73 research outputs found

    Contribución de los isótopos de He al origen de los fluidos hidrotermales: aplicación al estudio de las mineralizaciones de fluorita de Asturias (N de España)

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    En este trabajo se ha realizado un estudio de isótopos de He con objeto de determinar la influencia mantélica o cortical de los volátiles en los fluidos implicados en la formación de las mineralizaciones de F-Ba de Asturias (N de España). Estas mineralizaciones se presentan como capas, mantos y filones encajados en materiales Permotriásicos y Paleozoicos. La mineralogía está constituida por fluorita, barita, calcita, cuarzo y sulfuros y los yacimientos encuadran en la tipología Mississippi Valley (MVT) asociados con eventos hidrotermales de rifting en relación con la apertura del Océano Atlántico. Los valores de 3He/4He (≤ 0,1 Ra) obtenidos en los fluidos de Asturias indican un origen cortical y se excluye cualquier implicación mantélica. Estos resultados son consistentes con el modelo convencional de formación de yacimientos de fluorita tipo MVT a partir de la circulación de fluidos de cuenca altamente salinos, con la ausencia de actividad ígnea en la zona contemporánea con la mineralización, y con datos de isótopos de He en otros yacimientos similares en Europa. [ABSTRACT] Helium isotopes have been measured in fluorite and sulphides in order to obtain conclusive means of assessing the involvement of mantle and crustally derived volatiles in F-Ba deposits from Asturias (N of Spain). Fluorite mineralizations are hosted in Mesozoic (Permotriassic) and Paleozoic age rocks. Mineralization is composed of fluorite, barite, calcite, dolomite, quartz and sulphides, and shares the characteristics of most Mississippi Valley Type (MVT) deposits associated with rifting events related to the opening of the Atlantic Ocean. The 3He/4He values of the Asturias ore fluids (≤ 0,1 Ra) indicate a crustal fluid source and exclude the involvement of a mantle helium component. These values are consistent with the acceptance of the existing basinal model for MVT genesis and sedimentary brines migration, with the lack of igneous activity in the area contemporary with the mineralization, and also consistent with similar helium isotope data recorded in other fluorite deposits in Europe

    Origen de las dolomías en la zona de Riópar (SE España): implicaciones sobre la geología de la Zona Prebética

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    In the present study a petrographic description and C-O stable isotope data of dolostone occurrences at the Riópar area (Mesozoic Prebetic Zone) are presented. Results constrain the origin and dolomitization processes for each dolomitic unit providing new insights on the geology of the Prebetic. Dolostones are grouped in: i) large seismicscale stratabound dolostones hosted in limestones of Lower Jurassic, Middle Jurassic and Upper Cretaceous ages; and ii) stratabound and patchy dolostones hosted in a carbonatic sequence of Upper Jurassic to Lower Cretaceous age. Two dolomitizing origins have been distinguished: i) a low-temperature dolomitization originated from seawater (seismicscale stratabound dolomitized limestones); ii) a hydrothermal dolomitization originated by high temperature brines (stratabound and patchy dolomitized limestones). Results of this study can be used as a guide for other poorly known dolomitic areas in the Prebetic Zone.En este estudio se presenta la descripción petrográfica y los datos isotópicos de C y O de distintos cuerpos de dolomías en la zona de Riópar (Zona Mesozoica del Prebético). Los resultados obtenidos permiten acotar el origen de cada miembro dolomítico, aportando nuevos datos geológicos en el Prebético. Dichos cuerpos se agrupan en: i) dolomías estratiformes de gran extensión hospedadas en calizas del Jurásico Inferior y Medio, así como del Cretácico Superior; ii) dolomías de tipo estratiforme y en forma de parches hospedadas en una secuencia carbonatada del Jurásico Superior al Cretácico inferior. El origen de estas dolomitizaciones se atribuye a: i) interacción con agua marina presumiblemente a baja temperatura (dolomías estratiformes de gran extensión); ii) presencia de salmueras hidrotermales de alta temperatura (dolomías estratiformes y parcheadas). Estos resultados pueden servir de guía para otras áreas dolomitizadas poco estudiadas en la zona del Prebético.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)pu

    C and O isotopes of the Riópar Non-Sulfide Zn Ores (Albacete, SE Spain)

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    Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasFALSEEspaña. Ministerio de Economía y Competitividadpu

    Dolomitization Related to Zn-(Pb) Deposits in the Río Mundo Area (Riópar, Albacete)

