Thesis (M. Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 141-161).

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 382-389).

Hamburg, Universiẗat, Diss., 1999.

Göttingen, Universiẗat, Diss., 2003.

Texte remanié de: Th.--Faculté de droit et de sciences économiques--Paris, 1963. / Bibliogr. p. 249-259.

The achievement of a sustainable future for Scotland's coastal communities is subject to, and dependent upon, a complex policy landscape of stakeholders and policy documents within which resource and information is transferred where relationships and dependencies, are linked to the power and influence of policy actors and documents. Understanding the dynamics of the policy network is critical for effective stakeholder engagement. This study investigated four policy themes and explored their impact and relevance on government and civil society efforts for Scottish coastal community sustainability. This was informed by a review of the marine and coastal estate, policy and planning in addition to sustainable economics, behaviour, innovation and governance. The four policy themes of low carbon economy, marine renewable energy, zero waste and sustainability were subject to a literature reviews and to policy network analysis using a new method developed here called Rapid Policy Network Analysis. This method provides a broadly applicable, relatively simple, replicable mechanism, with cost to its application for non-policy specialists to understand those issues which are most pertinent to their objectives. The research considered established theories and models for achieving sustainable equilibrium in complex systems including common pool resources and recent initiatives in developing sustainable communities. A working hypothesis for a future policy framework supporting sustainable development in the Scottish coastal region was proposed and tested using the results of the policy network analysis and literature review based on specific questions. Across all policy themes the Climate Change (Scotland) Act 2009, the Electricity Act 1989, the Environmental Protection Act 1990, the Second National Planning Framework (NPF2), the UK and Scottish Governments and Scottish Local Authorities were amongst the most important and influential. The study shows that there continues to be a gap between the national development of sustainability policy and the authority required at the coastal scale.

No description available.

Ce manuscrit présente une étude expérimentale de la diffusion de l’hydrogène (H) dans la wadsleyite à basses températures et pression ambiante et une analyse par spectroscopie infrarouge des défauts OH de la wadsleyite et de la ringwoodite, les constituants majeurs de la zone de transition du manteau (ZT ; entre 410 et 670 km de profondeur). Après synthèses des échantillons par presse multi-enclume, des expériences d’échange isotopique hydrogène-deutérium (H-D) entre 450 et 300°C et à pression ambiante permettent de suivre l’évolution des concentrations en défauts OH dans la wadsleyite polycristalline par spectrométrie infrarouge en fonction du temps de recuit. Ces expériences montrent 2 cinétiques d’extraction clairement distinctes avec 6 bandes OH plus lentes. Des mesures sur monocristaux en polarisation et d’autres entre -194 et 50°C tendent à les lier à des défauts impliquant des sites tétraédriques. Des différentes mesures du coefficient de diffusion d’échange H-D, nous tirons 2 lois logDH=-6.04(±1.49)-153(±11)/RTln(10) pour la limite basse et logDH=-4.26(±1.36)-164(±10)/RTln(10) pour la limite haute. Selon les modèles de conductivité électrique terrestre, en supposant celle-ci comme étant la résultante de la mobilité de H+ uniquement, ces lois permettent une estimation des teneurs en eau dans la ZT très probablement supérieure à 0,1 wt%H2O et atteignant la saturation pour les régions à très forte conductivité électrique. Ceci impliquant une teneur en eau au moins 10 fois plus élevée que l’estimation de référence pour la wadsleyite (Hae et al., 2006) et compatible avec celle (1 wt%H2O) d’un échantillon naturel de ringwoodite découvert récemment (Pearson et al., 2014). / This manuscript presents an experimental study of hydrogen (H) diffusion in wadsleyite at low temperatures and ambient pressure and an infrared spectroscopy (FTIR) analysis of H-related defects for wadsleyite and ringwoodite, the main components of the mantle transition zone (TZ; from 410 to 670 km depths). These mineral phases ability to incorporate high H-contents suggests that the mantle TZ is an important potential H reservoir. Hydrogen-deuterium (H-D) isotopic exchange experiments have been done at low temperatures (between 450 and 300°C) and ambient pressure and evolution of wadsleyite H-defects is followed by FTIR spectroscopy in function of annealing time. These experiments show two clearly distinct kinetics of extraction with 6 slower OH bands that polarized FTIR spectroscopic measurements on monocrystals, other at very low temperatures (-194 to 50°C) tend to link with defects involving tetrahedral sites.The measured H-D exchange diffusion coefficients show that the H “self diffusivity” in wadsleyite is delimitated by two diffusion laws in m2/s: logDH=-6.04(±1.49)-153(±11)/RTln(10) for the lower limit and logDH=-4.26(±1.36)-164(±10)/RTln(10) for the upper limit.According to the Earth’s electrical conductivity models and assuming this one as the only product of the proton’s mobility, we show that water content in TZ is most likely higher than 0.1 wt% H2O and potentially up to saturation concentrations. This implies a water content at least 10 times higher than the previous estimate from the diffusion study of Hae et al.(2006) and compatible with the recent discovery of a natural 1wt%H2O water content ringwoodite sample included in a diamond (Pearson et al.,2014).

