Heterogeneidad de facies en una rampa carbonatada del Kimmeridgiense (Jabaloyas, Este de España): análisis de campo y geomodelización tridimensional

The Upper Kimmeridgian outcrops exposed around the village of Jabaloyas (NE Spain) have been analyzed to document the facies heterogeneity across the shallow portion of a low angle carbonate ramp. The studied area covers a total surface of 12 square kilometres. Seventeen stratigraphic profiles have provided basic information to carry out the detailed facies analyses presented in this work. The studied unit corresponds to a high-frequency sequence, bounded by discontinuities that can be traced at regional scale. This sequence shows the widespread development of coral-microbial reef buildups with conical to cylindrical shape (up to 19 m thick). The characterization and interpretation of the different sort of inter-reef and post-reef facies resulted in the reconstruction of the sedimentary domains of the studied carbonate ramp, from burrowed mud-dominated skeletal facies (distal middle ramp), to grainy (skeletal, peloidal, oolitic) shoal and backshoal facies (inner ramp). The studied sequence is divided into four sedimentary episodes bounded by sharp facies changes. The lower two episodes include the vertical reef growth during rapid accommodation gain; the upper two episodes are marked by the rapid progradation of the inner ramp facies. The depositional facies and their stacking patterns in the Jabaloyas outcrops are similar to those described in the subsurface Arab D reservoirs. This Late Jurassic carbonate unit forms major hydrocarbon fields in the Middle East. For improving the geological distribution of reservoir heterogeneity in this kind of low angle carbonate ramp system, two 3D models have been created. A Fullfield Model of the overall geometry of the facies belts has allowed the quantification of vertical and lateral extension of the inter-reef and post-reef facies. A Sector Model, which includes individual reef bodies has been used to better simulate reservoir heterogeneity resulting from different diagenetic overprint.Los afloramientos del Kimmeridgiense Superior en las cercanías de Jabaloyas (NE de España) han sido estudiados para documentar la heterogeneidad de facies en las zonas más someras de una rampa carbonatada de bajo ángulo. El área de estudio cubre una superficie de 12 kilómetros cuadrados en la que se han levantado diecisiete columnas estratigráficas y se ha realizado un análisis detallado de facies. La unidad estratigráfica estudiada corresponde a una secuencia de alta frecuencia limitada por discontinuidades que pueden ser cartografiadas a escala regional. Dicha secuencia presenta bioconstrucciones arrecifales coralinas y microbianas con morfologías cónicas o cilíndricas de hasta 19 m de potencia. La caracterización e interpretación de las diferentes facies inter- y post-arrecifales ha permitido la reconstrucción de los diferentes dominios de la rampa carbonatada, desde facies no granosostenidas bioturbadas (rampa media distal), hasta facies granosostenidas (bioclásticas, peloidales, oolíticas) desarrolladas en bajíos activos y en zonas someras protegidas. La existencia de superficies bien cementadas y de cambios abruptos de facies asociados ha permitido la división de la secuencia en cuatro episodios de sedimentación. Los dos primeros incluyen el crecimiento de los arrecifes durante los periodos de ganancia de acomodación, mientras que los dos últimos vienen marcados por una rápida progradación de las facies de rampa interna. El patrón de apilamiento de esta unidad en los afloramientos de Jabaloyas muestra similitudes con aquellos descritos en los reservorios desarrollados en el Arab D, el cual genera campos de hidrocarburos de gran tamaño en Medio Oriente. Con el fin de precisar la heterogeneidad de facies a escala de reservorio en este tipo de rampas carbonatadas de bajo ángulo, se han elaborado dos modelos tridimensionales. Un modelo de campo completo ha permitido precisar la extensión y la geometría de los diferentes cinturones de facies; y un modelo sector, que incluye los cuerpos arrecifales, posteriormente utilizado para simular la heterogeneidad del reservorio con ayuda de estudios diagenéticos previos

Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project

In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory

Forward seismic modeling as a guide improving detailed seismic interpretation of deltaic systems: Example of the Eocene Sobrarbe delta outcrop (South-Pyrenean foreland basin, Spain), as a reference to the analogous subsurface Albian Cenomanian Torok-Nanushuk Delta of the Colville Basin (NPRA, USA)

A forward seismic model of the Middle Eocene Sobrarbe delta outcrop (South-Pyrenees, Spain) has been made to investigate its seismic signature. The Sobrarbe delta complex corresponds to a syntectonic sedimentary wedge locally thicker than 1000 m. This 15 km-long, highly-progradational and moderately aggradational sedimentary system presents sigmoid and oblique clinoforms, characterized by slopes ranging from 0.2° to 5.7°. Along the clinoforms, the classical deltaic depositional environments grade progressively from one to the other: alluvial plain, delta plain, delta front and prodelta. Locally, specific carbonate deposits occur, corresponding to transgressive pulses. The transition from delta front to prodelta is locally marked by large slide scars affecting clinoform morphology. A detailed outcrop transect of the Sobrarbe delta was converted to an acoustic impedance model by assigning petrophysical properties to each geological facies. This model was then used to create synthetic seismic lines characterized by various input wavelets. The resulting various peak frequency synthetic seismic lines have been interpreted, and the seismic interpretation compared to the outcrop description to calibrate the seismic interpretation and assess the 'limits' of that interpretation. This work shows that the 'seismic stratigraphy' methodology is consistent and allows the correct interpretation of most seismic sequences. However, composite reflections from rapid lateral facies transitions and higher-frequency sequence boundaries can clearly lead to seismic interpretation mistakes. The seismic facies of seven facies associations have been described, providing guidelines to recognize them on actual seismic lines. The synthetic seismic image of four selected systems tracts comprising good reservoir bodies has been analyzed to highlight recognition criteria which can be used to interpret analog deltaic systems in the subsurface, and therefore enhance the prediction and characterization of the reservoir bodies that they hold. These guidelines were systematically applied to a direct subsurface analog: the Torok-Nanushuk Delta (Colville Basin, NPRA, USA)

An immunocapture PCR assay adapted to the detection and the analysis of the molecular variability of apple chlorotic leaf spot virus

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Fatty acid composition, glutathione peroxidase and superoxide dismutase activity and total antioxidant activity of avian

Abstract This work demonstrates that spermatozoa from five avian species (chicken, turkey, guinea fowl, duck and goose) are all characterised by high proportions of polyunsaturated fatty acids, from 46 (turkey) to 55% (duck) of total. For each of the species, the most abundant fatty acids were arachidonic (20:4n-6) and docosatetraenoic (22:4n -6) acids, representing between 22 (turkey) and 40% (chicken) of total. Significant activities of the major isozymes of superoxide dismutase and glutathione peroxidase, which protect against the peroxidation associated with high degree of fatty acid unsaturation, were found in spermatozoa from all species. The seminal plasma also had these activities and showed additional mechanisms for protecting spermatozoa from peroxidation. In general terms, these lipid and enzyme proteins were similar between the five avian species and different from those reported for mammalian sperm