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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Les gisements magdaléniens dans le Jura et les Alpes du nord et leurs industries osseuses / the Magdalenian site in Jura and the Alps North and their bone industries

Malgarini, Romain 15 December 2014 (has links)
Ces dernières années, le Magdalénien a connu un vif regain d’intérêt dans le Jura et les Alpes du nord, concernant la position chronologique de ces phases successives et de ces gisements. Le renouvellement et la production de données radiocarbones et paléoenvironnementales ont permis de préciser l’évolution du monde animal et la chronologie des occupations humaines tardiglaciaires. Ce cadre général nouvellement établi, a permis dans un second temps, de proposer une analyse inédite, comparée et diachronique de l’évolution des productions osseuses au Magdalénien, à partir d’un corpus de 22 gisements (décrit dans un second volume), en grottes et en abris, répartis sur le Massif du Jura et les Alpes du nord et situés entre 15500 et 12000 BP. Passés au crible de quatre paramètres évaluant leur potentiel, nous avons sélectionné 13 gisements les plus pertinents pour lesquels nous avons étudiés les différentes catégories de témoins (déchets, supports, ébauches et objets finis) par matières premières (bois de cervidé, os, ivoire vraie, dentine) et selon les stigmates liés à leur fabrication et à leur utilisation. A partir de ces gisements, nous avons projeté quelques bases sur le peuplement tardiglaciaire et décrit leur équipement osseux sous un angle typo-technologique ce qui n’avais jamais été fait jusqu’à aujourd’hui. / These last years, the Magdalenian knew a deep renewed interest in Jura and the Alps of the North, concerning the chronological position of the successive phases and these site. The renewal and the production of data radiocarbons and paleoenvironnemental allowed to specify the evolution of the animal kingdom and the chronology of the human tardiglacial activities. This general framework recently established, allowed secondly, to propose an unpublished, compared and diachronic analysis of the evolution of the osseous productions in the Magdalenian, from a corpus of 22 site (described in a second volume), in caves and in rock shelters, distributed on the Massif of Jura and the Alps of the North and situated between 15500 and 12000 BP. Examined closely of four parameters estimating their potential, we selected the most relevant 13 site for which the various categories of witnesses (waste, supports, sketches and finished objects) by raw materials (antler, bone, ivory, dentin) and according to stigmata bound to their manufacturing and to their use.
102

Traits d'histoire de vie et démographie face aux changements climatiques en milieu alpin : l’exemple de la marmotte alpine (Marmota marmota) / Life history traits and demography under climate change in the Alps : the case of the alpine marmot (Marmota marmota)

