Paleomagnetism, rock magnetism and geochemical aspects of early Cretaceous basalts of the Paraná Magmatic Province, from Misiones, Argentina

The basalts of the Posadas Formation were extruded during the huge continental volcanism that affected the Parana Basin in the Lower Cretaceous. We have carried out a paleomagnetic and rock-magnetic study on samples collected along a basalt outcrop section in Misiones, Argentina and determined that rocks classified as tholeiitic basalts and andesi-basalts are characterized by a low to intermediate content of Ti. Paleomagnetic and rockmagnetic studies suggest that the main magnetic mineral is low-Ti titanomagnetite of superparamagnetic (SP) to single-domain (SD) sizes, and very low amounts of multi-domain (MD) particles. The stable magnetic remanence enabled us to define characteristic remanent magnetizations (ChRMs) with a maximum angular deviation (MAD)<5◦ in most cases; and in all the cases, a MAD <10◦. The sequence has registered at least two polarity reversions, starting from a normal polarity at the base. The calculated virtual geomagnetic poles (VGPs) present an elongated distribution similar to other distributions of VGPs published for the Parana Magmatic Province. The elongated distribution of the VGPs could be a real feature of the geomagnetic field at a time of frequent changes of polarityThe basalts of the Posadas Formation were extruded during the huge continental volcanism that affected the Paran´a Basin in the Lower Cretaceous. We have carried out a paleomagnetic and rock-magnetic study on samplescollected along a basalt outcrop section in Misiones, Argentina and determined that rocks classified as tholeiitic basalts and andesi-basalts are characterized by a low to intermediate content of Ti. Paleomagnetic and rockmagneticstudies suggest that the main magnetic mineral is low-Ti titanomagnetite of superparamagnetic (SP) tosingle-domain (SD) sizes, and very low amounts of multi-domain (MD) particles. The stable magnetic remanence enabled us to define characteristic remanent magnetizations (ChRMs) with a maximum angular deviation (MAD)in most cases. The starting from a normal polarity at the base. The calculated virtual geomagnetic poles (VGPs) present an elongated distribution similar to other distributions of VGPs published for the Paran´a Magmatic Province. The elongated distribution of the VGPs could be a real feature of the geomagnetic field at a time of frequent changes of polarity. The sequence has registered at least two polarity reversions, starting from a normal polarity at the base. The calculated virtual geomagnetic poles (VGPs) present an elongateddistribution similar to other distributions of VGPs published for the Paran´a Magmatic Province. The elongated distribution of the VGPs could be a real feature of the geomagnetic field at a time of frequent changes of polarity.Fil: Orgeira, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Mena, Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Lagorio, Silvia Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentin

An empirical study of learners of English and their needs.

This paper is an attempt to analyse the needs of adult learners enrolled on an English course as part of a pioneer programme developed at University of Santiago de Compostela. I will confine myself to a description of the needs analysis carried out by means of a survey study. I aim at gaining a thorough understanding of the needs of the learners in this course so that teachers could capitalise on that knowledge when designing foreign language curricula. For this purpose, a questionnaire was prepared. The results of the poll should affect the programming of the course in terms of objectives, contents, methods, target skills, materials and assessment

Fintech report

FinTech refers to Financial Technology companies, particularly businesses that use technology to provide productsor solutions in the field of finance. The main goal of this report is to depict the Iberian Fin Tech environment. In order to do this, the report can be broadly divided in three different parts. The Global and European Fin Tech Environment, that show the growth of financial technology and its main players bothin European din the restof the World, and a deepdivein Iberia, where the Fin Tech market is show cased through at horough research of its main players, sectors and industries

La verdad y el honor

Fil: Orgeira, José María. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Penal II. Buenos Aires, ArgentinaTemas de Derecho Penal I

