The continental margin off the coast of Pakistan between the Murray ridge and the Gulf of Cambay has been studied in this work using gravity, magnetic and bathymetric data. Two dimensional gravity and magnetic models based on free-air gravity and residual magnetic data are developed along a north-south profile off the coast of Karachi. The purpose was to interpret the gross crustal structure of the region. A magnetic map has also been developed for the region between latitudes 20°N and 27°N and between longitude 60°E and 70°E. The gravity model extends to a distance of about 1200 km seaward south of Karachi. The seaward end of the gravity model is constrained by seismic refraction data which suggest the presence of typical oceanic crust. The Moho depth at this end of the profile is about 12 km. At the landward end of the profile A-A' the Moho depth is not constrained by seismic data. The gravity model suggests 27 to 17 km as the possible range of the depth of the Moho and a gradual thinning of the crust from land to sea. In addition, the gravity models as interpreted in this study show grabens at the distances of 350 and 450 km along the profile. If the graben-like structures are rift grabens formed during the rifting of India from Africa then transitional crust can be expected to extend to the 500 km mark along the profile A-A'. Two dimensional models for the magnetic data along the profile were also developed. These anomalies can be interpreted as due to oceanic crust or magnetic bodies embedded in transitional crust. The possibility that the observed magnetic anomalies are due to oceanic crust has been studied in detail in this work. The location of the observed magnetic anomalies with respect to marine magnetic anomaly (28) observed earlier on the Indian Ocean floor, were compared to a marine magnetic time scale. To get a reasonable correlation between the observed and theoretical anomalies requires a considerable amount of adjustment in the spreading rate of individual magnetic blocks. Also on the magnetic map the trend of the lineation of these anomalies is perpendicular to the continental margin instead of being parallel to the continental margin as expected for a rifted continental margin. The presence of horst-and-graben structures in the inland region suggests the rifted nature for the continental margin off Karachi than the sheared nature. This indicates that the lineations should be parallel to the margin. But the magnetic lineations are perpendicular to the continental margin and if they are from oceanic crust then they would suggest that the margin is a sheared margin, which contradicts the extensional structures observed inland. This makes it very unlikely that the source of these anomalies is oceanic crust. However, it is quite possible that the magnetic lineations observed in the map were parallel to the continental margin initially but later on the continent rotated clockwise along a fault landward of the magnetic lineation. This rotation is perhaps responsible for making the lineation perpendicular to the continental margin. One objective of this study was to locate the continent-ocean boundary, but with the available amount of data it is not possible to decide on the most appropriate source for the observed magnetic anomalies. Hence it was not possible to decide exactly on the location of continent-ocean boundary. However, on the basis of gravity and magnetic data it can be said that the continent-ocean boundary lies at a distance of 500 km or greater along the profile. / Graduation date: 1992