Tafani, Marion 20 February 2013 (has links)
Comprendre l'impact des changements globaux sur la dynamique des populations animales représente un enjeu sociétal majeur pour favoriser le maintien de la biodiversité. Le milieu de montagne permet de travailler sur de petites communautés d'herbivores à forte valeur patrimoniale, cynégétique ou emblématique. Il s'agit en effet d'un milieu en pleine mutation depuis plusieurs décennies à cause de la déprise agricole et du développement récent de l'écotourisme et des activités humaines récréatives. Ces changements ont conduit à l'aménagement et à la modification de nombreux habitats. Par ailleurs, le milieu montagnard est fortement saisonnier et semble particulièrement sensible au changement global actuel. L'effet des changements climatiques récents reste pourtant encore mal évalué. L'augmentation de la température moyenne des 30 dernières années est susceptible de modifier la dynamique des ressources disponibles pour les herbivores, mais aussi la chronologie d'accès à ces ressources, notamment à travers la diminution du couvert neigeux en hiver et sa fonte accélérée au printemps. L'objectif de cette thèse est donc d'évaluer l'effet des variables climatiques locales et globales sur les traits d'histoire de vie des herbivores de montagne, principalement à travers l'exemple de la marmotte alpine (Marmota marmota), un mammifère social et hibernant. Ce travail a permis de mieux appréhender les mécanismes d'action du climat sur la démographie des espèces de montagne, mais aussi de mettre en évidence le déclin continu d'une population de marmottes Alpines, dans les Alpes françaises, depuis les années 1990. Il pourrait ainsi servir de base pour établir les règles de gestion de cette espèce emblématique, et maintenir une forte biodiversité dans les écosystèmes de montagne / Natural systems responses to global change are of major concern for human societies to maintain high species diversity. Mountains, and particularly alpine climate, offer the opportunity to work with small mammalian herbivore communities, with a strong patrimonial, hunting or emblematic value. Since the last decades, mountains are indeed facing major changes, due to the loss of agricultural lands and the recent development of ecotourism and human recreational activities. Those changes have modified natural habitats and their management planning a lot. Additionally, alpine climate is strongly seasonal and seem particularly sensitive to the actual global change. However, the recent impact of climate change on species and natural habitats is still under-evaluated. The increase in the average global temperature of the last 30 years could modify resources dynamics for a wide variety of species. The availability of resources, but also the chronology of access to these resources, for example through the decrease of snow cover in winter and its accelerated thaw in spring, is of crucial importance for herbivore populations. The aim of this thesis is therefore to evaluate the potential role of local and global climatic factors on life history traits of mountain herbivores, mostly through the example of the alpine marmot (Marmota marmota), a social and hibernating mammal. This work allowed us to better understand the mechanisms underlying the effect of climate change on mountain mammal population dynamics and demography; but also to highlight the continuous decline of an alpine marmot population in the French Alps since the 90s. Conservation strategies and practices could thus arise from this work, in order to maintain biodiversity in mountainous ecosystems
103

Host Community Attitudes and Overtourism : The Case of the Puster Valley in South Tyrol, Italy

Weiss, Thomas January 2021 (has links)
This study investigates host community attitudes towards tourism in South Tyrol’s Puster Valley in Italy along with predispositions against the emerging phenomenon of overtourism and explores the factors influencing its formations, as similar research in the same European context with a more mature tourism industry is still underdeveloped. Applying quantitative methods, data was collected through an online survey between May and June 2021. A total of 17 attitude statements were analyzed using IBM’s SPSS and the results indicate that tourism impacts in the valley are perceived evenly throughout the whole community while it was proven with Social Exchange Theory that people involved within the tourism industry are less inclined to perceive negative impacts. Choosing the Pragser Wildsee as a case, the analysis further reveals that overtourism is not only affecting residents in its vicinity put has more far-reaching consequences. Even the results not being very surprising, the study is confirming tourism-related issues and suggests more need in investigating resident attitudes in similar environments.
104

Post-Depositional Effects Modifying the Relationships between Stable Isotopes and Air Temperature in an Alpine Ice Core

Ihle, Alexander C. January 2021 (has links)
No description available.
105

Farming with Draft Animals: Using Retro Innovations for Sustainable Agrarian Development. : A case study of organic small-scale farming in Northern Italy.

Garre, Anna January 2022 (has links)
To farm more sustainably, some farmers are rediscovering and innovating knowledge, skills, and technologies that were used before the modernisation of agriculture in the 1950s. One such 'retro-innovation' is the use of draft animals as a source of labour on farms. As modern farming and agronomy pay little attention to 'retro-innovations', not much is known about why and how farmers reintroduce draft animals on their farms. Therefore, the potential of draft power to contribute to the sustainable development of agriculture also remains unclear.   To fill this gap, this study uses interviews and participant observation with seven draft animals’ farmers in Northern Italy. Results indicate that these farmers are organic small-scale farmers using both draft animals and tractors. Engaging in multiple farming activities is an important aspect of these farms. Although draft animals are primarily used in vegetable growing, they can, among others, be involved in logging, marketing the farm production, and used for horse-riding. Their reintroduction as source of labour aligns with the so-called “peasant logic” to farming. This style of farming is reflected in farmers’ craftsmanship, co-production, and autonomy, and the use of draft animals as a skill-oriented technology. Farmers engaged in a peasant style of farming use draft animals as: (1) a technology to increase the farm autonomy and sustainability; (2) work companions with whom they collaborate and develop a strong relationship; and (3) a retro-innovation that is motivated by their self-perception as local stewards.   The study indicates that the relationship between farmers and their draft animals is the most rewarding aspect of animal traction, confirming the meaningful role of non-humans in farm practices and emphasising the central role animals can take in a peasant logic of farming. Future research should continue exploring the role of retro-innovation and of relationships between humans and non-humans for sustainable agricultural development.
106

