a highly saline lake-aquifer system(Science of The Total Environment, 2018) Valiente, Nicolás; Carrey, R.; Otero, Neus; Soler, A.; Sanz, D.; Muñoz Martín, Alfonso; Jirsa, F.; Wanek, W.; Gómez Alday, J.J.Endorheic or closed drainage basins in arid and semi-arid regions are vulnerable to pollution. Nonetheless, in the freshwater-saltwater interface of endorheic saline lakes, oxidation-reduction (redox) reactions can attenuate pollutants such as nitrate (NO3-). This study traces the ways of nitrogen (N) removal in the Pétrola lake-aquifer system (central Spain), an endorheic basin contaminated with NO3-(up to 99.2mg/L in groundwater). This basin was declared vulnerable to NO3-pollution in 1998 due to the high anthropogenic pressures (mainly agriculture and wastewaters). Hydrochemical, multi-isotopic (δ18ONO3, δ15NNO3, δ13CDIC, δ18OH2O, and δ2HH2O) and geophysical techniques (electrical resistivity tomography) were applied to identify the main redox processes at the freshwater-saltwater interface. The results showed that the geometry of this interface is influenced by land use, causing spatial variability of nitrogen biogeochemical processes over the basin. In the underlying aquifer, NO3-showed an average concentration of 38.5mg/L (n=73) and was mainly derived from agricultural inputs. Natural attenuation of NO3-was observed in dryland farming areas (up to 72%) and in irrigation areas (up to 66%). In the Pétrola Lake, mineralization and organic matter degradation in lake sediment play an important role in NO3-reduction. Our findings are a major step forward in understanding freshwater-saltwater interfaces as reactive zones for NO3-attenuation. We further emphasize the importance of including a land use perspective when studying water quality-environmental relationships in hydrogeological systems dominated by density-driven circulation.Item Bouguer anomalies of the NW Iberian continental margin and the adjacent abyssal plains(Journal of Maps, 2019) Druet Vélez, María; Muñoz Martín, Alfonso; Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Llanes Estrada, María Pilar; Catalán, Manuel; Maestro, Adolfo; Bohoyo, Fernando; Martín Dávila, JoséThe NW Iberian continental margin has a complex structure, resulting from the succession of several rifting episodes close to a ridge triple junction, and a superimposed partial tectonic inversion stage. The wide-ranging physiography matches the diverse tectonic deformation domains related to its evolution. Each deformation domain has a distinctive gravity signal, so the detailed Bouguer anomaly map presented here is a good first approach to the regional study of the whole margin. Moreover, as the presented chart is a complete Bouguer anomaly map (including terrain corrections), its analysis and interpretation can be done in terms of density, geometry and depth variations below the seafloor. This map is mainly based on the dataset obtained during seven one-month surveys carried out in the frame of the Spanish Economic Exclusive Zone project, and also includes two 2 + 3/4D density models illustrating the deep structure of the margin.Item Aplicación de técnicas geofísicas en caracterización de suelos contaminados(Introducción a la contaminación de suelos, 2017) Muñoz Martín, Alfonso; Granja Bruña, José Luis- Project number: 211
Item LVGPy: Diseño, desarrollo y puesta en marcha de un “Laboratorio Virtual de Geomatemática en lenguaje Python”(2017) Lahoz Beltrá, Rafael; López González-Nieto, María Pilar; Gómez Flechoso, María de los Ángeles; Arribas Mocoroa, María Eugenia; Muñoz Martín, Alfonso; García Lorenzo, María De La Luz; Cabrera Gómez, Gloria; Álvarez Gómez, José Antonio; Caso Fraile, Andrea; Orosco Dagan, Jefferson Mark; Merinero Palomar, RaúlSe describen los objetivos, metodología y resultados del Proyecto de Innovación con Nº de proyecto 211, Convocatoria 2017/2017. El proyecto fue desarrollado por profesores de las Facultades de Biología y Geología. Item Submarine morpho-structure and active processes along the North American-Caribbean boundary plate (Dominican Republic sector)(Marine Geology, 2019) Rodríguez Zurrunero, Álvaro; Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso; Gorosabel, José Miguel; Gómez de la Peña, Laura; Gómez Ballesteros, Mª Purificación; Pazos, Antonio; Catalán Morollón, Manuel; Espinosa, S.; Druet Vélez, María; Llanes Estrada, María Pilar; Ten Brink, UriThe northern margin of Hispaniola records the oblique collision/underthrusting of the Bahamas Carbonate Province with the island-arc. Due to the collision, northern Hispaniola has suffered several natural disasters caused by major earthquakes and tsunamis, such as the historic earthquake of 1842, the tsunami caused by earthquake-driven slumping in 1918 in the Mona Passage, the seismic crisis of 1943-1953 with five events of M>7.0 or the seismic crisis of 2003 with a main shock of M6.3 and a large aftershock of M5.3. Using new swath multibeam bathymetry data and vintage single- and multi-channel seismic profiles, we have performed a regional scale analysis and interpretation of the shallow surface and active processes along the northern margin of the Dominican Republic. We have identified three morphostructural provinces: a) the Bahamas Banks, b) the