Geoenvironmental Characterization of Sulfide Mine Tailings

Spain has a long mining tradition dating from pre-historic times up to the present day. The cessation of mining activity has generated a large amount of mine wastes, most of which represent geochemical hazards. Mine tailings are watery sludge composed of medium-to-fine-grained material, resulting from grinding and mineral processing (e.g., galena, pyrite, sphalerite, and arsenopyrite). They entail both an accumulation and a potential subsequent emission source of trace elements (i.e. As, Cu, Fe, Pb, and Zn) with formation of acid mine drainage (AMD). Mineralogical and geochemical techniques (in combination with geophysical surveys and aerial photographs studies) have been jointly applied to selected mine areas. Seven mine deposits from the most important mine districts in Spain have been selected: Iberian Pyrite Belt, Cartagena-La Unión, Alcudia Valley, and Mazarrón. The main goal is focused on getting a geoenvironmental characterization as complete as possible by determining the geometry, evolution in time and composition of mine ponds, and the possible occurrence of AMD, for identifying related environmental hazards

Filones de cuarzo del Sistema Central: Distribución y caracterización de los fluidos asociados.

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

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)

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

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

This work presents the results of a geochemical and geophysical characterization of the Monte Romero and La Naya mine ponds, belonging to the Cueva de la Mora and Riotinto mine districts, respectively, based on mineralogical, geochemical and geophysical techniques. In order to obtain a representative environmental characterization, two deposits showing different mineralogies, physico-chemical parameters, chemical compositions of tailings and pond conditions were selected. Monte Romero mine tailings showed an upper level mainly composed of silicates and a deeper level mainly composed of sulfides and barite. The toxic metal content was different in both levels but high enough to exceed the regional legal concentration limits for agricultural soils. An electrical resistivity tomography survey revealed a homogeneous upper unit (3 m thickness), which displayed low resistivity values, corresponding to water-saturated silt and clay materials with an abundance of sulfides which was interpreted as the pond infilling. The La Naya mine pond presented a homogeneous mineralogical composition made up of quartz as the main mineral and chlorite-smectite and jarosite as accessory phases. The absence of sulfide phases and the low contents of metal elements are directly related to the reworking processes of the sludge dumped in this pond. The geophysical survey revealed that the pond infilling did not have a constant thickness, but ranged between 15 and 20 m. An inner groundwater flow in the infilling was recognized. The low resistivity values allowed the presence of acid waters and related subsurface flows to be identified in both mine ponds, but no acid water drainage occurred across their vessels. When compared to the Aznalcóllar tailings spill, the La Naya pond is large enough to release a similar amount of sludge, but of a very low metal content. The Monte Romero sludge displays a similar, potentially toxic metal content to the Aznalcóllar sludge, but its size is significantly smaller

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

(The original publication is available at www.springerlink.com)This work presents the results of a geochemical and geophysical characterization of the Monte Romero and La Naya mine ponds, belonging to the Cueva de la Mora and Riotinto mine districts, respectively, based on mineralogical, geochemical and geophysical techniques. In order to obtain a representative environmental characterization, two deposits showing different mineralogies, physico-chemical parameters, chemical compositions of tailings and pond conditions were selected. Monte Romero mine tailings showed an upper level mainly composed of silicates and a deeper level mainly composed of sulfides and barite. The toxic metal content was different in both levels but high enough to exceed the regional legal concentration limits for agricultural soils. An electrical resistivity tomography survey revealed a homogeneous upper unit (3 m thickness), which displayed low resistivity values, corresponding to water-saturated silt and clay materials with an abundance of sulfides which was interpreted as the pond infilling. The La Naya mine pond presented a homogeneous mineralogical composition made up of quartz as the main mineral and chlorite-smectite and jarosite as accessory phases. The absence of sulfide phases and the low contents of metal elements are directly related to the reworking processes of the sludge dumped in this pond. The geophysical survey revealed that the pond infilling did not have a constant thickness, but ranged between 15 and 20 m. An inner groundwater flow in the infilling was recognized. The low resistivity values allowed the presence of acid waters and related subsurface flows to be identified in both mine ponds, but no acid water drainage occurred across their vessels. When compared to the Aznalcóllar tailings spill, the La Naya pond is large enough to release a similar amount of sludge, but of a very low metal content. The Monte Romero sludge displays a similar, potentially toxic metal content to the Aznalcóllar sludge, but its size is significantly smaller.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Fluid history through fractures in the upper part of the Armàncies Formation (Eocene, Pyrenean Basin)