The overall objective of this study is to address questions concerning the long-term mechanical strength of the lithosphere across the equatorial margin of Brazil. The approach used in this study consists of calculating the frequency response function estimates, also called admittance, using gravity and bathymetry data. These experimental estimates are then compared to theoretical admittance curves for Airy and thin elastic plate models for which estimates on the flexural rigidity or, equivalently, effective elastic thickness may be made. Twelve profiles, each 256 km long, were extracted from gridded gravity and bathymetry data (data sources: project EQUANT, Defense Mapping Agency, National Geophysical Data Center files and GEOS 3/SEASAT altimeter data). Three profiles were specifically used for testing truncation errors introduced by four different data treatment procedures (before Fourier transforming the data) : detrending, applying 10% cosine tapering, mirror imaging and the use of the first derivatives. The method I adopted is similar to the one used by McNutt (1983) and consists of testing how reliably a given admittance estimate can be recovered as a function of the data treatment procedure. A "predicted" gravity anomaly was obtained by convolving each bathymetric profile with a theoretical admittance filter. The edges of this anomaly are then submitted to the same treatment as the corresponding bathymetric profile before Fourier transforming both profiles and calculating admittance. The stability of the long-wavelength admittance estimates, in the presence of noise, was also investigated by introducing Gaussian noise, in the range of -50 to +50 mGals, in the "predicted" gravity signal. The results indicate that relatively unbiased long-wavelength admittance estimates can be obtained by using the first derivative of the data sets. In addition, it is shown that the mirroring technique, used in previous admittance studies across Atlantic-type margins, leads to overestimated admittance values and, therefore, overestimated flexural rigidities. Neither the theoretical curves for the Airy model nor the plate flexure model can explain the experimental admittance estimates. Not only are the experimental admittance estimates higher than the predicted values but they also have a narrower peak than the theoretical curves. This raises the question of the applicability of highly simplified isostatic models for tectonic provinces such as Atlantic-type continental margins. The following reasons may explain the discrepancies between the experimental and theoretical admittance estimates: (1) The abrupt nature of the transition between oceanic and continental crust controlled by the Romanche Fracture Zone - Unlike the eastern North American continental margin which was formed as a result of extensive rifling and pulling apart, the obliquely-rifled equatorial margin of Brazil has undergone a complex tectonic evolutionary process, where additional components such as shear and right-lateral wrenching were present. Therefore, representing the margin as a thin homogeneous elastic plate might be reasonable when the transition is gradual (for which the uniform flexural rigidity assumption seems reasonable) but is probably not a good approximation when it is as abrupt as the equatorial margin of Brazil (2) Presence of subsurface loads - Previous studies have shown that estimates of the average flexural rigidity of continental lithosphere using the admittance approach are biased when subsurface loads are present. In principle, the proximity of the Romanche Fracture Zone and associated volcanism suggest that shallow buried loads, caused by intrusive bodies, might be present in the area. This could partially account for the mismatch between theoretical curves and experimental admittance estimates. (3) "Masked" estimates - The admittance estimates presented here are likely to reflect the combination of two different signals: one related to the compensation of the Barreirinhas/Piaui-Camocim sub-basin which has no topographic/bathymetric expression and the other one related to the topography/bathymetry and its compensation which is of interest in the admittance studies. Since the wavelengths of these signals do not differ by much (around 80-100 km for the basin) it is possible that in the averaging process some overlapping occurs. The combination of these signals could yield anomalous results masking the admittance estimates in the diagnostic waveband. In addition, I present a two-dimensional cross section obtained by forward modelling the gravity anomaly along a profile using the line integral method. The uniform sedimentary infill of the Barreirinhas/Piaui-Camocim basin is enough to account for the gravity low over the inner shelf and no Moho topography is required. A plausible explanation for this "rootless" basin structure is that the lithosphere is capable of supporting the sediment infill load, and thus, has finite flexural rigidity (basin is locally uncompensated). / Graduation date: 1990

We map the regional physiography and surficial lithology (Surficial Geologic Habitat or SGH) over the continental margin of Oregon. This thesis develops, describes, and implements an iterative interpretive method to map seafloor habitat types from disparate geological and geophysical datasets including: bathymetric images, sidescan sonar images, seismic reflection profiles, sediment samples, geologic maps of structure, and observations from submersibles. An indirect technique for the assessment of map accuracy or habitat type misidentification error is also explored and used to derive supplemental maps of varying interpretative confidence, or "quality". The geological and geophysical datasets used to produce the SGH maps of the Oregon margin are by their nature patchy, and form an irregular mosaic of variable data density and quality. Uniform sampling of continental margins does not yet exist, thus these maps are an attempt to glean as much information as possible from the framework of existing data. In any given area the quantity and quality of data available varied considerably, and required a flexible method of interpretation based on this availability. The integrated interpretative GIS techniques are developed to facilitate mapping geologic habitat types over this region of discontinuous and patchy seafloor data. The SGH map and thematic map accuracy assessment support improved habitat-based inventory and assessment methods. They also serve as habitat reference materials for marine resources management and planning activities at local to national scales. SGH and data quality maps are incorporated as thematic layers within a broader habitat geodatabase for west coast groundfish and are directly applied for modeling Essential Fish Habitat (EFH) for these species. / Graduation date: 2004

Thesis (Ph. D.)--University of Alabama at Birmingham, 2006. / Title from first page of PDF file (viewed Feb. 22, 2007). Includes bibliographical references (p. 92-107).

This collection contains 13 papers presented in the workshop on the "The Celtic Languages in Contact" organised by Hildegard L. C. Tristram at the XIII International Celtic Congress in Bonn (Germany), July 23rd - 27th, 2007. The authors of two papers from another section also contributed their papers to this volume, as they deal with closely related issues. The time-span covered ranges from potential pre-historic contacts of Celtic with Altaic languages or Nostratic cognates in Celtic, through the hypothesis of Afro-Asiatic as a possible substrate for Celtic, Latin and Gaulish contacts in Gaul, the impact of Vulgar Latin on the formation of the Insular Celtic Languages as a linguistic area (Sprachbund), to various contact scenarios involving the modern Insular Celtic languages as well as English and French. The final paper reflects on the political status of the modern Insular Celtic languages in the Europe of the 27 EU countries.

