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Browsing by Author "Vegas, Ramón"

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A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
(Oxford University Press, 2011) Palencia Ortas, Alicia; Ruiz Martínez, Vicente Carlos; Villalain, J.J.; Osete López, María Luisa; Vegas, Ramón; Touil, A.; Hafid, A.; McIntosh, G.; Hinsbergen, D.J.J. van; Torsvik, T. H.
Available apparent polar wander (APW) paths for the 200 Ma configuration of Pangea, just prior to the opening of the Central Atlantic Ocean, differ as much as 10o in arc length. Here, we add new data from northwest Africa for this time, obtained from the northeasttrending Foum-Zguid and Ighrem dykes (ca. 200 Ma). These dykes form part of the northern domain of the Central Atlantic Magmatic Province (CAMP), and crosscut the Anti-Atlas Ranges in Morocco, and compositionally correspond to quartz-normative tholeiites intruded in continental lithosphere shortly before the opening of the Central Atlantic Ocean. The Foum-Zguid dyke has been intensively studied, whereas the Ighrem dyke has received less scientific focus. We sampled both dykes for paleomagnetic investigation along 100 km of each dyke (12 sites for Foum-Zguid and 11 for Ighrem, 188 samples included in the final analyses). Rock magnetic experiments indicate a mixture of multidomain and single-domain magnetite and/or low-Ti titanomagnetite particles as the principal remanence carriers. In both dykes, the primary nature of the characteristic remanent magnetization is supported by positive contact tests, related to Fe-metasomatism or baked overprints of the corresponding sedimentary country rocks. The directions of the characteristic magnetization exhibit exclusively normal polarity. Site-mean virtual geomagnetic poles are differently grouped in each dyke, suggesting distinct geomagnetic secular variation records. The Foum-Zguid paleomagnetic pole (N = 12, PLat = 67.9◦N, PLon = 247.9◦E, κ = 125, A95 = 3.9◦) plots close to that of Ighrem (N = 11, PLat = 78.4◦N, PLon = 238.2◦E, κ = 47, A95 = 6.7◦), confirming those mineralogical and geochemical evidences supporting that they represent dissimilar magmatic stages. Virtual geomagnetic poles dispersion from both dykes (S = 10.5◦13.0◦ 8.1◦ ) is in line with those obtained from recent studies of a CAMP-related dyke in Iberia and results from CAMP lavas in the Argana basin. These three new estimates of paleosecular variation at low latitudes around the Triassic–Jurassic boundary are concordant with a recently proposed dispersion curve for the Jurassic but suggest a slightly lower geomagnetic scatter than considered so far. After combining results from both dykes, the resulting paleomagnetic pole (PLat = 73.0◦N, PLon = 244.7◦E, N = 23, κ = 55, A95 = 4.1◦) is statistically compared with existing and coeval African paleopoles, and with global synthetic 200 Ma running mean poles in northwest Africa coordinates.
Adelgazamiento de la corteza en el margen septentrional del Golfo de Cádiz
(Sociedad Geológica de España., 2004) Medialdea Cela, Teresa; Córdoba Barba, Diego; Vegas, Ramón; Dañobeitia, J.J.
Refraction/wide angle seismic profiles acquired in 2000 during the Parsifal cruise across the Southportuguese Zone, the Algarve Basin and the South Iberian continental margin have allowed us to determine the crustal structure west of the Bank of Guadalquivir, which has been constrained by gravity modelling. According to the crustal model obtained, a crustal thinning of 11 km takes place from the shoreline to the Guadalquivir Bank area, where enhanced crustal attenuation has been found. Under the sedimentary cover, the velocity structure consists of a wedge-shaped upper crust with velocities between 5.8 and 5.9 km/s, characterised by a pronounced thickness variation. In the middle-lower crust, velocity increases from 6 to 7 km/s.
