WorldCat Identities

École doctorale Géosciences, ressources naturelles et environnement (Paris)

Overview
Works: 198 works in 198 publications in 2 languages and 199 library holdings
Roles: Other, Degree grantor
Publication Timeline
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Most widely held works by ressources naturelles et environnement (Paris) École doctorale Géosciences
La lithosphère du point triple Aden - Afar - sud mer Rouge et du golfe d'Aden : magmatisme et rupture continentale by Felicie Korostelev( )

1 edition published in 2015 in French and held by 2 WorldCat member libraries worldwide

The Afar triple junction is a unique region that links the Red Sea, the Gulf of Aden and the Ethiopian rift, and where it is possible to study the different stages of continental breakup, from early rifting to seafloor spreading and development of continental passive margins. Extension and magmatic activity are generally thought to be restricted to the active volcanic segments of the rift or to oceanic ridges. However, magmatic activity is also present on the continental margins flanks of the Afar rift, southern Red Sea and Gulf of Aden. The ambient noise tomography and teleseismic body-wave tomography are complementary methods that allow imaging the crust and upper mantle, and help to reveal magmatic systems. Our tomographic studies of the Afar region provide evidence for the presence of complex magmatic systems under the Afar rift flanks, currently modifying the crust and linked with hydrothermal systems near the surface. The emplacement of intruded or under-plated dense magmatic material in the Afar lower crust accommodates the extension outside of the active magmatic segments. In addition, the Red Sea margin flanks in Yemen are affected by magmatism caused by localized small-scale upwellings of mantle material, from a broad abnormally hot mantle zone located beneath Afar and southwestern Yemen. We also suggest the presence of magmatic systems with or without a volcanic expression at the surface, beneath the passive margins shoulders of the eastern Gulf of Aden. We propose that these systems could be fed by small-scale convection caused by lithosphere thickness variations at the edge of the Arabian plate and near the Gulf of Aden main fracture zones
Rôle des fluides pendant l'exhumation continentale : modélisation hydro-thermo-mécanique by Leila Mezri( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Strain localization is essential to the existence of plate tectonic on Earth. Yet, it is the result of non-linear interaction across several temporal and spatial scales and to date no unique rheological model exists that captures the effect of all these interactions at crustal scale. The work presented here is an attempt to fill part of the gap between out- crop scale and crustal scale models, between petrological scale and crustal scale. The central question is how to measure the effects of fluids and fluid-rock interactions on the dynamics and the kinematics of continental metamorphic core complexes by the mean of crustal scale numerical models. To answer this question, we have tried to esta- blish an empirical model of fluid flow and fluid-rock interaction, which could be valid at the scale of the crust. At that specific scale, it is important to capture the effects of free fluids both on the density of rocks, because it determines the body forces that are driving the exhumation of the crust, and on the strength of rocks and particularly on shear zones which constitute the 'hand-break', the surface tractions, which resist this exhumation. This empirical model is based on a first order observation related to the behaviour of metamorphic rocks along the retrograde P - T path of their exhumation. High-grade metamorphic rocks (amphibolite/granulite) are indeed exhumed to the sur- face with very little retromorphose except those located within the shear bands where deformation localises. This works first consisted in parameterising this observation in a manner that could be implemented into a 2D thermo-mechanical code as an hydro- thermo-mechanical coupling which could account for free-water/rock-water exchange. In second part, a simplified scheme is introduced to account for hydrothermal cooling of the crust in the late stage of exhumation. The results show that this parameterization al- lows to better account for field observation in a range of parameters that are compatible with laboratory experiments. Limiting the retromorphose of rocks by the availability of free water is shown to produce significantly different metamorphic domes kinematics as compared to prior studies. We indeed demonstrate that it is not necessary to introduce heterogeneity in crustal composition to form asymmetric structures but that the effect of water is modulated by the chemistry of the protolith rocks which influences strain localization
New Rock-Eval method for Pyritic and Organic Sulphur quantification : Application to study Organic Matter preservation in Jurassic sediments by Anabel Aboussou( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