Coastal low oxygen areas are expanding globally and are predicted to increase in size and duration due to climatic changes associated with a warming ocean. The Gulf of Mexico Hypoxic Zone (GoMHZ) is the second largest regularly occurring hypoxic habitat in the world and has increased in size since it was first mapped in the 1980s. The Mississippi Atchafalaya River System (MARS) floods the Louisiana continental shelf with fresh water high in nitrogenous compounds enhancing primary production which sinks to the sea floor. Stratification that occurs as a result of density differences and coastal currents creates a strong pycnocline that prevents bottom waters from being aerated causing seasonally hypoxic bottom waters (< 2.0 mg L^-1). The Mechanisms Controlling Hypoxia (MCH) project (hypoxia.tamu.edu) made regular cruises during 2004-2005 and 2007-2009 to the GoMHZ performing shelf wide hydrographic surveys and occupying central mooring sites within theoretical zones of differing hypoxic potential. Sediment cores were collected for incubation experiments using Batch Microincubation Chambers (BMICs) to measure rates of sediment community oxygen consumption and nutrient regeneration. Results of incubation experiments characterized sediments as net sources of dissolved inorganic nitrogen, mostly ammonium, and silicate and a net sink of phosphate. Modeling simulations of benthic-pelagic coupling focused in the western study zones related field measurements of benthic nutrient regeneration and primary production to important processes that maintain summertime hypoxia when surface waters are nitrogen limited. After incubations were completed macrofaunal individuals were removed from the cores enumerated and identified to the lowest possible taxon. Macrofauna communities in 2004-2005 were dominated by a hypoxia tolerant community dominated by polychaetes. Hurricanes Katrina and Rita in August and September of 2005 drastically reorganized macrobenthic communities decreasing abundances and negatively impacting diversity. These new communities collapsed under hypoxic stresses potentially impacting the ability of demersal foragers to utilize an important food resource. Large variations in biogeochemical fluxes and patchy distribution of fauna impeded the delineation of significant zones in benthic function and structure.

This thesis addresses the use of potential field data in two main topics: sub-basalt exploration and structure of the deeper crust. Synthetic models and forward models of the Møre margin were constructed to test the sensitivity of the various potential field methods. The synthetic models demonstrate that forward modelling of the gravity and magnetic data is a valuable tool in basement recognition in sub-basaltic settings and the use of gravity gradients further limits the modelling ambiguity and improves the basement mapping. Deep sills, as observed in the Møre Basin, cannot be identified from the gravity and magnetic data alone but the lava flows have a clear effect on the gravity and magnetic signature if thicker than ~1 km. Experiments with Euler Deconvolution reveal the limitations of the method in sub-basaltic settings. A 3D regional gravity and magnetic model of the Møre margin integrated with seismic and well data gives a novel view on the architecture of the continental crust, the distribution of high density lower crust, and the Moho topography. The isostatic response of the water and sediment loading reflected by the Moho provides further insight in the evolution of the margin. The results from the Møre margin model merged with results from a 3D model of the Vøring and Lofoten margins give a regional view on the deep structures on the mid-Norwegian margin. Combination of the modelling results and isostatic considerations provide means to address the origin of the lower crustal body on the margin and the evolution of the whole mid-Norwegian margin.

Dans le bassin du Sud-Est et plus particulièrement dans le bassin de Digne-Valensole, les dépôts continentaux des séries tertiaires sont identifiés sous le terme de Molasse Rouge et sont souvent peu ou mal contraints biostratigraphiquement. Les seuls éléments stratigraphiques disponibles sont les coquilles de gastéropodes et les dents de micromammiferes, qui déterminent des fenêtres de temps d'une durée moyenne de l'ordre de quelques Ma selon les assemblages faunistiques. La première partie de ce mémoire fait le point sur l'état des connaissances des conditions de sédimentation du bassin oligo-miocène de Digne. Les données biostratigraphiques relatives aux différentes coupes étudiées sont présentées en regard des échelles biostratigraphiques récentes ; * la deuxième partie expose les apports des analyses de signaux isotopiques des paléosols carbonatés à l'étude des séries continentales. Leurs applications diverses sont illustrées par des exemples choisis ; * la troisième partie présente l'ensemble des milieux de dépôts rencontrés qui couvrent les systèmes alluviaux et fluviatiles, les environnements lacustres, les dépôts littoraux et marins francs. Une attention particulière est portée à la description des paléosols carbonatés ; .Ia quatrième partie est d'abord consacrée à l'analyse des signaux 013C et 0180 sur les coupes de référence bien calées stratigraphiquement puis à l'extension de la méthode sur les autres coupes en comparant les outils isotopiques aux approches biostratigraphiques et en proposant une reconstitution des paléoenvironnements. * Enfin, la dernière partie s'attache à montrer les perspectives qui se dégagent des résultats de l'étude sur l'ensemble du bassin de Digne-Valensole en proposant des perspectives d'études dans des domaines aussi variés que la biozonation des micromammifères, la paléoécologie, la paléogéographie, le découpage séquentiel et l'architecture des séries sédimentaires.