Carboniferous subduction complex in the south portuguese zone coeval with basement reactivation and uplift in the Iberian Massif
(Seminario de Estudos Galegos. Area de Xeoloxía e Minería ; Instituto Universitario de Xeoloxía "Isidro Parga Pondal", 1980) Vegas, Ramón
The formation of thick piles of flysch-like sediments needs the existence of narrowed seas, active denouement of neighbouring continents and generaHzed marginal subsidence. These conditions are present during the initial and final stages of Wilson's perceptive cycle. In this context, the Late Precambrian flysch of the Iberian Masslf must be related to the initial rifting, whilst the Culm of southwestern Iberia was accumulated during an episode of Upper Palaeozoic subduction that remained active after impingement of Iberia against North America. Culm sediment~ shed from the uplifted collision zone and fed into a remnant ocean that remained at the nonsutured southern border of Iberia. This model of synorogenic flysch formation has been described elsewhere for similar plate arrangements. On other grounds this model provides a framework that explains the different structural and magmatic trends of the Ossa-Morena Zone (near the active margin) in the context of the rest of the Massif (basement reactivation). In addition to this, it seems to support a partly primary origin for the Iberian arc versus a secondary origin.
Cenozoic thick-skinned deformation and topography evolution of the Spanish Central System
(Elsevier, 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 José
The 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.
Corredores de desgarre cenozoicos en la Península Ibérica
(Sociedad Geológica de España., 2008) Vicente Muñoz, Gerardo de; Vegas, Ramón; Cabral, Joao; Wees, Jan Dierik van
El proceso de acomodación de la deformación cenozoica (en inicio, pirenaica) en Iberia se produjo mediante pliegues por buckling y cabalgamientos E-O en la corteza superior. Lateralmente, estas macroestructuras aparecen conectadas mediante corredores de desgarre de anchura variable y desplazamientos en fallas individuales de menos de 10 Km. La nucleación de estos corredores se produce sobre antiguas discontinuidades variscas y fallas extensionales, triásicas, jurásicas o cretácicas. Se comparan las características macroestructurales de tres de estos corredores: El Sistema de Fallas de Vilariça, la Rama Castellana de la Cadena Ibérica y la terminación SE de la Falla de Ventaniella. Se concluye que, buena parte de los pliegues NO-SE, “ibéricos”, son pliegues por bending a lo largo de los desgarres.
Datación de las calizas del Cámbrico inferior de Los Navalucillos (Montes de Toledo): faunas de arqueociatos
(Universidad de Oviedo, Instituto de Geología Aplicada de la Facultad de Ciencias, 1976) Perejón, Antonio; Moreno, F.; Vegas, Ramón
El cabalgamiento cenozoico de Boinás (Cordillera Cantábrica, España)
(Sociedad Geológica de España, 2007) Vicente Muñoz, Gerardo de; González Nistal, S.; Muñoz Martín, Alfonso; Vegas, Ramón; Olaiz Campos, Antonio José; Fernández Lozano, Javier; Vicente, Raquel de
The opencast gold mine of Boinás, has allowed to outcrops the contact between the variscan basement and the Cenozoic sediments. It is observable that the contact is a post - Lower Oligocene thrust, with a N40ºE trend. From a macrostructural point of view, Boinás thrust spreads along more than 10 km with a constant orientation, a vertical gap that reaches 400 m, and a NW vergence. Northwestwards another Alpine thrust develops (Tineo, A l o n s o y Pulgar , 2004) with a parallel orientation an opposite vergence. Between both thrusts a tectonic pop-down appears (Narcea Pop-down). The dynamic analysis shows that this structure was activated by a paleostress tensor with an horizontal s1 trending N139ºE, with a stress regime close to uniaxial compression (R=0.06). This stress allows the geometrical interchanges between s2 and s3. The outcrop also allows to observe a secondary population of normal faults, that fits to an extensional stress tensor (R=0.01) with s3 trending N146ºE, that is coaxial with the main compressive stress tensor. We interpret both fault populations as generated by the tectonic thrust emplacement.
El cabalgamiento de Valdesotos: consecuencias de la acomodación del acortamiento cenozoico en el zócalo del Sistema Central
(Sociedad Geológica de España., 2004) Olaiz Campos, Antonio José; Vicente Muñoz, Gerardo de; Vegas, Ramón; González Casado, José Manuel; Muñoz Martín, Alfonso; Álvarez, J.
We describe and study structural evidences concerning to Alpine tectonics at NE sector o f the Spanish Central System (SCS). In Valdesotos area, the Hercynian basement is uplifted over Mesozoic sediments, throughout a main SW verging thrust. Fault population analysis and geological mapping has been used to look at the relation between structures in the basement and in the cover. As a consequence of accommodation of strains in the basement, kink folds are developed, such as secondary thrust and folds in the tegument. All these meso- and macrostructures seem to answer to a shortening in agreement with the Cenozoic deformation.