This study was focused on development of the new Rock-Eval 7S which presents the same functionalities as the current version (Rock-Eval 6), complemented by a system of sulphur detection during the two phases of the analysis: pyrolysis phase and oxidation phase. The main goal of this PhD project was to provide and highlight different carbon and sulphur Rock-Eval 7S parameters which can be used to describe OM preservation in marine sediments. To reach this goal, a new Rock-Eval method for sulphur speciation and quantification was developed, and validated on a set of marine sediments and on sedimentary mixtures. This new method was then used to help the description of organic matter preservation in three marine sedimentary sections: (i) Kimmeridge Clay Formation; Grey Shale Member; (iii) Blue Lias Formation. This PhD project aims to lay the scientific foundation to apply Rock-Eval 7S carbon and sulphur parameters as routine descriptors in basin models
Dynamique d'une frontière transformante dans un contexte de collision oblique : étude de la limite nord de la plaque Caraïbe dans la région d'Haïti. by Jordane Corbeau( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The Northern Caribbean transpressive plate boundary is expressed in Haiti by the partitioning of the deformation between two strike-slip faults and compressive structures. Bathymetric, seismic reflection and receiver-functions studies are methods used here to constrain the structure and the dynamic of the Northern Caribbean transpressive plate boundary offshore and onshore. The bathymetric data acquired during the Haiti-SIS cruises provide a detailed mapping of the geometry and segmentation of the senestrial strike-slip fault systems. The seismic profiles in the Jamaica Passage show that basin structures exist prior to the initiation of the EPGFZ and are cross-cut and folded by the EPGFZ. We identify a distinct crustal domain that we relate to the Caribbean large igneous province. The present deformations offshore show that the EPGFZ is primary strike-slip, with an increasing compressive component of the deformation toward the east. The shortening estimates are very small (2 to 3%) compared to the short-term GPS modeling estimates. Onshore in Haiti, we image the crustal structure from a receiver-functions study. The crustal thickness is ~23 km in the northern part of Haiti, ~22 km in the southern part of Haiti and ~41 km in the middle part, delimiting 3 distinct domains. We propose that these domains correspond to 3 geological distinct terranes: the Cretaceous volcanic arc in the north, the oceanic igneous province in the south, and in between a continental crust underthrusted by dense material. The underthrusted material could be a subducted portion of the Caribbean large igneous province under the Trans-Haitian fold-and-thrust belt
Etude en chambre d'étalonnage du frottement sol-pieu sous grands nombres de cycles. Application au calcul des fondations profondes dans les sols fins saturés by Rawaz Dlawar Muhammed( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

This Ph.D. dissertation focuses on the behavior of the pile-soil interface under cyclic loading. In this context, an experimental program was conducted on the Navier calibration chamber using an instrumented pile-probe and a piezocone installed in saturated clay samples. In order to carry out this study, we developed, In particular a slurry consolidomètre prototype to reconstitute fully saturated clay samples. Special attention was given, during displacement controlled cyclic tests, to local friction evolution mobilized at the pile-soil interface and mobilized tip résistance. The experimental study has allowed the demonstration of the influence of the key parameters on the observed behavior and more specifically, on the local friction at the interface. We examined, in particular, the influence of amplitude of cyclic displacement, the frequency of cyclic loading and the applied number of cycles. Emphasis was put on the case of large number of a few hundred thousand of cycles that is still little studied in the literature. We also study the influence of initial consolidation pressure. The experimental results allowed us to identify, after an initial phase of stress softening, a new phase of stress hardening of local friction. This behavior is not yet described in the literature. The stress softening phase is related to the progressive generation of pore water pressure while the stress hardening, for its part, is related to a gradual dissipation of the generated pore water pressure. Furthermore, a complete sequence of monotonic and cyclic tests were conducted on a piezocone in order to quantify, in a precise manner, the generated pore water pressure at the pile-soil interface during different loading phases and thus validate interpretations given for stress-softening and stress-hardening phases based on the observed results
Interactions fluides-roches dans les chondrites carbonées : approche expérimentale et modélisation thermodynamique by Florent Caste( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Les serpentines riches en fer sont des composants majeurs des chondrites CM. Formées au cours d'épisodes d'altération hydrothermale sur leur corps parent astéroïdal, à une étape précoce de la formation du Système Solaire, elles peuvent constituer un proxy des conditions d'altération de ces roches et permettre de mieux comprendre l'évolution à long terme des colis de stockage des déchets nucléaires, car ces processus sont considérés comme un bon analogue des interactions fer-argiles-eau. Pendant cette thèse, nous nous sommes intéressés aux conditions de formation et d'équilibre des ces minéraux, en prêtant une attention particulière à l'évolution de la valence du fer pendant l'altération. Trois approches sont présentées : la synthèse de Fe-serpentines, l'altération expérimentale d'assemblages chondritiques à basse température, en milieu anoxique, et l'affinement d'un modèle thermodynamique incluant des serpentines de composition Fe2+-Fe3+-Mg-Al-Si-O-H. Le modèle thermodynamique, basé sur des données expérimentales, devrait permettre de mieux prédire les assemblages à l'équilibre dans les chondrites altérées. Nos expériences de synthèses suggèrent que la précipitation de phases de composition proche du pôle pur cronstedtite est contrôlée cinétiquement. Aux premiers stades de l'altération expérimentale de minéraux primaires anhydres, nous avons observé la formation de phases peu cristallines avec une proportion relativement faible de fer ferrique. Nos résultats suggèrent que le rapport Fe/Si et la teneur en Fe3+ favorisent la précipitation des serpentines. Ils apportent un éclairage intéressant aux premiers stades d'altération dans les chondrites carbonées
Etude des processus de biominéralisation des sulfures de fer et des mécanismes de piégeage du nickel : contexte des sédiments de mangrove de Nouvelle-Calédonie by Maya, Devi Ikogou( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

