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Understanding how wildlife utilize habitat at varying scales is important for understanding and predicting potential impacts of landscape changes (e.g., habitat loss and fragmentation, restoration efforts, climate change, etc.) and in determining effective strategies for conservation and management. This research examines fine-scale and landscape-level habitat use of black bears in Canyon de Chelly National Monument (CACH), Arizona, USA in the context of large-scale landscape change. Currently, CACH is undergoing a large-scale restoration effort to remove all of the non-native Russian olive (Elaeagnus angustifolia) and tamarisk (Tamarix ramosissima and T. chinensis) within the monument. As black bears rely on the Russian olive as a primary food source, a major goal of this research was to evaluate how bears currently use this resource and how its removal might affect bear habitat use and bear-human interactions within the monument. I developed a model of 3rd order (fine-scale) black bear habitat use in CACH using an occupancy modeling approach. Model results indicated that fine-scale habitat selection by bears in CACH is being driven by the presence of non-native Russian olive as well as native food sources. Thus availability of native foods may be sufficient to maintain the bear population in CACH, and bears may quickly adapt to the loss of the non-native food source. Similarly, results showed that bears avoid human areas and farmsteads and prefer higher elevations, suggesting that once olive is removed in the lower canyons near human areas, bear-human interactions may become less of a problem over the long term. I also developed a model of 2nd order (landscape-level) habitat use and evaluated movement patterns of black bears in CACH using location data collected from GPS collars. Model results showed that bears selected areas with higher tree canopy cover and terrain ruggedness, indicating that forest cover and escape cover are primary factors driving black bear habitat selection at the landscape scale in this region. Movement patterns revealed large mean daily movements and low average turning angles, indicating long, linear movements designed to take advantage of the mosaic of available habitats and food resources available over larger areas. I extracted DNA from hair samples collected throughout the study area to examine genetic variability and population structure of black bears in the region. Analyses revealed a relatively healthy, panmictic population across the wider landscape. No substantial genetic structuring was observed in multiple analyses, though I did find evidence of a slight isolation-by-distance pattern within the population. Measures of both current (Nb = 24) and long-term (Ne = 579) effective population size indicated a relatively high number of breeders in the current population and a sufficient amount of gene flow within the larger "superpopulation" to maintain long-term genetic viability. I focused the final portion of my dissertation research on understanding the factors that influence stakeholder acceptance capacity for black bears, which plays a central role in contemporary wildlife management issues, including human-wildlife conflict. I used data from telephone interviews of 1,546 residents in Virginia to develop conceptual models of black bear acceptance capacity at both county and state levels. Model results suggested that more deep-seated and less easily influenced factors (e.g., values and risk perceptions) are at the heart of stakeholder attitudes and perceptions of wildlife, making influencing these perceptions more difficult. Agencies can indirectly affect these attitudes and perceptions, however, by targeting more potentially pliable factors related to wildlife acceptance capacity such as knowledge, personal experience with wildlife, and trust in management agencies. / Ph. D.

