Las colecciones de anortositas canadienses del Museu de Geologia de Barcelona y de la Facultat de Geologia de la Universitat de Barcelona

Este trabajo aporta algunas precisiones sobre el origen y características petrográficas de las colecciones gemelas de rocas anortosíticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, así como sobre su idoneidad a efectos museísticos y didácticos. Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona.This work provides new insights on the origin and petrographic features of the twin collections of canadian anorthositic rocks from Museu de Geologia of Barcelona and Faculty of Geology of University of Barcelona, as well as some considerations on its interest as exhibition and didactic samples. Key words: Canada, Québec, Langelier anorthosite, Lac de Saint-Jean anorthosite, Alma quarry petrography, meta-anorthosite, didactics, anorthosite collections, Museu de Geologia, Universitat, Barcelona.Este trabajo aporta algunas precisiones sobre el origen y características petrográficas de las colecciones gemelas de rocas anortosíticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, así como sobre su idoneidad a efectos museísticos y didácticos. Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona

Impacto ambiental de la interacción agua-ceniza en la erupción del 2011 del volcán Grimsvötn (Islandia)

The Grímsvötn volcanic eruption, from 21 to 28 May, 2011, was the largest eruption of the Grímsvötn Volcanic System since 1873. The main geochemical features of the potential environmental impact of the volcanic ash-water interaction were determined using two different leaching methods as proxies (batch and vertical flow through column experiments). The main findings reveal that Na, K, Ca, Mg, Si, Cl, S and F show the largest geochemical fluxes caused by the interaction of water and ash. Additionally, the significant amounts of some of these elements (Ca, S and Mg) together with P, Cl, Fe, which are usually considered as macro/micronutrients, demonstrates the fertilising potential of the May 2011 emitted ash. On the other hand, release of F highlights the possible environmental problems arising from ash fallout on land or into fresh water syste ms. It is noteworthy that the chemical release is maximal during the first few hours of contact between tephra and water due to the dissolution of soluble salts from the ash surface. As time progresses, these constituents are exhausted, the release drops considerably and elements are freed instead by the incongruent dissolution of the volcanic glass.Este trabajo ha sido financiado por el proyecto QUECA (MINECO, CGL2011-23307).Peer Reviewe

Volcanic ash leaching as a means of tracing the environmental impact of the 2011 Grímsvötn eruption, Iceland

The Grímsvötn volcanic eruption, from 21 to 28 May, 2011, was the largest eruption of the Grímsvötn Volcanic System since 1873, with a Volcanic Explosivity Index (VEI) of magnitude 4. The main geochemical features of the potential environmental impact of the volcanic ash-water interaction were determined using two different leaching methods as proxies (batch and vertical flow-through column experiments). Ash consists of glass with minor amounts of plagioclase, clinopyroxene, diopside, olivine and iron sulphide; this latter mineral phase is very rare in juvenile ash. Ash grain morphology and size reflect the intense interaction of magma and water during eruption. Batch and column leaching tests in deionised water indicate that Na, K, Ca, Mg, Si, Cl, S and F had the highest potential geochemical fluxes to the environment. Release of various elements from volcanic ash took place immediately through dissolution of soluble salts from the ash surface. Element solubilities of Grímsvötn ash regarding bulk ash composition were <1 %. Combining the element solubilities and the total estimated mass of tephra (7.29 × 1014 g), the total inputs of environmentally important elements were estimated to be 8.91 × 109 g Ca, 7.02 × 109 g S, 1.10 × 109 g Cl, 9.91 × 108 g Mg, 9.91 × 108 g Fe and 1.45 × 108 g P The potential environmental problems were mainly associated with the release of F (5.19 × 109 g)We gratefully acknowledge the assistance of ICTJA-CSIC labGEOTOP (infrastructure co-funded by ERDF-EU Ref. CSIC08-4E-001) and DRX (infrastructure co-funded by ERDF-EU Ref. CSIC10-4E-141) Surveys (J. Ibañez, J. Elvira and S. Alvarez) and the CCiTUB (SEM Unit) in the analytical work. Financial support was provided by the QUECA Project (MINECO, CGL2011-23307). We appreciate the invaluable comments of Dr. N. Olgun on a previous version of the manuscript. This study was carried out in the framework of the Research Consolidated Groups GEOPAM (Generalitat de Catalunya, 2014 SGR 869) and GEOVOL and the Associated Unit CSIC-UB UAGEPE (UA 285P01)Peer reviewe

New constraints on the origin of the ophiolitic rocks within sinorogenic turbiditic sequences at Cilento region (southern Italy)

Mafic igneous rocks (pillow lavas and gabbros) embedded as olistoliths within Miocene turbiditic sequences crop out in the Cilento area at the Mount Centaurino (Campania region, Southern Italy). The concentration of major oxides, as well as trace element ratios (Nb/Yb, Nb/Ta, Th/Nb) and the chondrite-normalized Rare Earth Elements (REE) patterns suggest a tholeiitic character with Mid Oceanic Ridge Basalts (MORB) affinity. The chemical composition of pillow lavas is consistent with magmas generated by 10% degrees of non-modal fractional partial melting, of a spinel-bearing MORB-type asthenospheric mantle. Regarding gabbros, the calculated composition of parental melts in equilibrium with the clinopyroxenes show a wide compositional range, and there are very different from the pillow basalts of the Mount Centaurino, suggesting that the clinopyroxenes might have derived from more evolved melts compared to those that produced the basalts. The origin of these olistoliths is not yet understood. Here we suggest that these rocks represent fragment of a dismantled accretionary wedge embedded during the deposition of the Cilento group sedimentary successions in a thrust top basin

