Sobre el stock adamellítico de La Granja y el sector metamórfico encajante (Guadarrama Central)

[Resumen] El stock adamellítico de La Granja (Guadarrama Central) intruye en materiales metamórficos de alto grado (con cordierita-silnmanita-ortosa), provocando neoformación de andalucita. Se describen asímismo, algunas facies litológicas de «contacto» como son los gneises porfidoclásticos o los cinturones aplograníticos de borde del granitoide. Se describen los materiales metamórficos haciendo especial hincapié en los rasgos texturales de los mismos y en el fuerte control geoquímico que ejerce el medio petrológico a las diferentes blastesis minerales. El estudio geoquímico aunado al estructural nos define un carácter ortoderivado a las formaciones glandulares sálicas y leucogneísicas con las que forman Unidad. Además se apuntan pautas de variación geoquímica de los gneises porfidoclásticos de «contacto». El stock se define como adamellita de grano grueso porfídica de tendencias calco-alcalinas y como apéndice de los materiales de grano grueso leucocráticos de la vertiente meridional de la Sierra. Se describen las redes filonianas características del stock encontrando ciertas diferencias composicionales entre ambos materiales. Finalmente encontramos una variación geoquímica, clara en elementos menores, entre las facies de borde e interior del dique[Abstract] La Granja granitoid stock in Centrat Guadarrama (Spain) intrudes in high grade metamorphic rocks (cordierite-sillimanite-ortose) inducing neoformation of andalusite. There are lithological «contact» facies, such as porphyroclastic gneiss or aplogranitic belts of chilled margin.We describe here the metamorphic materials, in special the textural features and the geochemical control of mineral blastesis by the lithology. The geochemical and structural studies determine an orthogenesis for augen and leucocratic gneiss which belong to the same formation. We describe too, some geochemical features of the porphyroclastic gneiss. The porphyritic granitoid stock is adamellitic in composition (O-monzonite), coarse grained and has a calc-alcalic character. La Granja stock is the natural appendix of leucocratic coarse grained granites from the Sierra's southern side. In this paper we deal with the characteristic stock dike-swarm, finding compositional differences between both materials. Finally we find a clear geochemical variation, specially in minor elements, between margin and core in the dike

Igneous differentiation in porphyry dikes

[Resumen] Se aborda de manera teórica los principales procesos operativos de diferenciación ígnea en secciones transversales de los conductos filonianos, aplicándolo a los diques de pórfido granítico s. 1. del Sistema Central Español. Para estos magmas se deduce un régimen de flujo marcadamente laminar en el conducto (:~ 30 mts. potencia). Estos caracteres impiden tanto la efectividad de franccionamiento cristalino «in situ:\), como grados importantes de asimilación o contaminación en ruta hacia la superficie. Los diques simples, de flujos isoviscosos, van a diferenciarse por fenómenos, principalmente, de flujo ígneo, en ocasiones combinado con la presencia de varios magmas fluyendo a la vez en el mismo pulso (conductos gruesos o flujos veloces). Con estos mecanismos se tenderá a generar evoluciones del tipo félsico a máfico, de borde a centro del dique de pórfido. Los diques compuestos se formarán cuando los magmas son suficientemente contrastados en sus caracteres físicos (viscosidad, p. ej.) y químicos, o cuando son varíos pulsos magmáticos a través del mismo conducto. En estos casos podría haber fen6menos de mezcla magmática si la diferencia de viscosidad es alta y uno de esos magmas es poco viscoso (magmas básicos). En estos casos podrían generarse zonas básicas en el borde, o no, de los diques. de pórfido. En resumen la diferenciación de flujo, la mezcla magmática y la asociación de varios líquidos fluyendo en el mismo conducto (de manera simultánea o por pulsos magmáticos algo separados en el tiempo), parecen ser los mecanismos de diferenciación ígnea más efectivos de estos magmas graníticos que fluyen en angostos conductos filonianos[Abstract] We deal in theoretical way wíth the main differentiation proccesses taking place in dike conducts, applied to the porphyry dikes of the Spanish Central System. For these magmas we infer a strong laminar flow regime (~30 m dike witdh). This, prevent an efficient «in situ:\) cristal fractionation as well as large extent of assimilation-contamination processes during the ascent of the magmas «en route» to more surface levels. Simple dikes, with isoviscous flow, could differentiate mainley by igneous flow. Sometimes this mechanism is combinated with the possibility of severa! Magmas flowing togheter on the same pulse (thick dikes or fast flows). With these mechanisms felsic to mafic evolutions are favoured inward the porphyry dike. Composite dikes are formed when magmas are contrasted enough in their chemical or physical features (p. ej. viscosity), or when different magmatic pulses occur in the same channel. In these conditions commingling of magmas could exist if the viscosity ratio is high apd one of the magmas is very fluid (basic one). These processes could generate basic margins in the porphyry dikes. In short, flow differentiation, magmatic mixing and flowing of associated magmas (simultaneously or by successive pulses), seem to be the more efficient differentiation mechanisms for granitic magmas flowing in narrow dikes