Seabird Censuses at Antarctic and Subantartic Waters: results from 1987-1995

Un total de 182.810 aves marinas pertenecientes a 50 especies fueron censadas en diferentes localidades de Antártida y Océano Atlántico Sur en las temporadas de verano 1987 a 1995. Los censos fueron hechos a bordo de buques siguiendo la metodología recomendada por el S.C.A.R., realizando 9.281 observaciones de 10 minutos cada una. Fueron definidas seis subáreas antárticas y subantárticas. Las mayores abundancias fueron obtenidas en las sub áreas de las Islas Orcadas del Sur y Arco de Scotia e Islas Shetland del Sur. Las abundancias fueron comparadas con las distintas sub áreas y con factores ambientales tomados al momento del censo (temperatura del aire y cobertura de hielo). Se discute la influencia que estos factores ambientales ejercen en la distribución de las especies.A total number of 182,810 seabirds of 50 species was recorded at Antarctica and South Atlantic Ocean in consecutive summers from 1987 to 1995. 9,281 ten minute censuses were made onboard ships following S.C.A.R. methodology. Six Antarctic and Subantarctic sub-areas were considered for study. The largest abundance was recorded at South Orkney Is. and South Shetland Is. Abundance were compared with all sub-areas and with some environmental factors such air temperature and ice-cover. The influence between those environmental factors and species distribution is discussed

Magnetic properties and soil micro-morphology in the archaeological site Marazzi 2, Isla Grande de Tierra del Fuego, Chile

El objetivo del presente trabajo es investigar el origen de la señal magnética (natural y/o antrópica) y su vinculación con la micromorfología de suelos, en dos perfiles del sitio arqueológico Marazzi 2, perteneciente al Holoceno tardío y ubicado en el noroeste de la Isla Grande de Tierra del Fuego (Chile). Los resultados muestran que el perfil P1 presenta un pico de la señal magnética (presencia de magnetita y/o titanomagnetita) entre los 30 - 70 cm, que coincide con un horizonte Ab y ABb en el que se registra actividad antrópica intensa que incluye combustión. Se establece que el enriquecimiento de la señal magnética es mayormente por causas antropogénicas. Del perfil P2 se destaca un pico de coercitividad de la remanencia entre los 20 y 40 cm (presencia de hematita) que coincide con escasos componentes antropogénicos y un horizonte AB de suelo. El registro de “pigmentos rojos” (de origen cultural) en una excavación arqueológica aledaña plantea la posibilidad de que éstos sean total o parcialmente los responsables del incremento de dicho parámetro. Finalmente se plantea que la micromorfología de suelos ofrece un gran potencial para discriminar y explicar los procesos que afectan a las propiedades magnéticas.The aim of the present work is to get an insight into the origin of the magnetic signature (natural and/or anthropogenic) of archaeological deposits and its relation to soil micromorphology. For this purpose, two profiles were sampled from the Late Holocene archaeological site Marazzi 2, located in northwestern Isla Grande de Tierra del Fuego (Chile). The P1 profile shows a magnetic signature peak (due to magnetite and/or titanomagnetite) between 30 - 70 cm depth, which coincides with Ab and ABb soil horizons for which intense anthropic activity (including combustion) was recorded. It is states that the anthropogenic activity is the main cause of that enrichment. The P2 profile exhibits a peak in the coercivity of remanence parameter between 20 - 40 cm depth (due to hematite) which coincides with few anthropogenic components and an AB soil horizon. The record of “red pigments” (carried by past-human populations) in a surrounded excavation could explain the increment of this parameter. The study highlights that soil micromorphology can help in the understanding of the processes that affect the magnetic properties of soils and paleosols.Fil: Ozán, Ivana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Orgeira, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; Argentin

Autumn seabird observations off the South Shetland Islands

Los estudios de aves marinas entre las Islas Shetland del Sur y el norte de la península Antártica son numerosos durante el verano, mientras fuera de esta época son escasos en esta zona. El objetivo de este estudio fue registrar las especies de aves presentes en otoño en la zona comprendida entre el norte de la península Antártica y las islas Shetland del Sur. Las observaciones fueron hechas abordo del Rompehielos Alte. lrizar; se realizaron censos de 10 minutos seguidos de lO minutos de intervalo. durante el fotopedodo. Se calculó el índice de diversidad de Shannon. Fueron registradas 13 especies; se relaciona la aparición de estas aves en la zona en esta época con variables ambientales.SeabirdsSouth Shetland IslandsAntarcticaAutum

The same pathway to the Weddell Sea birdlife, after 65 years: similarities in the species composition, richness and abundances

