Dans le bassin de Franceville (Gabon), les sédiments détritiques non-métamorphosés d’âge Paléoprotérozoïque (2,15 Ga) des formations FA et FB ont fait l’objet d’une étude faciologique, pétrographique et géochimique. L’objectif était de déterminer l’origine de ces matériaux clastiques et des minéralisations uranifères associées, mais aussi d’en retracer l’histoire diagénétique à travers l’évolution des paléoconditions rédox et des fluides qui les ont percolés.La pétrographie des faciès montre que la minéralogie et la texture initiales de ces sédiments ont été fortement modifiées au cours de la diagenèse précoce. Au toît de la formation FA, les quartz-arénites faiblement granoclassées ont été très tôt cimentées par du quartz, s’opposant ainsi à l’action ultérieure de la diagenèse d’enfouissement. Dans les arènes arkosiques, la séquence paragénétique liée aux ciments authigènes suggère que les interactions fluides-roches ont été polyphasées et que les éléments chimiques nécessaires à leur précipitation trouvent leur origine dans l’altération de minéraux détritiques. Pour un ensemble lithologique donné, les effets de la diagenèse varient peu d’un faciès à l’autre, ce qui indique un fort contrôle des paramètres initiaux tels que la minéralogie, la texture et la composition du fluide poral. Par conséquent, ces faciès sédimentaires nous informent directement sur les propriétés hydrologiques qui régnaient dans le bassin sédimentaire, et sur la nature de la diagenèse précoce qui les a affectés.Les données pétrographiques et géochimiques montrent que la précipitation de l’hématite en lits ferrugineux a débuté juste après le dépôt des sédiments, dont l’altération des minéraux primaires a libéré le fer, plus tard redistribué durant la diagenèse. Ainsi, la mise en évidence d’une corrélation positive entre les valeurs de "delta" 56Fe et les rapports Fe/Mg mesurés sur échantillon total suggère que le fer se répartit entre deux pôles que sont l’hématite authigène et les silicates porteur du fer. En revanche, l’absence de relation entre les rapports Fe3+/FeT et les compositions isotopiques du fer démontre que des oxydes riches en isotopes lourds du fer préexistaient dans les sédiments lorsque la diagenèse précoce a débuté. Le fer présent initialement à l’état réduit dans des faciès sédimentaires verts s’est progressivement oxydé au cours de la diagenèse, processus à l’origine de la formation des lits ferrugineux.Dans la formation FA du Bassin de Franceville, les gisements uranifères résultent de la libération de l’uranium contenu à l’origine dans les grès oxydés des dépôts fluviatiles inférieurs puis de sa migration et de son piégeage dans les grès réduits et les mudstones silteux des formations de deltas de marée supérieures, où il s’est concentré par un mécanisme de type roll-front.L’analyse des éléments chimiques majeurs et traces des formations FA et FB indique que leurs matériaux constitutifs trouvent leur source dans des roches ignées felsiques. Tandis que les diagrammes de terres rares normalisés aux chondrites, les anomalies négatives en Eu et les rapports GdN/YbN plaident plus précisément en faveur des roches archéennes et paléoprotérozoïques. Enfin, des diagrammes discrimants et des rapports en éléments majeurs et traces montrent que, si la plupart des grès de la formation FA se sont déposés sur une marge passive, les mudstones et les grès fins des formations FA et FB ont sédimenté sur une marge continentale active en relation avec la tectonique paléoprotérozoïque de la Ceinture orogénique du Centre-Ouest de l’Afrique. / The FA and FB Formations clastic sediments have been subjected to detailed facies, petrographic, and geochemical analyses in relation to diagenesis, fluid flow, paleo-redox conditions, provenance, and uranium mineralization during the evolution of the unmetamorphosed Paleoproterozoic (ca 2.15 Ga) Franceville Basin, Gabon. Lithofacies analyses in combination with petrographic studies indicate that the original mineralogical and textural properties of the sediments have been greatly modified during diagenesis. The moderately sorted quartz arenite at the top of FA underwent early quartz cementation; thus preventing it from subsequent burial diagenetic processes. The inferred paragenetic sequence of authigenic cements in the arkosic arenites suggest a multiphase of fluid-rock interactions with most of the ions needed for their precipitations likely sourced during alteration of detrital precursors. The observed slight variations in the diagenetic pathways in different lithofacies associations are closely related to primary mineralogy, texture, and nature of pore fluid. This relationship suggests that depositional facies can provide an insight into the diagenetic pathways and hydrologic properties of sediments in sedimentary basins. Petrographic features coupled with whole rock geochemical and iron isotope analyses suggest that hematite precipitation in the red beds started after sediment deposition with the iron internally derived by alteration of iron-bearing minerals and redistributed during late diagenesis. Positive correlation between Fe/Mg ratio and "delta" 56Fe values of bulk samples suggests mixing relationship with end members being authigenic hematite and iron-bearing silicates. The lack of relationship between Fe3+/FeT ratios and iron isotope compositions suggest that the isotopically heavy iron oxide was already present in the sediments during early diagenesis, and was incorporated into green (reduced) facies that likely replaced red facies during diagenesis or burial. Uranium released from the lower, fluvial oxidized sandstones and added to the reduced sandstones and silty mudstones in the upper tidal-deltaic sediments potentially resulted in a uranium mineralization of a roll-front type in the FA Formation of the Franceville Basin. Major and trace element geochemical data for the FA and FB formation are consistent with sediments derived exclusively from felsic igneous source. Chondrite-normalized patterns with high LREE/HREE ratios, negative Eu anomalies, and GdN/YbN ratios favour mixture of Archean and Post-Archean felsic sources. Discriminant diagrams and elemental ratios of major and trace elements suggest deposition of most of the FA sandstone in a passive margin, while the mudstones and fine-grained sandstones of FA and FB were deposited in an active continental margin during Paleoproterozoic tectonic regimes of the West Central African Belt.