Buried culvert has its contribution in improving the convenience and quality of human life. The research of buried culvert in the past decades makes it to serve people more widely and efficiently. The research project of Cross Canyon culvert is one of them. A computer program was used in this study. The overburden-dependent soil model was chosen to represent the stress states of the soil in the backfill. The triaxial shear test data were converted into an overburden-dependent soil model and then this converted soil model was modified. The modified soil model was obtained when the difference of the measured and computed crown vertical displacement was minimized. The parametric studies were done after the modified soil model was obtained. In this research, the parametric studies were (1) Effects of different inclusion material on the culvert, (2) Effects of polystyrene plank wrapped around the culvert, (3) Effects of concrete bedding, (4) Effects of compaction. It was found that the material of inclusion had great influence on the moments of the culvert between the position of crown and 45 degrees. The concrete bedding was not a good practice because the moments were increased largely compared with those moments without concrete bedding. Finally, the compaction did not have much effects on the behavior of the culvert. / Master of Science

Dans le cadre du projet Européen GTS Next, nous avons obtenu des nouvelles contraintes sur l’âge des étages du Crétacé Supérieur à partir de plusieurs techniques de géochronologie et d’interprétations stratigraphiques au Canada et au Japon. Dans le bassin sédimentaire du Western Interior Canada, nous proposons une nouvelle détermination de l’âge de la limite Crétacé - Tertiaire (K/Pg) enregistrée dans la coupe de Red Deer River (Alberta). Il a été possible de calibrer par cyclostratigraphie haute-résolution cette série sédimentaire fluviatile non-marine et d’identifier 11-12 cycles associés à la précession orbitale de la Terre. En considérant la technique 40Ar/39Ar intercalibrée avec la cyclostratigraphie, l’âge apparent de la base du chron magnétique C29r suggère que la limite K/Pg se trouve entre un minimum et un maximum de l’excentricité, avec une durée pour C29r de 66.30 ± 0.08 à 65.89 ± 0.08 Ma. En supposant que le cycle contenant le niveau de charbon soit associé à un cycle de précession, l’âge révisé de la limite Crétacé - Tertiaire est donné par la plus jeune des populations de zircon datée par U-Pb à 65.75 ± 0.06 Ma.La limite Campanien – Maastrichtien est également enregistrée dans ce même bassin canadien, et se trouve à environ 8 m sous le niveau de charbon No. 10 dans la formation de Horseshoe Canyon. L’étude cyclostratigraphique montre que le dépôt de cette séquence sédimentaire est directement influencé par les changements du niveau marin dû à la précession et dominés par l’excentricité Notre travail montre que la position de la limite Campanien – Maastrichtien dans ce bassin sédimentaire du Western Canada est placée à environ 2.5 cycles d’excentricité au dessus d’un niveau de téphra de la base de la coupe dont l’âge U-Pb est donné par la plus jeune population des zircons, et ~4.9 Myr avant la limite Crétacé - Tertiaire. Nous en déduisons un âge absolu de 70.65 ± 0.09 Ma pour la limite Campanien – Maastrichtien, ce qui est ~1.4 Myr plus jeune que les études récemment publiées.Enfin, à partir des isotopes du carbone et des foraminifères planctoniques enregistrés au centre d’Hokkaido (Pacifique Nord-Ouest), les coupes Crétacé du groupe Yezo ont été corrélée avec les séries européennes et nord-américaines. Plusieurs niveaux de téphra prélevés au sein des coupes de Kotanbetsu et Shumarinai ont été datés par les méthodes 40Ar/39Ar and U-Pb. Deux d’entre eux, placés de part et d’autre de la limite Turonien – Coniacien, ont donné des âges de 89.31 ± 0.11 et 89.57 ± 0.11 Ma, ce qui suggère un âge de 89.44 ± 0.24 Ma pour cette limite. En combinant notre résultat avec les âges récemment publiés, nous pouvons proposer un âge de 89.62 ± 0.04 Ma pour la limite Turonien – Coniacien. / As part of the wider European GTS Next project, I propose new constraints on the ages of the Late Cretaceous, derived from a multitude of geochronological techniques, and successful stratigraphic interpretations from Canada and Japan. In the Western Canada Sedimentary Basin, we propose a new constraint on the age of the K/Pg boundary in the Red Deer River section (Alberta, Canada). We were able to cyclostratigraphically tune sediments in a non-marine, fluvial environment utilising high-resolution proxy records suggesting a 11-12 precession related cyclicity. Assuming the 40Ar/39Ar method is