Search

Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Multi-storey calcrete profiles developed in the Quaternary on strath terraces of the Cinca and Alcanadre rivers, tributaries of the Ebro River inNE Spain. Two calcrete profiles (Tor 1 and Tor 2) near the village of El Tormillo show horizons with an arrangement that differs from that of commonly described calcrete profiles. Significant lateral changes occur in these profiles within a distance of less than 200 m, reflecting their pedofacies relationship. The Tor 1 profile on terraceQt1 (the highest and oldest) consists of six horizons (frombottomto top): 1) coarse fluvial gravels; 2) mudstones with carbonate nodules; 3) a chalky horizon; 4) laminar horizons, including one peloidal horizon; 5) amulti-storey horizon formed of at least six minor sequences, each ofwhich includes a lower detrital layer, a pisolithic horizon, and a thin discontinuous laminar horizon (these sequences indicate several cycles of brecciation and/or reworking); and 6) a topmost laminar and brecciated horizon also including reworked pisoliths. Some200 mto the north of Tor 1, horizon 5 undergoes a lateral change to channel fill-deposits. The infill of the channels shows a fining-upwards sequence ranging fromclasts of about 10 cmin diameter to red siltswith sparse pebbles. All the clasts come fromthe underlying calcrete horizons. Laminar horizons are interbeddedwith the clastic channel deposits. The youngest calcrete profiles developed on terraceQt3 of the Cinca River and on the Qp4 and Qp6mantled pediment levels. All showrelatively simple profiles composedmostly of lower horizons of coated gravels, with thin laminar horizons at the top. Most of the horizons, especially the laminar ones, show biogenic features such as alveolar septal structures, calcified filaments, biofilms, spherulites, micropores and needle-like calcite crystals. These features indicate the important role of vegetation in the formation of all the above profiles. The interbedding of clastic sediments and pisolithic horizons withi, Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

This work represents an initial attempt to link the evolution of the topography in relation to the general tectonic framework of western Morocco. For this purpose, in a section of the Western Moroccan Meseta different tools are combined in order to attain the general objective. Apatite fission-track (AFT) data of granitic rocks of the Rabat–Khenifra area give ages around 200 Ma with track length distributions which are compatible with the thermal models already established for the area. An inverse correlation between AFT ages and elevation is observed which is compatible with previous models indicating northward tilting of the whole Western Moroccan Meseta which is younger than 20–25 Ma. In order to test this possibility a detailed analysis of the topography at different scales in the estern Moroccan Meseta has been performed. Results indicate that two open folds with different amplitudes are recognized and that the one with wider wavelength could correspond to a lithospheric fold as previously stated by other authors on the basis of independent geological arguments. The northward tilting proposed based on the AFT data agrees with the results obtained in the analysis of the topography which reinforces the presence of a very open fold with a wavelength of 200–300 km in the north-western limb of the Western Moroccan Meseta., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The assessment of gully erosion poses a great challenge because of the complexity and connectivity of the geomorphic processes involved. This study focuses on the quantification of sheet erosion rates in a set of slope gullies located on the northern piedmont of the Guadarrama Mountains (Spanish Central System). In order to delineate accurately the gully areas in which sheet erosion was predominant, the Hydrologic/Erosion Response Unit (HRU/ERU) approach was used and a dendrogeomorphological analysis of exposed tree roots was carried out to quantify sheet erosion rates in one selected HRU/ERU. Identification of the first year of exposure by erosion from anatomical criteria was therefore critical. The 29 samples taken were prepared for anatomical analysis and cross-dated. Anatomical analysis of the samples showed a reduction in the lumen area of earlywood tracheids following root exposure and also, in most cases, a slight increase in growth rings. Moreover, at the end of the ring, latewood tissue and visible annual borders were very clearly defined by several rows of thick-walled tracheids. A non-parametric test was used on the findings derived from this qualitative analysis to objectify determination of the first year of exposure. Estimates of sheet erosion were obtained by dividing the height of eroded soil by the number of years that each root was exposed. The mean value of soil erosion for the entire study site was then determined from statistical inference. Using this procedure, a range of sheet erosion rates between 6.2 and 8.8 mm y−1 (125.2 and 177.8 t ha−1 year−1) was obtained for the dominant HRU/ERU of these gullies in central Iberia. These estimates of eroded soil thickness were adjusted based on the recent finding that root anatomical changes occur prior to their exposure by erosion., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Results obtained by SASW and PS-logging (in-hole) seismic techniques are compared with the relatively new ReMi (Refraction microtremor) method at a common site with a well-known soil profile: a recently constructed high-speed railway embankment. PS-logging is the most accurate technique in identifying the soil profile of the embankment followed by Re-Mi and SASW. Mean shear wave velocity estimations are also higher for PS-logging, followed by SASW and ReMi, while mean deviation is similar in each technique. The ReMi technique has provided very accurate results in the study of the embankment profile, which in addition to its high operability and its fast data processing, makes it a very convenient technique for extensive geotechnical surveys, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The El Salvador earthquake of 13 February 2001 (Mw 6.6) caused tectonic rupture on the El Salvador fault zone (ESFZ). Right-lateral strike-slip surface rupture of the east–west trending fault zone had a maximum surface displacement of 0.60 m. No vertical component was observed. The earthquake resulted in widespread landslides in the epicentral area, where bedrock is composed of volcanic sediments, tephra, and weak ignimbrites. In the aftermath of the earthquake, widespread damage to houses and roads and the hazards posed by landslides captured the attention of responding agencies and scientists, and the presence of surface-fault rupture was overlooked. Additionally, the tectonic context in which the earthquake took place had not been clear until mapping of the ESFZ was completed for the present study.We identified several fault segments, the distribution of surface ruptures, the aftershock pattern, and fault-rupture scaling considerations that indicate the 21-km-long San Vicente segment ruptured in the 2001 event. Static Coulomb stress transfer models for the San Vicente rupture are consistent with both aftershock activity of the 2001 sequence and ongoing background seismicity in the region. At Mw 6.6, the 2001 earthquake was of only moderate magnitude, yet there was significant damage to the country’s infrastructure, including buildings and roads, and numerous deaths and injuries. Thus, earthquake hazard and risk in the vicinity of the ESFZ, which straddles the city of San Salvador with a population of >2 million, is high because even moderate-magnitude events can result in major damage, deaths, and injuries in the region., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El ciclo del carbono aglutina los almacenes de ese elemento en el sistema Tierra (litosfera, hidrosfera, biosfera, atmósfera y rizosfera) y los flujos que se producen entre ellos. Las capacidades de esos almacenes y las tasas de intercambio entre ellos son extraordinariamente diversas por lo que, según la escala temporal considerada, encontraremos diferentes “ciclos” del carbono. A escalas temporales de millones de años, los flujos son lentos y se producen entre la litosfera y el “sistema de superficie”, definiendo el ciclo del carbono de largo término, un concepto diferente del más difundido ciclo del carbono a escalas temporales breves (de años a siglos), que recoge los rápidos flujos entre la atmósfera, la hidrosfera, la biosfera y la rizosfera, y que hoy es analizado “en tiempo real”. Entre esas perspectivas temporales extremas existen situaciones intermedias, que precisan de la definición de nuevos ciclos relativos a esas escalas de tiempo. En este trabajo nos centramos en el ciclo del carbono de largo término, analizando los mecanismos que lo controlan y las consecuencias que han tenido sobre la historia ambiental de la Tierra durante el Fanerozoico. También analizamos situaciones de cambio en el ciclo del carbono a escalas temporales intermedias, como los hipertermales y las glaciaciones del Cuaternario. Entender el ciclo del carbono desde una perspectiva geológica resulta hoy esencial para valorar la perturbación global que el ciclo está experimentando en la actualidad y sus posibles consecuencias futuras., The carbon cycle involves the carbon reservoirs in the Earth system (i.e., lithosphere, hydrosphere, biosphere, atmosphere, and rhizosphere) and the carbon fluxes occurring among them. The capacity of each reservoir and the exchange rates are strongly diverse, and because of this, depending on the considered time perspective, different “cycles” will arise. At time scales of millions of years, carbon fluxes are slow and take place essentially between the lithosphere and the “surface system”, these defining the long-term carbon cycle, notably different to the more popular short-term carbon cycle (time scales of years to centuries) which involves the fast fluxes occurring among the biosphere, the oceans, the soils, and the atmosphere. Between the long- and the short-term cycles, many intermediate-scale situations appear which need of new cycle definitions according to time scales. This review concentrates in the long-term carbon cycle, its controlling mechanisms and its consequences during the environmental history of the Fanerozoic. Also, intermediate time-scale carbon perturbations are considered, as the so-called hyperthermals and the Quaternary glaciations. A firm understanding of the carbon cycles from a geological perspective is critical for understanding and evaluating the global perturbation that the cycle is now experiencing, as well as its future consequences, España. Ministerio de Ciencia e Innovación, Universidad de Jaén, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El artículo describe el método de adquisición (inventario), análisis (evaluación) y diagnóstico de información geomorfológica dirigida a la ordenación, el uso y la gestión de los espacios naturales de Covalagua y Las Tuerces (Palencia). También se explica la elaboración de la normativa que procede de esa información. Se trata, por tanto, de un articulo eminentemente metodológico, aunque también se describe la aplicación de los resultados obtenidos. El inventario se basó en la clasificación, cartografía y descripción de unidades geomorfológicas desde una óptica orientada a la ordenación de los espacios naturales. La evaluación se centró en una interpretación de dicha información en términos de capacidades dirigidas a fomentar o potenciar las cualidades naturales del territorio, así como sus limitaciones. Esta fase incluyó un análisis específico sobre la singularidad y representatividad del karst en callejones de Las Tuerces y del campo de dolinas de Covalagua. La información que emanó de esa evaluación constituyó un diagnóstico, dirigido a los fines de la ordenación, el uso y la gestión de los recursos naturales, cuyas directrices esenciales quedaron incorporadas en la parte normativa. [ABSTRACT] This paper describes the method for the acquisition (inventory), analysis (evaluation) and diagnosis of geomorphic information aimed at the planning, use and management of the protected areas of Covalagua and Las Tuerces (Palencia province, Spain). The preparation of the regulations which derived from that information is also explained. This is therefore a methodological paper, although the application of its results is also described. The inventory lied in the classification, mapping and description of geomorphic units, always from a perspective of natural resources and protected areas planning. The evaluation was based in an interpretation of that information in terms of capacities for promoting the natural characteristics of the land or restrictions for land uses. This ev, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullún), provides insight into the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and back-arc sector of Sierra de Pie de Palo and Ullún. The oldest rocks are the Andino-type granitic orthogneisses of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma. The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The emplacement of these mantle-derived magmas during an extensional episode produced a widespread thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and back-arc complexes dominated the Sierra de Pie de Palo–Ullún sector, that was fully developed ca. 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are registered in the Pie de Palo–Ullún sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibol, Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