A CINEMATIC VILLAGE FOR A CHANGING LANDSCAPE - AN ALPINE ROMANTIC STORY

Sacco, Diana January 2022 (has links)
Climate change has already had noticeable effects on the environment. Glaciers are retreating, ice on lakes and rivers is melting earlier, plant and animal species have relocated, and trees are blooming sooner. The Alpine landscape is one very good example of these dramatic shifts, which significantly impacted its identity and the economic stability of its communities. The effects on the classic forms of alpine tourism, especially the winter one, coupled with the mismanagement of the land and the lack of valorisation of the cultural heritage of the valleys have led to two equally disruptive phenomena: on one side, mass overtourism affects the most popular locations in the mountains requiring the construction of new infrastructures and resorts; on the other, the abandonment of the smallest or less known villages threatens the disappearing of rural communities with the consequent undermining of their surrounding landscape. Addressing the recovery plan drafted by the Italian Government after the pandemic (PNRR 2021), which includes giving new life to smaller villages and their ecological environment as well as reintroducing the Italian cinematographic industry as a competitive player within the international scene, the project aims to tackle the progress/paradox situation affecting the Italian Alps, Overtourism versus Abandonment, and its consequent impact on the landscape. The design is located in the Valle D’Aosta region, due to its proximity to Turin, a scenographic city where Italian cinema was born, and to its controversial nature which sees overbooked glamorous locations juxtaposed to the abandoned small rural realities. Particularly the proposal takes the story of the hamlet of Oyace, whose abandoned buildings are currently being sold at the symbolic price of 1 euro, in order to imagine a different future for alpine communities, which includes both economic growth and environmental awareness.Thought as a continuous dialogue between reality and fiction, the project starts in Oyace, taking shape as a film director’s studio in one of the currently abandoned buildings. It then continues as a new village envisioned by the director on the nearby artificial lake de Place Moulin, chosen for its symbiotic natural and man-made environment. The masterplan, drafted as a movie unfolding on site, borrows from the narrative of a romantic novel, Hypnerotomachia Poliphili, written by Italian Francesco Colonna and published in Venice in 1499, which is set in mythical and personified landscapes. The different chapters of the novel with their allegorical nature inspire the ethos of each of the buildings of the village.The architecture of the proposal, which accommodates different programs typically present in a traditional Italian alpine village alongside spaces and structures necessary to the moviemaking, borrows from alpine forms and heritage, set design and movie strategies and the landscape. The result is a series of performative infrastructures staging, re-enacting, revealing and counteracting issues currently experienced by the hamlet of Oyace, these can be environmental, social or economic, and their consequences on the alpine environment. Despite taking from the story of the book and manifesting itself as a village, the project is not limited to the novel, but rather it attempts to start an investigation into the role of architecture within the wider context of the endangered alpine environment, whilst arguing for a multidisciplinary approach and the use of narrative as critical tools for the production of impactful architecture in times of crisis.Ultimately the design aims to envision a new future for the community of Oyace and its ecological environment, speculating on a new approach towards giving new life to alpine communities based on a deeper awareness of their surrounding environment.
107

Alle origini del rogo votivo e della metallurgia alpina Il culto del fuoco nell’Età del Rame nel caso del Pigloner Kopf