inter-calibrated with the cyclostratigraphy, the apparent age for C29r suggests that the K/Pg boundary falls between eccentricity maxima and minima, yielding an age of the C29r between 65.89 ± 0.08 and 66.30 ± 0.08 Ma. Assuming that the bundle containing the coal horizon represents a precession cycle, the K/Pg boundary is within the analytical uncertainty of the youngest zircon population achieving a revised age for the K/Pg boundary as 65.75 ± 0.06 Ma. The Campanian - Maastrichtian boundary is preserved in the sedimentary succession of the Horseshoe Canyon Formation and has been placed ~8 m below Coal nr. 10. Cyclostratigraphic studies show that the formation of these depositional sequences (alternations) of all scales are influenced directly by sea-level changes due to precession but more dominated by eccentricity cycles proved in the cyclostratigraphic framework and is mainly controlled by sand horizons, which have been related by autocyclicity in a dynamic sedimentary setting. Our work shows that the Campanian - Maastrichtian boundary in the Western Canada Sedimentary Basin coincides with ~2.5 eccentricity cycles above the youngest zircon age population at the bottom of the section and ~4.9 Myr before the Cretaceous - Palaeogene boundary (K/Pg), and thus corresponds to an absolute age of 70.65 ± 0.09 Ma producing an ~1.4 Myr younger age than recent published ages. Finally, using advances with terrestrial carbon isotope and planktonic foraminifera records within central Hokkaido, Northwest Pacific, sections from the Cretaceous Yezo group were correlated to that of European and North American counterparts. Datable ash layers throughout the Kotanbetsu and Shumarinai section were analysed using both 40Ar/39Ar and U-Pb methods. We successfully dated two ash tuff layers falling either side of the Turonian - Coniacian boundary, yielding an age range for the boundary between 89.31 ± 0.11 Ma and 89.57 ± 0.11 Ma or a boundary age of 89.44 ± 0.24 Ma. Combining these U-Pb ages with recent published ages we are able to reduce the age limit once more and propose an age for the Turonian - Coniacian boundary as 89.62 ± 0.04 Ma.

Ce travail présente une analyse de la morphologie et de la dynamique sédimentaire des systèmes turbiditiques actuels du Cap-Ferret et de Capbreton (sud du Golfe de Gascogne). La reconnaissance effectuée sur le système de Capbreton est la première à le considérer dans son ensemble. Ce travail se base sur des données acoustiques de subsurface (sondeur multifaisceaux, sondeur de sédiments Chirp) et de carottages issues de la campagne océanographique Sargass menée par l’Université de Bordeaux. L’analyse morpho-bathymétrique révèle l’organisation amont-aval des géométries sédimentaires dans ces systèmes et, couplée aux données sédimentaires, de préciser les processus de dépôts liés aux écoulements gravitaires. Le fonctionnement holocène du canyon de Capbreton montre des processus gravitaires haute fréquence, révélant son rôle de dépôt-centre pour le sud du golfe de Gascogne. Dans le système du Cap-Ferret, la zone de transition chenal-lobe a été investiguée à fine échelle, documentant ainsi des structures sédimentaires rarement identifiées avec ce niveau de détails dans les systèmes turbiditiques modernes. La dynamique sédimentaire de chacun de ces systèmes est soumise à des forçages auto-cycliques et glacio-eustatiques qui affectent chacun des systèmes de façons différentes. Ces informations ont permis de proposer un modèle régional de fonctionnement sédimentaire au cours des derniers 50 000 ans. / This work presents an analysis of the morphology and sedimentary dynamic of the Cap-Ferret and Capbreton turbidite systems (south Bay of Biscay), containing the first recognition of the whole Capbreton turbidite system. The dataset comprises subsurface geophysical data (multibeam bathymetric and imagery, Chirp sub-bottom profiler) and piston cores, acquired during the oceanographic cruise Sargass conducted by the Bordeaux University. Studied by morpho-bathymetric analyses, the upstream-downstream evolution of the sedimentary bodies joined to the sedimentological data help to understand the active gravity processes of the systems. In the Capbreton system, a special focus is made on its Holocene gravity deposits occurring at high frequencies. In the Cap-Ferret system, the channel-lobe transition zone has been investigated at high resolution and revealed sedimentary structures poorly documented at this scale of details in recent turbidite systems. The glacio-eustatic and autocyclic forcing are expressed in different ways in each turbidite sytem. A regional sedimentary dynamic model is proposed for the last 50,000 years.

Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this question by providing insight into the processes responsible for producing and erupting silicic magmas. This study focuses on two extensive and well-preserved ash-flow tuffs from within the ~4-8 Ma Deschutes Formation of central Oregon, which formed after the transition from Western Cascade volcanism to the modern High Cascade. Documentation of outcrop extent, outcrop thickness, clast properties, and samples provide the means to estimate a source location, minimum erupted volumes, and to constrain eruptive processes. Major and trace element chemistry of glass and minerals constrain the petrogenesis and chemical evolution of the system. The tuffs selected for this study, the Lower Bridge and McKenzie Canyon, are the first known silicic units originating from the Cascade Arc following the reorganization from Western Cascade to High Cascade Volcanism at ~8 Ma. These eruptions were significant in producing a minimum of ~5 km�� DRE each within a relatively short timeframe. These tuffs are sourced from some vent or edifices related to the Three Sisters Volcanic Complex, and capture an early phase of the volcanic history of that region. The chemical composition of the tuffs indicates that the Lower Bridge erupted predominately rhyolitic magma with dacitic magma occurring only in small quantities in the latest stage of the eruption while McKenzie Canyon Tuff erupted first as a rhyolite and transitioned to a basaltic andesite with co-mingling and incomplete mixing of the two magma types. Major and trace element concentrations in minerals and glass indicate that the basaltic andesite and rhyolite of the McKenzie Canyon Tuff were well convected and stored in separate chambers. Geothermometry of the magmas indicate that the rhyolites are considerably warmer (~850��) than typical arc rhyolites. Trace element compositions indicate that both the Lower Bridge and McKenzie Canyon Tuff experienced mixing between a mantle derived basaltic melt and a rhyolitic partial melt derived from gabbroic crust. Rhyolites of the Lower Bridge Tuff incorporate 30-50% partial melt following 0->60% fractionation of mantle derived melts. The McKenzie Canyon Tuff incorporates 50-100% of a partial melt of a mafic crust with up to 15% post mixing fractionation. The results of this study suggest that production of voluminous silicic magmas within the Cascade Arc crust requires both fractionation of incoming melts from the mantle together with mixing with partial melts of the crust. This provides a potential explanation for the decrease in silicic melt production rates from the Western Cascades to the High Cascades related to declining subduction rate. As convergence along the Cascade margin became more oblique during the Neogene, the consequent slowing rate of mantle melt production will result in a net cooling of the crust, inhibiting the production of rhyolitic partial melts. Without these partial melts to provide the rhyolitic end member to the system, the system will evolve to the mafic melt and fractionation dominated regime that has existed along Cascadia throughout the Quaternary. / Graduation date: 2013

The interaction of numerous sedimentary processes at key transition points along the depositional profile results in a complex heterogeneity in ancient basin margin successions. This complexity is generally well studied along depositional dip sections, but lateral (strike) variability and consequent implications for sediment distribution and stratigraphic architecture is commonly less well constrained. In the Karoo Basin, continuous NW-SE-oriented exposure over 80 km has been characterized by 53 logs with 9910 m of cumulative thickness, >2500 palaeocurrent measurements, and ground-, drone- and helicopter-based photo panels. Palaeoflow indicators suggest dominant sediment transport was to the N-NE, with E-W and NE-SW bidirectional components. These are consistent with a strike orientation of the outcrop belt relative to the NE-N margin progradation direction and a NE-SW reworking by waves orientation. In the south of the study area, upper slope and shelf edge parasequences (50-75 m-thick), show current ripples and inverse-to-normal grading in micaceous and organic-rich siltstones and sandstones. They are interpreted as river-dominated prodelta and mouth bar deposits, locally incised by distributary channels (100 m-thick, 1.5 km-wide). Overlying shelf parasequences are thinner (15-50 m) with symmetrical ripple tops, HCS and low angle cross bedding, interpreted as wave-influenced deltaic or shoreface deposits. They transition upward into erosive-based, fining-up sandstones and isolated sharp-based tabular climbing-rippled sandstones, interpreted as channels and crevasse splays within delta plain mudstones. Along strike to the north, upper slope parasequences show more wave reworking indicators and no evidence of gullying or incision. Overlying shelf parasequences are sandier, more amalgamated and strongly influenced by wave action. They are interpreted as offshore, shoreface, foreshore and strandplain deposits. Southern nearshore environments were therefore more river-dominated with bypass and sediment delivery to deeper parts of the basin across a steep, more erosive margin. Wave and storm current redistribution along strike to the northern, lower gradient margin resulted in higher net-to-gross and sand connectivity on a wider shelf, without major incision, bypass and sand supply to the upper slope. No evidence of major avulsions in the upstream tributary and distributary systems are interpreted because the bypass and fluvial-dominated characteristics are persistent in the southern areas through time, whereas the northern margin maintained a sand-starved upper slope and a wave dominated shelf succession. The overall thicker and delta- dominated succession in the south, and the thinner, more condensed and wave dominated stratigraphy in the north are interpreted to be controlled by a combination of basement and basin configuration and differential basin margin physiography. However, relative sea level fluctuations controlled the stacking patterns, with an overall shallowing-upward profile that can be subdivided into two prograding phases, separated by a transgressive phase. At parasequence scale, climate, autocyclicity and coastal processes influenced the equilibrium between sediment input, redistribution and compensational stacking. This study demonstrates that although basin margin successions may be consistently progradational, the interaction of mixed coastal processes and differential spatial configuration can result in a complex along-strike sedimentary architecture, with major implications for sediment distribution through time and space.