The presence of oil shows associated with fractures provides a significant opportunity to unravel the type, origin and evolution of fluids involved in fractures cementation and their relationship to oil migration. Two stages of calcite cement were distinguished in the fractures of the Eocene Armàncies platform carbonates: i) C1 calcite cement is characterised by fence-like crystals with abundant twin planes and inclusions, dull red luminescence, relative high Fe and Mg content and d18O values ranging from -6.2‰ to -4.8‰ VPDB. C1 precipitated from meteoric fluids during burial in reducing conditions. ii) C2 calcite cement is characterised by blocky clean crystals showing dark brown to red luminescence alternating with bright yellow bands, relatively low Fe and Mg content, and d18O values from -9.6‰ to -8.9‰ VPDB. C2 contains aqueous and hydrocarbon fluid inclusions with mode homogenisation temperatures of 120ºC. This cement precipitated from a fluid at higher temperature and relatively less reducing conditions than C1. Porosity associated with C2 is filled with liquid oil that reached 115ºC. Therefore, free oil and fluid inclusions oil come from the same migration pulse. Oil migration timing was synchronous with C2 and continued when calcite cementation complete

Characterization of volcanic materials using shallow geophysical techniques: 1. Electrical resistivity imaging

Volcanic deposits and structures are characterized by a high variability in both geometry and physical properties. These changes are common not only in a vertical direction but in the horizontal one too. As a result, the geophysical study of this kind of materials has to be performed using a technique that combines a good horizontal and vertical resolution. Electrical resistivity imaging has been applied to the study of three profiles in different places of Tenerife island. The examples shown in this work are the location of lava tubes, the determination of the depth to the boundary of different lava flows, and the geometry at depth of a basaltic dyke intruding in pyroclastic deposits. In all the cases, the technique has revealed as a useful tool to determine the geometry and depth of different volcanic materials and therefore, the geophysical characterization of volcanic area

The Peña do Seo W-Sn deposit, NW Iberia: Petrology, fluid inclusions and O-H-S isotopes

The Peña do Seo W-Sn ore deposit in NW Iberia consists mainly of quartz veins hosted in schists. Vein mineralogy comprises wolframite, cassiterite and minor molybdenite. Peraluminous S-type granites and minor metaluminous granitoid breccias crop out in the same location. Whole rock geochemistry, mineral characterization, fluid inclusions and stable isotope geochemistry have been combined to infer hydrothermal mineralization conditions. A pre-ore stage (0) involving the alteration of host rocks, three stages of mineralization (I, II and III), and a supergene stage (IV) have been identified. Stage I (oxide-halide-sulfide stage) consisted of a cassiterite-pyrite-fluorite mineralization in granitoid breccias. Stage II (main oxide stage) involved wolframite-rich selvages and wolframite-cassiterite-(molybdenite) quartz veins. Stage III (main sulfide stage) consisted of a sulfide mineralization in quartz veins comprising pyrite and minor arsenopyrite and chalcopyrite. Three types of fluid inclusions were found in vein quartz: (1) aqueous two-phase inclusions, with homogenization temperatures (Th) between 445 °C and 280 °C and moderate salinities (9–14 wt% NaCl eq.), (2) aqueous-carbonic three-phase fluid inclusions, with Th from 340 °C to 260 °C and low salinities (2–7 wt% NaCl eq.), and (3) aqueous two-phase fluid inclusions, with Th from 270 °C to 155 °C and low salinities (0–6 wt% NaCl eq.). δ18O values in quartz from mineralized veins range from +11.2‰ to +13.4‰, and between +15.0‰ and +15.4% in quartz from mineralized granitoid breccias. δ34S values in sulfides (pyrite, arsenopyrite and chalcopyrite) range between +13.0 ‰ and +37.1 ‰, thus suggesting a marine source of sulfate and possible equilibration with host-rock sulfides. δD values in muscovite and chlorite from quartz veins range between −105.7 ‰ and −71.5 ‰ and between −69.4 ‰ and −67.1 ‰, respectively, indicating a transition from magmatic to magmatic-metamorphic conditions. An aqueous (H2O–NaCl) magmatic-hydrothermal fluid led to the W-Sn mineralization, as deduced from the studied fluid inclusions and isotopic signatures. High W and Sn contents in the peraluminous granites indicate that the W-Sn mineralization in Peña do Seo could partially be related to the granites and granitoid breccias. Whereas the Sn (±W) likely derived from hydrothermal fluids exsolving from the crystallizing magmas, host quartz schists would have supplied other elements required for wolframite deposition such as Fe and Mn. Sulfide mineralization in stage III was probably driven by fluid dilution.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEINTERREG V-A Spain-Portugal Cooperation Programme, 2014-20Junta de Castilla y Leónpu