The aims of the present work were (i) to study the behavior of iron and nickel in the biomineralization of iron sulfides by (thio)sulfate-reducing bacteria and (ii) to estimate the influence of open-cut mining activities on microbial communities development in mangrove sediments in New Caledonia. To achieve these objectives, incubation experiments were conducted under anoxic conditions with the (thio)sulfate-reducing bacteria (i.e. Desulfovibrio capillatus) and a consortium of sulfate-reducing bacteria native mangrove sediments of New Caledonia. These experiments were carried out with different Fe(III) precursors (i.e. goethite, ferrihydrite and ferric citrate) and in the presence of structural or soluble nickel. The results show that the sulfate-reducing bacterial activity leads, in all experiments, to the formation of mackinawite (FeS). This iron sulfide precipitates as nanosized crystallites that increase in size with incubation time. When nickel is present in solution, the total soluble amount can be substituted to iron (i.e. replacing 4 mol%) in the structure of mackinawite. Thus, the formation of a small proportion of mackinawite scavenged total soluble amount of nickel initially present in solution (e.g. FeS:Ni ratio of 1). This sequestration mechanism appears to be stable over time (no nickel was released in solution) and accelerates the crystal growth of mackinawite, leading to the stabilization of this mineral. These results highlight the effective role of sulfate-reducing bacteria in the biomineralization of iron sulfides such as mackinawite and in the sequestration of nickel, suggesting a stabilization of this element in mangrove sediments and limitation of its bioavailability. These results could explain the absence of negative impact of open-cut mining activities on the sulfate-reducing bacterial communities present in New Caledonia
High-pressure carbonation : a petrological and geochemical study of carbonated metasomatic rocks from Alpine Corsica by Francesca Piccoli( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