Water ice I rheology is a key factor for understanding the thermal and mechanical state of the outer shell of the icy satellites. Ice flow involves several deformation mechanisms (both Newtonian and non-Newtonian), which contribute to different extents depending on the temperature, grain size, and applied stress. In this work I analyze tidally heated and stressed equilibrium convection in the ice shell of Europa by considering a composite viscosity law which includes diffusion creep, basal slip, grain boundary sliding and dislocation creep, and. The calculations take into account the effect of tidal stresses on ice flow and use grain sizes between 0.1 and 100 mm. An Arrhenius-type relation (useful for parameterized convective models) is found then by fitting the calculated viscosity between 170 and 273 K to an exponential regression, which can be expressed in terms of preexponential constant and effective activation energy. I obtain convective heat flows between *40 and *60 mW m-2, values lower than those usually deduced (*100 mW m-2) from geological indicators of lithospheric thermal state, probably indicating heterogeneous tidal heating. On the other hand, for grain sizes larger than *0.3 mm the thicknesses of the ice shell and convective sublayer are*20–30 km and*5–20 km respectively, values in good agreement with the available information for Europa. So, some fundamental geophysical characteristics of the ice shell of Europa could be arising from the properties of the composite water ice rheology., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Large-scale folding is a key mechanism of lithospheric deformation and has been described in many parts of the Earth, both for the continental and oceanic lithospheres. Some aspects of this process such as the presence of coupling/decoupling between the crustal deformation and the mantle lithosphere, or between different lithospheres, make it necessary to accurately control the periodic characteristics of the elevation and of the gravity signal. 1D spectral analysis of gravity and topography profiles is sensitive to a series of factors: the location, length and orientation of the profiles, as well as the number of samples taken. We carry out a systematic analysis of the periodicities in the topography and gravity, both 1D and 2D, along the western border of the Africa–Eurasia plate tectonic boundary. We analyze the sensitivity of the 1D and 2D spectral analysis in order to compare the results along a plate boundary where oceanic and continental lithospheres are in contact with different tectonic, kinematic and rheological aspects. Our 1D spectral results indicate that the greater the profile length, the longer the wavelength peaks that are found. Nevertheless there are some periodic signals that appear in almost all the analyzed profiles: 100–250 km for the N–S profiles across oceanic plate boundary and 150–250 km where the plate boundary is developed over continental lithospheres. The 2D spectral analysis avoids the problems found in relation to the particular location of the profile but the resulting wavelengths are slightly higher than those obtained from the 1D spectral analysis. The wavelengths estimated for both oceanic and continental lithospheres at the Africa–Eurasia boundary (N250 km) show low values of mean mantle strength (b1013 Pa m). he presence of lithospheric folds means that the continental and oceanic lithospheres are mechanically oupled. This had previously been suggested for Iberia but not for the limit between S Iberia and the Terceira riple Jun, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, inpress