El nivel carbonatado de Los Navalucillos y su posición en la sucesión cámbrica de los Montes de Toledo occidentales (Centro de España)
(Universidad de Oviedo, Instituto de Geología Aplicada de la Facultad de Ciencias, 1976) Zamarreño, I.; Vegas, Ramón; Moreno, F.
Engrosamiento de la corteza y relieve intraplaca en el centro de Iberia
(Sociedad Geológica de España, 1987) Vegas, Ramón; Suriñach Cornet, Emma
A moderate thickening of the crust beneath the Spanish Central System has been determined by means of a wide angle seismic experiment. The value of this thickeníng - 5 km in form of 3 km of the Moho topography, 2 km of surface relief is coherent with the surface model of intracontinental distributed deformatíon already descríbed. In addition, the present model is in agreement with the intraplate uplíft, the reverse faults that bound the relief and to sorne extent with the intraplate shortening of Iberia.
Estructura alpina del antepaís ibérico
(Sociedad Geológica de España - Instituto Geológico y Minero de España, 2004) Vicente Muñoz, Gerardo de; Muñoz Martín, Alfonso; Guimerà Rosso, Joan; Vegas, Ramón; Cloetingh, Sierd; Vicente Muñoz, Gerardo de
Estudio paleomagnético del dique de Messejana-Plasencia
(Sociedad Geológica de España., 2004) Palencia Ortas, Alicia; Osete López, María Luisa; Maceira, M.; Villalaín Santamaría, Juan José; Vegas, Ramón
A paleomagnetic investigation of 39 sites (591 samples) across the 530 km ot the Messejana-Plasenciadike has been carried out. Rock magnetic experiments indicate PSD low Ti titanomagnetite and magnetite as the minerals carrying the NRM. The samples where mostly demagnetised by thermal demagnetisation. Most sites exhibit a characteristic remanent component of normal polarity with the exception of two sites, where samples with reversed polarities have been observed. The paleomagnetic pole derived from the sites is well defined, with values ot Plat=70.5, Plong=238.0, K= 47.8 and ags=3.5. Paleomagnetic data indicates: (i) the dike had a brief emplacement time, (ii) the age of intrusion can be constrained between 180-200 Ma, (Hi) the high grouping of the VGPs directions suggest no important tectonic perturbations of the whole structure of the dike since its intrusion to the present.
European continuous active tectonic strain–stress map
(Elsevier, 2009) Olaiz Campos, Antonio José; Muñoz Martín, Alfonso; Vicente Muñoz, Gerardo de; Vegas, Ramón
This paper shows a new continuous strain–stress map for Europe obtained from the direct inversion of earthquake focal mechanisms calculated from the centroid tensor method. A total of 1608 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 the present day. Values for the maximum horizontal shortening direction and brittle strain–stress regime defined by the k′ ratio (ey/ez, horizontal maximum/vertical strain) have been calculated following in Europe and Pannonian Basin the slip model of tri-axial deformation. The individual results including Dey and the shape of the active brittle strain ellipsoid have been interpolated to a final 15′ regular grid taking into account the relationship between the tectonic horizontal strain–stress value and the vertical load. Both continuous strain regime and maximum horizontal shortening (Dey) maps show a good correlation with the primary tectonic forces generated along the plate boundaries, plate kinematics and also some local perturbations related with main crustal heterogeneities and topography, as well as significant spatial variations in integrated crustal strength.
Gravity modeling of the lithosphere in the Calatrava Volcanic Province (Spain): geodynamic implications
(Universidad Complutense de Madrid, 2015) Granja Bruña, José Luis; Vegas, Ramón; Sentre Domingo, M.A.; Muñoz Martín, Alfonso; Sainz-Maza Aparicio, S.
