Kinematics of regional salt flow in the northern Gulf of Mexico

International audienceThe kinematics of regional-scale salt flow in the northern Gulf of Mexico is analysed using: (i) a map of shelf-break contours at the termination of successive depositional episodes; (ii) the location and geometry of large-scale structures of the slope domain as imaged by seismics; and (iii) digital slope bathymetry. In the north margin, salt has flowed towards the SW since the Cretaceous with three main stages of development prior to, during and after a massive salt extrusion in the Early Miocene time. The corresponding sequence of structural development is discussed using a laboratory model. Contrary to all previous interpretations that invoked sedimentary loading as the main driving force, the analysis of regional-scale salt flow implies that the salt tectonics of the northern Gulf of Mexico is predominantly controlled by gliding above the margin dip. The SWdirected salt flow indicates that the north margin of the northern Gulf of Mexico trendsNW-SE, in agreement with plate kinematic models in which the Yucatan continental block has undergone a 45-608 dextral rotation relative to its present orientatio

Exhumation of high-pressure rocks driven by slab rollback

International audienceRocks metamorphosed under high-pressure (HP) and ultra high-pressure (UHP) conditions in subduction zones come back to the surface relatively soon after their burial and at rates comparable to plate boundary velocities. In the Mediterranean realm, their occurrence in several belts related to a single subduction event shows that the burial­exhumation cycle is a recurrent transient process. Using the Calabria­Apennine and Aegean belts as examples, we show that the exhumation of HP rocks is associated in time and space with the subduction of small continental lithosphere blocks that triggers slab rollback, creating the necessary space for the exhumation of the buoyant continental crust that was deeply buried just before. The buoyancy force of the subducted crust increases until this crust detaches from the downgoing slab. It then exhumes at a rate that depends directly on the velocity of trench retreat to become part of the overriding plate. Heated from below by the asthenosphere that flows into the opening mantle wedge, the exhumed crust weakens and undergoes core-complex-type extension, responsible for a second stage of exhumation at a lower rate. The full sequence of events that characterizes this model (crust­mantle delamination, slab rollback and trench retreat, HP rock exhumation, asthenosphere heating and core-complex formation) arises entirely from the initial condition imposed by the subduction of a small continental block. No specific condition is required regarding the rheology and erosion rate of HP rocks. The burial­exhumation cycle is transient and can recur every time a small continental block is subducted