The balance between the carbon input in subduction zone, mainly by carbonate mineral-bearing rock subduction, and the output of CO2 to the atmosphere by volcanic and metamorphic degassing is critical to the carbon cycle. At fore arc-subarc conditions (75-100 km), carbon is thought to be released from the subducting rocks by devolatilization reactions and by fluid-induced dissolution of carbonate minerals. All together, devolatilization, dissolution, coupled with other processes like decarbonation melting and diapirism, are thought to be responsible for the complete transfer of the subducted carbon into the crust and lithospheric mantle during subduction metamorphism. Carbon-bearing fluids will form after devolatilization and dissolution reactions. The percolation of these fluids through the slab- and mantle-forming rocks is not only critical to carbon cycling, but also for non-volatile element mass transfer, slab and mantle RedOx conditions, as well as slab- and mantle-rock rheology. The evolution of such fluids through interactions with rocks at high-pressure conditions is, however, poorly constrained. This study focuses on the petrological, geochemical and isotopic characteristic of carbonated-metasomatic rocks from the lawsonite-eclogite unit in Alpine Corsica (France). The study rocks are found along major, inherited lithospheric lithological boundaries of the subducted oceanic-to-transitional plate and can inform on the evolution of carbon-bearing high-pressure fluids during subduction. In this work, it will be demonstrated that the interaction of carbon-bearing fluids with slab lithologies can lead to high-pressure carbonation (modeled conditions: 2 to 2.3 GPa and 490-530°C), characterized by silicate dissolution and Ca-carbonate mineral precipitation. A detailed petrological and geochemical characterization of selected samples, coupled with oxygen, carbon and strontium, neodymium isotopic systematic will be used to infer composition and multi-source origin of the fluids involved. Geochemical fluid-rock interactions will be quantified by mass balance and time-integrated fluid fluxes estimations. This study highlights the importance of carbonate-bearing fluids decompressing along down-T paths, such as along slab-parallel lithological boundaries, for the sequestration of carbon in subduction zones. Moreover, rock-carbonation by fluid-rock interactions may have an important impact on the residence time of carbon and oxygen in subduction zones and lithospheric mantle reservoirs as well as carbonate isotopic signatures in subduction zones. Lastly, carbonation may modulate the emission of CO2 at volcanic arcs over geological time scales
Simulation des transferts diphasiques en réservoir fracturé par une approche hiérarchique by Chahir Jerbi( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Pour effectuer des simulations d'écoulement diphasique dans les réservoirs fracturés, l'usage des modèles DFM entraîne des temps de calculs exorbitants. L'une des solutions envisageables est le recours aux modèles double milieu. Ces modèles nécessitent la détermination des dimensions du bloc équivalent et la mise à l'échelle des paramètres d'écoulement monophasique et diphasique. Concernant les paramètres d'écoulement monophasique, des méthodes de mise à l'échelle existantes ont déjà fait leur preuve. En contrepartie la mise à l'échelle des paramètres d'écoulement diphasique reste un sujet ouvert nécessitant l'identification de la nature des forces (capillaires, gravitaires ou visqueuses) contrôlant l'écoulement dans le réservoir. Dans le cadre de cette thèse, les formulations mathématiques et les modèles numériques liées à la simulation de type DFM et double milieu ont été explorés. Une étude bibliographique portant sur les méthodes existantes de mise à l'échelle a été développée. Une nouvelle méthode de détermination des dimensions du bloc équivalent (méthode OBS) a été mise en place. Une analyse dimensionnelle servant à identifier la nature des échanges matrice-fractures (capillaire ou visqueuses) lors d'un écoulement diphasique eau-huile, sans gravité, a été mise en place. Le nombre capillaire dérivé a été testé. Enfin, une méthodologie de mise l'échelle des paramètres équivalents double milieu a été mise en place. Cette méthodologie traite le cas d'un écoulement diphasique dans les réservoirs fracturés ayant un milieu matriciel hétérogène dans un contexte d'échanges matrice-fractures dominés par les effets visqueux
Tester les isotopes stables de l'azote des matières organiques fossiles terrestres comme marqueur paléoclimatique sur des séries pré-quaternaires by Romain Tramoy( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Evolution pétrologique et déformation des semelles métamorphiques des ophiolites : mécanismes d'accrétion et couplage à l'interface des plaques lors de l'initiation de la subduction by Mathieu Soret( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Les semelles métamorphiques sont des unités d'origine océanique (≤ 500 m d'épaisseur) situées à la base des grandes ophiolites obductées (≤ 20 km d'épaisseur). Ces unités sont caractérisées par un gradient métamorphique inverse, où les conditions de pression (P) et de température (T) de cristallisation augmentent de la base vers le contact avec l'ophiolite sus-jacente : depuis 500±100˚C et 0.5±0.2 GPa jusqu'à 800±100˚C et 1.0±0.2 GPa. Formées et exhumées au cours des 2 Ma suivant l'initiation des subductions océaniques, les semelles sont des témoins directs de leur dynamique précoce. Les assemblages minéralogiques qu'elles portent et leur déformation fournissent des contraintes majeures, et rares, sur l'évolution de la structure thermique et sur le comportement mécanique de l'interface de subduction naissante. Au terme d'une étude pétrologique, (micro-) structurale et expérimentale sur les amphibolites naturelles de la semelle de Semail (Oman, UAE) et synthétisées en laboratoire, nous proposons un modèle où la semelle métamorphique résulte d'épisodes multiples d'accrétion d'unités homogènes en P-T (donc sans gradient métamorphique) au cours des premières étapes de subduction océanique. L'écaillage subséquent résulte de changements majeurs dans la distribution de la déformation, du fait des variations des propriétés mécaniques des roches à l'interface de subduction lors de son équilibration thermique et de l'augmentation au cours du temps de la proportion de sédiments entrant en subduction. Ce modèle rend compte d'une grande complexité thermique et mécanique à l'interface de subduction, encore insuffisamment examinée dans les études numériques actuelles
Imagerie sismique de la proche sub-surface : modification de l'inversion des formes d'onde pour l'analyse des ondes de surface by Carlos Andrés Pérez Solano( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

