The example of the quartzite from the Upper Quartzite Formation, from Trás-os-Montes e Alto Douro (Northern Portugal); its characterization to use as natural stone

Comunicação apresentada em: "Global Stone Congress 2012", Borba, Portugal, 16-20 July, 201

Further constraints on the optical transmission spectrum of HAT-P-1b

We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting Hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo (TNG). Our measurements imply an average planet to star radius ratio equal to $\rm R_p/R_{\star}$=(0.1159$\pm$0.0005). This result is consistent with the value obtained from recent near infrared measurements of this object but differs from previously reported optical measurements being lower by around 4.4 exoplanet scale heights. Analyzing the data over 5 different spectral bins 600\AA$\,$ wide we observed a single peaked spectrum (3.7 $\rm\sigma$ level) with a blue cut-off corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in between 6180-7400\AA. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported.Comment: Accepted by Ap

O depósito de Sn-Li associado a granito de grande tonelagem da Argemela, Portugal central

The Argemela Sn-Li quartz vein stockwork, east of the Panasqueira tungsten mine, is hosted in Cambrian slates and greywacke. An underlying Variscan granitic cupola is inferred from spotted slates and albitic microgranite dykes, the last including a thick modified albitic microgranite, enriched in F and Li, exposed some 500 m away, on the hill top. Inferred resources for shallowest deposit portion are 20.1 million tonnes (Mt) at 0.1-0.2% Sn, 0.2% Li and 0.1% (estimate) Rb, but the 650-m vertical-extent of the deposit suggests a resource of >200 Mt (with identical grades). The hydrothermal paragenetic sequence is amblygonite-montebrasite (mostly montebrasite) (Stage I)–quartz I-II–cassiterite (with columbite-tantalite inclusions)─arsenopyrite I─carbonate I-white mica I ─chlorite I–fluorite–apatite–rutile (Stage II)– white mica II–molybdenite– tourmaline– carbonate II-quartz III–arsenopyrite II–sphalerite–stannite–chalcopyrite–pyrite– pyrrhotite-chlorite II (Stage III)–covellite– vivianite–goethite/lepidocrocite (Stage IV). Amblygonite-montebrasite is the main Li carrier; Sn is evenly distributed between cassiterite and stannite; Rb is mostly in white mica (with 0.25-1.23 wt % Rb2O in the hill-top albitic microgranite). Primary aqueous, 1-3 um-wide fluid inclusions in the deposit in quartz I, carbonate I, apatite and cassiterite growth zones yield overall salinities and homogenisation temperatures of 7.2-19.1 wt % NaCl equiv. and 290-360ºC, respectively. The trace concentrations (electronic microprobe analysis) in quartz vein cassiterite reach 1.95 wt % Nb, 0.39 wt % Fe, 0.13 wt % Ti, and low/negligible values of Sb, Zn, As, Ag and Bi showing its granite-hydrothermal affiliation. Fe-poor and Fe-rich sphalerite (lower-intermediate and upper deposit parts) contain 1.0-1.6 and 7.9-9.4 wt % Fe, 64.3-66.0 and 55.9-57.2 wt % Zn, 0.4-0.5 and 0.9-1.1 wt % Cd, respectively. The sphalerite-stannite geothermometer yields temperatures of 245-297ºC. Following higher temperature amblygonite-montebrasite deposition (Stage I), hydrothermal fluids (aCl-=0.25 m), related to the hidden granitic cupola, at a mean pressure-corrected (50 MPa) temperature of 350ºC, were responsible for Stage II minerals deposition. Calculated cassiterite deposition from Sn chloride complexes occurred likewise, from probable magmatic-hydrothermal fluids, at fO2 = 10-34 -10-32 atm and pH=3.5-4. Cassiterite deposition mechanisms were oxidation, mixing, neutralisation, possible aCl- increase, and cooling. Later Fe-poor sphalerite (+kesterite/ferrokesterite) and Fe-rich sphalerite (+stannite) deposited at higher and lower fS2, respectively, the latter probably at a higher fO2 (Stage III). The uniqueness of Argemela system with abundant amblygonite-montebrasite in hydrothermal quartz tin veins may be related to an extreme fractionated F-, Li- and P-rich granitic magma. After the emplacement of the granite/albitic microgranite dykes, an emerging pegmatitic fluid was unable, possibly due to insufficient depth, to form pegmatites but only modified the hill-top albitic microgranite. As a consequence, the system, where mixing of high- and low-salinity magmatic