La cartografía geomorfológica en la zona de transición entre el Sistema Central y la Cordillera Ibérica ha permitido identificar cuatro superficies de erosión, comunes en ambos orógenos. La génesis de estas superficies está relacionada con las unidades sedimentarias cenozoicas de la Cuenca de Madrid, especialmente con los sistemas de piedemonte localizados en el borde sur del Sistema Central. La superficie SE1 enlaza con un reducido afloramientos de gravas y bloques cuarcíticos, apoyados sobre un perfil de alteración en gneises. La segunda superficie (SE2), forma parameras en la Cordillera Ibérica y pediments en el Sistema Central, que conectan con un glacis con depósitos más antiguos que la unidad ocre del Turoliense superior. Por lo tanto, esta superficie se relaciona con la Unidad Intermedia, probablemente con sedimentos del Aragoniense superior, anteriores a deformaciones de dirección NE-SO que afectan a la superficie. La tercera superficie (SE3), está deformada en menor medida y su elaboración final está asociada con un glacis (Superficie de la Mierla, 1046 msnm), cuyos depósitos se apoyan discordantes sobre dicha unidad ocre y probablemente son equivalentes al desarrollo de la Superficie Poligénica del Páramo durante el Turoliense superior-Rusciniense. La superficie más reciente (SE4), conecta con un cuarto glacis del Plioceno, donde se encajan las primeras terrazas fluviales., The geomorphological mapping in the transition zone between the Central System and the Iberian Chain has allowed us to identify four planation surfaces, commons in both orogens. The genesis of these surfaces is closely related to the Cenozoic sedimentary units of the Madrid Basin, specially to the piedmont systems located in Central System margin. The oldest surface, or SE1, is located at the same morphological level that a little outcrop of gravels and blocks, burying a weathering mantle developed in gneisses. The second planation surface (SE2), forms parameras in the Iberian Chain and pediments in the Central System, connecting with a well-preserved glacis developed on piedmont deposits older than Turolian sediments (Upper Neogene Unit). Consequently, this surface is related to the Intermediate Unit, probably with Upper Aragonian sediments, previous to the deformation processes which caused NE-SO antiforms and synforms in the surface (Guadarrama direction). The third surface is deformed in lesser degree and shows a closely association with Upper Turolian sediments. However, the current morphology of the surface is associated with a glacis (La Mierla Surface, 1046 m asl), whose deposits are overlying Upper Turolian sediments and which are probably equivalents to the development of the Páramo erosional surface during the Upper-Turolian-Ruscinian. The youngest planation surface consist mainly of facets preserved in the slope valleys and connects with a four glacis of Pliocene age, which is located over the first fluvial terraces., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Las estructuras plegadas constituyen la deformación dúctil más frecuente en Geología, y por tanto es uno de los elementos más representados en Geología Estructural. El empleo de la proyección estereográfica para representar elementos tales como flancos del pliegue, líneas de charnela o planos axiales resulta muy útil por su facilidad para obtener las relaciones angulares entre estos elementos. Además, cuando existe superposición de diversas fases de plegamiento y/o el número de pliegues a representar es elevado, la proyección estereográfica constituye la técnica de mayor utilidad., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Episodic hydrothermal alterations in the Sierra de Guadarrama took place between ca. 300 Ma and 10 Ma. New K-Ar ages for hydrothermal minerals have been obtained that along with previous data allow to better constrain the late- to post-Variscan history of tectono-hydrothermal activity. This activity can further be correlated with Alpine tectonic events in central Iberia recorded in Permian to Cainozoic sedimentary basins. Dating of hydrothermal events in the basement is thus a useful tool to better constrain the chronology of tectono-sedimentary events in the cover., Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

The application of geomorphic principles to land reclamation after surface mining has been reported in the literature since the mid-1990s, mostly from Australia, Canada and the USA. This paper discusses the reclamation problems of contour mining and quarries on slopes, where steep gradients are prone to both mass movement and water erosion. To address these problems simultaneously, a geomorphic model for reclaiming surface mined slopes is described. Called the ‘highwall–trench– concave slope’ model, it was fi rst applied in the 1995 reclamation of a quarry on a slope (La Revilla) in Central Spain. The geomorphic model does not reproduce the original topography, but has two very different sectors and objectives: (i) the highwall–trench sector allows the former quarry face to evolve naturally by erosion, accommodating fallen debris by means of a trench constructed at the toe of the highwall; (ii) the concave-slope base sector, mimicking the landforms of the surrounding undisturbed landscape, promotes soil formation and the establishment of self-sustaining, functional ecosystems in the area protected from sedimentation by the trench. The model improves upon simple topographic reconstruction, because it rebuilds the surfi cial geology architecture and facilitates re-establishment of equilibrium slopes through the management and control of geomorphic processes. Thirteen years of monitoring of the geomorphic and edaphic evolution of La Revilla reclaimed quarry confi rms that the area is functioning as intended: the highwall is backwasting and material is accumulating at the trench, permitting the recovery of soils and vegetation on the concave slope. However, the trench is fi lling faster than planned, which may lead to run-off and sedimentation on the concave slope once the trench is full. The lesson learned for other scenarios is that the model works well in a twodimensional scheme, but requires a three-dimensional drainage management, breaking the reclaimed area into s, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

One recent project, Caribbean–North American Plate Boundary Analysis: From Beata Ridge (Dominican Republic) to Anegada Passage (Lesser Antilles) (CARIBENORTE), has conducted onshore and offshore surveys in the Dominican Republic region to study subduction, strike- slip, and collision processes in this area. This survey included a cruise aboard the Spanish R/V Hespérides in April 2009 and simultaneous fieldwork onshore. The CARIBE NORTE project complements the study of the northeastern Caribbean plate boundary carried out during the Structure and Geodynamics of the Northeastern Boundary of the Caribbean Plate: Puerto Rico (GEOPRICO- DO) project in 2005 [Carbó et al., 2005]., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Mw 7.7 2007 November 14 earthquake had an epicentre located close to the city of Tocopilla, at the southern end of a known seismic gap in North Chile. Through modelling of Global Positioning System (GPS) and radar interferometry (InSAR) data, we show that this event ruptured the deeper part of the seismogenic interface (30–50 km) and did not reach the surface. The earthquake initiated at the hypocentre and was arrested ∼150 km south, beneath the Mejillones Peninsula, an area already identified as an important structural barrier between two segments of the Peru–Chile subduction zone. Our preferred models for the Tocopilla main shock show slip concentrated in two main asperities, consistent with previous inversions of seismological data. Slip appears to have propagated towards relatively shallow depths at its southern extremity, under the Mejillones Peninsula. Our analysis of post-seismic deformation suggests that small but still significant post-seismic slip occurred within the first 10 d after the main shock, and that it was mostly concentrated at the southern end of the rupture. The post-seismic deformation occurring in this period represents ∼12–19 per cent of the coseismic deformation, of which ∼30–55 per cent has been released aseismically. Postseismic slip appears to concentrate within regions that exhibit low coseismic slip, suggesting that the afterslip distribution during the first month of the post-seismic interval complements the coseismic slip. The 2007 Tocopilla earthquake released only ∼2.5 per cent of the moment deficit accumulated on the interface during the past 130 yr and may be regarded as a possible precursor of a larger subduction earthquake rupturing partially or completely the 500-km-long North Chile seismic gap., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

la rotación de líneas o planos representa un ejercicio común en Geología Estructural que puede realizarse más fácilmente mediante proyección estereográfica que utilizando oras técnicas. Sin embargo, para ello es preciso conocer los diferentes métodos existentes en función de las características del eje de rotación, es decir, en función de que éste sea horizontal, vertical o inclinado. Se describen aquí los diferentes procedimientos acompañados de numerosos ejemplos prácticos., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Las fallas constituyen la deformación frágil más frecuente en Geología, y por tanto, al igual que en el caso de los pliegues, se trata de uno de los elementos más representados en Geología Estructural. La proyección estereográfica resulta muy útil a la hora de resolver los numerosos problemas asociados al estudio de las fallas, especialmente en el caso de determinar la orientación de los ejes principales de esfuerzos, así como de obtener el ángulo de rotación asociado a una falla de tipo rotacional. Se muestran numerosos ejemplos de resolución de problemas de fallas mediante el uso de la proyección estereográfica., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Muertos Trough in the northeast Caribbean has been interpreted as a subduction zone from seismicity, leading to infer a possible reversal subduction polarity. However, the distribution of the seismicity is very diffuse and makes definition of the plate geometry difficult. In addition, the compressive deformational features observed in the upper crust and sandbox kinematic modeling do not necessarily suggest a subduction process. We tested the hypothesized subduction of the Caribbean plate’s interior beneath the eastern Greater Antilles island arc using gravity modeling. Gravity models simulating a subduction process yield a regional mass deficit beneath the island arc independently of the geometry and depth of the subducted slab used in the models. This mass deficit results from sinking of the less dense Caribbean slab beneath the lithospheric mantle replacing denser mantle materials and suggests that there is not a subducted Caribbean plateau beneath the island arc. The geologically more realistic gravity model which would explain the N–S shortening observed in the upper crust requires an overthrusted Caribbean slab extending at least 60 km northward from the deformation front, a progressive increase in the thrusting angle from 8 to 30 reaching a maximum depth of 22 km beneath the insular slope. This new tectonic model for the Muertos Margin, defined as a retroarc thrusting, will help to assess the seismic and tsunami hazard in the region. The use of gravity modeling has provided targets for future wide-angle seismic surveys in the Muertos Margin., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

La proyección estereográfica es una de las mejores técnicas para resolver problemas geométricos en Geología Estructural. Trabaja con líneas y planos sin tener en cuenta sus relaciones espaciales, por tanto, solo se pueden representar valores angulares., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The aim of this study is the hydrogeological exploration and characterization using Geophisical surveying in the vicinity of Dakhla Basin (Algeria). To that end, it has been used the method of resistivities through Vertical Electric Sounding (VES) on a campaign carried out in April 2009. The work included 19 VES, which have been calibrated with existing wells and with field geological observations. The results have allowed the characterization of Tertiary deposits as well as Ordovician sandstones. With these data, it has been possible to identify the position and thickness of a shallow salty aquifer, and the roof of a deep freshwater aquifer developed on the Ordovician sandstones. The integration of the geometry of the aquifers with the resistivity values obtained in the Ordovician sandstones has allowed the location of a favorable area for the situation of a new well., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Analogue modelling contributes to the interpretation of lithosphere scale folds in Iberia as a result of largescale convergence during Oligocene-Miocene times between the Iberian and European Plates. Different tectonothermal events affected the microplate since late Paleozoic and resulted in lateral strength variations of the Iberian lithosphere. An old and cold lithosphere, Variscan in age, can be found in the westernmost part of Iberia whereas a relative weak and hot Mesozoic lithosphere affected by episodes of rifting and basin inversion during Mesozoic- Tertiary times covers the area of the Iberian Chain. Our study aims at deciphering whether deformation and topography evolution in Iberia are related to lateral strength variations and/or the inherited structural grain stemming from Variscan deformation. We also have studied the strength of the lithosphere to gain insights into the effects of rheological variations related to local thrusting or primary strength variations along the Iberian lithosphere., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The kinematics of the basal allochthon in the SW of the O´ rdenes Complex is analysed to constraint its evolution during collisional and postcollisional stages of the Variscan orogeny. Two distinct sequences have been identified in the basal allochthon of this sector: the upper and lower sequences, in close correlation with the subdivision of the basal allochthon in the Malpica–Tui Complex. Three main tectonic episodes have been established in the basal allochthon: a high-pressure event related to continental subduction, a mesozonal event of regional exhumation by thrusting and recumbent folding, and a regional-scale extensional episode that resulted in the development of the Bembibre–Pico Sacro detachment system. The Bembibre–Pico Sacro system rejuvenated pre-existing shear zones, whose weakness favoured the nucleation of the detachments. Shear zones associated with the detachments overprinted the previous tectonic fabrics under conditions ranging from lower amphibolite to greenschist facies, and with heterogeneously distributed ductile to brittle deformation. The detachment system is coeval with late orogenic collapse and widespread magmatism, and represents its upper crustal expression. It correlates with mid- and lower crustal flow and the development of gneiss domes at depth in such a way that the basal allochthon can be considered a rheological boundary between the more rigid allochthonous sequences above and the more viscous Schistose Domain and autochthon below., Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

The present-day thermal state of the martian interior is a very important issue for understanding the 22 internal evolution of the planet. Here, in order to obtain an improved upper limit for the heat flow at 23 the north polar region, we use the lower limit of the effective elastic thickness of the lithosphere loaded 24 by the north polar cap, crustal heat-producing elements (HPE) abundances based on martian geochem- 25 istry, and a temperature-dependent thermal conductivity for the upper mantle. We also perform similar 26 calculations for the south polar region, although uncertainties in lithospheric flexure make the results 27 less robust. Our results show that the present-day surface and sublithospheric heat flows cannot be 28 higher than 19 and 12 mWm2, respectively, in the north polar region, and similar values might be 29 representative of the south polar region (although with a somewhat higher surface heat flow due to 30 the radioactive contribution from a thicker crust). These values, if representative of martian averages, 31 does not necessarily imply sub-chondritic HPE bulk abundances for Mars (as previously suggested), since 32 (1) chondritic composition models produce a present-day total heat power equivalent to an average sur- 33 face heat flow of 14–22 mWm2 and (2) some convective models obtain similar heat flows for the pres- 34 ent time. Regions of low heat flow may even have existed during the last billions of years, in accordance 35 with several surface heat flow estimates of 20 mWm2 or less for terrains loaded during Hesperian or 36 Amazonian times. On the other hand, there are some evidences suggesting the current existence of 37 regions of enhanced heat flow, and therefore average heat flows could be higher than those obtained 38 for the north (and maybe the south) polar region., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