L'amélioration des images sismiques peut aider à mieux contraindre l'exploration deshydrocarbures. Les ondes élastiques qui se propagent dans la Terre peuvent être classifiéescomme ondes de volume et ondes de surface. Si ces dernières sont les plus énergétiques,seules les ondes de volume sont couramment considérées comme des signaux utiles.Cependant, les ondes de surface sont utiles pour caractériser la proche sub-surface.Classiquement, les ondes de surface sont analysées dans des contextes de propriétésélastiques localement 1D.Nous proposons une modification de l'inversion des formes d'onde classique pourreconstruire des profils de propriétés 2D (la windowed-Amplitude Waveform Inversion, w-AWI). La w-AWI est spécialement robuste en ce qui concerne le choix du modèle initial.Nous appliquons la w-AWI aux données synthétiques ainsi qu'aux données réelles, montrantque cette approche permet de récupérer des propriétés 2D
Dynamique lithosphérique et architecture des marges du bassin du Levant : approche géophysique intégrée by Lama Inati Smaily( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

D'importantes découvertes de gaz ont été faites récemment en Méditerranée orientale (www.nobleenergyinc.com), incitant les compagnies pétrolières à s'intéresser de plus près au bassin du Levant, considéré aujourd'hui comme une véritable province pétrolière. Par conséquent, une quantité considérable de données géophysiques a été produite et une série d'études académiques et industrielles ont été réalisées. La compréhension de l'architecture crustale et sédimentaire associée à celle de la thermicité actuelle et passée des marges de ce bassin, notamment la marge continentale du Liban, présente des enjeux industriels et scientifiques majeurs. Cette question a des implications majeures pour l'évolution tectonique, les prévisions des tremblements de terre ainsi que celle des systèmes pétroliers. Malgré les différents travaux géophysiques menés sur la Méditerranée orientale ces dernières années, la configuration crustale profonde du bassin du Levant, connu pour avoir été le siège d'un rifting à la fin du Paléozoïque et au début du Mésozoïque, reste imprécise. La transition d'une croûte continentale épaisse vers une croûte atténuée en mer (peut-être même une croûte océanique) a été invoquée, mais pas encore prouvée. Des approches géophysiques intégrées ainsi qu'un travail de modélisation ont été utilisés dans cette thèse pour étudier la structure profonde de la lithosphère sous la région Est de la Méditerranée.Une modélisation crustale 2D à l'échelle régionale (du delta du Nil au sud à la Turquie au nord, et du bassin Hérodote à l'ouest à la plaque arabe à l'est) a été effectuée dans le but d'étudier l'architecture de la croûte dans cette partie de la méditerranée orientale. L'algorithme utilisé est une méthode d'essai-erreur qui fournit l'épaisseur crustale et la profondeur de la limite lithosphère- asthénosphère (LAB) ainsi que la distribution de la densité crustale par l'intégration du flux de chaleur surfacique, l'anomalie gravimétrique à l'air libre, les données du géoïde et la topographie. La profondeur du Moho et l'épaisseur de la croûte ont été contraintes localement par des données de sismique réfraction là où elles sont disponibles. Les résultats montrent une croûte cristalline progressivement atténuée dans une direction EW. Dans le bassin du Levant, la croûte est interprétée comme continentale et composée de deux croûtes distinctes, une supérieure et une inférieure, contrairement au bassin Hérodote qui repose sur une croûte mince, probablement océanique.Une inversion 3D jointe des données de gravité, du géoïde et de la topographie appliquée sur la même région a confirmé les résultats de la modélisation crustale 2D. A total of 168 simulations ont été réalisées, parmi lesquelles, la simulation avec les erreurs les moins grandes sur les données correspond à l'inversion d'un modèle dans lequel la profondeur du Moho varie entre 23 et 26 km dans le bassin du Levant et devient plus profond dans le bassin Hérodote et aux larges des côtes africaines. La profondeur de la LAB est située entre 100 et 150 km dans le bassin du Levant et atteint plus de 180 km dans le bassin Hérodotes. L'interprétation de cinq lignes de sismique réflexion 2D PSTM à 14 s TWT couvrant la partie nord du bassin du Levant a révélé un total de 10 horizons, dont le plus profond pourrait être une interface croûte-manteau. L'interprétation des paquets sismiques, leurs surfaces de raccord ainsi que l'analyse des facies ont été contraints par les interprétations sismiques 2D publiées de la partie nord de l'offshore Libanais (Hawie et al., 2013b), dans lesquelles les connaissances stratigraphiques et sédimentologiques récentes de la marge libanaise ont été extrapolées jusqu'au bassin. Un total de huit paquets sédimentaires a été identifié dans le bassin aux âges variant du Jurassique Moyen au Quaternaire