At the nexus of the seemingly disparate art-theoretical topics of color and the female nude is a critical consideration of phenomenology in both one of its most basic senses—as the first-person experience of perceived phenomena—and as a larger philosophical position which, through its abstraction of perception to subject-object relationships, implicates the painted figure. Specifically, this paper conflates the phenomenology of color with the transcendental phenomenology of Edmund Husserl and Maurice Merleau-Ponty in investigating empathy. Structured as a dialectic, it establishes the most prominent views of both color and the female nude—the nude as a symbolic figure, color as perceptual experience—before delving into their various points of theoretical and art-historical intersection within these categories. This analysis ultimately forms the argument that color can be a powerful tool in reclaiming the female nude figure, stimulating emotive bodies that inspire empathetic viewers and intersubjective rather than objectifying, or abjectifying, dialogues.

L'INFLUENCE DES LIGANDS ORGANIQUES SUR LA VITESSE DE DISSOLUTION DE LA FLUORAPATITE (CA#1#0(PO#4)#6F#2) ET DE VERRES SILICOPHOSPHATES (SI-P-CA-MG) A PU ETRE APPRECIEE PAR UNE APPROCHE A L'ECHELLE DU SOLIDE ET DES SOLUTIONS. POUR CE FAIRE, DES ESSAIS PARALLELES ONT ETE MENES EN MILIEUX ACIDES CITRIQUE ET CHLORHYDRIQUE DE PH INITIAL IDENTIQUE. LA PRESENCE DE LIGANDS ORGANIQUES DANS LE MILIEU D'ATTAQUE NE MODIFIE PAS LA VITESSE DE DISSOLUTION DE LA FLUORAPATITE. EN SOLUTION CHLORHYDRIQUE, CE MECANISME EST BLOQUE PRECOCEMENT EN RAISON DE LA FORMATION D'UNE COUCHE SUPERFICIELLE DE COMPOSITION CHIMIQUE DIFFERENTE DE CELLE DU CRISTAL SAIN. L'AJOUT D'ACIDE CITRIQUE A LA SOLUTION D'ATTAQUE DIFFERE LES PHENOMENES OBSERVES EN MILIEU CHLORHYDRIQUE. UN PROTOCOLE EXPERIMENTAL IDENTIQUE A ETE ADOPTE POUR L'ETUDE DE LA DISSOLUTION DE VERRES SILICOPHOSPHATES. CEUX DONT L'EDIFICE VITREUX PRESENTE DES ENTITES SIO#4 LIBRES SONT SENSIBLES A L'AJOUT D'ACIDE CITRIQUE DANS LA SOLUTION D'ATTAQUE. LEUR CINETIQUE DE DISSOLUTION EST D'ORDRE 1 PAR RAPPORT A LA CONCENTRATION D'ACIDE CITRIQUE. L'INFLUENCE DES LIGANDS ORGANIQUES EST MOINS MARQUEE POUR DES VERRES DONT LE RESEAU SILICATE EST FORTEMENT POLYMERISE. LA LIMITE DE SOLUBILITE DE LA SILICE AMORPHE DANS L'EAU EST DEPASSEE D'UN FACTEUR 8 EN PRESENCE DE L'ACIDE CITRIQUE 2%. CETTE OBSERVATION NOUS AMENE A SUSPECTER L'EXISTENCE D'UN COMPLEXE ORGANOSILICIQUE QUI N'A PU ETRE CARACTERISE. L'ENSEMBLE DES RESULTATS PRESENTE DANS CE MEMOIRE S'APPLIQUE A DE NOMBREUX DOMAINES ET PLUS PARTICULIEREMENT A LA FERTILISATION PHOSPHATEE SUR SOLS ACIDES. COMPTE-TENU DE L'INADAPTATION D'ENGRAIS CLASSIQUES HYPERSOLUBLES DE TYPE NPK, L'EMPLOI DE ROCHES PHOSPHATEES OU DE VERRES PHOSPHATES SUR CES TYPES DE SOLS EST PRECONISE. LE PHOSPHORE CONTENU DANS CES MATERIAUX INSOLUBLES DANS L'EAU EST ALORS ASSIMILE DIRECTEMENT PAR LES PLANTES GRACE AUX ACIDES CARBOXYLIQUES CONTENUS DANS LES EXUDATS RACINA