La marge provençale, localisée au Nord-Ouest de la Méditerranée, constitue avec la marge du Golfe du Lion et la marge ligure, la bordure septentrionale du bassin Liguro-Provençal. L'objectif principal de ce travail est la reconstitution de l'histoire géodynamique, structurale et géomorphologique de la marge depuis le Tertiaire. Sa structure est principalement le résultat des phases tectoniques anté-miocènes. Sur la marge provençale la transition entre le plateau continental et le bassin est étroite et caractérisée par des pentes abruptes affectées par des phénomènes d'instabilité gravitaire dans l'axe du canyon sous-marin de Cassidaigne. A terre, la marge provençale est caractérisée par une compression pyrénéenne, des fossés oligocènes, et une sédimentation mésozoïque à cénozoïque essentiellement carbonatée propice à l'infiltration des eaux en profondeur. L'origine des cours d'eau de la région est essentiellement karstique, et les sources côtières de Port-Miou et Bestouan constituent des réseaux karstiques noyés développés sur plusieurs kilomètres dans le calcaire urgonien, au droit du canyon de Cassidaigne. Les travaux antérieurs suggèrent que l'absence de réseau fluviatile de surface en amont et la forme de reculée karstique de la tête du canyon de Cassidaigne sont le résultat d'une connexion karstique entre les sources côtières et le canyon, que la marge provençale n'ait pas été affectée par l'érosion messinienne et la transgression pliocène, que certains dépôts transgressifs marins miocènes sont situés à des altitudes anormalement élevées par rapport à leurs niveaux de dépôt théorique. / The Provence Margin is situated in the north-western Mediterranean and constitutes the northern edge of the Liguro-Provençal Basin with the margins of the Gulf of Lion and Ligurian sea. The main objectif of this thesis is the reconstruction of the geodynamic, structural and geomorphologic history of the margin since the Tertiary. This margin is mainly structured by ante-miocene tectonic events. On the Provence Margin, transition between the continental plate and the basin is narrow and characterized by abrupt slopes and associated gravitary instability within the axis of the Cassidaigne canyon. The Provence Margin is characterized by Pyrenean compression and Oligocene extension. The Mesozoïc-Cenozoïc sedimentary pile is dominated by carbonate rocks favorable to water circulation. The origin of the river system in the region is essentially karstic, and the coastal springs of Port-Miou and Bestouan correspond to drowned karstic network that develop along tens of kilometers within the Urgonian limestone, updip of the Cassidaigne Canyon. Previous work suggest (1) that the lack of updip river system and the karst pocket valley shape of the canyon head are the result of an active karstic connexion between the coastal springs and the canyon, (2) that the Provence Margin is not affected by the Messinian erosion and Pliocene transgression, and (3) that Miocene marine transgressions are preserved at higher altitudes than their theoretical level. These facts witness a recent tectonic deformation that is not well understood. This work is based on the integration of geology, geomorphology and hydrogeology with the aim to understand evolution and functioning of coastal karsts