O gênero Aulacoseira Thwaites é exclusivo de águas continentais e possui ampla distribuição mundial. As espécies do gênero vêm sendo estudadas, principalmente para regiões temperadas da América do Norte e Europa. Atualmente, Aulacoseira conta com aproximadamente 60 espécies, dentre fósseis e atuais. No Brasil, apenas 17 espécies foram registradas e poucos trabalhos apresentaram informações sobre a ultra-estrutura da frústula. Desta forma, o presente estudo teve por objetivos analisar as características morfológicas e estruturais das espécies de Aulacoseira do Brasil e a distribuição geográfica das espécies em ambientes aquáticos brasileiros. O estudo baseou-se em 286 amostras de plâncton e perifíton, procedentes de diversos tipos de ambientes, como rios, lagos, lagoas e reservatórios, abrangendo 24 estados brasileiros. Exemplares de Aulacoseira foram analisados sob microscopia óptica e eletrônica de varredura e transmissão. Os táxons encontrados foram descritos, mensurados, ilustrados e comentados. Uma chave dicotômica foi providenciada para auxiliar na determinação das espécies e glossário para compreensão das estruturas. A análise do material permitiu a identificação de 23 táxons infragenéricos de Aulacoseira, sendo 18 espécies, três variedades não típicas e duas formas taxonômicas. Dentre estas, seis constituíram novas espécies para ciência (A. brasiliensis, A. calypsi, A. minuscula, A. pantanalensis, A. samariana e A. simoniae) e duas não foram determinadas em nível específico. Aulacoseira pseudoamericana e A. herzogii var. minor constituíram citação pioneira para o Brasil e A. gessneri teve sua ultra-estrutura documentada pela primeira vez. Dos 29 táxons infragenéricos de Aulacoseira já registrados para o Brasil, apenas 13 foram encontrados durante o estudo, alguns táxons foram reidentificados e outros puderam ser revistos devido há ausência de informações complementares nas publicações. Aulacoseira calypsi, A. gessneri, A. pantanalensis, A. pseudoamericana, A. samariana e A. herzogii var. minor apresentaram distribuição restrita à áreas de clima tropical enquanto que Aulacoseira cf. alpigena, A. granulata var. angustissima f. spiralis e Aulacoseira sp.2 ocorreram exclusivamente em regiões subtropicais. O elevado número de novas espécies encontradas ressalta a importância de estudos taxonômicos mais aprofundados para melhor conhecimento das características diacríticas das espécies que ocorrem em ambientes continentais brasileiros. Palavras-chave: ambientes continentais, diatomáceas cêntricas, taxonomia, ultra-estrutura. / The genus Aulacoseira Thwaites is exclusive of continental waters and has worldwide distribution. The species of this genus have been widely studied, mainly to temperate regions of North America and Europe, and the taxa that occur in South America are poorly known. Currently, Aulacoseira has approximately 60 species, among fossil and recent. In Brazil, only 17 species were recorded and few studies presents data on the ultrastructure of the frustule. Thus, this study aimed to analyze the structural and morphological features of the Aulacoseira genus and geographical distribution of species in aquatic environments in Brazil. The study was based on 286 samples of plankton and periphyton, collected in different types of environments such as rivers, lakes, ponds and reservoirs distributed in 24 states. Specimens of Aulacoseira were examined under light and electron microscopy. The taxa were described, measured, illustrated and discussed. Dichotomous key was provided to assist in determining the species and glossary for understanding the structures described. The analysis allowed the identification of 23 infrageneric taxa of Aulacoseira, with 18 species, three varieties and two non typical taxonomic forms. Among these, six new species for science were found (A. brasiliensis, A. calypsi, A. minuscula, A. pantanalensis, A. samariana e A. simoniae) and two were not determined at specific level. Aulacoseira pseudoamericana and A. herzogii var. minor were first recorded in Brazil and A. gessneri its ultrastructure was first revealed. Of the 29 taxa of Aulacoseira already recorded in Brazil, only 13 were found during the study, some taxa were reidentified and others could not be revised because there is no additional information in publications. Aulacoseira calypsi, A. gessneri, A. pantanalensis, A. pseudoamericana, A. samariana and A. herzogii var. minor present distribution restricted to tropical areas while Aulacoseira cf. alpigena, A. granulata var. angustissima f. spiralis and Aulacoseira sp.2 occurred exclusively in the subtropics.The high number of new species found highlights the importance of more detailed taxonomic studies to improve knowledge of diacritical features of the species occurring in Brazilian environments.

