143 research outputs found

    Provenance and geochemistry of exotic clasts in conglomerates of the Oligocene Torehina Formation, Coromandel Peninsula, New Zealand

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    Non-marine pebble to cobble conglomerates of the lower Torehina Formation (Oligocene) crop out along western Coromandel Peninsula and overlie, with strong angular discordance, continental-margin metasedimentary rocks (Manaia Hill Group) of Mesozoic (Late Jurassic to ?Early Cretaceous) age. The conglomerates contain provenance information that identifies a pre-Oligocene depositional history obscured by the unconformable juxtaposition of these Tertiary and Mesozoic strata. Most clasts in the lower Torehina Formation are visually similar to local bedrock lithologies, including metamorphosed sandstones and argillites, but are kaolinitic and contain more detrital and authigenic chert, quartz, and potash feldspar. Local derivation of these clasts seems unlikely. By comparing geochemical ratios with those defined for continental margin sandstones, and well characterised New Zealand tectonic terranes, we interpret the majority of clasts in the lower Torehina Formation to have been derived from a dissected orogen, with mixtures of felsic and volcanogenic-derived sediment. The most likely sources are the Waipapa and Torlesse Terranes. The remaining 20–30% of the clasts in the lower Torehina Formation were originally friable, are coarse grained, and appear to be lithologically exotic relative to known metamorphosed sandstones in basement terrane sources on North Island. Some clasts contain coal laminae and particles, and all contain detrital kaolinite as lithic fragments and matrix. Such characteristics imply a non-marine to marginal-marine source containing sediment derived from strongly weathered granite or granodiorite. Mechanical fragility implies a likely proximal, easily erodible source. We propose that this group of clasts was derived from an Upper Cretaceous sedimentary cover, either part of a locally developed basin fill or part of a once regionally extensive cover on North Island. Either case defines a more widely distributed Cretaceous source than found today

    Age of Ruth and Landis: The Economics of Baseball During the Roaring Twenties

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    As the 1919 World Series scandal simmered throughout the 1920 season, tight pennant races drove attendance to new peaks and presaged a decade of general prosperity for baseball. Babe Ruth shattered his own home-run record and, buoyed by a booming economy, professional sports enjoyed what sportswriters termed a “Golden Age of Sports.” -- Provided by publisherhttps://scholarworks.uni.edu/facbook/1455/thumbnail.jp

    Incompatible building materials within the stereotomic Avalos sculptures of the Valley of Fallen (Madrid, Spain)

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    El estudio de un boquete abierto recientemente en la cabeza de la escultura de la Piedad de Avalos confirma que está recubierta por placas caliza negra de Calatorao (CNC) de unos 20 cm de espesor sujetas con morteros de yeso sin áridos. El análisis de estas muestras de morteros mediante microscopía óptica (MO), difracción de rayos X (DRX) y Microscopía Electrónica de Barrido Ambiental con Espectroscopia de Dispersión de Energías dispersivas de rayos X (MEBA-EDS) muestra mezclas de portlandita, mirabilita, etringita, taumasita y yeso, es decir, fases hidratadas bien conocidas por ser peligrosas para una adecuada preservación del patrimonio arquitectónico. Las gigantescas estructuras estereotómicas de Avalos están abiertas a las aguas de lluvia llegando a alcanzar sus núcleos de hormigón, que tienen áridos de granitos con feldespatos alcalinos alterados que están aportando sodio al ambiente sulfatado formando nuevos sulfatos cálcicos y sódicos hidratados como etringita y mirabilita que limitan la cohesión de los granos entre sí.The examination of the recently open pit in top of head of the La Piety sculpture of Avalos confirms that the external outer of Black Limestone Calatorao (BLC) composite is made by slabs 20 cm thick joined with gypsum mortars without aggregates. The analyses of these mortars samples performed by optical microscopy (OM), X-ray diffraction (XRD) and Environmental Scanning Electron Microscopy with Energies Dispersive Spectrometry (ESEM EDS) techniques show hydrous admixtures composed by portlandite, mirabilite, ettringite, thaumasite and gypsum, all of them are well-know dangerous phases for a suitable preservation of the architectural heritage. The huge stereotomic structures have open access to the raining waters reaching the internal core of the sculptures made by concrete with weathered alkali-feldspar aggregates providing sodium to the surrounding sulfated environment facilitating the formation of hydrous calcium and sodium sulfates such as ettringite and mirabilite which reduces the inter-grains adherence.Apoyo financiero de los proyectos nacionales CGL2008-04296, CGL2010-17108 y CGL2009-09247 del Plan Español Nacional de I+D+i

    Understanding the coping strategies of international students: A qualitative approach

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    International students encounter a range of additional challenges as a part of their tertiary study experience. A qualitative approach was used to understand the challenges faced by international students, coping strategies that promoted their personal resilience and advice they have for future international students. Twenty-two international students from an Australian university participated in four focus groups. The challenges identified by students included adjustment, social isolation, English language skills, academic difficulties, unmet expectations, employment, culture shock and psychological distress. Participants shared their own personal experiences and strategies used by them to cope and identified strategies that future students could use prior to leaving their home country and whilst in Australia to improve their adjustment. Uses of international student stories in prevention interventions are discussed
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