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
6 results
Search Results
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Item Estructura alpina del antepaís ibérico(Geología de España, 2004) Vicente Muñoz, Gerardo de; Muñoz Martín, Alfonso; Guimerà Rosso, Joan; Vegas, Ramón; Cloetingh, Sierd; Vicente Muñoz, Gerardo deItem Local stress fields and intraplate deformation of Iberia: variations in spatial and temporal interplay of regional stress sources(Tectonophysics, 1999) Andeweg, Bernd; Vicente Muñoz, Gerardo de; Cloetingh, Sierd; Giner, Jorge; Muñoz Martín, AlfonsoTertiary to present deformation in the interior of the Iberian Peninsula reflects spatial and temporal variations of the activity of the plate boundaries. Local deformation patterns observed in many of the numerous intraplate Tertiary basins and their borders, such as the Madrid Basin and the Sierra de Altomira, are at first sight incompatible with the regional stress field under which they were formed. We demonstrate, however, that they can be explained as the effect of several stress fields that acted on the Iberian Peninsula from earliest Tertiary onward. Data on local deformation can constrain both magnitudes and directions of forces acting on the plate boundaries of Iberia, enabling us to estimate the relative importance of the different plate driving and deforming mechanisms providing further constraints on the tectonic evolution of Iberia.Item Inversion of moment tensor focal mechanisms for active stresses around the Microcontinent Iberia: Tectonic implications(Tectonics, 2008) Vicente Muñoz, Gerardo de; Cloetingh, Sierd; Muñoz Martín, Alfonso; Olaiz Campos, Antonio José; Stich, Daniel; Vegas, Ramón; Galindo-Zaldívar, Jesus; Fernández Lozano, JavierThe Iberian microcontinent and its connected oceanic crust are affected by deformations related to the Eurasian-African plate boundary. Active stress inversions from populations of moment tensor focal mechanisms have been performed around and inside the Iberian peninsula, using a total of 213 moment tensor estimates. Main results are: 1) The tensorial solutions show better consistency and lower misfits compared to those obtained previously from first P arrival focal mechanisms. 2) Along the Eurasia- Africa western boundary, the type of active stresses progressively changes easternwards from triaxial extension to uniaxial compression along the Terceira Ridge, the Gloria Fault zone and the Gulf of Cadiz. 3) In the Betics-Alboran-Rif zone, uniaxial extension predominates with Shmax N155ºE trending. 4) In N Algeria, uniaxial compression reappears. 5) The Iberian foreland is currently under strike-slip to uniaxial extension tensorial conditions.Item Finite-element modelling of Tertiary paleostress fields in the eastern part of the Tajo Basin (central Spain)(Tectonophysics, 1998) Muñoz Martín, Alfonso; Cloetingh, Sierd; Vicente Muñoz, Gerardo de; Andeweg, BerndThree subsequent Tertiary paleostress fields that are deduced from fault-slip data for the eastern part of the Tajo Basin are analyzed by finite-element studies. The modelling results show that maximum horizontal stresses (SHmax) are mainly controlled by the geometry of the model limits and the boundary conditions applied. The models are used to test two hypotheses on the origin of the Altomira Range. A local stress field responsible for its formation (‘Altomira') can be modelled successfully by superposition in time and place of two major paleostress fields (‘Iberian' and ‘Guadarrama'). Stress trajectories have been modelled with respect to a homogeneous cover and heterogeneous basement to investigate the role of rheological contrasts between different basement blocks on the orientation of the stress field. Results of this kind of modelling suggest a mechanical decoupling between the cover and the basement, especially for the ‘Altomira' paleostress field.Item Cenozoic thick-skinned deformation and topography evolution of the Spanish Central System(Global and Planetary Change, 2007) Vicente Muñoz, Gerardo de; Vegas, Ramón; Muñoz Martín, Alfonso; Silva Barroso, Pablo Gabriel; Andriessen, Paul; Cloetingh, Sierd; González Casado, José Manuel; Van Wees, Jan Diederik; Álvarez García, Juan; Carbó Gorosabel, Andrés; Olaiz Campos, Antonio JoséThe Spanish Central System is a Cenozoic pop-up with an E-W to NE-SW orientation that affects all the crust (thick-skinned tectonics). It shows antiform geometry in the upper crust with thickening in the lower crust. Together with the Iberian Chain it constitutes the most prominent mountainous structure of the Pyrenean foreland. The evolutionary patterns concerning the paleotopography of the interior of the Peninsula can be established by an analysis of the following data: gravimetric, topographical, macro and micro tectonic, sedimentological (infilling of the sedimentary basins of the relative foreland), P-T-t path from apatite fission tracks, paleoseismic and instrumental seismicity. Deformation is clearly asymmetric in the Central System as evidenced by the existence of an unique, large (crustal-scale) thrust at its southern border, while in the northern one there is a normal sequence of north verging thrusts, towards the Duero Basin, whose activity ended during the Lower Miocene. This deformation was accomplished under triaxial compression, Oligocene- Lower Miocene in age, marked by NW-SE to NNW-SSE shortening. Locally orientations of paleostresses deviate from that of the regional tensor, following a period of relative tectonic quiescence. During the Upper Miocene-Pliocene, a reactivation of constrictive stress occurred and some structures underwent rejuvenation as a consequence of the action of tectonic stresses similar to those of today (uniaxial extension to strike-slip with NW-SE shortening direction). However, the westernmost areas show continuous activity throughout the whole of the Tertiary, with no apparent pulses. At the present time there is a moderate seismic activity in the Central System related to faults that were active during the Cenozoic, with the same kinematic characteristics.Item Análisis integrado de la topografía y anomalías gravimétricas en la Península Ibérica: nuevas metodologías en modelación análoga(Revista de la Sociedad Geológica de España, 2011) Fernández-Lozano, Javier; Sokoutis, Dimitrios; Willingshofer, Ernst; Muñoz Martín, Alfonso; Vicente Muñoz, Gerardo de; Cloetingh, SierdEl análisis integrado de la topografía y las anomalías gravimétricas en la Península Ibérica invoca a la presencia de grandes pliegues que afectan a toda la litosfera como precursores de los relieves E-O a NE-SO que se distribuyen por el Macizo Varisco, así como a un mecanismo de engrosamiento cortical nucleado a partir de fallas Tardi-Variscas, como origen del relieve del este peninsular (Cadena Ibérica-Costero Catalana) con patrones dominantes E-O, NE-SO y NO-SE. El modo de deformación, así como el estilo, dependen tanto de las propiedades reológicas iniciales de una litosfera a otra (litosfera resistente Varisca hacia el oeste peninsular/litosfera débil y caliente resultado de la extensión Mesozoica hacia el este) como a los accidentes tectónicos pre-existentes. Presentamos una nueva metodología aplicada a la modelación análoga, basada en el estudio del espectro de las anomalías gravimétricas y la topografía que nos han permitido inferir los procesos responsables de la asimetría en el patrón del relieve intra-placa de la Península Ibérica. A su vez, nuestros resultados arrojan luz sobre los mecanismos generadores del relieve en zonas de intra-placa donde la escasez o falta de resolución de los perfiles sísmicos y geomagnéticos impide la interpretación de la parte más profunda de la litosfera como Asia Central o los Atlas del norte de África