9 research outputs found

    IBERLID: A lead isotope database and tool for metal provenance and ore deposits research

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    [EN] Although sometimes controversial, the use of Pb isotope data in geological research of ore deposits and metal provenance studies in archaeology has proved a useful tool for investigation of the relations between ore sources and raw materials used by humans. Users of this kind of information have often asked for complete datasets that would include not only numerical values of isotope ratios but also mineralogical and geological information about the samples analysed so as to allow for conscientious data comparison. The IBERLID database here presented has been designed to include available information for nearly 3000 samples from the Iberian Peninsula and Balearic Islands in a unique, complete to the extent possible, upgradable dataset using standardized variables. This allows to compare data and establish groups based upon isotopic ratios, mineralogy and other geological characteristics of the samples. The database is available through an online interactive public tool (www.ehu.eus/ibercron/iberlid) that provides for data search, comparison and graphics design, and may be furthermore exported for enhanced statistical treatment. By direct use of the proposed standardized variables, the compiled results allow to discern among 3 main mineralization events within the Iberian realm, while interpolation of Pb isotope data allow to draw the first maps of model age, mu and kappa parameters. The problem of radiogenic lead in some compiled data requires additional analyses of elemental concentrations, which so far has been generally neglected.Financial support was provided by the Spanish Ministry of Economy, Industry and Competitiveness, and the European Regional Development Fund (MINECO/ERDF CGL2015-63530-P) , and by the UPV/EHU (GIU15/05) . The authors are grateful to Sabine Klein and two anony-mous reviewers for constructive comments which improved this manuscript, and to Huayong Chen for suggestions and editorial handling

    Geochemical dataset of high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain)

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    This brief note presents geochemical data from rock samples from the Cabo Ortegal Complex (NW Spain). The samples belong to acid lithologies within the mainly basic to intermediate granulite unit that have been poorly investigated so far. For this communication, five samples of the migmatites and an amphibolitic enclave within them have been analysed. The whole-rock major and trace-element analyses were accomplished by means of Q-ICPMS. The dataset provides new and useful information relevant to the origin of the acid migmatites and can be used in addition to information from neighbouring lithologies to enhance understanding of the geological evolution of the Western Variscan Belt

    Calako skarn-a: ezaugarri geokimikoak eta U-Pb datazioak

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    Cala mine is located in the southwest of the Iberian Massif, in the Ossa-Morena Zone (OMZ). Due to the complexity of its mineralisation, there has been much debate in recent years but, according to recent studies, it is interpreted that part of the mineralisation is related to a calcic skarn that outcrops nearby. In this work, garnets from this skarn have been dated using the U-Pb geochronology by LA-ICP-MS, and the obtained age is 335 ± 1 Ma. Calcic garnets (Gros52-59Andr40-44) show homogeneous major elements distribution. A weak chemical zonation can be observed in trace elements and REE, more evident in trivalent elements. This chemical homogeneity has been related to a stable system, where P-T conditions have remained quite stable.; Cala meategia Ossa-Morena Zonaldean (OMZ) kokatzen da, Iberiar Mazizoaren hego-mendebaldean. Hango mineralizazioa nahiko konplexua denez, az- ken urteotan asko eztabaidatu da horren inguruan, baina berriki egin diren ikerketa- lanen arabera, mineralizazioaren zati bat bertan azaleratzen den skarn kaltziko bate- kin erlazionatuta dagoela interpretatu da. Lan honetan skarn-eko granateak datatu dira U-Pb sistema eta LA-ICP-MS metodoaren bidez. Mineral horiek primarioak direnez, metasomatismoa datatzea ere posible izan da skarna bera ere datatuz. Lortutako emai- tzen arabera skarna duela 335 ± 1 Ma sortu zela ondorioztatu da. Granate kaltzikoen (Gros52-59Andr40-44) konposizio kimikoa nahiko homogeneoa da, batez ere elementu nagusiak aztertzean, eta aztarna elementuen zein REE-en kontzentrazioak zonazio oso ahula erakusten dute, batik bat elementu tribalenteetan. Honenbestez, granate hauen so- rreran sistemako P-T baldintzak nahiko konstante mantendu zirela ondorioztatu da