Au début des temps modernes (16ème - 18ème siècles), la construction de grands navires était primordiale pour le développement des rencontres culturelles dans ce qui est devenu l'âge de la découverte et de l'expansion européenne. L’Espagne était une des grandes puissances de l’époque. Le projet européen « ForSEAdiscovery » cherche dans ce contexte à répondre aux questions clés suivantes : les ressources forestières ibériques de l’époque soutenaient-elles la demande croissante de bois, ou bien ce bois était-il importé d’autres pays ? Si ces bois ne provenaient pas de l’Espagne, comment les réseaux de commerce étaient-ils organisés ? Ce projet aborde ces questions à travers un programme de recherche multidisciplinaire et innovant pour améliorer la compréhension de notre passé historique et de notre patrimoine culturel, et développer notre connaissance sur l'utilisation passée des ressources en bois pour la construction navale. L'objectif de cette thèse, qui s’insère dans ce projet, est d’identifier la provenance des bois utilisés dans la construction navale ibérique en utilisant des traceurs géochimiques. L’hypothèse est que les arbres se développant sur des roches et des sols contrastés possèdent des signatures géochimiques spécifiques héritées des roches. Les signatures isotopiques en strontium (87Sr/86Sr) peuvent notamment être des indicateurs de provenance géographique. Dans ce contexte, la démarche suivie dans la thèse a consisté à caractériser la signature isotopique en Sr dans des bois d'épaves de bateaux et dans les bois d’arbres actuels, les sols et roches prélevés dans les principaux peuplements forestiers espagnols pointés comme lieux de production des bois entre le 16ème - 18ème siècles. Les signatures en δ88/86Sr, traceur peu connu encore, ont également été caractérisées dans les échantillons. Les types et les âges des roches ont été caractérisés et les liens entre les rapports isotopiques 87Sr/86Sr et δ88/86Sr dans les roches, sols et arbres ont été étudiés sur les sites espagnols échantillonnés. La signature locale des sites espagnols potentiels de provenance de bois a été déterminée. Nos résultats mettent en évidence que le rapport isotopique 87Sr/86Sr dans les arbres reflète la signature de la fraction échangeable des sols sur lesquels ils croissent alors que le δ88/86Sr est affecté par le fractionnement, les isotopes légers (86Sr) étant préférentiellement incorporés dans les arbres laissant la fraction échangeable du sol enrichie avec les isotopes lourds (88Sr). Ce fractionnement observé pour les chênes, n’est pas marqué dans le bois des pins suggérant que le fractionnement isotopique durant le transfert du Sr entre le sol et l’arbre est dépendant de l’espèce. La contamination des bois d’épaves par les éléments marins a été identifiée. Le Sr marin se retrouve notamment sous forme adsorbée ou dans la structure des minéraux précipités dans les bois immergés. Différentes expériences d’extractions ont été testées et un protocole adapté a été développé pour extraire les éléments marins et retrouver la signature originelle du bois archéologique. Nous avons réussi à valider un protocole d’extraction et retrouver la signature originelle d’un échantillon de bois d’épave. Ce résultat souligne le potentiel et l’importance d’une nouvelle méthode combinant 87Sr/86Sr et δ88/86Sr pour des futures études de provenance de bois ou autres matériaux. Cependant, nos résultats indiquent également que beaucoup de nos échantillons de bois archéologiques n’ont pas conservé leur Sr originel. Partant de ce constat, des préconisations sont proposées pour améliorer la possibilité d’utilisation de ce traceur dans les études futures de provenance de bois archéologiques sous-marins / In the Early Modern Age (16th - 18th centuries), the construction of ocean-going ships was paramount to the development of cultural encounters in what became the Age of Discovery and European expansion. Spain was one of the biggest forces of that time. The European project “ForSEAdiscovery” seeks answers in this context to the following key questions: Could Spanish forest resources sustain the increasing demand of timber, or were the wood imported from elsewhere? If Spanish forests were not the only wood supplier, how were the trade networks organized? This project will address these questions through a multidisciplinary and innovative training research program to improve the understanding of our historical past, our cultural heritage, and our knowledge of the use of resources for shipbuilding. The objective of this PhD thesis, taking part of this project, is to identify the provenance of the Iberian shipbuilding wood using geochemical tracers. The hypothesis is that trees growing on contrasted rocks and soils have specific geochemical signatures, which can be an indicator of geographic provenance. In this context, the Sr isotopic signature (87Sr/86Sr) was characterized in shipwreck wood samples and wood from living trees, soils and rocks collected from the Spanish