Triassic redbeds in the Malaguide Complex (Betic Cordillera — Spain): petrography, geochemistry and geodynamic implications

Sandstone petrography and mudstone mineralogy and geochemistry of Triassic mudstones and sandstones from continental redbeds of the Malaguide Complex (Betic Cordillera, southern Spain) provide useful information on provenance, palaeoclimate and geodynamics during the early stages of the Pangea break-up, and on their diagenetic evolution. The sandstones are quartzarenites to sub-litharenites, with minor lithic fragments and rare feldspars. The mudstone samples show a PAAS like elemental distribution. The samples likely record recycling processes from their metasedimentary basement rocks that significantly affected the weathering indices, and monitors cumulative effects, including a first cycle of weathering at the source rocks. Sandstone composition and chemical–mineralogical features of mudstones record a provenance derived from continental block and recycled orogen that were weathered under warm and episodically wet climate. Source areas were located towards the east of the present-day Malaguide outcrops, and were formed by fairly silicic rock types, made up mainly of Palaezoic metasedimentary rocks, similar to those of the Paleozoic underlying series, with subordinate contributions from magmatic–metamorphic sources, and a rare supply from mafic metavolcanic rocks. Clay-mineral distribution of mudstones is dominated by illite and illite/smectite mixed-layer that result from differences in provenance, weathering, and burial/temperature history. Illite crystallinity values, illitization of kaolinite, occurrence of typical authigenic minerals and apatite fission-track studies, coupled with a subsidence analysis of the whole Malaguide succession suggest burial depths of at least 4–6 km with temperatures of 140–160 °C, typical of the burial diagenetic stage, and confirm the Middle Miocene exhumation of the Betic Internal Domain tectonic stack topped by the Malaguide Complex.

Compositional and Geochemical Signatures for the Sedimentary Evolution of the Middle Triassic–Lower Jurassic Continental Redbeds from Western-Central Mediterranean Alpine Chains

Compositional and chemical analyses suggest that Middle Triassic–Lower Liassic continental redbeds (in the internal domains of the Betic, Maghrebian, and Apenninic chains) can be considered a regional lithosome marking the Triassic-Jurassic rift-valley stage of Tethyan rifting, which led to the Pangaea breakup and subsequent development of a mosaic of plates and microplates. Sandstones are quartzose to quartzolithic and represent a provenance of continental block and recycled orogen, made up mainly of Paleozoic metasedimentary rocks similar to those underlying the redbeds. Mudrocks display K enrichments; intense paleoweathering under a hot, episodically humid climate with a prolonged dry season; and sediment recycling. Redbeds experienced temperatures in the range of 100°–160°C and lithostatic/tectonic loading of more than 4 km. These redbeds represent an important stratigraphic signature to reconstruct a continental block (Mesomediterranean Microplate) that separated different realms of the western Tethys from Middle-Late Jurassic to Miocene, when it was completely involved in Alpine orogenesis.

Evaluación del contenido sobre educación alimentaria en páginas web de servicios de catering: estudio piloto en el ámbito escolar

Introducción: Analizar la calidad de las páginas web de los servicios de catering en el ámbito escolar y su contenido en educación alimentaria, y tener una primera experiencia con la herramienta de evaluación EDALCAT. Material y métodos: Estudio descriptivo transversal. La población de estudio son páginas web de empresas de catering encargadas de la gestión de los comedores escolares. La muestra se obtuvo utilizando el buscador Google y un Ranking de las principales empresas de catering por facturación, escogiendo aquellas que tenían página web. Para la prueba piloto se seleccionaron diez páginas web según proximidad geográfica a la ciudad de Alicante y nivel de facturación. Para la evaluación de los sitios web se diseñó un cuestionario (EDALCAT), compuesto de un primer bloque de predictores de calidad con 19 variables de fiabilidad, diseño y navegación; y de un segundo bloque de contenidos específicos de educación alimentaria con 19 variables de contenido y actividades educativas. Resultados: Se han obtenido resultados positivos en 31 de las 38 variables del cuestionario, excepto en los ítems: “Buscador”, “Idioma” (40%) y “Ayuda” (10%) del bloque predictores de calidad y en los ítems: “Talleres”, “Recetario”, “Web alimentación-nutrición” (40%) y “Ejemplos” (30%) del bloque de contenidos específicos de educación alimentaria. Todas las páginas web evaluadas superan valores del 50% de cumplimiento de criterios de calidad y de contenidos mínimos en educación alimentaria, y sólo una de ellas, incumple el nivel de actividad mínimo establecido. Conclusiones: Los predictores de calidad y los contenidos específicos en educación alimentaria dieron buenos resultados en todas las páginas web evaluadas. La mayoría de ellas obtuvieron una alta puntuación en su valoración, y en su análisis individual por bloques. Tras el estudio piloto el cuestionario se ha modificado y se obtiene el EDALCAT definitivo. En líneas generales EDALCAT parece ser adecuado para evaluar la calidad de las páginas web de servicios de catering y su contenido en educación alimentaria, sin embargo el presente estudio no puede considerarse como validación del mismo.

Comparison of Lattice-Fluid Binary Parameters For Mixtures and Block Copolymers

The aim of this report is to discuss the method of determination of lattice-fluid binary interaction parameters by comparing well characterized immiscible blends and block copolymers of poly(methyl methacrylate) (PMMA) and poly(ϵ−caprolactone) (PCL). Experimental pressure-volume-temperature (PVT) data in the liquid state were correlated with the Sanchez—Lacombe (SL) equation of state with the scaling parameters for mixtures and copolymers obtained through combination rules of the characteristic parameters for the pure homopolymers. The lattice-fluid binary parameters for energy and volume were higher than those of block copolymers implying that the copolymers were more compatible due to the chemical links between the blocks. Therefore, a common parameter cannot account for both homopolymer blend and block copolymer phase behaviors based on current theory. As we were able to adjust all data of the mixtures with a single set of lattice-binary parameters and all data of the block copolymers with another single set we can conclude that both parameters did not depend on the composition for this system. This characteristic, plus the fact that the additivity law of specific volumes can be suitably applied for this system, allowed us to model the behavior of the immiscible blend with the SL equation of state. In addition, a discussion on the relationship between lattice-fluid binary parameters and the Flory–Huggins interaction parameter obtained from Leibler's theory is presented.