Porter plainte pour harcèlement psychologique au travail : Un récit difficile

Cet article brosse un portrait des plaintes écrites déposées à la Commission des normes du travail du Québec entre le 1er juin 2004 et le 30 avril 2005. Au total, 236 plaintes de harcèlement psychologique au travail ont constitué le corpus d’analyse. Les principaux résultats montrent que parmi l’ensemble des cas analysés, 63 % des plaignants sont des femmes. Près de 95 % des plaignants ont avancé avoir subi du harcèlement à caractère répétitif. Les cinq premiers motifs de plainte sont les propos et les gestes vexatoires, les atteintes aux conditions de travail, la menace de congédiement, la mise en échec de la personne et l’isolement. Par ailleurs, ce sont généralement les gestionnaires qui sont désignés comme personnes mises en cause. À la lumière de ces résultats, il est important que les organisations se dotent de systèmes de veille pour détecter les cas et d’outils de gestion pour désamorcer les situations qui comportent un potentiel de harcèlement psychologique.Following in the wake of several European countries, Quebec adopted a bill in December 2002 to modify the Labour Code and other legislative measures by the introduction of measures pertaining to psychological harassment (art. 81.18 to 81.20). These standards, which are accompanied by specific means of legal recourse (art. 123.6 to 123.16) and fall under the responsibility of the Commission des normes du travail (CNT), came into effect on June 1, 2004 (Lippel, 2005). This article presents an overview of the written complaints filed with the Commission des normes du travail (CNT) between June 1, 2004 and April 30, 2005.At the present time, most of the studies on psychological harassment, moral harassment or other forms of violence in the workplace use a survey with worker populations (Brun and Plante, 2004; Byrne, 1997; Hirigoyen, 1998, 2001; Hoel, Rayner and Cooper, 2003; Leymann, 1996a, 1996b; Salin, 2003; Vandekerkhove and Commers, 2003; Wornham, 2003). Although these surveys are very useful, they have the limitation of being centred on identifying the types of events, the forms, or the sources of psychological harassment in the workplace. Scientific studies are rare (Garcia, Hacourt and Bara, 2005; Lapeyrière, 2004; Lewis and Orford, 2005); this type of study focuses on the inside story of cases of psychological harassment, the difficulties of putting into the experience into words, the doubts that the outward expression of facts may raise, and the ambiguities hidden by complex situations.For this reason, our research study adopted the point of view and the arguments put forward by the main players, that is to say, the men and women filing the complaints, as well as the situations that are being denounced. Our objective was to give an overview of the complaints filed with the Commission des normes du travail over a period of one year. In so doing, we hope to better understand the complexity of the phenomenon of psychological harassment through the situations as experienced and expressed by the complainants.In total, 236 complaints of psychological harassment at work and more than 1,500 pages written by the complainants made up the corpus for analysis. The research method used includes a first section on socioprofessional and economic factors (e.g., sex, age, profession, employment status, etc.), a second section on the business itself (e.g., sector, number of employees, etc.) and a third section focused on the complaint itself (e.g., causes, frequency, form, witnesses, consequences, etc.).The main study results show that among the set of cases analysed, 63% of complainants are women. Two-thirds of the complaints (68%) mention one individual as being involved, while 32% of cases identify several people as being the source of the psychological harassment. More than 95% of the complainants claimed to have been the target of harassment that was repetitive in nature. The five most common causes for complaint are vexatious words and gestures (132 complaints), infringement on working conditions (77 complaints), threat of firing (49 complaints), causing failure for the person (39 complaints), and isolation (39 complaints). Psychological harassment is socially distributed, that is to say, that it touches, as either author or victim, many employment categories, whether one be a secretary, technician, or senior management. As well, managers usually are identified as people being involved. In the majority of cases analyzed, attempts to find a resolution (e.g., discussion with the person involved, information given to the supervisor, complaint letter, etc.) are solely made by the complainant; colleagues are almost always uninvolved, and only in rare cases has another colleague intervened to make a situation stop or to speak out against a situation of which those in the complainant’s immediate environment are aware.The phenomenon of psychological harassment is far from being simple; the remarks and the stories that we have related clearly show that these are complex situations for many reasons. One of these reasons is that psychological harassment is a direct manifestation of the private nature of violence (Cooney, 2003) that concerns individuals rather than groups, and is addressed at individuals and in the context of face to face relations, that is to say, without the presence of any direct witnesses.Psychological harassment is also socially distributed, meaning that it involves, in terms of victims or perpetrators, people from all types of employment: secretary, technician, or upper management. However, the direction of psychological harassment is not randomly distributed. Generally, managers are identified as instigators, and women state they are harassed by men.In analysing the 236 cases, we were astonished by the large number of cases of psychological harassment involving situations of rudeness, vexatious or blasphemous remarks (132/236 complaints). An insult, “the sentence that kills!” and public denigration are common among the complaints of psychological harassment filed at the Commission des normes du travail. The situation seems to be similar in the United States, where, according to research by Pearson and Porath (2005), 20% of workers surveyed said they are the target of rude remarks at least once a week. The respect of others is a value which is losing ground, and individualism often justifies any remark when a person wishes to reach his or her ends.The individualization of conflicts is also revealed in the attempts at case resolution. In fact, in most of the cases studied, attempts at resolution (e.g., discussion with the person involved, information for the supervisor, letter of complaint, etc.) come directly from the complainant. Colleagues are almost always uninvolved; rare are the cases where another colleague has intervened in order to put a stop to or to speak out against a situation which is known in the immediate environment of the complainant. It is also important to mention that, in general, a person does not know how to intervene or stop a conflict (Lapeyrière, 2004). Other staff members usually plead being unsure or the overly complex nature of the situation.One of the challenges linked to psychological harassment in the workplace for employers and employees is to not become caught up within a legal debate, wondering if the situation does or does not fit with the definition provided by the law. From a point of view of good management within the organization and so as to avoid the courts becoming involved in cases, the problems brought forward by the complainants must first and foremost be analyzed in the light of individual and collective ethics (Wornham, 2003) and in the light of problems associated with work relations (Legoff, 2003). Whether or not it may be a case of harassment, the situations we have analyzed are, in many cases, quite simply inadmissible in modern organizations and may, as well, lead to psychological or physical health problems (Vartia, 2004). Seen from an ethical and a public health perspective, the employer and the employees have the duty of making sure that such situations not occur (Leclerc, 2005). For these reasons, it is important to establish boundaries which may not be crossed, to define as clearly as possible what is acceptable and what is not, to make it understood that respect of another person’s dignity is not a privilege, but rather a right and a fundamental duty and that it is crucial not to wait until the situation is deemed unacceptable before an intervention is made.Este artículo esboza una descripción de las quejas escritas presentadas a la Comisión de las Normas de trabajo del Quebec entre el 1ro de junio 2004 y el 30 de abril 2005. En total, 236 quejas de hostigamiento/acoso sicológico en el trabajo constituyeron el corpus del análisis. Los principales resultados muestran que del conjunto de casos analizados, 63% de los demandantes son mujeres. Cerca del 95% de demandantes sostuvieron haber sufrido hostigamiento sicológico de manera repetitiva. Los cinco primeros motivos de queja son las declaraciones y gestos ofensivos, el perjuicio de las condiciones de trabajo, la amenaza de despido, inducir la persona al fracaso y el aislamiento. Mas aún, son generalmente los directivos que son designados como personas acusadas. A la luz de estos resultados, es importante que las organizaciones se doten de sistemas de vigilancia para detectar los casos y que se procuren útiles de gestión capaces de frenar las situaciones que comportan un potencial de hostigamiento sicológico