forest stands indicated as potential source of wood between the 16th - 18th centuries. The δ88/86Sr signatures were also characterized in the samples. The rock types and ages were characterized at the selected sites and the link between the 87Sr/86Sr and δ88/86Sr in rocks, soils and trees was studied on the sampled Spanish sites. The local signature of Spanish potential sites was determined for provenance of wood. Our results indicate that 87Sr/86Sr isotope ratios in trees reflect the signature of the corresponding soil exchangeable pool while δ88/86Sr was shown to be affected by mass-dependent fractionation with trees taking up lighter (86Sr) isotopes, leaving the soil exchangeable pool enriched with the heavier isotopes (88Sr). This fractionation observed for oak trees, was not found in pines suggesting that the isotopic fractionation during tree uptake is species dependent. The contamination of wood from shipwrecks by seawater elements was identified. Marine Sr was found to be adsorbed on the wood or included in the precipitated minerals in the waterlogged wood. Several extraction experiments were tested and an adapted protocol was developed to extract the seawater elements and retrieve the original signature of the archaeological wood. We succeeded to validate an extraction protocol and retrieve the original signature of one wood sample. This result underline the potential and importance of a new method combining 87Sr/86Sr and δ88/86Sr values for future provenance studies on wood or other materials. However, our results also indicated that most of our shipwreck wood samples did not conserve their original Sr. Therefore, preconizations were suggested in order to extend the use of this tracer in future provenance studies on archaeological wood from shipwrecks

Le plan de thèse comprend les objectifs spécifiques suivants: D'après les observations de terrain, la carte géologique structurale sera obtenue en couvrant la zone géoréférencée entre le lac Buenos Aires et la rivière Mayer dans le sud des Andes de la Patagonie, province de Santa Cruz. L'analyse de la provenance a été faite par des études pétrographiques en grès à cinq coupes stratigraphiques représentatives des séquences considérées appartenant au Crétacé inférieur et au Miocène dans le secteur nord du bassin Austral. D'autres études préliminaires de diffraction des rayons X à un profil (appelé Veranada de Gómez). Aussi, deux unités lithostratigraphiques ont été datées et étudiées par provenance des zircons détritiques. Il est prévu de déterminer pour la zone d'étude, le début de l'avant-pays d'étape, et une estimation est obtenue l'âge de l'exhumation des régions d'origine, et donc une approche semi-quantitative à la fois de l'apparition du soulèvement, comme modèles de dispersion des sédiments. L'analyse complète de ces données donnera la structure générale de la dispersion paléogéographique et des sédiments de la bordure nord du Bassin du Sud pour s'harmoniser avec le patron du secteur sud, qui a alimenté la zone d'étude. De plus, une déformation fragile sera étudiée en analysant les failles striaes pour caractériser les déformations dans la zone. / The thesis plan includes the following specific objectives: According to field observations structural geological map will be obtained georeferenced area covering between the lake Buenos Aires and Mayer River in the Southern Andes Patagonian, Santa Cruz province. Provenance analysis were done by petrographic studies in sandstones at five stratigraphic sections representative of the sequences considered belonging to the Lower Cretaceous and Miocene in the northern sector of the Austral basin. Further X-ray diffraction preliminary studies at one profile (called Veranada de Gómez). Also, two lithostratigraphic units were dated and study by detrital zircons provenance. It is expected to determine for the study area, the beginning of the stage foreland, and an estimate is obtained the age of the exhumation of the regions of origin, and thus a semi-quantitative approach at a time the age of onset of uplift, as sediment dispersion models. The comprehensive analysis of these data will give the general pattern of palaeogeographic dispersal and sediments of the northern edge of Southern Basin to mesh with the southern sector pattern, which fed the study area. Moreover fragile deformation will be studied by analyzing faults striaes to characterize the deformation events in the area.