Modélisation numérique de la sédimentation organique : réévaluation des processus gouvernant sa distribution au Jurassique inférieur en Europe by Benjamin Bruneau( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Marine source-rocks have heterogeneities both in their distribution and quality over time and space. The deposition of these organic-rich sediments and their variations are complex phenomena resulting from the convergence of several processes which were the subject of many studies. However, the debate on their relative roles and impacts remains strong. The evolution of numerical modelling tools now allows a quantitative approach and new studies about the interaction between these processes. Because of their general context and the presence of several source-rocks, the Lower Jurassic sedimentary basins of Europe are an ideal case to characterize the processes governing the distribution of organic matter (OM). This thesis present the study and the numerical modelling of these basins which allowed to determine the relative influence of the control factors of the OM distribution at various scales. These works bring new elements into the debate about the relative role of these processes. The primary impact of the basin morphology highlighted by these works goes against the dominant literature in which the production and preservation of OM conceal the other factors. Both of these processes obviously play an important role in the distribution of organic-rich layers, but their setting are entirely dependent on the basin morphology. All this work highlights the need to widen the debate for a better understanding of the source rock global distribution, by using the same modelling approach with others organic-rich intervals, others palaeogeographic contexts and for others kind of kerogens
Agriculture biologique et qualité des ressources en eau dans le bassin de la Seine : caractérisation des pratiques et applications territorialisées by Juliette Anglade( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The intensive agriculture characterizing the Seine watershed since half a century is based on the generalization of the use of synthetic fertilizers and pesticides and by the rupture of the connection between crop and livestock systems. This system is nowadays compromising ground- and surface water quality, namely through nitrate contamination which mostly originates from agricultural losses. The implementation of technically proven and socially acceptable alternatives, allowing reconciling agricultural production and water quality preservation, encounters lots of obstructions of technical and social nature. From a technical point of view, sound reference data and rigorous indicators are lacking to assess the agronomical and environmental performance of alternative agro-systems. The first objective of this thesis is therefore to develop a sound conceptual framework to evaluate the productive capacity and the risk of nitrate lixiviation of agro-systems, through an improved version of the nitrogen soil surface balance. We first developed, based on a meta-analysis of the literature, robust relations to determine symbiotic nitrogen fixation by grain and forage legumes crops, which plays a central role in organic farming systems. We then could establish the relationship between total N fertilization, harvested yield and surplus of agro-systems, in order (i) to draw the trajectories of 124 countries over 50 years based on FAO data, and (ii) to compare the performance of the main organic crop rotations of the Seine basin and those of the conventional 'reasoned' agriculture. Finally, we established an empirical relationship linking N surplus, lixiviation and nitrate concentration in drainage water for arable land and permanent grassland. We show in a second part of this thesis how this conceptual framework of analysis can be useful in particular territories to highlight and guide stakeholder action, as well as to make more credible some alternatives which can feed the necessary transition toward more sustainable agro-systems. We analyze the situation of the drinking water abstraction areas of La Plaine du Saulce, supplying the city of Auxerre (Burgundy) as well as that of Flins-Aubergenville, supplying the western part of Paris agglomeration. We elaborate alternative scenarios for these regions, going much farther than the mere improvement of agricultural practices, and taking into account the peculiar geographical and hydro-geological context of each study case
Transition from compression to strike-slip tectonic styles along the northern margin of the Levant Basin by Vasilis Symeou( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