Propuesta de la Sociedad Española de Farmacia Comunitaria sobre prácticas tuteladas

La asignatura Prácticas Tuteladas (PT) es obligatoria en el grado de Farmacia, siendo la de mayor carga lectiva, entre 24 y 30 ECTS. Su objetivo es completar la formación del alumno e iniciarlo en las actividades asistenciales desarrolladas en la farmacia comunitaria (FC) y/o en la farmacia de hospital. Una gran mayoría de estudiantes las realizan en la FC donde, por primera vez, entran en contacto real con la profesión. Sin embargo cada universidad establece de manera autónoma la forma en que se imparten la asignatura, existiendo una gran diversidad en el desarrollo de las PT entre las distintas facultades de Farmacia.La Sociedad Española de Farmacia Comunitaria (SEFAC) elabora este documento para contribuir a homogeneizar la docencia de esta asignatura y unificar criterios entre todas las partes implicadas: responsables académicos, profesores asociados y farmacéuticos tutores encargados de la formación de los estudiantes. En definitiva, para contribuir a mejorar su calidad docente.Se propone la creación de un Departamento específico de PT, actualmente inexistente, se abordan los criterios para acreditar farmacias y farmacéuticos tutores (FT), se revisan las funciones del profesor asociado (PA) y de los coordinadores académicos, los requisitos que deben cumplir los alumnos para cursar esta asignatura, las competencias y habilidades mínimas que necesitan adquirir y los contenidos del programa docente. También se abordan la evaluación del alumno por el FT así como la evaluación de los profesores, de la metodología docente y de las FC donde se realizan las estancias por los estudiantes

Geomorphological Mapping and Erosion of Abandoned Tailings in the Hiendelaencina Mining District (Spain) from Aerial Imagery and LiDAR Data

The Hiendelaencina district in Spain was the most important silver producer in Europe during 1844–1925. At the end of the 20th century, with mines having closed, some waste rock dumps were reprocessed, and the sludge from the flotation process was stored in two tailings ponds. When this activity ceased, the residues began to be eroded and disperse. In this study, the state of degradation of both deposits was evaluated using historical mapping and light detection and ranging (LiDAR) data, incorporated into a Geographic Information System. In the aerial images (1946–2018), mine tailings and their main erosive and sedimentary forms were mapped. Geoforms linked to hydrological (channels, gullies, alluvial cones), wind (eolian mantles), hydric–gravitational (colluvium) and anthropic (motorbike tracks) processes which move sludge into the surrounding areas were identified. A net loss of 8849 m3 of sludge, a release of 10.3 t of potentially polluting substances and a high erosion rate of 346 t/ha*year were calculated based on LiDAR data from 2009 and 2014. The ponds show a current high degree of erosion that could increase due to both human activity and the growing frequency of drought and torrential rain periods if stabilization measures are not undertaken