Petrología y geoquímica de las tonalitas de Villarejo de Montalbán

[ES] Las tonalitas de Villarejo de Montalbán son rocas ricas en biotita en las que se observan segregados más félsicos con abundante titanita. Los datos geoquímicos e isotópicos de roca total ((87Sr/86Sr)300 = 0,7084-0,7089; εNd = -4,79, -4,80) sugieren que el magma tonalítico se formó por fusión de rocas metaígneas de composición básica/intermedia (anfibolitas o granulitas). A su vez, los segregados félsicos parecen haberse formado por acumulación del magma residual diferenciado a partir de una matriz formada sobre todo por plagioclasa y biotita. Las condiciones de cristalización estimadas por geotermobarometría del anfíbol indican temperaturas de 890- 920ºC, y presiones de 1,3-2,4 kbar, las cuales implican niveles aproximados de emplazamiento cercanos a los 5-10 km de profundidad. [EN] The tonalites of Villarejo de Montalbán are biotite-rich rocks showing felsic segregates with abundant titanite. Whole-rock geochemical and isotopic data ((87Sr/86Sr)300 = 0.7084-0.7089; εNd = -4.79, -4.80) suggest that the tonalitic magma was formed by melting of metaigneous rocks of basic/intermediate composition (amphibolites or granulites). At the same time, the felsic segregates seem to have formed through the accumulation of a differentiated residual magma after crystal fractionation of plagioclase and biotite. Crystallization conditions estimated according to amphibole geothermobarometry indicate temperatures between 890 and 920ºC, and pressures in the range 1.3-2.4 kbar, which is in accordance with an approximate emplacement level close to 5-10 km deep.Peer Reviewe

Relaciones entre ortogneises y series volcano-sedimentarias en el macizo de El Caloco (Guadarrama Central)

El macizo de El Caloco está constituido por dos formaciones metamórficas de caracteres distintos. Una es fundamentalmente paradcrivada (metapelitas con niveles carbonatados asociados>, con tramos de origen voleano-sedimentarios o subvolcánico (gneises glandulares fémicos) y que se ha denominado «serie fémica heterogénea». Aparecen también metabasitas con clinopiroxeno, granate y plagioclasa, en parte anfibolitizadas. La otra formación es de naturaleza cuarzo-feldespática y está compuesta por ortogneises glandulares y leucogneises de origen mctagranítico. En función de los caracteres petrológicos y geoquimicos interpretamos los ortogneises cuarzo-feldespáticos como representantes de antiguos granitos de dos micas con silicatos de aluminio (granitos tipo 8). El estudio geoquimico pone de manifiesto en las facies más diferenciadas (leucogneises con nidos de turmalina y/o granate> un trend evolutivo de carácter sílico-potásico. Existe un contacto neto y discordante entre ambos conjuntos, encontrándose localmente facies mosqueadas en los esquistos metapelíticos próximos al mismo.Peer reviewe

Diques lamprofíricos norteados con facies brechoidales eruptivas en la región de La Palamera de Ávila (Sistema Central español)

[Resumen] Según direcciones N-S afloran diques diabásicos y lamprofíricos en los sectores centrales del Sistema Central, estos últimos, muy localmente (Sierra de La Paramera), presentan facies brechoidales eruptivas que podrían explicarse como fenómenos de tipo diatrema, generados en un proceso de fluidizaci6n del magma lamprofírico. Los lamprófiros pueden considerarse términos alcalinos, en cuyas facies brechoidales engloban gran cantidad de xenolitos, tanto de las rocas encajantes (granitos, pórfidos graníticos, apIopegmatitas, ...), como de rocas esquistosas y granul1ticas varias (charnockitas, granoblastitas de granate y rutilo, ... ), de niveles más profundos[Abstract] In the central part oE the Sistema Central thelamprophyre dikes of N-S direction locally show (Sierra de La Paramera) an eruptive breccia facies that ve explain by a fluidization process similar to diatreme types. This lamprophyres, alkaline in composition, contain a lot oE xenoliths in that breccia facies. They are not also wall rocks xenoliths (granites, microgranites, aplopegmatites, ... ) but schistose and granulitic types (foliated or massives with charnockitic character, granoblastites with garnet and rutile, ... ), from deeper level