As part of a multi-year study of top predators in Antarctica, we conducted a seabird shipbased survey on board Almirante Irizar icebreaker in the Weddell Sea to the Filchner Ice Shelf in the austral summer 2020. We carried out 10-minute counts along 1843 km during 125 hours of observation. We analyzed the species distributions and the relationships with the ice cover. We registered 15 species of which four represented more than 85% of the total abundance: Antarctic petrel Thalassoica antarctica (43.9%), snow petrel Pagodroma nivea (16.3%), Arctic tern Sterna paradisaea (15.2%) and emperor penguin Aptenodytes forsteri (10.1%). Species distribution and its relationship with ice cover were analyzed statistically. The ice cover concentration was estimated by using satellite images. We compared our results with the first ship-based bird survey conducted up to the Filchner Ice Shelf in the austral summer 1955/56 to analyze possible changes in the bird community over time. Out of 13 recorded species in the 1955/56 cruise, 11 were present in this study with similar abundance proportions. In both cruises, the bird community consisted of a group of non-numerous species associated with icefree waters and another group of very numerous species associated with high concentrations on ice cover. The similarities between the two cruises, spaced 65 years apart, suggest a temporal persistence of the bird community of the central and the southern Weddell Sea that could be explained by the dynamics of the ice cover and the presence of reproductive colonies within the study site. The current environmental warming is alarming in this bird community because more than 85% of all its individuals belong to four species strongly dependent on ice cover

Terrestrial aeromagnetic survey of waste deposits: a pilot study in Gualeguaychú, Entre Ríos

La presente contribución contiene  resultados de la aplicación de relevamiento magnetomètrico terrestre en el estudio de rellenos sanitarios. Se ha elegido como caso testigo el área situada hacia el sur de la localidad de Gualeguaychú, en el extremo sudoriental de la provincia de Entre Ríos. Esta fue seleccionada pues se tenía conocimiento del cese de operaciones  y existía interés de autoridades locales en verificar la ausencia de anomalías indicadoras de potenciales residuos peligrosos para el ambiente. La interpretación de la respuesta magnética obtenida sugiere que los objetos enterrados  con alta susceptibilidad magnética,  no serìan de grandes proporciones (menores a tanques de 1 m de altura) . Por ello,  se descartarìa la presencia de tambores, eventuales contenedores de elementos tòxicos. La profundidad de soterramiento de los objetos de alta susceptibilidad magnética aumenta a mayor distancia del camino de acceso a la zona.This paper presents the results of the application of terrestrial magnetometry in the study of waste deposits. The area chosen for the pilot study was located toward the south of the town of Gualeguaychú, in the southeastern Entre Rios province. This location was selected because it was known that operations were to cease and local authorities had an interest in verifying the presence of anomalies indicative of potentially dangerous environmental pollutants. Interpretation of the magnetic signal suggests that buried objects of high magnetic susceptibility are not large (smaller than containers of 1m in height). For that reason we discount the presence of drums of standard dimensions, the possible containers of toxic elements. The estimated depth of the objects of high susceptibility increases with the distance from the access road to the the area.Fil: Orgeira, Maria Julia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vásquez, Cristian A.. Universidad de Buenos Aires. Ciclo Básico Común; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ostera, Hector Adolfo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Occurrence of seabirds and marine mammals in the pelagic zone of the Patagonian Sea and north of the South Orkney Islands

The Patagonian Sea is one of the most productive ecosystems in the Southern Hemisphere. Unlike other coastal regions, however, few studies exist on the top predators in its pelagic zone. In March 2017, a survey of seabirds and marine mammals was carried out on board the R/V Puerto Deseado in the Patagonian Sea, which extends from the South Atlantic Ocean to the north of the South Orkney Islands, Antarctica. Four of the five oceanographic regimes described in this region were studied, and 23 seabird species and five marine mammal species were recorded. Great shearwater Puffinus gravis, Antarctic prion Pachyptila desolata, and fin whale Balaenoptera physalus were the most abundant species. In the 2615 km traveled, two hotspots for top predators were found, coinciding with frontal zones: one in the shelf-break front and the other in the Southern Front of the Antarctic Circumpolar Current. The highest bird diversity and the greatest cetacean concentrations were recorded in the polar regime in the presence of low ice-field debris (5%). The results suggest that at the end of the austral summer, the distribution of top predators in this section of the South Atlantic Ocean is highly unequal. Some oceanic areas have a few species aggregations which contrast with the vast pelagic areas that have scarce species presence and activity. The hotspots were associated with high-productivity areas, but it is likely that they were also facilitated by the time of year (post-reproductive season), as most of the species were concentrated and had fed prior to their migrations