Premiers résultats des plongées Nautile de la campagne SUBPSO 1 sur la zone de collision "ride des Loyauté arc des Nouvelles-Hébrides" (Sud-Ouest Pacifique)

International audienceFour dives were conducted over the collision zone "Loyalty ridge/New Hebrides arc". On the Loyalty ridge, basaltic and rhyolitic breccias overlain by reef limestones were observed. An andesitic volcaniclastic sequence outcrops on the western flank of the New Hebrides arc. Near the trench, the Loyalty ridge has been sliced by normal faults along which the reef limestones collapsed of at least 4,000m. The unusual existence ofSW verging anticlines on the outer wall, 1,000m above the trench, was confirmed. These folds affect rocks ofthe lowerpartofthe ridge flank.Quatre plongées, réalisées sur la zone de collision «ride des Loyauté/arc des NouvellesHébrides », ont permis d'observer: (1) sur la ride des Loyauté, en mur externe de la fosse, des formations volcano-détritiques basaltiques et rhyolitiques, coiffées par des calcaires récifaux, le toutintensément fracturé; (2) sur le flanc occidental de l'arc néo-hébridais, en mur interne de la fosse, une série volcano-détritique andésitique. A l'approche de la fosse, des failles normales ont découpé la ride des Loyauté, amenant les calcaires récifaux jusqu'à des profondeurs de plus de 4000m. Enfin, la présence inhabituelle de plis déjetés vers le SW sur le mur externe, 1000 m au-dessus de la fosse, a été confirmée; ils semblent s'être développés aux dépens de matériel de la partie inférieure du flanc de la ride

Using tracer experiments to determine deep saline aquifers caprocks transport characteristics for carbon dioxide storage

It is shown how a simple gas tracer technique can contribute to the determination of transport characteristics of tight rock formations. Main obtained parameters are intrinsic permeability and the Klinkenberg coefficient; permeability as low as 10-21 m2 is easily attainable. Some information is also gained on diffusion characteristics and porosity. An example of application is given using caprocks from a deep saline aquifer in the Paris basin

Premiers résultats des plongées de la campagne SUBPSO 1 dans la zone de collision des rides d'Entrecasteaux et de l'arc des Nouvelles-Hébrides

International audienceGeological cross-sections,constructed from observations and samples collected during seven dives of theFrench submersible Nautile,reveal that the inner wall of the New Hebrides trench, in front of the North d'Entrecasteaux ridge and the Bougainville guyot,is primarily composed of volcanic and volcaniclastic rocks, most likely shed from the arc. Observations indicate that the bedding of thearc-slope rocks,which generally slopes trench ward in this collision zone,dips steeply (40-80°) arcward near the contact of the colliding features. In this particular area, arc-slope rocks are generally highly fractured and sheared, an exception being rocks forming the ridge east of the Bougainville guyot.Arc-slope rocks are deeply incised by erosional channels and show numerous fresh slump scars. These scars confirm the importance of mass wasting along the deformation front. No evidence for fluid venting,such as clams and mud volcanoes,was observed during the dives.Les coupes géologiques réalisées à partir de sept plongées du Nautile ont montré que le mur interne de la fosse des Nouvelles-hébrides,en face de la ride Nord d'Entrecasteaux et du guyot Bougainville,est essentiellement constitué par des formations volcaniques et volcano-détritiques provenant probablement de l'arc. Ces formations, généralement inclinées vers la fosse, ont,au contact de la ride et du guyot,rebroussées vers le haut et pentées de 40 à 80°vers l'arc. A ces niveaux,les roches sont intensément fracturées et cisaillées à l'exception de celles constituant le bourrelet qui surplombe le toit du guyot Bougainville.Le mur interne présente enfin une morphologie remarquable comprenant des loupes d'arrachement gravitaire,des chenaux d'érosion, des canyons et,localement,des marmites de géant.Ces figures confirment l'importance de l'érosion gravitaire le long du front de déformation.Aucune manifestation de sorties de fluides n'a été observée lors de ces plongées

Gender differences in working at home and time use patterns: evidence from Australia

Despite a wealth of research on working at home, few studies have examined the effects of working at home in relation to its regularity and fewer still have used time use studies to do so. Using data from the 2006 Australian Time Use Survey this article investigates the association between working at home, gender and time use, in relation to amount of time spent in paid work, unpaid work and recreational labour, as well as multi-tasking, fragmentation of time and scheduling flexibility. It examines time use patterns according to whether employees do no work at home or whether they work at home rarely, occasionally or regularly. Results show there is an association between working at home and time in paid and unpaid work and that this differs by the regularity of working at home and gender. Working at home does not create more time for recreational labour, although it may help women juggle work and family. © 2015, © The Author(s) 2015

Geology of the d'Entrecasteaux - New Hebrides arc collision zone : results from a deep submersible survey