Oberrauch, Hanns 02 December 2021 (has links)
The archaeological site Pigloner Kopf (Vadena/Pfatten, South Tyrol, Italy) has revealed unexpected elements related to the local Bell Beaker culture, like the local production of shaft-hole axes, typologically linked to the Balkans and the Danube region. The site also shows the oldest evidence of ritual burnt offerings in the Eastern Alps. The mostly burnt animal bones, cereals, flint tools and fragments of pottery could be interpreted as the remains of a rock sanctuary with burnt offerings. The site can be considered as a prototype of the alpine places of worship and mountain sanctuaries. These burning rituals were practised from the beginning of the Bronze Age until the late Roman Empire. The aim of the paper is to present the results of the study of materials and their analyses, focussing on the metallurgical industry, composed mostly by objects produced with local copper, like 10 miniaturised shaft-hole axes, 7 awls and a pin and also by imported objects like a dagger blade and spiral ornaments. The deposition of copper tools in hoards in association with burnt offerings suggest a ritual interpretation of the site, dated to the late Copper Age with Bell Beaker elements in lithics and pottery.
108

Macroparasite transmission and dynamics in Apodemus flavicollis

Ferrari, Nicola January 2005 (has links)
This thesis examines the parasite dynamics and the mechanisms affecting parasite load and transmission focalising on the role played by host and habitat heterogeneities. This study is based on the gastrointestinal nematode Heligmosomoides polygyrus and the small mammal yellow necked mouse and uses data gathered from experimental field manipulations of parasites intensities and data gathered from trapping monitoring. Initially the parasite community of yellow-necked mouse (Apodemus flavicollis) was explored in North-Eastern Italian Alps with the aim to describe the major patterns and identify the factors affecting parasite community structure. Despite the observed spatial variability it has been found that differences within the host population such age and secondly sex and breeding conditions, were the major factors acting on parasite occurrence and intensity. Habitat differences had a less apparent effect on parasite community structure. The consequences of H. polygyrus infection on other parasite species infections have been analysed, in specific the infestation of the tick Ixodes ricinus in populations of A. flavicollis. H. polygyrus load and tick infestation were monitored as well as were carried out field manipulations of H. polygyrus intensity and were monitored changes in tick infestation. It has been found that H. polygyrus load was negatively related to I. ricinus infestations. Host factors mediated the H. polygyrus-I. ricinus interaction such that young and non-breeding mice exhibited higher I. ricinus to H. polygyrus intensity respect breeding adults. The role of host sex on parasite abundance was then investigated carrying out a field experiment where the H. polygyrus intensity were manipulated in relation to mice gender. In specific, H. polygyrus was removed alternately from either sexes and the parasite load was analysed in the untreated sex. It was found that males mice were responsible to drive parasite transmission in the host population and this was observed in absence of sex-bias in parasite infection, suggesting that this pattern was not a mere consequence of quantitative differences in parasite loads between sexes. To disentangle the possible mechanism causing this sex bias in parasite transmission mathematical simulations based on parameters obtained for the field experiment were used. Two non mutually exclusive hypotheses causing sex bias in parasite transmission were tested: a- males immune response is less efficient and this causes the development of more successful parasite infective stages or b-males behaviours allow them to be more efficient is spreading in more exposed areas parasite infective stages. Multi-host models were developed and simulations were compared with field results. While it was not disentangled the most dominant mechanism causing sex bias in parasite transmission this study underlined the importance of host sexes in affecting parasite dynamics and host-parasite interaction. In conclusion this thesis highlighted the importance of considering host and environmental differences when investigating host parasite interactions. This finding could be extremely important when planning measured of disease control or to avoid disease outbreak. Controlling target group of individuals host could avoid economical losses and a more effective measure of intervention.
109

La circulation dans les Alpes à l'époque romaine : l'exemple des Alpes Cottiennes / Traffic over the Alps in Roam times : the case of Cottian Alps