A U-Pb Study of Zircons from a Lower Crustal Granulite Xenolith of the Spanish Central System: A Record of Iberian Lithospheric Evolution from the Neoproterozoic to the Triassic

A U-Pb laser ablation inductively coupled plasma mass spectrometry and secondary ion mass spectrometry geochronological study has been performed on zircons from a felsic granulite xenolith from the lower crust under the Variscan belt of Iberia. The ages obtained reveal zircon-forming events that span from the late Neoproterozoic (Cadomian-Avalonian orogeny) to the early stages of the opening of the Atlantic Ocean in the Mesozoic, through Cambro-Ordovician rifting, Devono-Carboniferous Variscan-Alleghenian collision, and Permian-Triassic extension and uplift. The U-Pb age groups found in zircons from this single lower crustal xenolith (ca. 220, 250, 280–310, 460–490, 525, and 550–490 Ma) record at least one complete cycle of closing and opening of oceanic basins and collision of continental masses. Zircons from the felsic granulite xenolith contain a synthesis of the geochronological information found on the surface geology and record most but not all major lithospheric events in the region in a ca. 400-m.yr. period

Exercise Capacity in Children and Adolescents With Congenital Heart Disease: A Systematic Review and Meta-Analysis

Congenital heart disease (CHD) entails structural defects in the morphogenesis of the heart or its main vessels. Analyzing exercise capacity of children and adolescents with CHD is important to improve their functional condition and quality of life, since it can allow timely intervention on poor prognostic factors associated with higher risk of morbidity and mortality.To describe exercise capacity in children and adolescents with CHD compared with healthy controls.A systematic review was carried out. Randomized clinical trials and observational studies were included assessing exercise capacity through direct and indirect methods in children and adolescents between 5 and 17 years-old. A sensitive analysis was performed including studies with CHD repaired participants. Additionally, it was sub-analyzed by age range (< and ? 12 years old). Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of the evidence.5619 articles were found and 21 were considered for the review. Eighteen articles used the direct exercise capacity measurement method by cardiopulmonary exercise test (CPET). The CHD group showed significant differences in peak oxygen consumption (VO2peak) with a value of -7.9 ml/Kg/min (95% CI: -9.9, -5.9, p = 0.00001), maximum workload (Wmax) -41.5 (95% CI: -57.9, -25.1 watts, p = 0.00001), ventilatory equivalent (VE/VCO2 ) slope 2.6 (95% CI: 0.3, 4.8), oxygen pulse (O2 pulse)-2.4 ml/beat (95% CI: -3.7, -1.1, p = 0.0003), and maximum heart rate (HRmax) -15 bpm (95% CI: -18, -12 bpm, p = 0.00001), compared with healthy controls. Adolescents (? 12 yrs) with CHD had a greater reduction in VO2peak (-10.0 ml/Kg/min (95% CI: -12.0, -5.3), p < 0.00001), Wmax (-45.5 watts (95% CI: -54.4, -36.7), p < 0.00001) and HRmax (-21 bpm (95% CI: -28, -14), p<0.00001).Suffering CHD in childhood and adolescence is associated with lower exercise capacity as shown by worse VO2peak, Wmax, VE/VCO2 slope, O2 pulse, and HRmax compared with matched healthy controls. The reduction in exercise capacity was greater in adolescents.www.crd.york.ac.uk/prospero/display_record.php?RecordID=208963, identifier: CRD42020208963.Copyright © 2022 Villaseca-Rojas, Varela-Melo, Torres-Castro, Vasconcello-Castillo, Mazzucco, Vilaró and Blanco

Transient Stability Test Systems for Direct Stability Methods

A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presente

Measurements of Extended Magnetic Fields in Laser-Solid Interaction

Magnetic fields generated from a laser-foil interaction are measured with high fidelity using a proton radiography scheme with in situ x-ray fiducials. In contrast to prior findings under similar experimental conditions, this technique reveals the self-generated, Biermann-battery fields extend beyond the edge of the expanding plasma plume to a radius of over 3.5 mm by t=+1.4 ns, a result not captured in state-of-the-art magneto-hydrodynamics simulations. An analysis of two mono-energetic proton populations confirms that proton deflection is dominated by magnetic fields far from the interaction (>2 mm) and electric fields are insignificant. Comparisons to prior work suggest a new physics mechanism for the magnetic field generation and transport in laser-solid interactions.Comment: 9 pages, 8 figure

Transient Stability Test Systems for Direct Stability Methods

A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presente