fluids probably occurred, remained very enriched in F, Li and P and by the time the hydrothermal stockwork developed amblygonite-montebrasite (Stage I) was the first mineral to deposit abundantly before Stage II minerals deposition in those Argemela Sn-Li quartz veins.El filón de cuarzo Sn-Li de Argemela, al este de la mina de wolframio de Panasqueira, está alojado en pizarras y gravas del Cámbrico. Se infiere una cúpula granítica subyacente del Varisco a partir de pizarras moteadas y diques de microgranito albítico, este último incluye un grueso microgranito albítico modificado, enriquecido en F y Li, expuesto a unos 500 m, en la cima de la colina. Los recursos inferidos para la parte más superficial del yacimiento son de 20,1 millones de toneladas (Mt) con 0,1-0,2% de Sn, 0,2% de Li y 0,1% (estimado) de Rb, pero la extensión vertical de 650 m del yacimiento sugiere un recurso de >200 Mt (con idénticas calidades). La secuencia paragénica hidrotermal es ambligonita-montebrasita (mayoritariamente montebrasita) (etapa I)-cuarzo I-II-casiterita (con inclusiones de columbita-tantalita)─arsenopirita I─carbonato I- mica blanca I ─clorita I-fluorita-apatita-rutilo (Estadio II)-mica blanca II-molibdenita-turmalina-carbonato II-cuarzo III-arsenopirita II-esfalerita-estanita-calcopirita-pirrotita-clorita II (Estadio III)-covellita-vivianita-goethita/lepidocrocita (Estadio IV). La ambligonita-montebrasita es el principal portador de Li; el Sn está distribuido uniformemente entre la casiterita y la estannita; el Rb se encuentra mayoritariamente en la mica blanca (con 0,25-1,23 % en peso de Rb2O en el microgranito albítico de la cima). Las inclusiones fluidas primarias acuosas de 1-3 um de ancho en el yacimiento en las zonas de crecimiento de cuarzo I, carbonato I, apatito y casiterita arrojan salinidades globales y temperaturas de homogeneización de 7,2-19,1 wt % de NaCl equiv. y 290-360ºC, respectivamente. Las concentraciones de trazas (análisis por microsonda electrónica) en la casiterita de las vetas de cuarzo alcanzan el 1,95 % en peso de Nb, el 0,39 % en peso de Fe, el 0,13 % en peso de Ti, y valores bajos/negligibles de Sb, Zn, As, Ag y Bi, lo que demuestra su filiación granítica-hidrotermal. La esfalerita pobre en Fe y rica en Fe (partes inferior-intermedia y superior del yacimiento) contienen 1,0-1,6 y 7,9-9,4 % en peso de Fe, 64,3-66,0 y 55,9-57,2 % en peso de Zn, 0,4-0,5 y 0,9-1,1 % en peso de Cd, respectivamente. El geotermómetro de esfalerita-estanita arroja temperaturas de 245-297ºC. Tras la deposición de ambligonita-montebrasita a mayor temperatura (Etapa I), los fluidos hidrotermales (aCl-=0,25 m), relacionados con la cúpula granítica oculta, a una temperatura media corregida por presión (50 MPa) de 350ºC, fueron los responsables de la deposición de minerales de la Etapa II. La deposición de casiterita calculada a partir de complejos de cloruro de Sn se produjo igualmente, a partir de probables fluidos magmáticos-hidrotermales, a fO2 = 10-34 -10-32 atm y pH=3,5-4. Los mecanismos de deposición de casiterita fueron la oxidación, la mezcla, la neutralización, el posible aumento de aCl- y el enfriamiento. Más tarde, la esfalerita pobre en Fe (+kesterita/ferrokesterita) y la esfalerita rica en Fe (+estanita) se depositaron a una fS2 más alta y más baja, respectivamente, esta última probablemente a una fO2 más alta (estadio III). La singularidad del sistema de Argemela, con abundante ambligonita-montebrasita en las vetas hidrotermales de cuarzo-estaño, puede estar relacionada con un magma granítico extremadamente rico en F, Li y P. Tras el emplazamiento de los diques de granito/microgranito albítico, un fluido pegmatítico emergente fue incapaz, posiblemente debido a la insuficiente profundidad, de formar pegmatitas, sino que sólo modificó el microgranito albítico de la cima. Como consecuencia, el sistema, en el que probablemente se produjo la mezcla de fluidos magmáticos de alta y baja salinidad, permaneció muy enriquecido en F, Li y P y, en el momento en que se desarrolló el stockwork hidrotermal, la ambligonita-montebrasita (Etapa I) fue el primer mineral que se depositó abundantemente antes de la deposición de los minerales de la Etapa II en esas vetas de cuarzo con Sn-Li de Argemela

Heterozygosity decrease in wild boar mating system. A case of outbreeding avoidance?