Cette étude met en évidence le rôle de la subduction Pacifique dans la genèse des basaltes est- chinois à l’aide de la mesure de leur teneur en eau par infrarouge en transformé de Fourier (IRTF) et de leur composition isotopique en oxygène analysée par sonde ionique (SIMS). Les valeurs en δ18O des phénocristaux de clinopyroxènes (cpx) des basaltes de Shuangliao, varient entre 4.10‰ et 6.73‰. Elles suggèrent la présence d’une croûte océanique recyclée (ROC) dans la source magmatique. La forte valeur de la concentration en H2O et du rapport H2O/Ce de la source magmatique (0.90-3.06 pds.%, 158-737), suggère également la contribution de sédiments riches en eau à la source. Par contre, les basaltes de Wulanhada ont une teneur en eau nettement plus faible (0.21-0.69 pds.%). Leur δ18O élevé (5.49-7.38 ‰) et la corrélation du rapport H2O/Ce avec 87Sr/86Sr, Ba/Th, Nb/La, Nb/U et Ce/Pb indiquent clairement une contribution de sédiments déshydratés dans la source, en plus de la croûte (ROC). Dans les basaltes de Chaihe-aershan, le δ18O des cpx ainsi que la teneur en H2O initiale du magma varient sur une large gamme (4.27-8.57‰, 0.23-2.70 pds.%). À partir de la comparaison entre le δ18O des phénocristaux de cpx, H2O/Ce, Ba/Th et l’anomalie en Eu en roche totale, nous avons clairement identifié trois composantes distinctes dans la source magmatique : une croûte océanique supérieure avec des sédiments marins, une croûte océanique inférieure gabbroïque altérée et le manteau au voisinage de la source. Les mesures faites sur les basaltes ultra potassiques de Xiaogulihe révèlent des teneurs en H2O et des rapport H2O/Ce faibles (0.36-0.50 pds.%, ~15). Les valeurs en δ18O des phénocristaux d’olivine de ces basaltes, couplées à des valeurs basses en 206Pb/204Pb et relativement hautes en 87Sr/86Sr de la roche, suggèrent que l’origine de ces basaltes est très probablement liée à la présence de sédiments anciens fortement déshydratés, riches en potassium. / This work is focused on the role of the Pacific subduction on the genesis of the Cenozoic continental basalts in eastern China, based on the approaches of the water contents (analyzed by Fourier transform infrared spectroscopy (FTIR)) and oxygen isotope compositions ( analyzed by Secondary ion mass spectrometry (SIMS)).The δ18O values of cpx phenocrysts in the Shuangliao basalts range from 4.10‰ to 6.73‰, which provides a strong evidence for the contribution of recycled oceanic crust (ROC) in the mantle source. Combined with the high H2O content and H2O/Ce ratios of the “primary” magma (0.90-3.06 wt.%, 158-737), the contribution of water-rich sediment component has also been suggested. Unlike the Shuangliao basalts, the Wulanhada basalts have lower H2O contents (0.21-0.69 wt.%). The high oxygen isotope compositions (5.49-7.38 ‰) and the correlations of H2O/Ce with 87Sr/86Sr, Ba/Th, Nb/La, Nb/U and Ce/Pb ratios indicate that the contributions of a significantly dehydrated sediments and ROC to the mantle source. In Chaihe-aershan basalts, the δ18O values of cpx phenocrysts and the H2O contents of “primary” magmas vary widely (4.27-8.57‰, 0.23-2.70 wt.%).Three components (altered upper oceanic crust and marine sediments, altered lower gabbroic oceanic crust, ambient mantle) have been identified in the mantle source based on the relations between δ18O values of the cpx phenocrysts, H2O/Ce and Ba/Th ratios and the Eu anomaly of bulk rock. For the Xiaogulihe ultrapotassic volcanic rocks, the estimated H2O contents and H2O/Ce ratios are low (0.36-0.50 wt%, ~15). Combined with the high δ18O values of olivine phenocrysts, the low 206Pb/204Pb ratios and moderately high 87Sr/86Sr ratios of the bulk rock, we concluded that highly dehydrated ancient sediments could be a most likely candidate for the K-rich component in the mantle source.

The Bella Coola area geographically straddles two zones of known Early to mid-Cretaceous sinistral ductile strain; the Grenville, Kitkatla, and Principe-Laredo shear zones to the northwest located near Prince Rupert, B.C., and the Tchaikazan fault system to the southeast. At the latitude of Bella Coola in west-central B.C., the Pootlass High Strain Zone (PHSZ) is a ductile, subvertical, shear zone system at least 2 km wide and at least 30 km long. The purpose of this study is to determine the age, kinematics, and tectonic significance of the PHSZ, and to investigate whether or not it was active as a kinematic link to Early to mid-Cretaceous sinistral ductile strain zones in the western Canadian Cordillera. This thesis reports recent observations from field mapping and new geochronological, microstructural, and petrological data, from which the PHSZ is characterized and placed into a regional tectonic framework. U-Pb and 40Ar/39Ar isotopic geochronology indicate that regionally extensive, southwest-vergent folding in the PHSZ area was active prior to 114 Ma and persisted until at least 73 Ma. High-temperature, ductile, sinistral non-coaxial strain in the PHSZ was accommodated between 76 (or earlier) and 62 Ma. Localization of high strain is associated with the emplacement of plutonic rock and abundant intrusive sills, which likely acted as a strain-softening mechanism. L-tectonites within the deformed plutonic rocks attest to the weakness of the rocks during deformation and support syn-kinematic magmatism. Geothermometric and petrological data suggest that deformation occurred at temperatures of 537 to 731°C and at crustal depths of —23 km. The PHSZ is interpreted to be kinematically related to the Talchako Fault to the east, which was active as a sinistral mylonitic shear zone between 70 and 65 Ma. A kinematic relationship between the PHSZ and the Grenville, Kitkatla and Principe-Laredo shear zones near Prince Rupert imply a protracted history of sinistral transpression in the Coast Mountains of British Columbia that persisted in the Bella Coola region through Late Cretaceous time. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate