Paleontología y ambientes del Triásico Medio en el sector noroccidental de la cordillera ibérica (provs. de Soria y Guadalajara, España)

El Triásico Medio del sector noroccidental de la Cordillera Ibérica está compuesto por dos formaciones carbonáticas, que se corresponden con la unidad carbonática superior del Muschelkalk, y que hacia el NW pasan lateralmente a una formación terrígena. El registro fósil se encuentra en ambos tipos de formaciones. Tanto el estudio tafonómico como sedimentológico, permiten inferir la presencia de elementos acumulados que podrían corresponder a asociaciones autóctonas, compuestas en su mayoría por bivalvos infaunales de medios marinos someros y sometidos a fuerte influencia de terrígenos. Se caracterizan en la zona tres asociaciones faunísticas: 1. Asociación CostatoriaLyriomyophoria, que aparece tanto en la formación carbonática inferior como en la formación terrígena equivalente; 2. Asociación «Fauna de Terue!», que aparece en la formación carbonática superior, y 3. Asociación Lingula-Pseudocorbula, que aparece también en la formación carbonática superior, pero en niveles más altos. La «Fauna de Terue!» es característica de la Formación «Dolomías, Margas y Calizas de Royuela», y está bien representada en toda la Cordillera Ibérica. La presencia de la misma en nuestra zona constituye el registro más noroccidental de esta asociación en la misma. Por tanto, significa la penetración más occidental en la península de las faunas endémicas del «Dominio Sefardí» durante el Ladiniense.The Triassic of the NW Iberian Ranges consists of two carbonatic formations equivalent to the Upper Carbonatic Formation of the Muschelkalk Facies and pass laterally into siliciciastic deposits to the NW. Fossillocalities have been found in both formations. Taphonomic and sedimentologic studies allow for the interpretation as autochthonous associations of the infaunal Bivalves of shallow water marine environments with siliciciastic input. Three faunal associations have been distinguished: 1. Costatoria-Lyriomyophoria association, found in the lower carbonatic formation and the equivalent siliciciastic formation; 2. «Teruel Fauna» association, found in the upper carbonatic formation; 3. Lingula-Pseudocorbula association, found near the top of the upper carbonatic Formation. The «Teruel Fauna» is well represented in the Iberian Ranges, and always occur in the «Royuela Marls and Limestones» Formation, and our fossil localities are its most Northwestern record in the Iberian Ranges up to now, thus extending the presence of the endemic «Sephardic Faunas» during the [email protected]

A Gravitational Wave Background from Reheating after Hybrid Inflation

The reheating of the universe after hybrid inflation proceeds through the nucleation and subsequent collision of large concentrations of energy density in the form of bubble-like structures moving at relativistic speeds. This generates a significant fraction of energy in the form of a stochastic background of gravitational waves, whose time evolution is determined by the successive stages of reheating: First, tachyonic preheating makes the amplitude of gravity waves grow exponentially fast. Second, bubble collisions add a new burst of gravitational radiation. Third, turbulent motions finally sets the end of gravitational waves production. From then on, these waves propagate unimpeded to us. We find that the fraction of energy density today in these primordial gravitational waves could be significant for GUT-scale models of inflation, although well beyond the frequency range sensitivity of gravitational wave observatories like LIGO, LISA or BBO. However, low-scale models could still produce a detectable signal at frequencies accessible to BBO or DECIGO. For comparison, we have also computed the analogous gravitational wave background from some chaotic inflation models and obtained results similar to those found by other groups. The discovery of such a background would open a new observational window into the very early universe, where the details of the process of reheating, i.e. the Big Bang, could be explored. Moreover, it could also serve in the future as a new experimental tool for testing the Inflationary Paradigm.Comment: 22 pages, 18 figures, uses revtex

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

First high-resolution multi-proxy palaeoenvironmental record of the Late Glacial to Early Holocene transition in the Ría de Arousa (Atlantic margin of NW Iberia)

A 322-cm-long sedimentary sequence obtained in the shallow marine basin of the Ría de Arousa—a submerged unglaciated river valley on the Atlantic margin of northwestern Iberia—was analysed using a multi-proxy approach to study how climatic and sea level changes affected the coastal ecosystems during the Last Glacial–Interglacial Transition. Past sedimentation, vegetation and marine productivities were inferred from palynological, radiocarbon, seismic and lithological data. A substantial reduction in the pollen and dinoflagellate cyst accumulation rates is observed at ∼12,700 to 11,700 cal a BP, suggesting lower marine and vegetation productivities likely as a response to the Younger Dryas cooling event. Overall, the regional vegetation changed from cold-tolerant open woodlands (Pinus sylvestris/P. nigra and Betula) dominating before ∼10,200 cal a BP to coastal wetlands and the regional spread of Quercus-dominated forests after ∼9800 cal a BP. Cluster analysis and principal component analysis allowed the identification of several small environmental oscillations, such as the 11.4 ka and 10.5 ka cooling events. After that, a conspicuous heath expansion was likely favoured by the palaeotopography, the increased precipitation and the relative sea level rise, which might have caused a profound change in the coastal configuration. Concurrently, both the dinoflagellate cyst and non-pollen palynomorph records reveal variations in the marine productivity and coastal hydrodynamics that also agree with a period of marked marine transgression, warming and increasing river flow. New sedimentary data highlight the high sensitivity of the ria's ecosystems to environmental oscillations and show a close temporal correspondence between terrestrial and marine responses to climate change

El gas somero en los sedimentos de la Ría de Muros-Noia (NO de España): formas de aparición y cartografía

High-resolution seismic reflection and side-scan sonar records have been analysed and interpreted in order to detect shallow gas signatures in the Ría de Muros-Noia (NW Spain). The different gas features have been classified into four types according to their specific seismic signatures: 1) acoustic blankings s.s., with a flat top surface and kilometric extent, 2) acoustic curtains, with a convex top surface and some tens of meters of lateral extent, 3) acoustic columns, with an enhanced reflector at the top and an averaged extent of 20 m, and 4) acoustic turbidity, distinguishable as a diffuse perturbation of the records. At the same time, two different types of gas escape features have been also distinguished: a) acoustic plumes into the water column, rising up to 10 m above the present seafloor, and b) pockmarks on the present seabed, recognised as highly reflective areas in the side-scan sonar records. Mapping of acoustic blankings s.s. reveals the presence of a large gas field (11.5 km2) in the inner part of the ría. In this field the top of the gas accumulates from the close seabed surface up to 4 ms TWT (3.2 m) in depth. Moreover a map with the spatial distribution of the gas accumulations and of the gas escape features is shown

Cambios en la representación polínica de los ecosistemas fluvio-marinos de transición del entorno de la Ría de Vigo durante los últimos 1500 años

XV lnternational A.P.L.E. Symposium of Palynolog

Evolution of the upper proterozoic continental deposits from «La Serena», (Southern Central Iberian Zone) Badajoz, Spain

[Resumen] Se describen por primera vez afloramientos, recientemente descubiertos, del Alcudiense Superior, en «La Serena», Badajoz. Se demuestra el carácter continental de la parte basal de varias secuencias, y se esboza un esquema paleogeográfico, que implica una línea de,costa hacia el Oeste, y la diferenciación de tres ciclos sedimentarios.[Abstract] Sorne recently discovered Upper Alcudian outcrops, from «La Serena» region in Badajoz province, are described in this paper for the first time. The basal pan of most of the studied logs shows continental characteristics here depicted; a paleogeographical scheme is also submitted. This latter implies moving the suggested coast line westward for the first cycle. Three local sedimentary cycles are here proposed and correlated with those from well known areas

A scale to measure educators’ musical skills in early childhood education

Evaluating skills of students training to become teachers in early childhood education (ECE) is a key measure to improve their training and, subsequently, to bring about improvements in the way they train their pupils. No research literature specifically describing a scale designed to measure educators’ musical skills at the ECE level has been previously published. In view of this lack, we carried out the customary procedures for designing and validating a psychological measurement scale: on the basis of a sample of university students (n = 209), we created a valid, reliable tool that allows researchers to evaluate and quantify how teacher trainees perceive their own musical skills. By applying EFA, Parallel Analysis, and CFA, we observed the emergence of four differentiated categories distributed along 25 items in the questionnaire''s final version. To improve and refine this tool, further research and study replication in a series of different educational contexts would be required. © 2021 The Author(s

Magnetic Field Effects on the Transport Properties of One-sided Rough Wires

We present a detailed numerical analysis of the effect of a magnetic field on the transport properties of a `small-$N$' one-sided surface disordered wire. When time reversal symmetry is broken due to a magnetic field $B$, we find a strong increase with $B$ not only of the localization length $\xi$ but also of the mean free path $\ell$ caused by boundary states. Despite this, the universal relationship between $\ell$ and $\xi$ does hold. We also analyze the conductance distribution at the metal-insulator crossover, finding a very good agreement with Random Matrix Theory with two fluctuating channels within the Circular Orthogonal(Unitary) Ensemble in absence(presence) of $B$Comment: 5 pages, 4 figures, to appear in Phys. Rev.