xviii, 177 p. : ill., maps. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This dissertation explores several important consequences of H 2 O-rich fluids in magmatic and ore-forming systems within continental arc crust. North Sister, a stratovolcano in the Oregon High Cascades, provides a window into magma generation processes in the deep crust. Eruption of a remarkably limited basaltic andesite composition over the lifespan of this volcano may reflect last equilibration of mantle derived magma within a deep crustal hot zone. High pressure, water-undersaturated phase equilibrium experiments show that an anhydrous, augite-rich gabbro at ∼12 kbar (40 km depth) and ∼ 1175°C is the most probable lithology with which North Sister basaltic andesite with ∼3.5 wt% H 2 O last equilibrated within the deep crust before erupting. While magma often erupts at the planets surface as at North Sister, a greater volume never reaches the surface and solidifies within the upper crust. Exsolution of magmatic fluids is an inevitable consequence of crystallization of hydrous crustal magmas. The fate of these fluids is the focus of the remainder of this dissertation. Modeling of CO 2 and H 2 O variations during crystallization of granitic magma reveals that exsolution of a large mass of fluid occurs only after CO 2 is largely degassed, creating ideal conditions for hydrofracturing and formation of porphyry copper deposits. CO 2 and H 2 O solubility relations suggest that H 2 O-rich magma was required to produce the porphyry-Cu-Mo deposit at Butte, Montana, which may explain its distinctively deep generation. Electron microprobe analyses of Ti in quartz and Zr in rutile in samples from Butte yield porphyry magma temperatures (630-770°C) that overlap substantially with hydrothermal vein temperatures (<430-750°C). Veins display large temperature ranges (50-250°C) that signify variable degrees of cooling of hot magmatic fluids upon contact with cooler wall rock during vein growth. Modeling of Ti diffusion in quartz suggests that individual dikes and veins likely cooled over short timescales (10s-1000s years), indicating that porphyry systems may evolve by episodic magmatic fluid injections with discrete thermal spikes. Modeling of Ti diffusion in quartz combined with electron backscatter diffraction maps show that small hydrothermal quartz veins likely formed by epitaxial growth. This dissertation includes co-authored material both previously published and in preparation for submission. / Committee in charge: A. Dana Johnston, Chairperson, Geological Sciences; Mark Reed, Member, Geological Sciences; Paul Wallace, Member, Geological Sciences; Richard P. Taylor, Outside Member, Physics

xv, 95 p. : ill. (some col.), maps (some col.) Plate 1. Geologic Map of the Sierra Bacha, Coastal Sonora, Mexico (1:30,000 scale) attached as a separate file. / The Gulf of California is an active rift basin formed by late Cenozoic dextral-oblique extension along the Pacific-North America plate boundary. Well exposed volcanic and sedimentary rocks in the Sierra Bacha, coastal Sonora, Mexico, preserve a history of proto-Gulf (late Miocene) deformation and offer insight into the structures and kinematics responsible for localization of the plate boundary and inception of the Gulf at about 6 Ma. Geologic mapping, fault kinematic analysis, and paleomagnetic data suggest that proto-Gulf deformation in the Sierra Bacha occurred primarily by ENE-WSW extension and that vertical-axis rotation related to dextral strain was minor. Lack of significant dextral shear supports an emerging model for proto-Gulf deformation in which dextral strain was not ubiquitous across Sonora but instead became localized during latest Miocene time in a narrow coastal shear zone that mechanically weakened the lithosphere and helped facilitate continental rupture. This thesis includes the "Geologic Map of the Sierra Bacha, Coastal Sonora, Mexico" as supplemental material. / Committee in charge: Dr. Rebecca J. Dorsey, Chairperson; Dr. Marli B. Miller, Member; Dr. Ray J. Weldon II, Member