la orientación y representación estereográfica de elementos lineales tales como ejes de pliegues, lineamientos minerales, estrías de falla, etc. presentan algunas diferencias importantes respecto a los elementos planares que hay que conocer. Conceptos como inmersión y cabeceo son descritos en detalle, junto con numerosos ejemplos de representación., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El temporal de lluvia y frío que afectó a Mallorca durante los meses de octubre de 2008 a enero de 2009, ha desencadenado numerosos movimientos de ladera, registrándose 12 movimientos significativos en la Serra de Tramuntana, algunos de los cuales han afectado seriamente a las vías de comunicación. La noche del 19 de diciembre de 2008 tuvo lugar, en la vertiente oriental del Puig de s’Alcadena (tm de Alaró), un gran desprendimiento de rocas que generó una avalancha sobre la ladera, con un alcance de unos 650 m. La avalancha arrasó el bosque de pinar que encontró a su paso, dejando una lengua de bloques de unos 60.000 m2 de superficie y 300.000 m3 de volumen. Algunos de los bloques movilizados presentan volúmenes superiores a 1.500 m3 y varios miles de toneladas de peso. La rotura en cuña del escarpe rocoso del Puig de s´Alcadena se produce a través de dos planos, que coinciden con las principales directrices tectónicas de la Sierra. La coincidencia de lluvias intensas y continuadas en la zona (150 mm en 24 horas y 672 mm de lluvia acumulada), con la ocurrencia de bajas e inusuales temperaturas (inferiores a 0ºC), fue el motor desencadenante de la avalancha. Afortunadamente, no se registraron daños personales ni materiales., From October 2008 to January 2009, Majorca island was affected by a period of intense rainfall and low temperatures which triggered numerous slope movements, 12 being registered in the Tramuntana Range, some of which seriously affected the road network. On the night 19th December 2008, a rockfall on the eastern slope of the Puig de s´Alcadena (Alaro) took place, generating a rock avalanche with a length of 650 m. The rock avalanche destroyed the pine wood in its path, leaving a tongue of blocks over an area of 60.000 m2and 300.000 m3 in volume. Some of the blocks have a volume of over 1,500 m3 and are several tones in weight. The wedge failure on the scarp of Puig de s´Alcadena is produced on two planes which coincide with the main tectonic features of the Range. The fact that heavy and continuous rainfall (150 mm in 24 h and 672 mm of accumulated rainfall) coincided with unusually low temperatures (below 0ºC), was the triggering factor of the avalanche. Fortunately, no serious damage occurred., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

las muestras de roca obtenidas en los sondeos proporcionan información fundamental acerca de los materiales geológicos que no llegan a aflorar en superficie. Además, mediante la aplicación de la proyección estereográfica se puede conocer la orientación de las estructuras planares atravesadas por el sondeo. Este proceso no es sencillo e implica realizar rotaciones alrededor de ejes, y combinar la proyección estereográfica con la ortográfica. Cuanto mayor sea el número de sondeos que cortan una misma estructura planar, mayor será el grado de fiabilidad de la solución obtenida., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Los elementos planares en Geología Estructural (superficies de estratificación, discordancias, fallas, flancos de pliegues, planos axiales, etc.) son muy comunes y por tanto deben saber representarse correctamente en proyección estereográfica. Comprender y manejar correctamente conceptos como dirección, buzamiento y sentido de buzamiento de un plano es fundamental., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