The Cyprus Arc system is major plate boundary of the Eastern Mediterranean where different plates interact, namely Arabia, Africa, Eurasia, as well as the Anatolian micro-plate. It constitutes the northern boundary of the Levant Basin (of thin stretched continental crust) and the Herodotus Basin (of oceanic crust). The Cyprus Arc is directly linked with the northward convergence of the African continental plate with respect to the Eurasian continental plate since Late Cretaceous time. The indentation of the Arabian plate and the slab pull effect of the African plate roll back in the Aegean region on the eastern and western part of the Anatolian plate respectively, leads to the westward escape of Anatolia from Late Miocene to Recent, which results in a strike-slip component along the Cyprus Arc system and onshore Cyprus. Several scientific questions with regard to the geological setting of the region were investigated during this project. How is the deformation accommodated at the Cyprus Arc system? Is this deformation style affected by the variation of the crustal nature at each domain? How is this deformation recorded on the sedimentary pile onshore Cyprus? How does the onshore and offshore deformation connect within the geodynamic context of the region? In order to answer these scientific questions, 2D reflection seismic data were utilized, that image the main plate structures and their lateral evolution south and east of Cyprus. Interpretation of these data lead to the identification of nine tectono-sedimentary packages in three different crustal domains south of the Cyprus Arc system: (1) The Levant Basin (attenuated continental crust), (2) The Eratosthenes micro-continent (continental crust) and (3) The Herodotus Basin (oceanic crust). Within these domains, numerous tectonic structures were documented and analysed in order to understand the mechanism and timing of deformation. At the northern boundary of the Levant Basin domain, thrust faults verging towards the south were documented in the Cyprus Basin with the thrust movement commencing in Early Miocene time as indicated by on the Larnaca and Margat Ridges. On the Latakia Ridge no activity was identified during this time interval. The acme of deformation occurred in Middle to Late Miocene time, with the activity of the Latakia Ridge indicating the forward propagation of the deformation front towards the south. This southward migration was documented from the development of flexural basins and from stratigraphic onlaps in the Cyprus Basin. Successive tectonic pulses through the Late Miocene until Recent times, are indicated from the angular unconformities and the piggy back basins. In Plio-Pleistocene time, the westward escape of the Anatolian micro-plate resulted in the reactivation of existing structures. The evolution of deformation along the plate boundary is identified from the creation of positive flower structures revealing transpressive movements along the Larnaca and Latakia Ridges (eastern domains). The central domain includes the Eratosthenes Seamount which is characterized as a Mesozoic carbonate platform covered by a thin sequence of sediments ranging from Miocene-Messinian to Pliocene-Pleistocene depositions
Tectonostratigraphic evolution of the Western Niger Delta from the Cretaceous to Present by Kelvin Ikenna Chima( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Le basculement du delta du Niger occidental au début de son évolution au Crétacé a entraîné le développement d'une surface sismique régionale à centre de bassin, ce qui a facilité le glissement de la gravité du Crétacé au Serravallien. Une augmentation globale des taux de sédimentation s'est produite dans l'ouest du delta du Niger, du Serravallien au Pliocène et pendant la plus grande partie du Pléistocène, ce qui a favorisé la propagation de la gravité. Des schistes mobiles ont été actifs dans l'ouest du delta du Niger, au moins pour le Burdigalien, et ont contrôlé la morphologie, la distribution et les schémas de dépôt des canaux sous-marins jusqu'au Pliocène et au Pléistocène. La stratigraphie du Pliocène et du Pléistocène des bassins intra-pente du Delta du Niger occidental a été contrôlée par des forçages allocycliques de 400 ka et 100 ka d'excentricité, liés aux changements glacio-eustatiques du niveau de la mer au cours du Pléistocène moyen-messinien et du Pléistocène moyen-présent respectivement, et par des forçages tectoniques des bassins liés à la tectonique des schistes. Malgré les taux de sédimentation relativement plus faibles estimés sur le plateau continental et le talus du delta du Niger occidental depuis le début du Pliocène, l'augmentation globale de l'effondrement par gravité, de l'épaisseur des sédiments et de leur distribution du plateau au bassin profond, suggère une augmentation globale de la sédimentation dans cette région. Toutefois, dans l'est du delta du Niger, l'affaissement actif des failles normales régionales et la migration déduite des lobes du delta auraient contribué à la réduction continue de la sédimentation depuis le Pléistocène. Cette thèse améliore non seulement notre compréhension de l'évolution tectono-stratigraphique du delta occidental du Niger, mettant en évidence les styles complexes de piégeage structurel et stratigraphique notamment dans les systèmes en eau profonde sous-explorés, mais montre également la présence de dépôts syn-rift pouvant héberger un prospect Crétacé-Paléogène dans le delta occidental du Niger
Processus microbiens de formation des gisements sédimentaires de phosphates actuels by Sara Rivas Lamelo( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This work aimed at deciphering the contribution of microbial activities to the speciation and fluxes of phosphorus particles in the water column of Lake Pavin. This ferruginous and meromictic (i.e. permanently stratified) lake is a model case for phosphatogenesis; the oxic/anoxic boundary is located within the water column, delimiting a zone where precipitation of phosphate mineral phases occurs. While it was previously assumed that this precipitation was induced by abiotic processes only, recent clues highlighted the contribution of microbial communities. Yet, the nature and magnitude of this contribution were poorly known.Here, we show that the highest activity of alkaline phosphatases (APA) occurred within the mixolimnion (the upper layer affected by seasonal mixing). Moreover, we found a negative correlation between the concentration of dissolved orthophosphates and the APA. We quantified the flux and the composition of the phosphorus particles settling to the phosphatogenesis zone. We also quantified the intracellular polyphosphate (poly-P) inclusions in the mixolimnion, by using spectrofluorimetry. We showed that poly-P were particularly abundant at depths where the photosynthetic biomass dominated. Furthermore, the development of a poly-P quantification protocol enabled us to detect several associated issues. Finally, using a correlative approach with different types of microscopy, we identified abundant magnetotactic bacteria at the redox interface, containing intracellular inclusions of sulfur and phosphorus (poly-P). These bacteria may therefore play a major role in the biogeochemical cycles of these elements
Libération et migration du méthane depuis le charbon dans un contexte hydrogéologique post-minier : développement d'un protocole expérimental et approche numérique by Nils Le Gal( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Dans le but d'une meilleure caractérisation de l'aléa gaz dans les bassins houillers miniers ennoyés, un dispositif expérimental a été développé pour quantifier la libération du méthane depuis le charbon. Des échantillons de charbon saturés en méthane ont été soumis à des pressions hydrostatiques allant de 3 à 4,3 MPa, dans une cellule autoclave. Le protocole développé à partir du système initial et des moyens techniques apportés au cours des travaux de thèse s'est révélé opérationnel. Les résultats des expériences et leur analyse ont mis en évidence deux phénomènes : une désorption significative du méthane initialement adsorbé et l'effet de la pénétration de l'eau dans les pores du charbon sur la pression dans la cellule. Les différents niveaux de pression imposée au charbon ont montré que la fraction de méthane désorbé augmente avec la pression, du fait d'une sollicitation plus profonde des pores saturés en méthane.Les constantes d'équilibre déterminées ont été utilisées dans des modèles numériques visant à simuler la migration du méthane dans des structures minières ennoyées. Les modèles les plus simples ont montré l'importance des perméabilités du charbon et des vides miniers, ainsi que l'effet inhibiteur de l'ennoyage sur la libération de méthane. La concentration atteinte en méthane dissous est limitée par la constante de sorption attribuée au charbon et à sa teneur initiale en méthane. D'autres scénarios reprenant un contexte de gestion de la remontée des eaux de mine illustrent l'impact d'un pompage sur la sollicitation du méthane et son influence quant à une possible émission en surface, au terme d'une durée de l'ordre de la décennie, voire du siècle
Integrated hydrogeological study of San Cristobal Island (Galapagos) by Christian Dominguez( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