The origin of the intraplate volcanism in the Calatrava Volcanic Province (CVP) is controversial. On the basis of its geochemical signature, it has been ascribed to an “aborted” rift, implying lithospheric thinning. However, the volcanism occurred during the generalized Cenozoic NW−SE-oriented compressive tectonic regime. On the other hand, on the basis of evidence for its deep-seated origin, it has been linked to the existence of a baby-plume detached from an active megaplume below the Canary-Azores Islands and the western Mediterranean. In order to understand better the aforementioned geodynamic scenarios for the origin of the CVP, we address here the study of the lithosphere in the CVP and its vicinity by means of gravity analysis and 2+1/2D modeling. Gravity modeling results do not support the rifting model adopted for the intraplate volcanism occurred in the CVP because the crust shows a quasi-constant thickness. Density models suggest the existence of a sub-crustal, anomalous low-density block that could be underplated magmatic material at the base of the crust, suggesting that only a minor part of it intruded up into the crust and erupted. The localized magmatism of the CVP can be related to the combination of two factors: active, the gentle folding of the Iberian lithosphere and associated uplifting of the Variscan basement due to the NW-directed transmission of compressive stresses in the upper plate yielded by the subduction/collision in the south Iberian margin. The formation of the lithospheric folding in the Calatrava region results in a decrease of the pressure beneath the swell of the antiform that is likely to bring about basaltic magmatism below the swell; and one passive, the existence of a Variscan right-lateral shear band, which yields a weakened crust that facilitates the ascent of the magmatic materials. The relatively small volume, but large extension, of the volcanic outcrops could be associated with the preferential ascent of the magmas along the weakened crust of this NW−SE-trending Variscan shear band.
Inversion of moment tensor focal mechanisms for active stresses around the Microcontinent Iberia: Tectonic implications
(2008-02-07) Vicente Muñoz, Gerardo de; Cloetingh, Sierd; Muñoz Martín, Alfonso; Olaiz Campos, Antonio José; Stich, Daniel; Vegas, Ramón; Galindo-Zaldívar, Jesus; Fernández Lozano, Javier
The 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.
Investigaciones paleomagnéticas en la Zona Subbética
(Servicio de Publicaciones de la Universidad Complutense de Madrid, 1988) Osete López, María Luisa; Freeman, R.; Vegas, Ramón
Se ha realizado un estudio palomagnético en la parte central de la Zona Subbética, en rocas volcánicas (pillow-lavas, material intrusivo y coladas de basaltos) y sedimentarias (calizas, margocalizas y calizas nodulosas de facies Ammonitico Rosso) de edad jurásica. Con objeto dc analizar las propiedades magnéticas de las rocas estudiadas se han determinado las curvas termomagnéticas de los materiales volcánicos y se han realizado experimentos sobre adquisición gradual de remanencia magnética isoterma y de desimanación de dos componentes isotermas ortogonales con las rocas sedimentarias. A pesar dc que el comportamiento magnético ha sido diferente en cada una de las litologías investigadas, en la mayoría de los casos ha sido posible aislar una componente magnética estable durante los procesos de lavado magnético. Los resultados obtenidos han sido comparados con las direcciones esperadas para Iberia estable y se ha observado una importante discrepancia en el valor de la declinación magnética. La desviación hacia el Este de la paleodeclinación encontrada en esta área indica que se han producido rotaciones horarias en la Zona Subbética.
La deformación alpina en el Sistema Central Español
(Sociedad Geológica de España, 2019) De Vicente Muñoz, Gerardo; Muñoz Martín, Alfonso; Olaiz, A.J.; Vegas, Ramón; Antón López, Loreto; Martín Velázquez, Silvia; Giner Robles, J.; 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].