Artru, Francois 28 September 2012 (has links)
L’étude vise à apprécier l’importance exacte du système routier du Mont-Genèvre et de l’entité administrative des Alpes Cottiennes dans les relations transalpines à l’époque romaine. Une première partie, sorte d’introduction à la circulation alpine dans l’Antiquité, envisage successivement les sources documentaires, en particulier la Table de Peutinger, les nouvelles données paléoenvironnementales, l’exploitation du trafic comme élément fondateur du découpage territorial préromain, la part du mythe et des connaissances réelles dans l’image des Alpes chez les Romains et, enfin, les conditions pratiques de déplacement dans le massif alpin. Tout au long des cinq siècles de domination romaine sont analysées les relations entre les évènements politico-militaires, la géographie administrative et le réseau viaire de la région étudiée. Le passage du royaume indigène indépendant à la préfecture romaine est revu à partir d’une remise en question de l’idée d’un vaste royaume préexistant à la conquête augustéenne et de la prétendue hostilité initiale de Cottius envers Rome. Parmi les arguments qui plaident pour une alliance de Cottius et d’Auguste vue comme un préliminaire à la conquête alpine et non comme son dernier acte, l’accent est mis sur le degré avancé de romanisation des Cottii, de la cité de Suse et de la voie du Mont-Genèvre. Le témoignage d’Ammien Marcellin sur la résistance du roi de Suse est récusé et le passage de Pline sur ‘les douze cités cottiennes qui ne furent pas hostiles’ interprété en faisant l’hypothèse de deux états successifs de la préfecture de Cottius.Il est montré ensuite comment, au cours des cinq siècles qui ont suivi la création de la préfecture, la voie du Mont-Genèvre demeura la voie transalpine la plus commode et, sans doute, la plus utilisée de toutes les Alpes occidentales. L’effet déterminant du développement du réseau routier cottien sur la municipalisation, la romanisation et l’économie des hautes vallées est mis en relief. La possibilité du passage de l’activité d’élevage de montagne à un stade productiviste basé sur la pratique de la transhumance est envisagée. Parmi les aspects du trafic transalpin sont abordées la place primordiale du cursus publicus, l’organisation douanière de la région et l’arrière-plan religieux des déplacements en montagne. La mise en évidence d’un véritable ‘système routier du Mont-Genèvre’, aménagé à partir de l’époque préfectorale, s’appuie sur l’étude de la carte archéologique et sur une prospection de terrain. Celle-ci a porté d’abord sur la voie du Mont-Genèvre, révélant pour le secteur durancien un tracé différent de celui envisagé par les rares études antérieures. De nombreux arguments sont rassemblés en faveur de l’existence d’une voie romaine franchissant le col du Petit Mont-Cenis et conduisant au limes rhénan. En ce qui concerne la voie qui empruntait probablement le col de Larche, le tracé proposé franchit sans grande difficulté le prétendu obstacle de la basse vallée de l’Ubaye. Deux autres voies du système du Mont-Genèvre ont été étudiées en détails. Sur la voie du col du Lautaret sont apportés quelques éléments nouveaux, en particulier dans la zone de la Porte Romaine de Bons et dans celle de la section taillée près de Bourg d’Oisans. Quant à la voie tracée sur la Table de Peutinger entre Luc-en-Diois et le Mont-Genèvre, elle fait l’objet d’un examen graphique sur le document et de reconnaissances sur le terrain, sans réussir à démontrer la réalité de cette liaison. / The study addresses the Mont-Genèvre road and the Cottian Alps district as playing a major rôle in the transalpine traffic during the Roman period. A general chapter upon alpine circulation in the Antiquity reviews the following subjects: recent paleoclimatic data, control of an itinerary in the genesis of preroman tribes’ settlement, actual knowledge of Alps by Romans, and practical traveling conditions through mountains.Relationships between politico-military events, territorial limits and road network are analysed along five centuries of Roman presence. The idea of a vast preroman kingdom ruled by Cottius is not shared. The transition from independence to the status of roman prefecture is viewed as a preliminary decision of August and not as a final event of the Alps conquest. Ammianus alleged hostility of Cottius to Rome, but his testimony has to be rejected. Pline’s allusion to the twelve cottian cities which were not hostile is explained by supposing an early transitory state of the prefecture.It is explained how the development of the road network allowed promotion of some cities to municipal status, favoured romanisation and boosted the economy of high valleys. An intensification of pastoralism through the practice of transhumance is suggested. Related aspects of the alpine traffic, as cursus publicus, Quadragesima Galliarum and religious beliefs of travellers are examined. Evidences for the existence of a ‘Mont-Genèvre roads system’, constructed since the time of the prefecture, are derived from archaeological registries and local exploration. Concerning the road of the Durance valley, within cottian frontiers, it appears to follow a quite different course from the one proposed until now. Arguments are gathered favouring the existence of a roman road running across the Petit Mont-Cenis and leading to the Rhenan limes. The road which very likely runs over the col de Larche (or de la Madeleine) and through the Ubaye valley appears to join easily the Durance valley contrary to some previous opinions. Two other routes of the Mont-Genèvre system are studied in detail. One crosses the col du Lautaret and its two remaining sections are carefully examined, namely the Porte Romaine de Bons and the rock-cutted segment near Bourg d’Oisans. The second road, between Luc-en-Diois and the Mont-Genèvre, appears only on the Tabula Peutingeriana. Graphical examination of the drawing and local investigation does not allow a definitive conclusion upon the reality of this route.
110

