Caracterización petrológico-metalogénica de un granito especializado : el stock de Logrosán (Cáceres)

Tesis inédita presentada en la Universidad Complutense de Madrid, Facultad de Ciencias Geológicas, Departamento de Cristalografía y Mineralogía, leída el 04-12-2015Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEunpu

Origin, ore forming fluid evolution and timing of the Logrosán Sn-(W) ore deposits (Central Iberian Zone, Spain)

The Logrosán Sn–(W) ore deposits in the metallogenic Sn–W province of the European Variscan Belt consist of endo- and exogranitic greisen-type and quartz–cassiterite veins associated with a S-type granite. Mineral characterization, fluid inclusion study, isotope geochemistry and Ar–Ar geochronology have been combined in order to reconstruct the conditions for Sn–(W) mineralization. The endo- and exogranitic mineralization must have been developed in a relatively long-lived system (~ 308–303 Ma), during or soon after the emplacement of the Logrosán related-granite (at ca. 308 Ma). The mineralizing fluids are characterized by complex aqueous and volatile (H2O–N2–CO2–CH4–NaCl) fluid inclusions. Microthermometry and Raman analyses indicate that fluid composition evolved from N2–CH4 to N2-rich, followed by CO2-rich fluids, with varying amounts of H2O. The presence of N2 and CH4 suggests the interaction with fluids derived from the nearby metasedimentary host rocks. A model of host-rock interaction, assimilation, and mixing of metamorphic and magmatic fluids, resulting in change of the redox conditions, is proposed for tin deposition. Later sulfide minerals were precipitated as a result of pressure and temperature release

Zircon U-Pb and Hf isotopic constraints on the genesis of a post-kinematic S-type Variscan tin granite: the Logrosán cupola (Central Iberian Zone)

The Variscan orogeny produced widespread granites along the European Variscan belt. In relation to crustal thickening, post-collisional multiple tin-bearing highly fractionated S-type leucogranites were emplaced. The Logrosán granite represents one of those granitic bodies and is a focus of this study. The Logrosán granite is located in the Central Extremadura Batholith (CEB), within the Central Iberian Zone (CIZ) and was emplaced during post kinematic stages of the Variscan orogeny at ca. 308 Ma, as determined by combined ID-TIMS U–Pb and LA-ICPMS geochronology. The granitic body intruded the metasedimentary Schist Greywacke Complex (SGC) of Neoproterozoic age. A moderately evolved medium- to coarse-grained two mica leucogranite (Main unit) and some highly evolved aplitic or microporphyritic units (evolved units) are distinguishable on the basis of their petrography and whole rock geochemistry.  Initial 87Sr/86Sr ratios vary from 0.7134 to 0.7311, whereas initial εNd shows a restricted range from -4.3 to -4.0 and εHf(t) ranges from  +2.0 to -4.6 for Variscan-age zircons. Inherited zircons exhibit mostly Neoproterozoic ages and juvenile Hf-isotope composition (eHf up to +14.6), analogous to that of zircons from the SGC metasediments. The available geological, geochronological, geochemical and isotopic data allow to propose the partial melting of heterogeneous Neoproterozoic metasedimentary material, similar to the outcropping SGC, for the genesis of the Logrosán granite.La orogenia Varisca produjo una gran cantidad de granitos a lo largo del Cinturón Varisco Europeo. En relación con el engrosamiento cortical se emplazaron tardíamente granitos de tipo-S, muy fraccionados y ricos en Sn. El presente estudio se centra en uno de esos cuerpos graníticos, el granito de Logrosán. El plutón de Logrosán forma parte del Batolito de Extremadura Central (BEC), en la Zona Centroibérica (ZCI), y se emplazó durante las etapas tardías de la orogenia Varisca, a los ca. 308 Ma, según los datos combinados de geocronología de U-Pb por ID-TIMS y por LA-ICPMS. El cuerpo granítico intruyó los metasedimentos del Complejo Esquisto Grauváquico (CEG) de edad fundamentalmente Neoproterozoica. En el plutón se distinguen, de acuerdo a la petrografía y a la geoquímica de roca total, un leucogranito de dos micas de tamaño de grano medio-grueso moderadamente evolucionado (Main Unit) y varias unidades aplíticas o microporfídicas altamente evolucionadas (Evolved Units). Las relaciones isotópicas iniciales de 87Sr/86Sr varían de 0.7125 a 0.7286, mientras que el εNd inicial muestra un rango restringido de -4.3 a -4.0 y el εHf(t) en circones variscos oscila de +5.7 a -10.5. Los circones heredados del granito de Logrosán muestran edades principalmente Neoproterozoicas y composiciones isotópicas de Hf juveniles (εHf > +14.7), análogas a las encontradas en los circones del CEG. Los datos geológicos, geoquímicos, geocronológicos e isotópicos de los que se dispone sugieren que el granito de Logrosán se originó por la fusión parcial de materiales metasedimentarios Neoproterozoicos similares a los del CEG

Na-Li-F-Metasomatism related to a highly fractionated peraluminous I-type granite (La Pedriza, Spain, Iberian Variscan Belt)

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEsubmitte

Analysis of the isometric activation of the gluteus medius and the intrinsic musculature of the sole in the prevention of injuries in elite basketball players: a pilot study