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-03-29T19:09:28Z No. of bitstreams: 1 DissRRS.pdf: 3751863 bytes, checksum: 950bef628d03f26a109436e96c9ac337 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-11T13:45:04Z (GMT) No. of bitstreams: 1 DissRRS.pdf: 3751863 bytes, checksum: 950bef628d03f26a109436e96c9ac337 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-11T13:45:15Z (GMT) No. of bitstreams: 1 DissRRS.pdf: 3751863 bytes, checksum: 950bef628d03f26a109436e96c9ac337 (MD5) / Made available in DSpace on 2017-04-11T13:53:54Z (GMT). No. of bitstreams: 1 DissRRS.pdf: 3751863 bytes, checksum: 950bef628d03f26a109436e96c9ac337 (MD5) Previous issue date: 2016-08-09 / Não recebi financiamento / The quality of the geographic data must be a relevant concern for providers and consumers of this type of data because the manipulation and analysis of low quality geographic data may result in errors, which will be propagated through the consequent data. Thus it is important to properly document the information which allows for certifying the quality of the geographic data. In order to provide a minimum amount of metadata for such purpose, this dissertation presents an approach based on the provenance of the geographic data, which corresponds to the information about the history of such data from its origin until the processes that resulted in its current state. For this purpose, a provenance model called ProcGeo was proposed, in which it was defined a minimum amount of metadata that must be considered for the analysis of the quality of a certain geographic data. Although a few works and geographic metadata standards, such as Federal Geographic Data Committee (FGDC) and ISO 19115, consider the information about the provenance in the analysis of the quality of geographic data, it´s the opinion of the author that some metadata considered important for this purpose are not adequately contemplated. In this work, the prototype of an interface called ProcGeoInter was also implemented, aiming to guarantee the completeness and correctness in the filling out of the defined metadata in the ProcGeo model as well as the visualization of their content. The validation of the ProcGeo model and of the ProcGeoInter interface were made through tests and surveys applied to providers and consumers of geographic data. As a means of comparison, the interface for filling out and visualization of metadata available by SIG Quantum GIS (plugin Metatools) was used, which implements the FGDC geographic metadata standard. The obtained results indicated that the metadata defined in the ProcGeo model helped the geographic data provider in the description of the provenance of such data, when compared to those defined in the FGDC geographic metadata standard. Through the consumer´s focus it was possible to notice that the information filled out in the metadata defined by the ProcGeo favored the analysis of the quality of the consumed data. It was clear that both providers and consumers do not possess the habit of providing or consuming the information predicted in the FGDC and ISO 19115 geographic metadata standards. / A qualidade do dado geográfico deve ser uma preocupação relevante para provedores e consumidores desse tipo de dado, pois a manipulação e análise de um dado geográfico com baixa qualidade podem resultar em erros que vão se propagar nos dados gerados a partir desse. Assim, é importante que a informação que permita atestar a qualidade do dado geográfico seja adequadamente documentada. Com o propósito de oferecer um conjunto mínimo de metadados para essa finalidade, esse trabalho apresenta uma abordagem baseada na procedência do dado geográfico, que corresponde à informação sobre a história do dado, desde a sua origem até os processos que resultaram no seu estado atual. Para tanto, foi proposto um modelo de procedência denominado ProcGeo no qual foi definido um conjunto mínimo de metadados que devem ser considerados para a análise da qualidade de um dado geográfico. Embora alguns trabalhos e padrões de metadados geográficos, como o Federal Geographic Data Committee (FGDC) e o ISO 19115, considerem a informação da procedência para a análise da qualidade do dado geográfico, sob o ponto de vista da autora deste trabalho, alguns metadados considerados importantes para essa finalidade não são adequadamente contemplados. Neste trabalho também foi implementado o protótipo de uma interface denominada ProcGeoInter, que tem como finalidade garantir a corretude e completude do preenchimento dos metadados definidos no modelo ProcGeo e a visualização do conteúdo dos mesmos. A validação do modelo ProcGeo e da interface ProcGeoInter foram realizados por meio de testes e questionários aplicados a provedores e consumidores de dados geográficos. Para efeito de comparação, foi considerada a interface para preenchimento e visualização de metadados disponibilizada no SIG Quantum GIS (plugin Metatoools), que implementa o padrão de metadados geográficos FGDC. Os resultados obtidos indicaram que os metadados definidos no modelo ProcGeo auxiliaram o provedor de dados geográficos na descrição da procedência desses dados, quando comparados aos definidos no padrão de metadados geográficos FGDC. Pelo foco do consumidor foi possível perceber que as informações preenchidas nos metadados definidos pelo ProcGeo favoreceram a análise da qualidade dos dados consumidos. Ficou evidente que tanto provedores quanto consumidores não possuem o hábito de prover ou consumir as informações previstas nos padrões de metadados geográficos FGDC e ISO 19115.