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    España. Ministerio de Economía y CompetitividadDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

    Sulfur and lead isotope systematics: Implications for the genesis of the Riópar Zn-(Fe-Pb) carbonate-hosted deposit (Prebetic Zone, SE Spain)

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    The Zn-(Fe-Pb) deposits of the Riópar area (Prebetic Zone, SE Spain) are hosted by dolostones that replace Berriasian to Valanginian (Upper Jurassic-Lower Cretaceous) limestones. Mineralization consists of hypogene sphalerite, marcasite and galena, and supergene calamine zones. The hypogene ores are associated with a saddle dolomite gangue. The ore bodies occur as discordant and stratiform lenses, ore-cemented breccias, cm- to mm wideveins and veinlets, disseminations and stylolite porosity filling within the host dolomites. The main ore controls include stratigraphy and/or lithology, tectonics (faults, fractures and breccias) and availability of metals and sulfur. The morphologies and epigenetic character of the hypogene ore bodies are consistent with the classification of this mineralization as a Mississippi Valley-type (MVT) deposit. The Ga/Ge geothermometer in sphalerite yielded a temperature range of 194–252 °C, which represents the temperature of the source region of the ore solution. This value is comparable to the temperature obtained in the ore deposition site, 159 ± 15 °C from the Δ34S geothermometer in sphalerite galena pairs. This similitude points to a hydrothermal fluid that did not cool down significantly during flow from the fluid reservoir area to the precipitation site. δ34S values of basemetal sulfides (−7.5 to +3.5‰) are consistent with thermochemical reduction of Triassic sulfate (seawater and/or derived from dissolution of evaporites) by interaction with organic compounds (e.g., hydrocarbons, methane), which reduced sulfate to sulfide in the deposition site. The lead isotope ratios (206Pb/204Pb=18.736–18.762; 207Pb/204Pb=15.629–15.660; 208Pb/204Pb=38.496–38.595) of galena suggest that Pb, and probably other metals as Zn, is derived from continental crustal rocks. On the other hand, these relations points to a unique metal source probably derived from the Paleozoic basement rocks. The relationship between bedding-parallel stylolites, dolomitization, sulfide precipitation and Alpine tectonic affecting the MVT ore, suggests a relative timing range for the mineralization in the Riópar area of 95–20 Ma (Upper Cretaceous-Tertiary). The sulfide mineralization and the associated dolomitization are thus explained by the contribution of two fluids that mixed in different proportions during dolomitization and mineralization: i) a fluid probably derived from Cretaceous seawater saturating Mesozoic sediments (Fluid A), characterized by being dilute and initially low temperature, which should have contained organic rich compounds in the ore deposition site (e.g., hydrocarbons and CH4 dissolved gas); and ii) a high salinity hydrothermal brine (Fluid B) rich in both metals and sulfate, circulated through the Paleozoic basement. During the pre-ore dolomitizing stage the fluid phase was dominated by the diluted fluid (Fluid A > Fluid B), whereas in a later fluid pulse, the proportion of the high salinity fluid increased (Fluid A < Fluid B) which allowed sulfide precipitation. MVT exploration in the Prebetic Zone should focus towards the SW of the Riópar mines, in the vicinity of the Alto Guadalquivir-San Jorge fault

    Improved ozone monitoring by ground-based FTIR spectrometry

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    Accurate observations of atmospheric ozone (O3) are essential to monitor in detail its key role in atmospheric chemistry. The present paper examines the performance of different O3 retrieval strategies from FTIR (Fourier transform infrared) spectrometry by using the 20-year time series of the high-resolution solar spectra acquired from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain) within NDACC (Network for the Detection of Atmospheric Composition Change). In particular, the effects of two of the most influential factors have been investigated: the inclusion of a simultaneous atmospheric temperature profile fit and the spectral O3 absorption lines used for the retrievals (the broad spectral region of 1000–1005 cm−1 and single microwindows between 991 and 1014 cm−1 ). Additionally, the water vapour (H2O) interference in O3 retrievals has been evaluated, with the aim of providing an improved O3 strategy that minimises its impact and, therefore, could be applied at any NDACC FTIR station under different humidity conditions. The theoretical and experimental quality assessments of the different FTIR O3 products (total column (TC) amounts and volume mixing ratio (VMR) profiles) provide consistent results.This research research has been supported by the European Research Council under FP7/(2007–2013)/ERC grant agreement no. 256961 (project MUSICA), by the Deutsche Forschungsgemeinschaft for the project MOTIV (Geschäftszeichen SCHN 1126/2-1), by the Ministerio de Economía y Competitividad of Spain through the projects CGL2012-37505 (project NOVIA) and CGL2016-80688- P (project INMENSE), and by EUMETSAT under its fellowship programme (project VALIASI)