    The late-Variscan peraluminous Valdepeñas pluton (southern Central Iberian Zone)

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    The Valdepeñas pluton is the easternmost outcrop of the Cáceres-Valdepeñas magmatic alignment (southern Central Iberian Zone). This massif is constituted by a cordierite-bearing porphyritic monzogranite and may be grouped within the so-called "Serie Mixta" granitoids. The Valdepeñas monzogranite is of magnesian [FeOt /(FeOt +MgO)~0.76], alkali-calcic [(Na2O+K2O)-CaO=7.8-8.5] and peraluminous (A/CNK=1.14-1.20) composition. Multielemental- and REE-normalized patterns are comparable to those of similar rocks in the NisaAlburquerque-Los Pedroches magmatic alignment, and slightly differ from those of the Montes de Toledo batholith, both in the southern Central Iberian Zone. The U-Pb zircon age of 303±3Ma is consistent with the late-orogenic character of the intrusion and is in accordance with most of the granitic peraluminous intrusions in the southern Central Iberian Zone. 86Sr/87Sr300Ma ratios (0.707424-0.711253), εNd300Ma values (-5.53 to -6.68) and whole-rock major and trace element compositions of the studied rocks, suggest that the parental magma of the Valdepeñas monzogranite could derive from a crustal metaigneous source. The U-Pb ages (552-650Ma) of inherited zircon cores found in Valdepeñas monzogranite samples match those often found in Lower Paleozoic metavolcanics and granitic orthogneisses of Central Iberia and, furthermore, point to Upper Neoproterozoic metaigneous basement rocks as possible protoliths at the magma source. Based on the solubility of monazite in peraluminous melts, the estimated emplacement temperature of the studied monzogranite is 742-762ºC. The results obtained in this work would contribute to a better understanding of the origin of the "Serie Mixta" granitoids

    An evaluation of Rb-Sr isotope dilution analyses with a 86Sr-enriched tracer and Multiple Collection-ICP-MS

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    International audienceA straightforward method is described allowing to determine on a routine basis Rb and Sr concentrationsand 87Rb/86Sr isotope by using the isotope dilution method with isotopic tracers enriched in 87Rb andin 86Sr, respectively, and MC-ICP-MS for mass spectrometric measurements. The 87Sr/86Sr isotope ratiosare measured separately on unspiked sample aliquots, thereby alleviating the need for correcting thecontribution that would arise in case of total spiking with an 84Sr enriched tracer. The sample preparationinvolves sample dissolution with hydrofluoric acid, and the separation of Rb and Sr from matrixelements and from each other by combining extraction chromatography and cation exchange in nitricacid medium. The concentration and 87Rb/86Sr data measured on replicate dissolutions of several internationalgeostandards display the very good reproducibility typical of the isotope dilution method, evenat low analyte concentration. The within-run precisions of 87Sr/86Sr isotope ratios (2 S.E. from 1 10−5 to3 10-5) are not as good as those typically achieved by TIMS, but the data show a good reproducibility(0.002% RSD) and are accurate, based on their fair agreement with recommended values. However, thesefigures are significantly worse at low Sr concentration, indicating that 87Sr/86Sr ratios should preferablybe measured by TIMS when Sr-poor samples are processed

    The late-Variscan peraluminous Valdepeñas pluton (southern Central Iberian Zone)

