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
5 results
Search Results
Now showing 1 - 5 of 5
Item Waste dump erosional landform stability – a critical issue for mountain mining(Earth surface processes and Landforms, 2017) Martín Moreno, Cristina; Duque, José F. Martín; Ibarra, José M. Nicolau; Muñoz Martín, Alfonso; Zapico, IgnacioMining is the largest producer of solid wastes which, when released to land or into waterways, can cause harmful environmental impacts. This is mostly due to fluvial erosion, which is highly increased in mountain areas, due to abrupt slopes. We have analysed this situation at a mountain watershed (192 ha), where steep mined sites and their waste dumps are the main source of sediment in a Natural Park. This problem was tackled by building gabion check dams downstream from the mined sites. We used the DEM of Differences (DoD) method to quantify erosion and sediment yield from three waste dumps (5 ha). Their topography and substrate properties were analysed to understand the erosion problem. The sediment trapped by the check dams was quantified by Electrical Resistivity Tomography. The rainfall characteristics triggering an episode that filled the check dams with sediment in the winter of 2009-2010, were studied to confirm whether it was a case of extreme precipitation conditions. The waste dumps sediment yield (353 ± 95 Mg ha-1 yr-1) suggests severe landform instability. Analysis of topographic and substrate properties confirmed long, steep slopes combined with highly erodible materials. The check dams proved to be inefficient in controlling sediment loads, as they had only functioned for four years of 31 of existence, having trapped 13000 ± 660 m3 of sediment, whereas we estimated that the waste dumps have yielded approximately three times more sediment for the same period. Rainfall analyses showed that neither intense nor extreme conditions (return period of 25-35 years) triggered the mobilization of 37 ± 2 Mg ha-1 in a month. This study highlights the fact that mining operations in similar mountainous settings, with equivalent waste dump construction and reclamation practices, are currently unfeasible. We conclude that landform stability cannot be achieved at this site without landform changes.- 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, Maria Eugenia; Muñoz Martín, Alfonso; García Lorenzo, Mari 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 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; Pedraza Gilsanz, Javier de; 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 Aplicación de técnicas geofísicas en caracterización de suelos contaminados(Introducción a la contaminación de suelos, 2017) Muñoz Martín, Alfonso; Granja Bruña, José LuisItem Iberia, a natural laboratory for the quantification of the large scale erosional response to the fluvial capture processes(8º Congresso Nacional de Geomorfologia - Geomorfologia 2017, Congresso Nacional de Geomorfologia (8. 2017. Porto), 2017) Antón, Loreto; Muñoz Martín, Alfonso; De Vicente, Gerardo; Alberto Gomes, António; Teixeira, José; Soares, LauraDue to its geological location and diversity, Iberia is a key natural laboratory for the study of tectonic and geological processes. Within those it is especially suitable for the study of large-scale fluvial capture processes, and their influence on topography and landscape evolution. Nowadays, Iberia is characterized by the presence of highly elevated extensive flat surfaces (Iberian Mesetas). Those high plains correspond to planation surfaces developed mainly on Palaeozoic and Mesozoic rocks, and sedimentation surfaces of Neogene rocks. These last mostly represent the sedimentary deposits related to infill of the, formerly closed Foreland Basins. Three main rivers (Duero, Ebro and Tajo) which watersheds cover an area over 250 km2, drain almost half of the total Iberia surface. For these basins the development of the present-day drainage network was related to the opening of formerly closed fluvial systems, developed within ancient Cenozoic basins. In The Iberian Peninsula, the signature of that change in drainage conditions is still preserved in some areas, and can be studied through the analysis of longitudinal profiles shapes and the relief characterization. The analysis of present and former topography represents a powerful qualitative tool for a relative quantification of fluvial dissection and basin denudation, allowing to illustrate the spatial distribution of surface erosion, associated to the exorheic history of the basins. This work approaches the analysis of the denudation processes for the main formerly endorheic Iberian basins.