Ce document constitue l'aboutissement de trois années de thèse. Après avoir introduit et dégagé la problématique générale se rapportant à mon sujet de thèse, à savoir « comment utiliser les données de provenance pour favoriser un Cloud de confiance ? », je présente une description des concepts, modèles et langages se rapportant à ma thèse et l'état de l'art qui peut répondre en partie à cette problématique. En second lieu, je présente la solution basée sur la provenance que j'apporte aux contrôles d'accès, dans les systèmes distribués comme le Cloud : PBAC². Elle repose sur un système combinant à la fois des modèles de provenance (PROV-DM) et de contrôles d'accès (règles génériques de type RBAC avec des politiques d'embrigadement ou de réglementation). Ce système utilise un moteur d'exécution central appelé le médiateur pour renforcer la sécurité et favoriser la confiance dans le Cloud, via la vérification de règles sur une partie du graphe de provenance rétrospective qu'il a reçue. Par ailleurs, je décris l'étude que j'ai faite de trois extensions de PBAC² : (1) l'intégration de l'ontologie PROV-O et ses avantages et inconvénients quant à la taille du (sous-)graphe de provenance reçu par le médiateur ; (2) la construction de l'adaptation de PBAC² avec l'approche de sécurité qu'est la réglementation; (3) la traduction des règles PBAC² en contraintes PROV-CONSTRAINTS. De plus, PBAC² est appliqué sur un exemple réaliste propre au secteur médical. Un prototype de PBAC² et une démonstration sur des exemples concrets avec une machine locale et un système de Cloud réel illustrent la portée de ce travail. En conclusion de la thèse, je propose quatre perspectives de ce travail. / This document is the culmination of three years of thesis. Having introduced and cleared the general issue related to my thesis subject, i.e. « how to use provenance data to enforce trust in the Cloud? », I present a description of the concepts, models and languages related to my thesis and the state of the art that can partially address this issue. Secondly, I present the solution based on provenance that I bring to access controls, in distributed systems such as the Cloud: PBAC². It is based on a system combining both provenance models (PROV-DM) and access controls (generic rules of RBAC type with regimentation and regulation policies). This system uses a central execution engine denoted the mediator to enforce security and foster trust in the Cloud, via rule checking over a part of the retrospective provenance graph it received. Furthermore, I describe the study I made of three PBAC² extensions: (1) the integration of the PROV-O ontology and its pros and cons regarding the size of the (sub)graph received by the mediator; (2) the construction of the PBAC² adaptation with the regulation security approach; (3) the translation of PBAC² rules into PROV CONSTRAINTS constraints. Moreover, PBAC² is applied to a realistic example that belongs to the healthcare sector. A PBAC² prototype and a demonstration on some practical examples with a local machine and a real Cloud system illustrate the scope of this work. In conclusion of the thesis, I propose four perspectives of this work.

La quantité croissante des données s’accompagne par l’augmentation du nombre de programmes de transformation de données, généralement des requêtes, et par la nécessité d’analyser et comprendre leurs résultats : (a) pourquoi telle réponse figure dans le résultat ? ou (b) pourquoi telle information n’y figure pas ? La première question demande de trouver l’origine ou la provenance des résultats dans la base, un problème très étudié depuis une 20taine d’années. Par contre, expliquer l’absence de réponses dans le résultat d’une requête est un problème peu exploré jusqu’à présent. Répondre à une question Pourquoi-Pas consiste à fournir des explications quant à l’absence de réponses. Ces explications identifient pourquoi et comment les données pertinentes aux réponses manquantes sont absentes ou éliminées par la requête. Notre travail suppose que la base de données n’est pas source d’erreur et donc cherche à fournir des explications fondées sur (les opérateurs de) la requête qui peut alors être raffinée ultérieurement en modifiant les opérateurs "fautifs". Cette thèse développe des outils formels et algorithmiques destinés au débogage et à la réparation de requêtes SQL afin de traiter des questions de type Pourquoi-Pas. Notre première contribution, inspirée par une étude critique de l’état de l’art, utilise un arbre de requête pour rechercher les opérateurs "fautifs". Elle permet de considérer une classe de requêtes incluant SPJA, l’union et l’agrégation. L’algorithme NedExplain développé dans ce cadre, a été validé formellement et expérimentalement. Il produit des explications de meilleure qualité tout en étant plus efficace que l’état de l’art.L’approche précédente s’avère toutefois sensible au choix de l’arbre de requête utilisé pour rechercher les explications. Notre deuxième contribution réside en la proposition d’une notion