[Resumen] Introducción: El valgo dinámico de rodilla es uno de los principales factores de riesgo de lesión de deportes de impacto como el Baloncesto. Mejorar los sistemas de análisis de identificación de los factores de riesgo y los protocolos de prevención de lesiones se ha convertido en uno de los objetivos principales del fisioterapeuta deportivo, con el objetivo de disminuir el riesgo de lesión del deportista. Material y Métodos: Se analizó la distribución de las presiones plantares y los ángulos de alineación de los segmentos corporales en el plano frontal durante el Single-Leg-Squat Test en 10 sujetos deportistas de élite, con el objetivo de y observar la modificación a corto plazo asociada a la activación isométrica del glúteo medio y la musculatura intrínseca de la planta del pie. Resultados: Variaciones significativas en el aumento de la presión plantar del primer metatarsiano se registraron tras la activación del glúteo medio y de la musculatura intrínseca del pie. No se obtuvieron resultados significativos en la modificación de los ángulos de alineación en el plano frontal. Conclusiones: Un aumento de la presión plantar de la cabeza del primer metatarsiano puede relacionarse con una mayor estabilidad del miembro, mediante la activación del glúteo medio y de la musculatura intrínseca del pie. Son necesarios estudios con muestras más amplias que correlacionen los datos obtenidos en una muestra más homogénea.[Abstract] Introduction: Dynamic knee valgus is one of the main injury risk factors of impact sports such as basketball. Systems improvement for the analysis of identification of risk factors and injury prevention protocols has become one of the main objectives of the sports physiotherapist, with the aim of reducing the risk of athletes injury. Material and Methods: The distribution of plantar pressures and the angles of alignment of the body segments in the frontal plane during the Single-Leg-Squat Test in 10 elite athletes was analyzed, with the objective of observing the modification in short-term associated with the isometric activation of the gluteus medius and the intrinsic plantar musculature of the foot. Results: Significant variations in the increase of plantar pressure of the first metatarsal were recorded after activation of the gluteus medius and the intrinsic plantar muscles of the foot. No significant results were obtained in the modification of the alignment angle in the frontal plane. Conclusions: An increase in the plantar pressure of the head of the first metatarsal can be related to greater stability of the limb, through activation of the gluteus medius and the intrinsic plantar muscles of the foot. Studies with larger samples that correlate the data obtained in a more homogeneous sample are necessary

Hydrothermal phosphate vein-type ores from the southern Central Iberian Zone, Spain: Evidence for their relationship to granites and Neoproterozoic metasedimentary rocks.

Hydrothermal quartz–apatite veins, called “Iberian-type”, occur exclusively in the southern Central Iberian Zone. This study presents a multidisciplinary approach leading to the mineralogical, fluid inclusions, and geochemical characterization of these veins fromtwo representative areas, Logrosán and Belvís–Navalmoral, in order to establish their relationshipwith nearby phosphorous-rich granites and apatite in Neoproterozoicmetasediments. The mineral assemblage of these veins comprises quartz, apatite, minor sulfides, dolomite, Fe–Mg-carbonates and Fe–Mn-oxides. Three texturally different types of apatite have been recognized in the veins: apatite I showing prismatic habit associated withminor sulfides, apatite II occurring as white fibrous radial crystal aggregates called “dahllite”, and apatite III as grayish to greenish hexagonal crystals. Hydrothermal apatite from veins (H-apatite) is enriched in Sr and depleted in Mn–Y–REE–Th–U–Pb compared to magmatic apatite (M-apatite) from the granitic plutons. However, trace element compositions of apatite from metasedimentary phosphorousrich levels or nodules (S-apatite) of the Schist–Greywacke Complex show similar characteristics to the H-apatite, although the H-apatite stands out for its relatively high Sr-contents. This relative Sr enrichment in H-apatite is interpreted as inherited from both phosphate in Neoproterozoic metasediments (S-apatite) and carbonate levels. REE, fluid inclusion and stable isotope data are consistent with a long episode of hydrothermal activity implying cooling and dilution processes while interacting with phosphate-rich shale and carbonate beds in the SGC. Fluid inclusion study undertaken on hydrothermal apatite and quartz reveals the presence of aqueous low salinity fluids (0.2–6.7 wt.% NaCl equiv.) at moderate to low Th (125–350 °C). All available data point at a recycling event of the southern CIZmetasediments (the SGC) during post-Variscan hydrothermal fluid circulation as the more plausible origin of the phosphate vein-type mineralizations

Implementación de la metodología flipped classroom en los laboratorios de Química Analítica

Adaptar el sistema tradicional de aprendizaje a las necesidades actuales del alumnado empleando la metodología flipped classroom en el laboratorio de Química Analítica I, con el objetivo de fomentar el aprendizaje utilizando herramientas digitales.Depto. de Química AnalíticaFac. de Ciencias QuímicasFALSEsubmitte

Contribución a la puesta en valor del patrimonio geológico y minero del geoparque de las Villuercas: el cerro de San Cristóbal (Logrosán, Cáceres)

El Cerro de San Cristóbal (Logrosán, Cáceres) es una cúpula granítica cuyo relieve destaca con respecto a las rocas encajantes de la Unidad Inferior del Complejo Esquisto Grauváquico. En el Cerro de San Cristóbal habitaron civilizaciones de la Edad del Bronce que dejaron herramientas arqueológicas relacionadas con una posible actividad minera temprana. Localizado en un pueblo con una importante tradición minera del fosfato, este monte ha sido ignorado durante siglos. En 1949 se redescubrieron los depósitos de estaño y se iniciaron labores mineras, vigentes hasta 1962. Además del patrimonio minero e histórico, el Cerro de San Cristóbal posee un notable interés geológico, tanto geomorfológica como mineralógico.Peer reviewe