La extraña topografía de la Península Ibérica
(Asociación Española para la enseñanza de las Ciencias de la Tierra, 2007) Vicente Muñoz, Gerardo de; Vegas, Ramón
España posee una topografía promedio muy elevada (la 2ª de Europa, después de Suiza) que evidencia la intensidad y gran dispersión de las deformaciones tectónicas recientes (Terciarias). El relieve de Iberia es el resultado de los esfuerzos transmitidos hacia el interior desde el borde activo durante el Oligoceno-Mioceno Inferior: Los Pirineos. Estas deformaciones se organizaron de una forma altamente regular, dando lugar a una serie de altos (cadenas) y bajos (cuencas) estructurales, que se interpretan como pliegues de escala litosférica. En este sentido, toda la placa ibérica aparece deformada durante el Cenozoico. Estos grandes pliegues (Pirineos-Cordillera Cantábrica, Sistema Central-Cadena Ibérica, Sierra Morena) aparecen conectados en la corteza superior mediante una serie de corredores de desgarre lateral izquierdos (Vilariça, Messejana-Plasencia) y lateral derechos (Ventaniella, Cadena Ibérica), que son también importantes para explicar la morfología de La Península. El emplazamiento hacia el oeste del bloque de Alborán desacopló mecánicamente este dispositivo, que sólo continúa activo en la costa atlántica-Golfo de Cádiz. Es en estas estructuras, grandes pliegues y corredores de desgarre, donde se concentra la sismicidad actual.[ABSTRACT]Spain has a very high mean topography (2nd in Europe, after Switzerland) that demonstrates the intensity and great dispersion of the recent tectonic (Tertiary) deformations. The relief of Iberia is the result of the transmitted stresses towards the interior from the active border during the Oligocene-Lower Miocene: The Pyrenees. These deformations were organized in a highly regular way, giving place to a series of structural highs (ranges-chains) and lows (basins), which are interpreted as lithospheric scale folds. From this perspective, the whole Iberian plate turns out to be deformed during the Cenozoic. These large folds (Pyrenees-Cantabrian Mountains, Central System- Iberian Chain, Sierra Morena) turn out to be connected in upper crust by means of a series of left lateral (Vilariça, Messejana-Plasencia) and right lateral (Ventaniella, Iberian Chain) strike slip corridors, that are also important to explain the morphology of The Peninsula. The emplacement towards the west of the Alborán block mechanically decoupled this device, which only continues active on the Atlantic coast - gulf of Cadiz. It is in these structures, large folds and strike-slip corridors, where the current seismicity concentrates.
La secuencia litoestratigráfica del Neoproterozoico-Cámbrico Inferior
(SGE-IGME, 2004) Rodríguez Alonso, M. D.; Díez Balda, M.A.; Perejón, Antonio; Pieren Pidal, Agustín Pedro; Liñán, Eladio; López Díaz, F.; Moreno, F.; Gámez Vintaned, J.A.; González Lodeiro, F.; Martínez Poyatos, D.; Vegas, Ramón; Vera, J.A.
Large-scale distributed deformation controlled topography along the western Africa-Eurasia limit: Tectonic constrains
(Elsevier, 2009) Vicente Muñoz, Gerardo de; Vegas, Ramón
In the interior of the Iberian Peninsula, the main geomorphic features, mountain ranges and basins, seems to be arranged in several directions whose origin can be related to the N-S plate convergence which occurred along the Cantabro-Pyrenean border during the Eocene-Lower Miocene time span. The Iberian Variscan basement accommodated part of this plate convergence in three E-W trending crustal folds as well as in the reactivation of two left-lateral NNE-SSW strike-slip belts. The rest of the convergence was assumed through the inversion of the Iberian Mesozoic Rift to form the Iberian Chain. This inversion gave rise to a process of oblique crustal shortening involving the development of two right lateral NW-SE shear zones. Crustal folds, strike-slip corridors and one inverted rift compose a tectonic mechanism of pure shear in which the shortening is solved vertically by the development of mountain ranges and related sedimentary basins. This model can be expanded to NW Africa, up to the Atlasic System, where N-S plate convergence seems also to be accommodated in several basement uplifts, Anti-Atlas and Meseta, and through the inversion of two Mesozoic rifts, High and Middle Atlas. In this tectonic situation, the microcontinent Iberia used to be firmly attached to Africa during most part of the Tertiary, in such a way that N-S compressive stresses could be transmitted from the collision of the Pyrenean boundary. This tectonic scenario implies that most part of the Tertiary Eurasia-Africa convergence was not accommodated along the Iberia-Africa interface, but in the Pyrenean plateboundary. A broad zone of distributed deformation resulted from the transmission of compressive stresses from the collision at the Pyrenean border. This distributed, intraplate deformation, can be easily related to the topographic pattern of the Africa-Eurasia interface at the longitude of the Iberian Peninsula. Shortening in the Rif-Betics external zones – and their related topographic features – must be conversely related to more “local” driven mechanisms, the westward displacement of the “exotic” Alboran domain, other than N-S convergence. The remaining NNW-SSE to NW-SE, latest Miocene up to Present convergence is also being accommodated in this zone straddling Iberia and Morocco, at the same time as a new ill-defined plate boundary that is being developed between Europe and Africa.

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