The understanding of the hydrogeological functioning in regions such as San Cristobal Island (Galapagos), where water is limited, is fundamental for a suitable management of its resources. This work is the first study of this type on high-level aquifers in San Cristobal using a multi-disciplinary approach, based in the implementation of an experimental site and modeling strategies. For this purpose, a hydrological network was installed in Cerro Gato (CG) and surrounding watersheds. Inputs to the watershed are estimated using the joint modeling of a canopy and soil water transfer. Recharge rates are mainly affected by altitude in mid-elevation watersheds, whereas land cover is the main controlling factor at high-elevation watersheds because of the additional input of fog interception in forests. A hydrological analysis shows that losses from the high-elevation basins become groundwater inputs in the mid-elevation basins, while others have inputs from watersheds at the same altitude, such as CG. The detailed geometry of its hydrogeological watershed is obtained from the dataset of a high resolution AEM SkyTEM survey, which confirms the assumption that its hydrogeological watershed is bigger than its hydrological one. Results from these approaches allow proposing a hydrogeological conceptual model for the springs of CG, where the groundwater flow of springs is fed by a perched aquifer suspended by a low permeability thin layer. This model is tested with numerical simulations, which confirm the plausibility of the existence of a perched aquifer. This thesis provides scientific basis for an effective water management strategy
 
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Alternative Names
École doctorale 398

École doctorale Géosciences et ressources naturelles (Paris)

ED 398

ED GRN

ED GRNE

ED398

GRN

GRNE

Languages
French (13)

English (7)