Influence des barrières sur la propagation de la déformationle long des surfaces de décollement : étude expérimentale

International audienceA series of small-scale experiments has been done to study the influence of gap and thickness variations along a layer of potential decollement on the fault sequence in a thrust system. It is shown that a local thinning or discontinuity of the decollement layer can become a barrier which localises the deformation, initiates a ramp, and controls the order of fault development above the decollement layer.Une série d'expériences sur modèles réduits a été réalisée afin d'étudier l'influence des lacunes et des variations d'épaisseur d'un niveau de décollement potentiel sur la propagation d'un système chevauchant. Les résultats montrent qu'un amincissement ou une discontinuité de ce niveau crée une barrière qui peut bloquer au moins temporairement le décollement, localiser la déformation, servir de site d'initiation d'une rampe, et déterminer aissi l'ordre d'apparition des rampes suivantes

Du Fondo Barbatelli à la Porte du Vésuve : Une fenêtre d’étude dans le faubourg septentrional de Pompéi

Données scientifiques produites :https://centrejeanberard.cnrs.fr/spip.php?article106&lang=fr Chroniques de l’EFR :http://journals.openedition.org/cefr/4941 Introduction Le faubourg septentrional de Pompéi, en avant de la porte du Vésuve, a été dégagé de manière discontinue à partir de l’extrême fin du XIXe siècle et la première décennie du siècle suivant. En effet, bien que repérée dès 1811, la porte du Vésuve fut dégagée de manière intermittente dès 1902, jusqu’aux fouilles de la zone dir..