La proyección de grandes conjuntos de datos puede suponer un problema debido a lo complicado que resulta sacar conclusiones a partir del análisis de diagramas con un elevado número de medidas representadas. Tal es el caso de estructuras plegadas definidas a partir de múltiples medidas de estratificación, o bien el problema de la superposición de estructuras de deformación. Se hace imprescindible entonces el uso de falsillas que conserven las áreas para realizar estudios estadísticos. Se muestran numerosos ejemplos del empleo de diagramas de contornos mediante el uso de la proyección estereográfica., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The study of intraplate tectonics is crucial for understanding the deformation within plates, far from active plate boundaries and associated stress transmission to the plate interiors. This paper examines the tectonic evolution of the Variscan basement at the western margin of the Cenozoic Duero basin. Located east of the Vilariça Fault System in NW Iberia, this intraplate zone is a relatively flat but elevated area with an intense NNE-SSW trending fault system and associated moderate seismicity. Although the area has played an important role in the Duero basin configuration, its Alpine to present-day tectonic evolution has not been well constrained. In order to characterize the successive paleostress fields, 1428 pairs of fault-striae were measured at 56 sites and two focal mechanisms were used. Stress inversion methods have been applied to analyze paleostress regimes. Results show the existence of three dominant maximum horizontal stress (Shmax) trends: N-S, NE-SW and E-W. Relative and absolute dating of the activated faults for each Shmax shows that the clearly predominant N-S paleostress field in the zone has been active since the Oligocene up to the present day; while a NE-SW stress field is found to have been active during the Cretaceous and an older E-W paleostress field was active in the earlier Alpine cycle (Late Triassic)., Ministerio de Educación y Ciencia, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Complex landslides in clay-bearing sediments are investigated in two moderate-relief regions of Southeast Spain. Both regions, more than 100 km apart show landslides affecting the same Flysch formation, which outcrops widely in the central and western Betic Cordillera along the contact between the External (South Iberian Domain) and Internal (Alborán Domain) zones. Intense rainfall episodes can be considered as the main triggering factor for slope failures in these two areas. We have chosen two landslides (Diezma and Riogordo landslides), one from each area of study, to investigate their morphological and geotechnical features in order to establish the relative importance of the different controlling factors. From a kinematic point of view, the two features studied in detail can be referred as to rotational failures, evolving downhill to slow earthflows. The movement was concentrated on several surfaces developed on a clay-rich layer mostly constituted by smectite. This clay mineral is of critical relevance to the mechanical behaviour of soils and Flysch-like formations, being very consistent at dry conditions, but rapidly losing its strength at wet conditions. Thus, softened smectite-rich clay layers with high water contents can approach the properties of a lubricant, which, in turn, can be critical for slope stability. In addition to their high plasticity, these clays have a high swelling potential, which can induce significant vertical overpressure, thus reducing even more the strength properties of the Flysch formation. In Southeast Spain, a region with a Mediterranean rainfall regime, slope stability can be seriously influenced by the presence of these smectite-rich clay layers in a formation of regional extent, as is the case of the Flysch formation. Therefore, this lithologically-controlled factor should be taken into account when evaluating landslide hazard in the Betic Cordillera., Consejería de Obras Públicas de la Junta de Andalucía, Spanish Ministry of Science and Innovation, TOPO-IBERIA CONSOLIDER-INGENIO, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Fracture characterization in granites has been an important subject of study during these last years, by means of geological-structural cartography, hydrogeology and geochemical analysis. All these works have been carried out to investigate the hydromechanics and permeability in low-permeability rocks. In this study we apply a surface geophysical method in order to characterize the permeability of the fault zones affecting “El Berrocal” granite (Central System, Spain). The low-induction electromagnetic method (EM) gives us the apparent resistivity values of the rocks at a maximum depth, allowing us to differentiate between soil / altered rock from fresh granites. As the apparent resistivity depends on the granite alteration and/or the water content, this parameter allows to estimate the relative permeability of different fracture zones. The obtained results show that the high-permeability fractures are those that are larger ones which were active during Alpine deformation (Eocene-present)., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Large areas of strongly magnetized crust are located in Terra Cimmeria and Terra Sirenum, in the southern highlands of Mars, the older terrains on the planet. The typical depth to the base of the magnetized layer, deduced from the magnetic spectrum of Mars and modeling of isolated magnetic anomalies, would 40–60 km. In this paper the thermal state of Terra Cimmeria is revisited by calculating heat flows and crustal geotherms consistent with a previous estimation of the effective elastic thickness of the lithosphere, and with crustal abundances of heat-producing elements based on surface measurements performed by the Mars Odyssey Gamma Ray Spectrometer. The results suggest that, at the time of formation of the magnetized terrains surface (which have a minimum age of 4.1 Ga), Curie depths for magnetite and hematite were shallower and similar, respectively, than the typical depth to the base of the magnetized layer. This implies that hematite is an important (if not dominant) contributor to the magnetization of the martian crust. However, an early warm climate would enhance the chance of magnetite to be a significant, even dominant, magnetization carrier in the lower portion of the magnetic layer., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Los sistemas torrenciales se caracterizan por corrientes efímeras pero súbitas, que alcanzan rápidamente su caudal punta e incorporan abundante carga sólida que depositan también de forma brusca al desvanecerse la crecida. Se manifiestan desde formas métricas de ladera o cabecera (cárcavas y barrancos) hasta kilométricas, como ramblas y grandes abanicos aluviales. Pero su morfología y dinámica son equiparables: cuenca de recepción muy activa, corto canal de transferencia y zona de producción, generalmente abanico. Estas tres zonas se repiten a diferentes escalas dentro de la misma línea de drenaje, generando depósitos sobre los que el cauce se vuelve a encajar o que abandona migrando a zonas más deprimidas. Esta dinámica esporádica y cambiante, su capacidad erosiva, así como los altos caudales líquidos y sólidos, confieren a estos sistemas una gran peligrosidad, The torrential stream dynamics is characterized by ephemeral but sudden streamflows (flashfloods) that quickly reach their peak flow, entraining abundant load that also deposits abruptly when the flood vanishes. They offer wide range morphologies, from metric forms (gullies) on headwaters and slopes, to kilometric ones like ramblas (arroyos) and large alluvial fans. But their morphology and dynamics are similar: very active reception basin, short transference channel and widespread production area, commonly an alluvial fan. These three zones may be recurring at different scales within the same drainage line, generating deposits on which the channel either entrenches or abandons, migrating towards more depressed areas. This erratic and changing dynamics, the erosive capacity, as well as the high load and discharge, confer to these systems a great hazard, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Claritas rise is a prominent ancient (Noachian) center of tectonism identified through investigation of comprehensive paleotectonic information of the western hemisphere of Mars. This center is interpreted to be the result of magmatic-driven activity, including uplift and associated tectonism, as well as possible hydrothermal activity. Coupled with its ancient stratigraphy, high density of impact craters, and complex structure, a possible magnetic signature may indicate that it formed during an ancient period of Mars' evolution, such as when the dynamo was in operation. As Tharsis lacks magnetic signatures, Claritas rise may pre-date the development of Tharsis or mark incipient development, since some of the crustal materials underlying Tharsis and older parts of the magmatic complex, respectively, could have been highly resurfaced, destroying any remanent magnetism. Here, we detail the significant characteristics of the Claritas rise, and present a case for why it should be targeted by the Mars Odyssey, Mars Reconnaissance Orbiter, and Mars Express spacecrafts, as well as be considered as a prime target for future tier-scalable robotic reconnaissance., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El municipio de Peñalén (Guadalajara) alberga un conjunto de minas y escombreras degradadas, cuyo impacto ambiental sobre el inmediato Parque Natural del Alto Tajo es objeto de constante discusión. En este trabajo se ha llevado a cabo una primera aproximación al problema, tratando de caracterizar los condicionantes geomorfológicos del impacto hidrológico, de identificar las principales fuentes de sedimentos y de cuantificar los sedimentos que son emitidos desde estas zonas mineras y desde sus alrededores a la red fluvial. Esta aproximación ha puesto de manifiesto tres evidencias claras: (i) las zonas mineras de Peñalén se sitúan en localizaciones muy vulnerables a la erosión hídrica; (ii) los procesos erosivos y de emisión de sedimentos hacia el río Tajo son muy importantes desde esas zonas mineras y desde cárcavas naturales; (iii) existe una conexión hidrológica directa entre las fuentes de sedimentos de las zonas mineras degradadas de Peñalén y el río Tajo., The Peñalén municipality (Guadalajara Province) houses a series of derelict kaolin mines. The environmental impact of these mined lands upon the close Upper Tagus Natural Park is subject to constant discussion. This works shows a characterization of the geomorphic setting of the mines, as a main determining factor of the hydrological impact. In addition, an evaluation of the soil erosion rates of the Peñalén catchment was carried through RUSLE 1.06, to identify the main sediment sources. Additionally, sediment yield quantification was feasible from the evaluation of the stored sediments at a check-dam located at the the Peñalén catchment’s mouth. Finally, a descriptive analysis of the erosive landforms at these mined areas has been made both from field work and a combination of oblique aerial photos of different times. The higher erosion rates obtained by RUSLE 1.06 are: highwall (202.54 Mg ha-1 year-1); highwall’s debris slope deposits (87.55 Mg ha-1 year-1); outslope spoil heaps (86.12 Mg ha-1 year-1) and natural gullies (197.93 Mg ha-1 year-1). The quantification from the check-dam sedimentation offers a realistic value of the sediments that are being emitted from the Peñalén catchment to the Tagus River (approximately 3200 Mg year-1). Finally, the geomorphic analysis from oblique aerial photos and field work shows that the outslope spoil heaps of Santa Engracia mine are the main source of sediments, in contradiction with the RUSLE 1.06. From these results, three evidences are noticeable: (i) the derelict mined areas of Peñalén are located in very vulnerable topographical positions to the hydric erosion; (ii) these mined areas are subject to very high erosion rates; (iii) there is a direct hydrological connection between the sediment sources of these mined areas and the Tagus River within the protected area, and therefore a permanent and severe ecohydrologic impact is taking place., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Gamma Ray Spectrometer (Mars Odyssey spacecraft) has revealed elemental distributions of potassium (K), thorium(Th), and iron (Fe) on Mars that require fractionation of K (and possibly Th and Fe) consistent with aqueous activity. This includes weathering, evolution of soils, and transport, sorting, and deposition, as well as with the location of first-order geomorphological demarcations identified as possible paleoocean boundaries. The element abundances occur in patterns consistent with weathering in situ and possible presence of relictor exhumed paleosols, deposition of weathered materials (salts and clastic minerals), and weathering/transport under neutral to acidic brines. The abundances are explained by hydrogeology consistent with the possibly over lapping alternatives of paleooceans and/or heterogeneous rock compositions from diverse provenances (e.g., differing igneous compositions)., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