O perifíton é formado por uma complexa comunidade de organismos aderidos a um substrato orgânico ou inorgânico, dos quais as diatomáceas (Bacillariophyta) constituem importante parcela. Mais recentemente inventários florísticos que contemplam as diatomáceas bentônicas em sistemas lóticos vêm incrementando o conhecimento da flora na região Neotropical e Neosubtropical, porém grande parte desses sistemas permanece inexplorado, especialmente em águas oligotróficas, de altitude e de baixo pH. Tais ecossistemas em geral possuem uma flora bastante peculiar, e são importantes referências em termos qualidade de água. Desta forma, o presente estudo teve por objetivos contribuir para o conhecimento da flora de diatomáceas perifíticas do Parque Estadual do Ibitipoca, localizado na serra da Mantiqueira em Minas Gerais. Como resultado, foram identificados 15 gêneros, 18 espécies e duas variedades taxonômicas. Duas novas espécies do gênero Eunotia são propostas e três espécies do gênero Nupela não puderam ser identificadas de acordo com a literatura, sendo provavelmente novas para a ciência. São feitos 16 registros pioneiros para o estado de Minas Gerais, sendo quatro delas primeiras ocorrências em território brasileiro. A composição taxonômica das diatomáceas perifíticas do Parque Estadual do Ibitipoca apresenta semelhanças com a flora de outros ambientes oligo-distróficos já inventariados nos Neotrópicos. Palavras-chave: ambientes continentais, águas oligotróficas, Eunotia, Nupela, taxonomia de criptógamos. / The periphyton is composed by a complex community of organisms adhered to an organic or inorganic substrate, and diatoms (Bacillariophyta) constitute an important part of it. More recent floristic inventories in lotic systems that include benthic diatoms increased the knowledge of the Neosubtropical Neotropical flora for the region, but most environments remains unexplored, especially those with oligotrophic and low pH waters in altitude sites. Such ecosystems in general have a very peculiar flora and are important indicators of water quality. Thus, the present study aimed to contribute to the knowledge of periphytic diatom flora of Ibitipoca State Park, located in the Mantiqueira ridge, in Minas Gerais. As a result, we identified 15 genera, 18 species and two taxonomic varieties. Two new species of Eunotia are proposed and three species of the genus Nupela could not be identified according to the literature, and are probably new to science. Sixteen new records were made for the state of Minas Gerais, including four first occurrences for Brazil. The taxonomic composition of the periphytic diatoms of Ibitipoca State Park share similarities with other oligo-dystrophic environments already surveyed in the Neotropics.

Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-10-01T14:28:49Z No. of bitstreams: 1 Antonio Fernando Menezes Freire.pdf: 16026413 bytes, checksum: ca3be2d63da2a13843fab438bd9af4d9 (MD5) / Made available in DSpace on 2014-10-01T14:28:49Z (GMT). No. of bitstreams: 1 Antonio Fernando Menezes Freire.pdf: 16026413 bytes, checksum: ca3be2d63da2a13843fab438bd9af4d9 (MD5) / Cinqüenta testemunhos foram coletados no fundo do mar, na plataforma continental central do Estado da Bahia, entre a Península de Marau e a cidade de Olivença. Destes testemunhos, 36 foram coletados através de mergulhadores e limitados a profundidades máximas de 40m, enquanto 14 testemunhos foram coletados a pistão, por gravidade (piston cores), utilizando-se embarcação apropriada, sem limite de profundidade. Todos os testemunhos foram descritos, fotografados e amostrados para análises granulométricas e bioestratigráficas sendo, a partir destes dados, confeccionados mapas texturais e faciológico do sedimento de fundo. Durante a coleta dos testemunhos a pistão foi feito um levantamento com perfilador de sub-fundo. Este levantamento permitiu identificar um forte refletor a uma profundidade média de 3-4m, que limitou a penetração dos testemunhos. Esta superfície representa um limite de seqüências, separando a seqüência holocênica da pleistocênica e, sobre esta, se acumulou um trato de sistema transgressivo e os estágios iniciais do desenvolvimento de um trato de sistemas de mar alto, principalmente na plataforma interna. A plataforma apresenta características de uma plataforma “faminta”, notadamente na sua porção externa, limitando a aplicação mais detalhada dos conceitos estratigráficos modernos à plataforma interna e face da costa, onde é evidente a sedimentação siliciclástica progradando sobre sedimentos carbonáticos. Inúmeros vales não preenchidos dissecam a plataforma externa e o talude, servindo como conduto para o transporte de sedimentos da plataforma continental para regiões mais profundas.