Tectonics of the Syros blueschists (Cyclades, Greece): From subduction to Aegean extension

On Syros, high‐pressure metamorphism affects a lithological pile that is composed of, from base to top: (1) the Komito‐Vari granitic basement, (2) a margin sedimentary sequence that is predominantly made of marbles and schists (the Pyrgos and Kastri units), and (3) the Kambos metaophiolitic mélange. The tectonic history occurred in three main stages. During the first stage, in the mid‐Eocene, the Kambos oceanic unit was thrust southward on top of the sedimentary pile. Top‐to‐the‐south‐southwest ductile senses of shear are synchronous with prograde high‐pressure metamorphism and associated with this thrusting event. The second stage corresponds to a top‐to‐the‐northeast ductile shear that affects the whole metamorphic pile and is synchronous with the metamorphic retrogression from eclogite to greenschist facies. However, the Kambos oceanic unit remained partly undeformed, as shown by significant volumes containing undeformed lawsonite pseudomorphs. No major extensional detachment related to this exhumation event outcrops on the island. The localized semibrittle to brittle deformation of the third stage is associated with the postmetamorphic development of (1) a ramp‐flat extensional system at the island scale, whose southward minimum displacement is estimated at approximately 7 km, and (2) two sets of steeply dipping strike‐slip faults with a normal component, trending either east–west or around north–south, indicating that the mean stretching and shortening directions are trending NNE–SSW and ESE–WNW, respectively. This sequence of major tectonic events and their relationship to metamorphism are interpreted within the framework of the subduction of the Pindos Ocean and then of the Adria continental passive margin

Work Activity and Subjectivity: A Behind-the-Scenes Look at the Work of Linemen

Depuis ses débuts l'ergonomie n'a cessé d'enrichir et de préciser sa conception de l'être humain au travail et de son activité. Le constat que l'on peut dresser est que cette discipline scientifique a réalisé et continue de réaliser des avancées importantes pour faire valoir la contribution des individus dans le travail. Mais dans la poursuite de cette quête de la connaissance, les ergonomes ont très peu considéré les dimensions émotionnelles et subjectives de l'individu. Pourtant, travailler n'est pas uniquement se mobiliser, s'activer ou agir, c'est aussi vivre, ressentir et expérimenter. Pour reprendre un concept cher à l'ergonomie, nous dirions que l'être humain n'est pas qu'un opérateur ou une opératrice, il est aussi un sujet qui entretient non seulement des rapports utilitaires avec le travail, mais aussi des rapports affectifs. Cela signifie donc que le vécu intime (ex. : souffrance, plaisir, peur, anxiété, etc.) du sujet constitue un déterminant, au même titre que les propriétés physiologiques ou cognitives de l'acte de production. À ce titre, l'ergonomie ne peut plus faire l'économie de l'étude de la subjectivité qui accompagne l'acte de production.Pour parvenir à questionner le vécu subjectif du sujet et son articulation avec l'activité de travail, l'ergonomie doit inévitablement redéfinir son cadre d'analyse et ouvrir ses frontières à une discipline comme la psychodynamique du travail. Cette approche pose comme postulat de base que l'être humain entretient avec l'acte de travail une relation subjective, voire identitaire et non une simple relation utilitaire et distante. En fait, le sujet et sa subjectivité sont considérés comme des opérateurs fondamentaux de la construction de l'activité de travail. La mise au jour du rapport concret qui s'inscrit entre l'individu et les réalités du travail constitue une contribution importante à la compréhension de l'activité humaine de travail. Malheureusement, les points de vue analytiques et théoriques développés par la psychodynamique du travail demeurent encore peu intégrés dans les analyses ergonomiques. Cet article présente donc, à travers une étude chez les monteurs de lignes électriques, comment l'ergonomie peut interroger le travail humain à partir de ses dimensions subjectives.Using a study of linemen, this article shows how analyzing the subjective experience of linemen can enrich the understanding of work activities. The démonstration is based essentially on the phenomenon of defensive strategies, which allow human beings to maintain their psychic equilibrium despite the harmful effects of work organization. Finally, it is proposed that ergonomics should pay doser attention to the more personal phenomena that inevitably influence work activities