Hispaniola Trench and c) the Insular Margin, which are divided into two tectonic domains, the Collision Domain and Underthrusting Domain. The southern slope of the Bahamas Carbonate Province shows a very irregular morphology produced by active erosive processes and normal dip-slip faulting, evidence of an extensional tectonic regime and margin collapse. This collapse is of major extent in the Oblique Collision Domain where there are erosive and fault escarpments with higher dip-slip fault throws. The Hispaniola Trench, is formed by the Caicos and Hispaniola basins in the underthrusting domain, and by the Santisima Trinidad and Navidad basins in the Oblique Collision Domain. They have a flat seafloor with a sedimentary filling of variable thickness consisting of horizontal or sub-horizontal turbiditic levels. The turbiditic fill mostly proceeds from the island arc through wide channels and canyons, which transports sediment from the shelf and upper slope. The Insular Margin comprises the Insular Shelf and the Insular Slope. The active processes are generated on the Insular Slope where the Northern Hispaniola Deformed Belt is developed. This Deformed Belt shows a very irregular morphology, with a WNW-ESE trending N verging imbricate thrust-and fold system. This system is the result of the adjustment of the oblique collision/underthrusting between the North American plate and the Caribbean plate. In the Oblique Underthrusting Domain the along-strike development of the imbricate system is highly variable forming salients and recesses. This variability is due to along-strike changes in the sediment thickness of the Hispaniola Trench, as well as to the variable topography of the underthrusting Bahamas Carbonate Province. In the Oblique Collision Domain, the morphology of the Insular Slope and the development of the Deformed Belt deeply change. The imbricate system is barely inferred and lies upslope. These changes are due to the active collision of Bahamas Carbonate Province with the Insular Margin where the spurs are indented against the Insular Margin. Throughout the entire area studied, gravitational instabilities have been observed, especially on the Insular Margin and to a lesser extent on the southern slope of the Bahamas Carbonate Province. These instabilities are a direct consequence of the active underthrusting/collision process. We have mapped large individual slumps north of Puerto Plata in the Oblique Underthrusting Domain and zones of major slumps in the Oblique Collision Domain. These evidences of active processes must be considered as near-field sources in future studies on the assessment of tsunami hazards in the region.Item Crustal structure and continent?ocean boundary along the Galicia continental margin (NW Iberia): insights from combined gravity and seismic interpretation(Tectonics, 2018) Druet Vélez, María; Muñoz Martín, Alfonso; Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Acosta, Juan; Llanes Estrada, María Pilar; Ercilla, GemmaThe magma?poor rifted continental margin of Galicia has an extremely complex structure. Its formation involved several rifting episodes that occurred ultimately during the early Cretaceous near a ridge triple junction, which produced a change in the orientation of the main structures in its transition to the north Iberia margin. In addition, there is a superimposed partial tectonic inversion along its northwest and northern border which developed from the Late Cretaceous to at least Oligocene times. The present study integrates a large volume of new geophysical information (mainly marine gravity data and 2D seismic reflection profiles) to provide insights on the formation of this rift system and on the development of its later inversion. The combined interpretation and modeling of this data enable the presentation of a new crustal and structural domains map for the whole Galicia margin. This includes the rift domains related to the extreme thinning of the crust and the lithospheric mantle (stretched, necking, and hyperextension and mantle exhumation (HME) domains), as well as a domain of intense compressional deformation. New constraints arise on the origin, the deep structure, and the characterization of the along? and across?strike variation of the continent?ocean transition of the margin, where a progressive change from hyperextension to partial inversion is observed. The development of both rifting and later partial tectonic inversion is influenced by the existence of former first?order tectonic features. Most of the tectonic inversion is focused on the HME domain, which in some areas of the northwestern margin is completely overprinted by compressional deformation.Item La deformación alpina en el Sistema Central Español(Geo-guías, Rutas geológicas por la Península Ibérica, Canarias, Sicilia y Marruecos, 2019) De Vicente Muñoz, Gerardo; Muñoz Martín, Alfonso; Olaiz, A.J.; Vegas Martínez, Ramón; Antón López, Loreto; Martín Velázquez, Silvia; Giner Robles, Jorge Luis; Rodriguez Pascua, M.A.La idea del origen compresivo del Sistema Central (SC) se debe a Birot y Solé Sabarís (1954) [1], antes del establecimiento del papel que la tectónica de placas juega en el desarrollo de las estructuras intraplaca. Sin