In sexually reproducing organisms, the specific combinations of parental alleles can have important consequences on offspring viability and fitness. Accordingly, genetic relationship between mates can be used as a criterion for mate choice. Here, we used microsatellite genetic markers to estimate the genetic relationship between mating pairs in the wild boar, Sus scrofa. Males, females and foetuses proceeding from Portugal, Spain and Hungary were genotyped using 14 microsatellite markers. The genetic relationship between mates was estimated using different measures of foetus heterozygosity. We found that the observed heterozygosity of foetuses was lower than that expected under random mating. This result occurred mainly when Sd2 (relatedness of parental genomes) was used as the heterozygosity measure. After simulations, we concluded that the observed low heterozygosity was possibly due to outbreeding avoidance. Outbreeding avoidance based on genetically different genomes might play an important role in species evolution and its genetic conservation

Veinte años de arqueología de la Prehistoria tardía en la Península Ibérica. Mirando hacia atrás y hacia adelante

Archaeological investigations of the agrarian communities of the 6th-2nd millennia BC in the Iberian Peninsula have undergone fundamental transformations over the past 25 years. This paper attempts to provide an overview of this research by considering three topics: 1) changes in theory, perspective, and practice, 2) the discovery of new sites or site types, and 3) developments in analytical methodologies and techniques. It concludes with some thoughts about possible future challenges and directions for research.Las investigaciones arqueológicas de las comunidades agrarias del VI al II milenios a. C. en la Península Ibérica han sufrido transformaciones fundamentales en los últimos 25 años. Este artículo trata de proporcionar una visión general de esta investigación considerando tres temas: 1) los cambios en la teoría, la perspectiva y la práctica, 2) el descubrimiento de nuevos sitios o tipos de sitios, y 3) la evolución de las metodologías y técnicas analíticas. Se concluye con algunas reflexiones sobre posibles futuros desafíos y direcciones para la investigación

Automata Serialization for Manipulation and Drawing

GUItar is a GPL-licensed, cross-platform, graphical user interface for automata drawing and manipulation, written in C++ and Qt5. This tool offers support for styling, automatic layouts, several format exports and interface with any foreign finite automata manipulation library that can parse the serialized XML or JSON produced. In this paper we describe a new redesign of the GUItar framework and specially the method used to interface GUItar with automata manipulation libraries

Resultados da primeira campanha de escavação na Anta dos Currais do Galhordas (Castelo de Vide - Centro Leste de Portugal) : breve síntese

A Anta dos Currais do Galhordas é um monumento megalítico composto por câmara poligonal, corredore mamoa. A primeira campanha de escavação permitiu identificar vários aspectos relacionados com a sua arquitectura; permitiu igualmente a recolha de diversos artefactos, nomeadamente em pedra lascada (raros) e em pedra polida, placas de xisto (uma lisa e uma gravada) e vasos cerâmicos. No âmbito do estudo destes últimos procedeu-se à análise do conteúdo de três recipientes através de cromatografia gasosa com detecção por massa.Alguns dos recipientes cerâmicos exumados relacionam a anta com uma cronologia que deverá estar próxima da transição do IV para o III milénio cal. BC. Não se exclui, no entanto, a possibilidade da sua construção ser anterior a esta fase, o que terá de ser verificado através de datações absolutas pelo radiocarbono. Outros recipientes sugerem reutilizações mais tardias (Idade do Bronze).Anta dos Currais do Galhordas is a megalithic passage tomb complete with mound and a chamber of polygonal plan. The first season of excavation has identified several of the building techniques that were employed in its construction; and recovered associated artefacts such as flaked (rare) and polished stone-tools, engraved and non-engraved slate plaques, and pottery. Three vessels have been sent for content analysis by gas chromatography coupled to mass spectrometry. Absolute dating is not yet available, but some of the pottery suggests that the monument was built between the end of the 4th millennium cal. BC and the beginning of the 3rd millennium cal. BC. However, an earlier chronology is also accepted. Other vases document more recent burials (Bronze age)