Serpentinites, vecteurs des circulations fluides et des transferts chimiques de l'océanisation à la subduction : exemple dans les Alpes occidentales / Serpentinites, vectors of fluid circulation and chemical transfer from the mid-oceanic ridge to subduction : Example from the Western Alps

Debret, Baptiste 08 November 2013 (has links)
Les serpentinites sont un composant important de la lithosphère océanique formée niveau de rides lentes à ultra-lentes. Ces roches représentant un vaste réservoir de l'eau, d’éléments mobiles dans les fluides (FME), halogènes et volatils, il a été proposé qu'elles jouent un rôle important pendant l'échange chimique se produisant entre la lithosphère subduite et le coin mantellique dans des zones de subduction. L’objectif de mon doctorat a été de caractériser la nature et la composition des fluides transférés depuis la plaque plongeante jusqu’au coin mantellique en étudiant des ophiolites alpines métamorphiques. Celles-ci se composent en grande partie de serpentinites et ont enregistré différentes conditions métamorphiques modélisant un gradient de subduction. Les études pétrologiques des ophiolites alpines montrent que celles-ci ont enregistré différentes étapes de serpentinisation et de déserpentinisation : (1) serpentinisation océanique et la formation d’assemblages à lizardite et à chrysotile ; (2) déstabilisation prograde de la serpentine océanique en antigorite, à la transition des faciès schistes verts – schistes bleus ; (3)déshydratation de l'antigorite en olivine secondaire dans les conditions du facies d'éclogite. Les analyses chimiques des éléments en trace par LA-ICPMS et constituants volatils et halogènes par SIMS prouvent que, pendant la subduction, les processus de serpentinisation se sont réalisés sans contamination significative par des fluides externes provenant de la déshydratation des sédiments. Dans la partie la superficielle de la lithosphère océanique, la déformation augmente la mobilité des éléments en trace et permet leur redistribution et l'homogénéisation de la composition d'antigorite à l'échelle kilométrique. Au contraire, dans la partie la plus profonde de la lithosphère serpentinisée, la mobilité des éléments en trace est réduite et localisée dans des veines métamorphiques qui constituent des chenaux de circulation des fluides. Les cristallisations successives de l'antigorite et de l'olivine secondaire sont accompagnés d'une diminution des concentrations en FME (B, Li, As, Sb, Ba, Rb, Cs…), halogènes (F, Cl) et volatils (S). La quantification de Fe3+/FeTotal, par chimie humide et spectroscopie XANES, des serpentinites et serpentines montrent que, dans les premières phases de subduction, la transition de lizardite en antigorite est accompagnée d'une réduction forte du fer. Cette réduction est non linéaire avec le degré métamorphique, mais dépend également de la chimie initiale du protolithe péridotitique. À un degré métamorphique plus élevée, le début du processus de déserpentinisation se produit dans un environnement ferreux, menant à une nouvelle oxydation de l'antigorite résiduelle. En conclusion, les serpentinites sont un vecteur de transfert d'éléments depuis la ride jusqu’aux zones de subduction. Pendant la subduction et pendant les changements de phases de la serpentine, les teneurs en FME, en éléments volatils et halogènes de la serpentine diminuent, suggérant que ces éléments sont soustraits dans une phase fluide qui peut potentiellement contaminer le coin mantellique. La nature de ce fluide varie au cours de la subduction. Dans les premiers kilomètres de la subduction, lors de la transition lizardite vers antigorite, les fluides relâchés sont riches en FME, volatils et halogènes. Ils pourraient oxyder le coin mantellique (e.g. SOX, H2O ou CO2) où ils initieraient la cristallisation d’une serpentine riche en ces éléments. A l’inverse, à plus grande profondeur, la déshydratation de l’antigorite libère une quantité moindre de FME, volatils et halogènes. De plus, l’observation d’antigorite riche en Fe3+ associée à l’olivine de déserpentinisation pourrait suggérer la production d’hydrogène lors de la déshydratation de la plaque plongeante. / Serpentinites are an important component of the oceanic lithosphere formed at (ultra-) slow spreading ridges. Because these rocks are a large reservoir of water, fluid mobile elements (FME), halogens and volatiles, it has been proposed that they play a major role during chemical exchange occurring between the subducted lithosphere and the mantle wedge in subduction zones. The aim of my PhD was to characterize the nature and the composition of the fluids transferred from the slab to the mantle wedge by studying metamorphic alpine ophiolites. Those ones are mostly composed of serpentinites and have recorded different metamorphic conditions modeling a subduction gradient. The petrological studies of alpine ophiolites demonstrate that they record different serpentinization and deserpentinization steps: (1) from oceanic serpentinization and the formation of lizardite and chrysotile assemblages, (2) to the prograde destabilization of oceanic serpentine into antigorite, from greenshist to blueschist facies, and (3) finally the dehydration of antigorite into secondary olivine at eclogite facies. The chemical analyses of trace elements by LA-ICPMS and volatiles and halogens by SIMS show that during subduction, the serpentinization processes took place in a relatively closed system without significant external fluid contamination from sediments. In the shallowest part of the oceanic lithosphere, the deformation enhances the mobility of trace elements and permits their redistribution and the homogenization of antigorite composition at kilometric scale. While in the deepest part, the trace element mobility is reduced and localized in metamorphic veins that correspond to channel fluid flows. The successive crystallization of antigorite and secondary olivine are accompanied by a decrease of FME (B, Li, As, Sb, Ba, Cs…), halogens (F, Cl) and volatiles (S) concentrations. The quantification of Fe3+/FeTot by wet chemistry and XANES spectroscopy in serpentinites and serpentine show that, in the first stages of subduction, the transition lizardite to antigorite is accompanied by a strong reduction of the iron. This reduction is nonlinear with metamorphic grade, but also depends on the initial chemistry of the peridotitic protolith. At higher metamorphic grade, the beginning of the deserpentinization process occurs in a ferrous environment, leading to a new oxidation of the remaining antigorite. To conclude, serpentinites are a vector of element transfer from the ridge to subduction zones. During subduction and during the phase changes of serpentine, the FME, volatile and halogen concentrations of serpentine decrease, suggesting that they are removed in a fluid phase that can potentially contaminate the mantle wedge. The composition and the nature of this fluid phase vary during prograde metamorphism. In the first stages of subduction, during the transition lizardite to antigorite, the released fluids are FME, volatiles and halogens rich. They could oxidize the mantle wedge peridotite (e.g. SOX, H2O or CO2) where they allow the crystallization of a FME, volatils and halogens-rich serpentine. At greater depth, the formation of a Fe3+-rich antigorite associated with secondary olivine suggests a H2 production during slab dehydration.

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