plus générale d’explication sous forme de polynôme qui capture toutes les combinaisons de conditions devant être modifiées pour que les réponses manquantes apparaissent dans le résultat. Cette méthode s’applique à la classe des requêtes conjonctives avec inégalités. Sur la base d’un premier algorithme naïf, Ted, ne passant pas à l’échelle, un deuxième algorithme, Ted++, a été soigneusement conçu pour éliminer entre autre les calculs itérés de sous-requêtes incluant des produits cartésien. Comme pour la première approche, une évaluation expérimentale a prouvé la qualité et l’efficacité de Ted++. Concernant la réparation des requêtes, notre contribution réside dans l’exploitation des explications polynômes pour guider les modifications de la requête initiale ce qui permet la génération de raffinements plus pertinents. La réparation des jointures "fautives" est traitée de manière originale par des jointures externes. L’ensemble des techniques de réparation est mis en oeuvre dans FixTed et permet ainsi une étude de performance et une étude comparative. Enfin, Ted++ et FixTed ont été assemblés dans une plate-forme pour le débogage et la réparation de requêtes relationnelles. / With the increasing amount of available data and data transformations, typically specified by queries, the need to understand them also increases. “Why are there medicine books in my sales report?” or “Why are there not any database books?” For the first question we need to find the origins or provenance of the result tuples in the source data. However, reasoning about missing query results, specified by Why-Not questions as the latter previously mentioned, has not till recently receivedthe attention it is worth of. Why-Not questions can be answered by providing explanations for the missing tuples. These explanations identify why and how data pertinent to the missing tuples were not properly combined by the query. Essentially, the causes lie either in the input data (e.g., erroneous or incomplete data) or at the query level (e.g., a query operator like join). Assuming that the source data contain all the necessary relevant information, we can identify the responsible query operators formingquery-based explanations. This information can then be used to propose query refinements modifying the responsible operators of the initial query such that the refined query result contains the expected data. This thesis proposes a framework targeted towards SQL query debugging and fixing to recover missing query results based on query-based explanations and query refinements.Our contribution to query debugging consist in two different approaches. The first one is a tree-based approach. First, we provide the formal framework around Why-Not questions, missing from the state-of-the-art. Then, we review in detail the state-of-the-art, showing how it probably leads to inaccurate explanations or fails to provide an explanation. We further propose the NedExplain algorithm that computes correct explanations for SPJA queries and unions there of, thus considering more operators (aggregation) than the state of the art. Finally, we experimentally show that NedExplain is better than the both in terms of time performance and explanation quality. However, we show that the previous approach leads to explanations that differ for equivalent query trees, thus providing incomplete information about what is wrong with the query. We address this issue by introducing a more general notion of explanations, using polynomials. The polynomial captures all the combinations in which the query conditions should be fixed in order for the missing tuples to appear in the result. This method is targeted towards conjunctive queries with inequalities. We further propose two algorithms, Ted that naively interprets the definitions for polynomial explanations and the optimized Ted++. We show that Ted does not scale well w.r.t. the size of the database. On the other hand, Ted++ is capable ii of efficiently computing the polynomial, relying on schema and data partitioning and advantageous replacement of expensive database evaluations by mathematical calculations. Finally, we experimentally evaluate the quality of the polynomial explanations and the efficiency of Ted++, including a comparative evaluation.For query fixing we propose is a new approach for refining a query by leveraging polynomial explanations. Based on the input data we propose how to change the query conditions pinpointed by the explanations by adjusting the constant values of the selection conditions. In case of joins, we introduce a novel type of query refinements using outer joins. We further devise the techniques to compute query refinements in the FixTed algorithm, and discuss how our method has the potential to be more efficient and effective than the related work.Finally, we have implemented both Ted++ and FixTed in an system prototype. The query debugging and fixing platform, short EFQ allows users to nteractively debug and fix their queries when having Why- Not questions.