International audienceDuring the SuBPSOl cruise, seven submersible dives were conducted between water depths of 5350 and 900 m over the collision zone between the New Hebrides island arc and the d'Entrecasteaux Zone (DEZ). The DEZ, a topographic high on the Australian plate, encompasses the North d'Entrecasteaux Ridge (NDR) and the Bougainville guyot, both of which collide with the island-arc slope. In this report we use diving observations and samples, as well as dredging results, to analyse the geology of the Bougainville guyot and the outer arc slope in the DEZ-arc collision zone, and to decipher the mechanisms of seamount subduction. These data indicate that the Bougainville guyot is a middle Eocene island arc volcanocapped with reef limestones that appear to have been deposited during the Late Oligocene to Early Miocene and in Miocene-Pliocene times. This guyot possibly emerged during the Middle and Late Miocene, and started to sink in the New Hebrides trench after the Pliocene. The rocks of the New Hebrides arc slope, in the collision zone, consist primarily of Pliocene-Recent volcaniclastic rocks derived from the arc, and underlying fractured island-arc volcanic basement, possibly of Late Miocene age. However, highly sheared, Upper Oligocene to Lower Miocene nannofossil ooze and chalk are exposed at the toe of the arc slope against the northern flank of the NDR. Based on a comparison with cores collected at DSDP Site 286, the ooze and chalk can be interpreted as sediments accreted from the downgoing plate. East of the Bougainville guyot an antifonn that developed in the arc slope as a consequence of the collision reveals a 500-m-thick wedge of strongly tectonized rocks, possibly accreted from the guyot or an already subducted seamount. The wedge that is overlain by less deformed volcaniclastic island-arc rocks and sediments includes imbricated layers of Late Oligocene to Early Miocene reef and micritic limestones. This wedge, which develops against the leading flank of the guyot, tends to smooth its high-drag shape. A comparison between the 500-m-thick wedge of limestones that outcrops southeast of the guyot and the absence of such a wedge over the flat top of the guyot, although the top is overthrust by island-arc rocks and sediments, can be interpreted to suggest that the wedge moves in the subduction zone with the guyot and facilitates its subduction by streamlining

Signification géodynamique des calcaires de plate-forme en cours de subduction sous l'arc des Nouvelles-Hébrides (Sud-Ouest de l'océan Pacifique)

Note présentée par Jean DercourtInternational audienceThe analysis of carbonates from New Hébrides Trench shows that three main épisodes of shallow water carbonate déposition occurred during Late Eocene,Late Oligocene-Early Miocène,Mio-Pliocene-Quaternary, controlled by eustatism and tectonic.L'analyse de carbonates issus de la fosse des Nouvelles-Hébrides a permis de reconnaître trois périodes favorables au développement de plates-formes(Éocène supérieur,Oligocène supérieur-Miocène inférieur,Mio-Pliocène-Quaternaire)contrôlé par l'eustatisme et la tectonique

Las prácticas profesionales supervisadas y la mejora académica de los estudiantes de la carrera de Contador Público Nacional de la Universidad del Aconcagua

La Facultadde Ciencias Económicas y Jurídicas, instituyó, desde 2008 las Prácticas Profesionales Supervisadas (PPS), de carácter obligatorio para todos los estudiantes del último año de la carrera de Contador Público Nacional.Las PPS fueron instauradas ya que permiten centrar el aprendizaje en el estudiante; diseñar la curricula basada en resultados de aprendizaje y competencias; procurar diversidad, pertinencia y calidad educativa; brindarle al futuro egresado una empleabilidad pertinente y preparar al alumno universitario para el mundo del trabajo y mejorar el rendimiento académico con la retroalimentación e interdependencia de los conocimientos teóricos y los prácticos desarrollando competencias académicas.Las PPS son una obligación académica de 150 horas, que se realizan dentro de Empresas, Organismos Públicos o Privados, ONGs u otras instituciones. En este ámbito los alumnos realizarán residencias programadas u otras formas de prácticas, relacionadas con su formación y especialización, acompañados por un tutor.

Work-time underemployment and financial hardship: class inequalities and recession in the UK

The economic crisis that led to recession in the UK in 2008–9 impacted in multiple ways on work and economic life. This article examines changes to the work-time of employees. The UK stood out for its recessionary expansion of work-time underemployment. Working in a job that provides ‘too few’ hours can have serious ramifications for the economic livelihood of workers. Working-class workers are central here. Drawing on analysis of large-scale survey data, the article identifies that workers in lower level occupations experienced the most substantial post-recessionary growth in the proportions working ‘too few’ hours. Did these work-time changes narrow or widen class inequalities in feelings of financial hardship? The article concludes that although middle-class workers also saw their financial positions damaged, this so-called ‘first middle-class recession’ did not erode class inequalities in financial hardship among UK workers