embargo, sus observaciones de campo no fueron tenidas en cuenta y, durante mucho tiempo, el SC fue considerado como una estructura extensiva [2]. Los primeros modelos de estructura del SC, en un contexto compresivo intraplaca, fueron propuestos por Vegas y Suriñach (1987) [3], que calcularon un engrosamiento cortical de 5 km, mientras que Warburton y Álvarez (1989) [4] construyeron una sección transversal con el desarrollo de una tectónica de piel fina asociada a un detachment intracortical proveniente de las Béticas y con un acortamiento asociado de 50 km. Esta idea fue también propuesta con menos detalle para el sector portugués, pero en relación a un estilo tectónico de piel gruesa y un acortamiento menor [5]. No obstante, estos trabajos carecían de observaciones de campo. En concreto, la sección de Warburton y Álvarez adolece de numerosas inconsistencias. El estilo tectónico propuesto durante la celebración de la III reunión de la Comisión de Tectónica de la SGE, que es el que se tiene en cuenta hoy en día, fue el de una tectónica de piel gruesa, sin despegues en la cobertera, con la formación de cabalgamientos imbricados de piel fina con implicación del basamento y pop ups dentro del basamento varisco de direcciones NE-SO a E-O. El acortamiento asociado se calculó en un 14% (20 km) [6, 7].Item Late glacial and post-glacial deposits of the Navamuno peatbog (Iberian Central System): Chronology and paleoenvironmental implications(Quaternary International, 2017) Turu, Valenti; Carrasco González, Rosa María; De Pedraza Gilsanz, Javier; Ros, Xavier; Ruiz-Zapata, Blanca; Soriano-López, J.M.; Mur-Cacuho, E.; Pélachs-Mañosa, A.; Muñoz Martín, Alfonso; Sánchez, J.; Echeverria-Moreno, A.The Navamuno peatbog (Sierra de Bejar, western Spain) is a ~14 ha pseudo-endorheic depression with boundaries defined by a lateral moraine of the Cuerpo de Hombre paleoglacier and fault-line scarps on granite bedrock. The stratigraphy of the Navamu~no peatbog system is characterized here using borehole data to a depth of 20 m. An integrated interpretation from direct-push coring, dynamic probing boreholes and handheld auger drillings advances our knowledge of the Navamu~no polygenetic infill. Correlating this data with those obtained in other studies of the chronology and evolutionary sequence of the Cuerpo de Hombre paleoglacier has enabled us to establish the sequence of the hydrological system in the Navamuno depression. During the Late Pleistocene (MIS2), the depression was dammed by the Cuerpo de Hombre glacier and fed by its lateral meltwaters, and was filled with glaciolacustrine deposits. The onset of the Holocene in Navamuno is linked to a flat, fluviotorrential plain with episodes of local shallow pond/peat bog sedimentation. This evolutionary sequence is congruent with the age model obtained from available radiocarbon dating, obtaining 19 ages from ~800 cal yr BP (at depth 1.11 m) to ~16800 cal yr BP (at depth 15.90e16.0 m). Finally, the sedimentary record enabled interpretation of the environmental changes occurring in this zone during the late glacial (from the Older Dryas to the Younger Dryas) and postglacial (Holocene) stages, placing them within the paleoclimatic context of the Iberian Peninsula and Mediterranean regions.Item Late glacial and post-glacial deposits of the Navamuño peatbog (Iberian Central System): Chronology and paleoenvironmental implications(Quaternary International, 2018) Turu, Valenti; Carrasco González, Rosa María; De Pedraza Gilsanz, Javier; Ros, Xavier; Ruiz-Zapata, María Blanca; Soriano-López, Joan Manuel; Mur-Cacuho, Elena; Pélachs-Mañosa, Albert; Muñoz Martín, Alfonso; Sánchez, Jesús; Echeverria-Moreno, AnnaThe Navamuño peatbog (Sierra de Béjar, western Spain) is a ∼14 ha pseudo-endorheic depression with boundaries defined by a lateral moraine of the Cuerpo de Hombre paleoglacier and fault-line scarps on granite bedrock. The stratigraphy of the Navamuño peatbog system is characterized here using borehole data to a depth of 20 m. An integrated interpretation from direct-push coring, dynamic probing boreholes and handheld auger drillings advances our knowledge of the Navamuño polygenetic infill. Correlating this data with those obtained in other studies of the chronology and evolutionary sequence of the Cuerpo de Hombre paleoglacier has enabled us to establish the sequence of the hydrological system in the Navamuño depression. During the Late Pleistocene (MIS2), the depression was dammed by the Cuerpo de Hombre glacier and fed by its lateral meltwaters, and was filled with glaciolacustrine deposits. The onset of the Holocene in Navamuño is linked to a flat, fluviotorrential plain with episodes of local shallow pond/peat bog sedimentation. This evolutionary sequence is congruent with the age model obtained from available radiocarbon dating, obtaining 19 ages from ∼800 cal yr BP (at depth 1.11 m) to ∼16800 cal yr BP (at depth 15.90–16.0 m). Finally, the sedimentary record enabled interpretation of the environmental changes occurring in this zone during the late glacial (from the Older Dryas to the Younger Dryas) and postglacial (Holocene) stages, placing them within the paleoclimatic context of the Iberian Peninsula and Mediterranean regions.