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    The Valdepeñas pluton is the easternmost outcrop of the Cáceres-Valdepeñas magmatic alignment (southern Central Iberian Zone). This massif is constituted by a cordierite-bearing porphyritic monzogranite and may be grouped within the so-called "Serie Mixta" granitoids. The Valdepeñas monzogranite is of magnesian [FeOt /(FeOt +MgO)~0.76], alkali-calcic [(Na2O+K2O)-CaO=7.8-8.5] and peraluminous (A/CNK=1.14-1.20) composition. Multielemental- and REE-normalized patterns are comparable to those of similar rocks in the NisaAlburquerque-Los Pedroches magmatic alignment, and slightly differ from those of the Montes de Toledo batholith, both in the southern Central Iberian Zone. The U-Pb zircon age of 303±3Ma is consistent with the late-orogenic character of the intrusion and is in accordance with most of the granitic peraluminous intrusions in the southern Central Iberian Zone. 86Sr/87Sr300Ma ratios (0.707424-0.711253), εNd300Ma values (-5.53 to -6.68) and whole-rock major and trace element compositions of the studied rocks, suggest that the parental magma of the Valdepeñas monzogranite could derive from a crustal metaigneous source. The U-Pb ages (552-650Ma) of inherited zircon cores found in Valdepeñas monzogranite samples match those often found in Lower Paleozoic metavolcanics and granitic orthogneisses of Central Iberia and, furthermore, point to Upper Neoproterozoic metaigneous basement rocks as possible protoliths at the magma source. Based on the solubility of monazite in peraluminous melts, the estimated emplacement temperature of the studied monzogranite is 742-762ºC. The results obtained in this work would contribute to a better understanding of the origin of the "Serie Mixta" granitoids

    Experiences with perinatal loss from the health professionals’ perspective

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    The purpose of this paper is to know the experience of health professionals in situations of perinatal death and grief and to describe their action strategies in the management of perinatal loss. A qualitative study with a phenomenological approach was carried out through interviews conducted with 19 professionals. Three thematic categories were identified: Healthcare practice, feelings aroused by perinatal loss and meaning and beliefs about perinatal loss and grief. The results revealed that the lack of knowledge and skills to deal with perinatal loss are identified as the main reason behind unsuitable attitudes that are usually adopted in these situations. This generates anxiety, helplessness and frustration that compromise professional competency. The conclusion reached is that the promotion of training programs to acquire knowledge, skills and abilities in management of perinatal bereavement and the development of a clinical practice guideline for perinatal loss are necessary.El objetivo de este artículo es conocer la experiencia vivida por los profesionales de la salud en situaciones de muerte y duelo perinatal y describir las estrategias de actuación ante la pérdida perinatal. Se trata de un estudio cualitativo con un enfoque fenomenológico realizado a 19 profesionales a través de entrevistas. Se identificaron 3 categorías temáticas: la práctica asistencial, los sentimientos que despierta la pérdida perinatal y significado y creencias sobre la pérdida y el duelo perinatal. Los resultados ponen de manifiesto que la falta de conocimientos y de recursos para enfrentar la pérdida perinatal hace que se adopten actitudes poco adecuadas en estas situaciones, generando una sensación de ansiedad, impotencia y frustración que compromete la competencia profesional. Se concluye que es fundamental promover programas de formación para adquirir conocimientos y destrezas sobre el duelo perinatal y elaborar una guía de práctica clínica para la atención a la pérdida perinatal.O objetivo deste artigo foi conhecer a experiência dos profissionais de saúde em casos de morte perinatal e o pesar decorrente e, ainda, descrever as estratégias de ação frente à perda perinatal. Trata-se de estudo qualitativo com abordagem fenomenológica, por meio de entrevista com 19 profissionais. Três categorias temáticas foram identificadas: a prática de cuidados de saúde, os sentimentos despertados pela perda perinatal e o significado e crenças sobre perda e pesar perinatal. Os resultados mostram que a falta de conhecimento e recursos para lidar com a perda perinatal torna inadequada as atitudes nessas situações, gerando sensação de desamparo, ansiedade e frustração que compromete a competência profissional. Conclui-se que é fundamental promover programas de treinamento para adquirir conhecimentos, aptidões e habilidades em pesar perinatal e desenvolver uma diretriz de prática clínica para o cuidado da perda perinatal
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