    Impact of instrumental line shape characterization on ozone monitoring by FTIR spectrometry

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    Retrieving high-precision concentrations of atmospheric trace gases from FTIR (Fourier transform infrared) spectrometry requires a precise knowledge of the instrumental performance. In this context, this paper examines the impact on the ozone (O3) retrievals of several approaches used to characterize the instrumental line shape (ILS) function of ground-based FTIR spectrometers within NDACC (Network for the Detection of Atmospheric Composition Change). The analysis has been carried out at the subtropical Izaña Observatory (IZO, Spain) by using the 20-year time series of the high-resolution FTIR solar absorption spectra acquired between 1999 and 2018. The theoretical quality assessment and the comparison to independent O3 observations available at IZO (Brewer O3 total columns and electrochemical concentration cell, ECC, sondes) reveal consistent findings. The inclusion of a simultaneous retrieval of the ILS parameters in the O3 retrieval strategy allows, on the one hand, a rough instrumental characterization to be obtained and, on the other hand, the precision of the FTIR O3 products to be slightly improved.The Izaña FTIR station has been supported by the German Bundesministerium für Wirtschaft und Energie (BMWi) via the DLR under grant no. 50EE1711A and by the Helmholtz Association via the research programme ATMO. In addition, this research was funded by the European Research Council under FP7/(2007–2013)/ERC grant agreement no. 256961 (project MUSICA), by the Deutsche Forschungsgemeinschaft for the project MOTIV (Geschäftszeichen SCHN 1126/2-1), the Ministerio de Economía y Competitividad of Spain through the projects CGL2012-37505 (project NOVIA) and CGL2016-80688-P (project INMENSE), and EUMETSAT under its fellowship programme (project VALIASI)

    Presentation of an Observation and Classification Guide of Therapists’ Verbal Behavior

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    El artículo presenta una guía de observación y clasificación de la conducta verbal de los terapeutas, la Guía de Observación de Terapeutas Aiglé (GOTA-v). Se revisan los estudios sobre la variable del terapeuta, especialmente el Estilo Personal y sus procedimientos de evaluación. Este nuevo instrumento fue aplicado a la transcripción de 44 sesiones de 12 terapeutas de Argentina con diferente orientación teórico-técnica y distinto grado de experiencia (bajo, medio y alto). Se delimitaron los textos de las sesiones en unidades de análisis y se clasificaron esas unidades con categorías pertenecientes a tres clases de actos de habla: Preguntas, afirmaciones e indicaciones. Se calculó el índice de acuerdo inter jueces de Kappa para cada clase. Se discuten los alcances y limitaciones del instrumento y sus posibilidades para la investigación en psicoterapia.The article presents an observation and classification guide of therapists’ verbal behavior, the Aiglé Therapists Observation Guide (ATOG-v). Studies on the therapist variables together with the assessment procedures are revisited. This new instrument was applied to the transcription of 44 sessions of 12 therapists in Argentina with different theoretical-technical orientation and different levels of experience (low, moderate and high). The session texts were delimited into analysis units and these units were classified with categories pertaining three types of speech acts: questions, statements and indications. The Kappa inter-judges index was applied for each class. The scope and limitations of the instrument and its possibilities for psychotherapy research are presented.Fil: Fernandez Alvarez, Hector. Fundación Aiglé. Sede Central Buenos Aires; ArgentinaFil: Castañeiras, Claudia Elena. Fundación Aiglé. Sede Central Buenos Aires; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Curtarelli, Alejandro. Fundación Aiglé. Sede Central Buenos Aires; ArgentinaFil: Garcia, Fernando. Fundación Aiglé. Sede Central Buenos Aires; ArgentinaFil: Gómez, Beatriz Margarita María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Fundación Aiglé. Sede Central Buenos Aires; ArgentinaFil: Lichtenberger, Aldana. Universidad Nacional de Mar del Plata; Argentina. Fundación Aiglé. Sede Central Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Corbella Santoma, Sergi. Universitat Ramon Llull; Españ
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