Plusieurs dépérissements du début du XXe siècle ont montré que le Douglas français était vulnérable à la sécheresse. La question de savoir si les forêts de Douglas peuvent s'adapter au nouveau climat plus chaud et plus sec est une préoccupation majeure en France. Nous avons estimé la variation de la résistance à la cavitation d'un ensemble de provenances de Washington, de l'Oregon et de Californie dans deux expériences de jardins communs situées dans le sud de la France. Nous avons étudié les relations entre la résistance à la cavitation, la microdensité du xylème et l'anatomie du tronc et des branches. Nous avons constaté que la pression de sélection climatique dans la zone naturelle a façonné l'adaptation locale pour la résistance à la cavitation, la microdensité et l'anatomie des ponctuations du xylème. Les provenances de Californie intérieure tendent à être plus résistantes à la cavitation, avec une plus grande densité de bois d'été et des ponctuation plus sûres que les provenances de Californie côtière, puis de Washington et d'Oregon. Cependant, nous avons également constaté des variations importantes à l'intérieur d'une même région qui ne pouvaient pas être expliquées par les données climatiques disponibles. Nous avons trouvé différentes relations structure-fonctions, selon le niveau d'observation (arbre ou provenance) et la partie de l'arbre (tronc ou branche). Par exemple, au niveau individuel, les arbres les plus résistants à la cavitation ont des branches plus denses avec une ouverture de ponctuation plus petite, tandis qu'au niveau de la provenance, les arbres les plus résistants à la cavitation ont du bois moins dense dans le tronc et les branches, et des ponctuations plus sûrs. Dans l'ensemble, nous concluons qu'il existe un potentiel d'adaptation évolutive pour la résistance à la sécheresse du Douglas, disponible à différents niveaux, individuel et de provenance. Cependant, dans un contexte d'amélioration des arbres, le réseau complexe de relations entre la résistance à la cavitation, la microdensité et les traits anatomiques doit être soigneusement examiné afin d'éviter une éventuelle réponse corrélative défavorable à la sélection. / Several turn-of-the-20th-century diebacks have shown that French Douglas-fir was vulnerable to drought. Whether the Douglas-fir forests can adapt to the new warmer and dryer climate is a key concern in France. We estimated variation of resistance to cavitation traits of a set of Washington, Oregon and Californian provenances in two common garden experiments located in the south of France. We studied the relationships between resistance to cavitation, xylem microdensity and pit anatomy in the trunk and branches. We found that climatic selection pressure in the natural area has shaped local adaptation for resistance to cavitation, microdensity and pit's anatomy. Inland California provenances tend to be significantly more cavitation resistant, with a denser latewood and safer pits than coastal Californian, then Washington and Oregon provenances. However, we also found significant within region variation that could not be explained by the available climatic data. We found different structure-functions relationships, according to the observation level (tree or provenance) and the tree part (trunk or branch). For example, at the individual level, the most cavitation-resistant trees have branches with denser latewood and smaller pit aperture, while at the provenance level, the most cavitation resistant provenances have less dense wood in both trunk and branches, and safer pits. Overall, we conclude that there is a potential for evolutionary adaptation for resistance to drought in Douglas-fir, available at different levels, individual and provenance. However, in a tree improvement context, the complex network of relationships among the resistance to cavitation, the microdensity and the anatomy traits should be carefully monitored in order to avoid possible unfavourable correlative response to selection.

The Andes Mountains provide an ideal natural laboratory to analyze the relationship between the tectonic evolution of a subduction margin, retroarc shortening, basin morphology, and volcanic activity. Timing of initial shortening and foreland basin development in Argentina is diachronous along strike, with ages varying by 20-30 million years. The Neuquén Basin (32°S-40°S) of southern-central Argentina sits in a retroarc position and provides a geological record of sedimentation in variable tectonic settings from the Late Triassic to the early Cenozoic including: 1.) active extension and deposition in isolated rift basins in the Late Triassic-Early Jurassic; 2.) post-rift back-arc basin from Late Jurassic-Late Cretaceous; 3.) foreland basin from Late Cretaceous to Oligocene; and 4.) variable extension and contraction along-strike from Oligocene to present. The goal of this study is to determine the timing of the transition from post-rift thermal subsidence to foreland basin deposition in the northern Neuquén Basin and then assess volcanic activity and composition during various tectonic regimes. The Aconcagua and Malargüe areas (32°S and 35°S) are located in the northern segment of the Neuquén Basin and preserve Upper Jurassic to Miocene sedimentary rocks, which record the earliest phase of shortening at this latitude. This study presents new sedimentological and detrital zircon U-Pb data from the Jurassic to latest Cretaceous sedimentary strata to determine depositional environments, stratigraphic relations, provenance, and maximum depositional ages of these units and ultimately evaluate the role of tectonics on sedimentation in this segment of the Andes. The combination of provenance, basin, and subsidence analysis shows that the initiation of foreland basin deposition occurred at ~100 Ma with the deposition of the Huitrín Formation, which recorded an episode of erosion marking the passage of the flexural forebulge. This was followed by an increase in tectonic subsidence, along with the appearance of recycled sedimentary detritus, recorded in petrographic and detrital zircons analyses, as well development of an axial drainage pattern, consistent with deposition in the flexural forebulge between 95 and 80 Ma. By ca. 70 Ma the volcanic arc migrated eastward and was a primary local source for detritus. Growth structures recorded in latest Cretaceous units very near both the Aconcagua and Malargüe study areas imply 35-40 km and 80-125 km of foreland migration between 95 and 60 Ma in the Aconcagua and Malargüe areas, respectively. Strata ranging in age from Middle Jurassic to Neogene were analyzed to determine their detrital zircon U-Pb age spectra and Hf isotopic composition to determine the relationship between magmatic output rate, tectonic regime, and crustal evolution. When all detrital zircon data are combined, significant pulses in magmatic activity occur from 190-145 Ma, and at 128 Ma, 110 Ma, 69 Ma, 16 Ma, and 7 Ma. The duration of magmatic lulls increased markedly from 10-30 million years during back-arc deposition (190-100 Ma) to ~40-50 million years during foreland basin deposition (100-~30 Ma). The long duration of magmatic lulls during foreland basin deposition could be caused by flat-slab subduction events during the Late Cretaceous and Cenozoic or by long magmatic recharge events. There are three major shifts towards positive Hf isotopic values and all are associated with regional extension events whereas compression seems to lead to more evolved isotopic values.