Green color chemical recipes in stained glass windows of NE Spain and N Italy (XIIIth to XVth centuries)

A great number of medieval religious buildings in Europe contain stained glass windows. A number of original glass fragments (i.e. with original medieval lead framework) coming from restoration projects (Girona, Tarragona, Pedralbes Monastery at Barcelona (Spain); the Siena Cathedral, the San Petronio Basilica and the San Giacomo Maggiore church in Bologna (Italy)) have been analyzed in term of major, minor and trace elements

La Història de les Mentalitats : una polèmica oberta

Com a presentació de la revista MANUSCRITS a la Universitat de Barcelona, s'organitzà el proppassat 5 de maig i a la Facultat de Geografia i Història, un debat-taula rodona sobre el tema "La història de les mentalitats: una polemica oberta". Hi varen participar : Josep Fontana, Ricardo Garcla Cárcel, Carlos Martínez Shaw, Josep Mª Salrach i Lluís Roura. La transcripció d'aquest debat és el que us oferim

Patient-centred outcomes with pituitary and parasellar disease

Over the last 2 decades advances in the diagnosis and management of pituitary diseases have made it possible to attain an endocrine 'cure' in a large proportion of patients. In other words, tumors can be excised or controlled with drugs, and mass effect of the lesion on surrounding structures be solved, and pituitary deficiencies can be substituted with all relevant hormones. While this is considered a satisfactory outcome for health care providers, patients often suffer from an aftermath of prior endocrine dysfunction exposure, with irreversible effects both physically and psychologically, which have a great impact on their everyday life. Diagnostic delay, often of several years, adds a negative impact on health perception. This affects their social, professional and family domains and determines their future life. Understanding that this may occur is important and health care providers should offer information to prepare the patient for this difficult journey, especially in the case of acromegaly, Cushing disease or hypopituitarism. In order to maintain in the long-term a good quality of life, patients need to adapt to this new situation, something that may be difficult, since they often cannot continue with all the activities and rhythm they used to do. Depression is often the consequence of maladaptation to the new situation, leading to impaired quality of life

The Holocene volcanism at El Hierro: insights from petrology and geochemistry

The Holocene volcanism at El Hierro consists of basaltic monogenetic volcanic fields associated with o the three rift systems present in this island. In this work we report preliminary petrological and geochemical data of Holocene lava flows belonging to the WNW-striking rift. Sampling was focused in three zones: Orchilla, Verodal-Sabinosa, and Tanganasoga. Petrography of the studied lavas shows that they are homogeneous. All samples are porphyritic with macrocrysts of clinopyroxene and olivine immersed in a groundmass formed by microcrysts of plagioclase, Fe-Ti oxides and clinopyroxene. Clinopyroxenes are diopsides, olivines have forsterite contents ranging from 74 to 84 % and anorthite in plagioclase varies from 66 to 76% (labradorite). Whole-rock geochemical results evidence that all magmas are basic in composition, ranging from picrobasalts to phonotephrites. Major, trace elements and isotope suppor fractional crystallization as the main process of magma evolution. However, petrography and chemistry of clinopyroxene cores agree with a xenocrystic nature of some of them. We suggest that these clinopyroxene cores crystallized from a genetically related magma and subsequently were entrapped o cannibalized by the basic rising magmas

Characterization of the Outer Coast Tuff Formation - A way to unravelling the magmatic processes preceding and triggering Deception Island's caldera-forming eruption (Antarctica)

Deception Island (South Shetland Islands), discovered in 1820, is one of the most active volcanoes in Antarctica with more than 20 eruptions (including the historic eruptions of 1967, 1969 and 1970) and three documented volcanic unrest events (1992, 1999 and 2014-15) over the past two centuries. Deception Island currently hosts two scientific bases, which operate every year during the Austral summer, and is also one of the most popular tourist destinations in Antarctica. The island is a composite volcano with a centrally located caldera of 8.5 x 10 km dated at 3,980 ± 125 yr. BP. During the caldera-forming event, between 30 and 60 km3 (Dense Rock Equivalent-DRE) of magma, erupted in the form of dense basaltic-andesitic pyroclastic density current deposits. During the last decades, Deception Island has been intensively investigated but some aspects regarding the magmatic processes associated with the formation of its caldera collapse are still under research and debate. For instance, characterizing the magmatic conditions and processes that triggered the huge explosive event is crucial to understand the past (and in turn the future) magmatic and volcanic evolution of the island

BCN Rocks: aprendiendo geología urbana a través de una aplicación App interactiva

BCN Rocks is an application (App) for personal mobile devices (Android and iOS versions) suitable for secondary and high school students as well as people without background in Earth Sciences. The main objective of this App is to learn geology using the city facades and pavements of two emblematic spaces of the city of Barcelona, the Passeig de Gràcia and the Barri Gòtic. The application has three main sections (ELEMENTS, EXPLORE, and LABORATORY) that are intended to satisfy the different needs of users. In the first section, Elements, the user will find all the information about rocks forming the selected buildings as well as a brief explanation about the history and architecture of each edifice. The second section, Explore, aims to arise the curiosity of users. In this sense, several routes are proposed according to different criteria including geographic position and age of the edifices. Finally, the third section, Laboratory, allows all users to investigate several geological aspects by means of interactive experiments.Este trabajo se enmarca en un proyecto financiado por la Fundación Española para la Ciencia y la Tecnología, FECYT (ref. 8524) en el que ha participado la Universitat de Barcelona, el Instituto de Ciencias de la Tierra Jaume Almera del Consejo Superior de Investigaciones Científicas (ICTJA-CSIC) y la empresa FUSTA. AG agradece su contrato Ramón y Cajal (RYC-2012-11024).Peer Reviewe