La Geomorfología Regional, definida como ciencia que se ocupa de describir y explicar la distribución espacial de las formas del terreno a escala regional y sub-regional, ha sido considerada por la planificación física y la ordenación del territorio más clásicas, como la única disciplina capaz de analizar las “líneas maestras” que definen el carácter complejo del territorio y del paisaje. La utilización del relieve como base física para la delimitación y definición de unidades territoriales integradas, básicas para gestionar el territorio y sus recursos, ha constituido además uno de los métodos tradicionalmente empleados por algunas de las disciplinas ambientales que en mayor medida han contribuido al acercamiento de la planificación física clásica hacia la nueva ordenación integral; es el caso de la Ecología del Paisaje, la Ecología Humana y la Geografía Ambiental. Paradójicamente, la importancia de los criterios fisiográficos y geomorfológicos de regionalización en planificación se ha ido reduciendo en la nueva “ordenación integral”, quedando relegados a determinados procedimientos de planificación sectorial. Entre los sectores en los que la Geomorfología ha conseguido mantener su peso, destacan la gestión de recursos hídricos, de Espacios Naturales Protegidos, de riesgos naturales e inducidos y del paisaje. En este sentido, es a partir del reciente auge de una serie de teorías y modelos en planificación territorial asociados al paradigma socio-ambiental, entre los que sobresalen particularmente la complejidad e incertidumbre de los sistemas territoriales, cuando se ha generado una crítica generalizada hacia las ciencias naturales más clásicas que, como la Geomorfología, han sido incapaces de generar propuestas actualizadas. Por ello, la Geomorfología aplicada a la planificación ha sido genéricamente acusada de inmovilista cuando no, incluso, de determinista. En el presente artículo se analiza la eficacia y posibilidades de implementación de una metodología de aná, Regional Geomorphology is defined as the scientific study of the spatial distribution of landforms at both regional and subregional scales, and has been traditionally considered by land use planners, as the discipline capable to explain the master lines that define the character of both territory and landscape. The use of landforms and land-units to delineate and define territorial units useful for land and resource management is a classical procedure used by both Land-Use and classic Spatial Planning. The design and use of either physiographic (synthetic) or parametric (analytical) landform-based methodologies to define homogeneous regions is a classic procedure, developed and used by sciences such as regional geography, landscape ecology and environmental geomorphology. Nevertheless, the former importance of the diverse existing regionalization criteria based upon physiographic and geomorphologic features, has recently suffered from a continuous decrease in both their technical and political popularity, being presently reduced almost exclusively to certain sectorial planning procedures. Amongst the territorial components and processes whose planning strategies have managed to retain the importance of landforms and land units specially outstand watersheds, Natural Protected Areas, natural and induced Hazards and Landscape. One of the main causes explaining the aforementioned decrease might probably lye upon the recent trend that is redirecting Spatial Planning towards a more complex socio-environmental, and each time less land-use-based, discipline. Even if Land-Use Planning still constitutes a very central component of complex modern Spatial Planning, it is no longer considered as its main core. Instead, issues such as the creation of places, public participation and governance-related strategies, and the capacity to link together the diverse actors, policies, scales and interests involved on sectorial planning in order to attain a sustainable development, have ar, Castilla-La Mancha. Junta de Comunidades. Consejería de Medio Ambiente y Desarrollo Rural, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Rheic Ocean formed during the Late Cambrian-Early Ordovician when peri-Gondwanan terranes (e.g. Avalonia) drifted from the northern margin of Gondwana, and was consumed during the collision between Laurussia and Gondwana and the amalgamation of Pangaea. Several mafic complexes, from the Acatlán Complex in Mexico to the Bohemian Massif in eastern Europe, have been interpreted to represent vestiges of the Rheic Ocean. Most of these complexes are either Late Cambrian-Early Ordovician or Late Palaeozoic in age. Late Cambrian-Early Ordovician complexes are predominantly rift-related continental tholeiites, derived from an enriched c. 1.0 Ga subcontinental lithospheric mantle, and are associated with crustally-derived felsic volcanic rocks. These complexes are widespread and virtually coeval along the length of the Gondwanan margin. They reflect magmatism that accompanied the early stages of rifting and the formation of the Rheic Ocean, and they remained along the Gondwanan margin to form part of a passive margin succession as Avalonia and other peri-Gondwanan terranes drifted northward. True ophiolitic complexes of this age are rare, a notable exception occurring in NW Iberia where they display ensimatic arc geochemical affinities. These complexes were thrust over, or extruded into, the Gondwanan margin during the Late Devonian-Carboniferous collision between Gondwana and Laurussia (Variscan orogeny). The Late Palaeozoic mafic complexes (Devonian and Carboniferous) preserve many of the lithotectonic and/or chemical characteristics of ophiolites. They are characterized by derivation from an anomalous mantle which displays time integrated depletion in Nd relative to Sm. Devonian ophiolites pre-date closure of the Rheic Ocean. Although their tectonic setting is controversial, there is a consensus that most of them reflect narrow tracts of oceanic crust that originated along the Laurussian margin, but were thrust over Gondwana during Variscan orogenesis. The relationship, Ministerio de Educación y Ciencia, Mobility Program, National Science Foundation, Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica, Consejo Nacional de Ciencia y Tecnología, Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub

This paper mainly focuses on the spatial distribution of plagioclase phases observed by Raman and spectra cathodoluminescence (CL) emission of in the Villalbeto de la Peña meteorite. Initially, we collected fragments countryside to determine the strewn field area and to perform spot chemical analyses by electron microprobe for the classification of the specimens (L6 Chondrite). Furthermore, the hyperspectral Raman mapping allow us identify amorphous Maskelynite feldspar in plagioclase micro-fissures since it is a molecular technique. The spectra CL emission bands observed at circa 290, 340, 390, 440, 510, 640 and 780 nm are characteristic in aluminosilicate lattices providing additional data on H+, OH- and H2O and Na+ self-diffusion along interfaces (290 nm), on strained Si—O bonds (340 and 650 nm), on [AlO4]° centers (380-390 nm and 420-440 nm), on O-—Si…M+ centers (510 nm) and on substitutional Fe3+ in aluminum positions (740—800 nm broad band). The CL and hyperspectral Raman techniques coupling demonstrates that the Villalbeto meteorite was shock-metamorphosed from the amorphous Maskelynite presence in Plagioclase fissures and from the strained Si—O bonds at room temperature., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The aim of this study is to evaluate electromagnetic induction methods to analyze low permeability rocks in desert areas, as a tool for groundwater surveying. We have focused the field work in large faults zones, previously mapped by satellite images and digital elevation models. This is because in low-permeability rocks (i.e. granites) the groundwater flow is mainly controlled by these discontinuities. The objective is to map the high conductivity zones and their geometry in depth. Obtained results allow us to identify well defined fractures with low apparent resistivities that are the most suitable areas to locate groundwater extractions., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Iberian Chain is a wide intraplate deformation zone formed by the tectonic inversion during the Pyrenean orogeny of a Permian –Mesozoic basin developed in the eastern part of the Iberian Massif. The N – S convergence between Iberia and Eurasia from the Late Cretaceous to the Lower Miocene times produced signi cant intraplate deformation. The NW –SE oriented Castilian Branch of the Iberian Chain can be considered as a “key zone ” where the proposed models for the Cenozoic tectonic evolution of the Iberian Chain can be tested. Structural style of basin inversion suggests mainly strike slip d–isplacements along previous NW –SE normal faults, developed mostly during the Mesozoic. To con rm this hypothesis, structural and basin evolution analysis, macrostructural Bouguer gravity anomaly analysis, detailed mapping and paleostress inversions have been used to prove the important role of strike slip deformation. In addition, we demonstrate that two main folding trends almost perpendicular (NE SW t–o E W an–d NW SE) w–ere simultaneously active in a wide transpressive zone. The two fold trends were generated by dierent mechanical behaviour, including buckling and bending under constrictive strain conditions. We propose that strain partitioning occurred with oblique compression and transpression during the Cenozoic., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