The Laurentine Shore is the Imperial Roman palaeo-shoreline preserved up to 1km inland of the southern, distal edge of the Tiber Delta coastline of Lazio, western Central Italy. The progradation of the delta is recorded on the site as a series of shore-parallel relict dune ridges. High-status villas developed along the roman period coastline, with a service village (Vicus Augustanus), and other infrastructure such as roads, aqueduct, piscinae and several baths (thermae), these structures have been examined using a multi-scale geoarchaeological approach. A sea level reconstruction based on multi-proxy palaeo-environmental analysis of a silt/peat sedimentary transition from the base of a Roman piscina suggests that the sea level at ca. 2400 ± 40 BP was around 1.25 ± 0.2 m below modern sea level. This analysis provides further context for assessing the development of the site during the late Holocene in relation to the progradation of the Tiber delta and for the important Imperial Roman period occupation of the Laurentine Shore and other important sites such as Portus and Ostia Antica in the central part of the Tiber delta. At several key periods in the late Holocene, the palaeo-shoreline has been reconstructed using a geochronological framework of optical luminescence dates and geomorphological survey of the Tiber Delta dune ridge record. In particular, during the Imperial Roman period, ca. 2000 BP) it has been shown that the Laurentine Shore was settled during a period of significant Tiber delta shoreline progradation. Two-major building phases at the Vicus Augustanus occur within this progradation phase. By the abandonment of the site in the 5th century AD, the shoreline was around 70 m seaward of the shoreline during the 1st building phase of the Vicus. This rate of shoreline change could be noticeable by the population over decadal timescales and may have driven the alteration of coastal building and property plots during the 500 year lifetime of the settlement. A combined methodology incorporating sedimentology, geochemistry and petrological analysis of diagenetically altered sediments found that early vadose diagenesis may have a deleterious effect upon luminescence dating dosimetry, inducing age underestimation, especially of reddened dune sands. Petrological analysis has also shown that a lack of anomalous fading in luminescence behaviour observed in K-feldspars may be due to a lack of complex microstructure in the mineral grains driven by the metamorphic, Alpine origin of these minerals. An assessment of the geoarchaeological approach used in this thesis shows that a scale-driven context provides a useful structure for examining the various processes and factors affecting the geomorphological and sedimentological records improving confidence in the examination of the archaeological record.

In the Canadian Cordillera, Mesozoic calcalkaline and alkaline intrusive igneous rocks that are prospective for hosting porphyry Cu-Au mineralization may be overlain by thick glacial overburden. Previous studies have shown that magnetite from ore deposits has a unique trace element signature that differs from magnetite in common igneous or metamorphic rocks. This study investigated if the composition of ore-related magnetite in till could provide a unique exploration tool to locate porphyry deposits in glaciated terrain. Bulk till samples were collected over an area of ~700 km2 surrounding the Mount Polley porphyry Cu-Au deposit, south-central British Columbia. Twenty elements were measured by LA-ICP-MS in ~50 detrital magnetite grains in each of 20 till samples. Previously proposed discrimination diagrams are proven to be of limited use in correctly identifying ore-related magnetite. Therefore, linear discriminant analysis (LDA) was performed on a compiled dataset of magnetite compositions from various porphyry deposits and intrusive igneous rocks in order to rigorously redefine the chemical signature of hydrothermal magnetite from porphyry systems. Application of the LDA models to magnetite in till found that the dispersal of hydrothermal grains from Mount Polley is coincident with the deposit and the interpreted ice-flow history. Anomalous concentrations of hydrothermal magnetite grains in till are detected up to 2.5 km west-southwest and 4 km northwest of the deposit, indicating that magnetite has a strong potential to be an effective indicator in mineral exploration for porphyry systems. / Graduate