La viticulture en Gaule tempérée

International audienceViticulture spread in non-Mediterranean Gaul much earlier and more widely than ancient sources let imagine and than our predecessors, Camille Jullian and Roger Dion, had assumed. The development of archaeology, especially rescue archaeology, in the whole territory resulted in the discovery of a vast amount of remains connected to vine cultivation and wine producing in the Tres Galliae and in Germania: plantation pits, pollen and carpological traces, press remains, wine grower tools, wine amphorae kilns. The generalization of wood and leather implements for wine making and as well for selling certainly still distorts our perception of this activity. Nevertheless we now can draw the following picture: vine planting as soon as the early 1st century AD wherever there are favourable soil conditions, especially in southern areas, quick expansion of vineyards for local or regional markets and continuation of viticulture up to Late Antiquity with regional fluctuations that still need to be described. Archaeological results underline the distortion effects of the few written sources available which can throw fragmented light without context upon a phenomenon which served as a vehicle for the spread of Roman culture as did religion or town planning.L’extension de la viticulture en Gaule tempérée a été bien plus précoce et plus large que les sources antiques laissaient supposer et que nos devanciers, Camille Jullian et Roger Dion, ne l’avaient estimé. L’archéologie, surtout préventive, de par son action sur tout le territoire, a permis la découverte de nombreux vestiges attribuables à la culture de la vigne et à la production de vin dans les Trois Gaules et les Germanies : trous de plantation de vignes, indices polliniques et carpologiques, vestiges de pressoirs, présences d’outils de vigneron, ateliers d’amphores vinaires. Certes, l’emploi généralisé d’instruments en bois et en cuir, tant pour la vinification que pour la vente, fausse encore notre perception. Toutefois le tableau qui se dessine aujourd’hui est le suivant : plantations de vignes dès le début du Ier s. apr. J.-C. partout où le terrain était favorable, avec une majeure densité dans la partie méridionale, rapide développement de vignobles produisant pour des marchés locaux ou régionaux et maintien de la viticulture jusqu’à l’Antiquité tardive, avec des fluctuations régionales encore à dessiner. Les acquis de l’archéologie soulignent les effets déformants des rares sources écrites disponibles donnant des lueurs partielles et hors contexte sur un phénomène qui joua un rôle de vecteur pour la culture romaine au même titre que la religion ou l’urbanisme

3. Viticulture et oléiculture grecques et indigènes en Grande Grèce et en Sicile

Are transfers of technology in fields of olive oil and wine production between Greek and Italic populations archaeologically detectable ? Although documentation is still scarce, we have learnt that from the Bronze Age local populations knew how to produce olive oil while from the Iron Age they produced wine. Recent discoveries at Poggiomarino near Pompeii show that vine cultivation, wine production and consumption were common among the Italic populations during the 9th c. BC. On the other hand, a revaluation of the content of Corinthian A and SOS amphorae, which were probably used to transport wine rather oil, implies that Greek settlers did not import their oil from mainland Greece but produced it locally as they did their wine. The first archaeological remains of wine production excavated so far are those of Punta Chiarito on the island of Ischia where, near to a small farm dated from the 6th c. BC, were discovered several vine plantation pits, a press and many jars used to make wine. Other plants, dating from the Classical period, are located in Sicily, around Gela and Camarina, and carpological studies show that the cultivation of olive trees reached a peak during the 4th c. BC in the territory of the Greek colony of Metaponto (Southern Italy). Oil presses are known in the Lucanian territory at Montegiordano near Sybaris, at Monte Moltone near Potenza and in the Sicanian zone at Monte Adranone (Sicily). Just as those of Greek mainland cities or western colonies, they might bear testimony to a rather large diffusion of Greek techniques in the indigenous world. But the available data are still too scant to precisely date these transfers