En este trabajo se presentan los sistemas radar satélite y terrestres, así como los métodos de análisis de imágenes radar clásicos y avanzados para la investigación de los movimientos del terreno, haciendo énfasis en la subsidencia y los movimientos de ladera. Para ello en primer lugar se describen los distintos sensores radar disponibles así como las principales características de las imágenes radar generadas. A continuación se detallan los aspectos fundamentales de la interferometría diferencial, de los distintos métodos de interferometría diferencial avanzada y del radar terrestre. Finalmente se presentan los resultados obtenidos en distintas zonas de estudio: la subsidencia por explotación del acuífero en el área metropolitana de Murcia, la subsidencia minera y los movimientos de ladera de la Sierra de Cartagena, los movimientos de ladera de la cuenca del río Gállego y el deslizamiento del Portalet, In this paper satellite and ground based radar systems are presented, as well as standard and advanced differential interferometry techniques, for subsidence and landslides research. In the fist part available radar sensors are described as well as the main characteristics of radar images (SAR images). Then the key aspects of standard differential interferometry, advanced differential interferometry and ground based radar are shown. Finally, results retrieved in different study areas are presented: subsidence due to ground water withdrawal in the metropolitan area of Murcia, mining subsidence and mass movements in Sierra de Cartagena, landslides in river Gállego basin and landslides in Portalet, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El estudio de la Geología incorpora cada vez técnicas de estudio más depuradas y de última generación (ablación laser, estudio de huellas de fisión, métodos de prospección sísmica, etc.). Sin embargo, algunas de las metodologías más convencionales siguen siendo un recurso de primera mano en la interpretación de los procesos geológicos tanto internos como externos que llevan al modelado de la topografía. Uno de estos ejemplos lo constituye la Modelación Análoga1, cuyos orígenes se remontan a principios del S.XIX. El fin último de este tipo de experimentos es el llegar a entender el por qué y el cómo en la formación de los relieves montañosos que observamos hoy en día, en nuestro caso aplicado a la Península Ibérica y su posible conexión con las cadenas montañosas que forman el Atlas marroquí. Este proceso podría estar relacionado con pliegues de gran longitud de onda que afectan a toda la litosfera., Earth Science integrates recent and new refined techniques (laser ablation, FT analyses, applied geophysics methods, etc). However, the most conventional methodologies still continue being relevant on the interpretation concerning both internal and external geodynamic processes that shape the landscape. Analogue Modelling was born in the beginning of the 19th Century and constitutes one of the main resources of geologic knowledge. We applied this technique to gain insight into the observable mountain building processes like those of the Iberian Peninsula and the connection with mountains that shapes the Moroccan Atlas. The process of mountain building might be linked to folding of the entire lithosphere., España. Ministerio de Educación y Ciencia., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Erosion and landslide processes played an important role in shaping the geomorphology of the Canary Islands. But for the heavily eroded La Gomera Island, those processes have been unclear. We conducted an integrated study of its offshore extension, onshore geology, and links between them in order to determine the geomorphological evolution of the island relative to the rest of the archipelago. The characteristics of the island's barrancos and its interfluves have led us to differentiate four types of morphological areas whose fluvial networks are in different stages of evolution. Those barrancos offshore are interrupted by La Gomera's shelf, and its erosion has been much greater than for the rest of the Canary Islands. Such erosion is both a function of time and varied swell action. La Gomera's insular slope is carved by a system of submarine canyons and channels that have morphology indicative of turbidity current erosion. Many of the barrancos onshore and the canyons offshore have steps or knickpoints: some are the result of varied resistance to erosion, and others are explained by other mechanisms. A ridge whose crest is covered by cone-like shape structures is interpreted as of volcanic origin, with the particularity that it lacks onshore continuation, the opposite of what has been observed elsewhere in the Canary Islands. Also in contrast with the other islands of the archipelago, La Gomera's margin does not seem to have resulted from destructive mass wasting and the only offshore sign of catastrophic events are the presence of two embayments along La Gomera's northern shelf edge and a lobe structure on the insular apron at 3000 m depth. These features may be the remains of the catastrophic failures that took place on the island 9.4-8.7 Ma ago. Alternatively, they could be due to recent catastrophic failures on the upper slope due to sediment steeping. Since the conclusion of the main volcanic activity 4.0 Ma ago, La Gomera has been intensively eroded by gradua, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The areas of volcanic units on Venus have been measured on the 1:5000000 geological maps published by NASA/USGS. These data were used to obtain a frequency-area distribution. The cumulative frequency-area distribution of 1544 specific occurrence of units cover six orders of magnitude from the largest unit (30 106 km2) to the smallest (20 km2). The probability distribution function has been calculated. The medium and large volcanic units correlate well with a power-law (fractal) relation for the dependence of frequency on area with a slope of 1.83. There are fewer small units than the expected values provided by the power-law relation. Our measurements cover 21.02% of the planetary surface, 3.59% of the study area was found to be tessera terrain and is excluded from this study of volcanism. The measurements were restricted to areas where geological maps have been published. The analysis was performed on two independent areas of the planet, with a complete coverage of published maps. In both areas the largest volcanic unit covers a significant portion of the surface (58.75% and 63.64%, respectively). For the total measured volcanic units (excluding tessera), these two largest units (that could correspond to the same unit or not) cover the 61.18% and they are stratigraphically superimposed on older volcanic units which cover 3.37% of the area. The remaining area (35.45%) is occupied by younger volcanic units stratigraphically superimposed on the large volcanic unit(s). These results are based on the independent mapping of a large number of geologists with different ideas about the geodynamical evolution of Venus and different criteria for geological mapping. Despite this fact, the presence of these very large units is incompatible with the equilibrium resurfacing models, because their generation at different ages would destroy the crater randomness. Our frequency- area distribution of the mapped volcanic units supports a catastrophic resurfacing due to the emplacement, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

The Quaternary lacustrine basin of Cordovilla (CB) represents one of the most active tectonic areas of the Prebetic Zone (Albacete, SE of Spain). The Quaternary sedimentary deposits of this basin are mainly endoreic lacustrine carbonate and alluvial deposits, developed in a semi-arid climate (Pleistocene-present). The basin is a NW–SE-elongated graben bounded by a major right-lateral oblique-fault, the Pozohondo Fault. This fault trendsNW–SE, with an approximate trace of 55 km, and is composed of various segments which are identified by fault scarps. In order to establish the slip-rate of the most active segment of the Pozohondo Fault, called the Cordovilla segment, we carried out a detailed study of the affected Quaternary lacustrine deposits. We found that the lacustrine facies could be related to episodic moderate paleoearthquakes. The slip-rate is calculated to be 0.05 and 0.09 mm/yr, using radiometric dating for the vertical offsets of the lacustrine facies. A trenching study at the northern part of the Cordovilla segment revealed two events caused by paleoearthquakes, with the most recent expressed as an oblique-fault off-setting a poorly-developed soil. The magnitude of the last event was greater than 6, using various empirical relationships for the fault displacement and the surface-length rupture. We estimate episodic activity across the Cordovilla segment, to be characterized by moderate-sized paleoearthquakes (M6), which is in agreement with the tectonic context of an intraplate zone of the Iberian plate., Ministerio de Ciencia e Innovación (MICINN), Depto. de Mineralogía y Petrología, Fac. de Ciencias Geológicas, TRUE, pub