Submitted by Morgana Andrade (morgana.andrade@ufes.br) on 2016-06-14T21:18:48Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_8998_Dissertacao_Mariana_Alves.pdf: 3989347 bytes, checksum: b1aa4f1cffaebdcf1ddb878565917acf (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-08-16T15:35:15Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_8998_Dissertacao_Mariana_Alves.pdf: 3989347 bytes, checksum: b1aa4f1cffaebdcf1ddb878565917acf (MD5) / Made available in DSpace on 2016-08-16T15:35:15Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_8998_Dissertacao_Mariana_Alves.pdf: 3989347 bytes, checksum: b1aa4f1cffaebdcf1ddb878565917acf (MD5) / CAPES / A plataforma continental adjacente à desembocadura do rio Doce, ambiente relativamente preservado e possivelmente sujeito a alterações e/ou intervenções antrópicas futuras, foi estudada quanto aos seus ecocaráteres e processos sedimentares associados. Dados de alta resolução de um perfilador de subfundo (3,5 KHz) foram coletados ao longo de 400 Km. Análises granulométrica e de porcentagem de Carbonato de Cálcio foram feitas em amostras de sedimentos superficiais, e os resultados submetidos às análises estatísticas de agrupamento e ACP. Foi observada boa correlação entre os cinco grupos sedimentares e ecocaráteres. O ecocaráter A1 (sem penetração) esteve restrito às regiões profundas (35-80 m.) indicando domínios sedimentares marinhos, associados à sedimentação biogênica (fundo arenoso a areno-cascalho-lamoso). Uma região transicional/marinha (25-35 m. & 55-80 m.), com processos sedimentares mistos (arenoso), foi indicada pelo ecocaráter A2 (refletores indefinidos). O ecocaráter B (vários refletores definidos, paralelos entre si e ao fundo marinho) esteve associado a elevados níveis de consolidação dos sedimentos (arenoso lamo-cascalhoso), refletindo domínios fluviais/costeiros relacionados a condições ambientais extremas (alta vazão com ventos alísios N/NE fortes e constantes). Os ecocaráteres C1 e C2 (camadas semitransparentes com resoluções distintas) distribuíram-se pelas regiões com o mesmo domínio sedimentar (mas entre 10 e 30 m.), em depósitos lamo-arenosos a areno lamosos. Sedimentação terrígena regular (aporte constante e menor consolidação dos sedimentos) foi associada ao ecocaráter C2 (mais raso e próximo à desembocadura). O ecocaráter C1 indicou sedimentação terrígena irregular e maiores consolidações de sedimentos, estando associado à atuação de frentes frias, por exemplo. / The continental shelf close to the Doce river mouth, environment relatively preserved and possibly subject to future changes and/or anthropogenic interventions, was studied about yours echo-characters and sedimentary processes associated. High resolution data from sub-bottom profiling (3.5 KHz) were collected along 400 Km. Particle size and content of Calcium Carbonate were obtained of superficial sediments samples, and the results submitted to clustering and ACP statistical analyses. Good correlation was observed between the five sedimentary clusters and echo-characters. The echo-character A1 (penetration absent) were been restricted to deepest regions (35-80 m.) indicating marine sedimentary domains, associated to biogenic sedimentation (sandy to muddy-gravely-sandy bottom). A transitional/marine region (25-35 & 55-80 m.), with mixed sedimentary processes (sandy bottom), was indicated by the echo-character A2 (indistinct reflectors). The echo-character B (many distinct, parallel to each other and to the seabed reflectors) were been associated to higher levels of sediments consolidation (gravelly-muddy sandy bottom), reflecting riverine/coastal domains related to extremely environmental conditions (high river discharge with strong and constant N/NE trade winds). The echo-characters C1 and C2 (semitransparent layers with different resolutions) were distributed by the same sedimentary domain (but between 10 and 30 m.), in sandy-muddy to muddy-sandy deposits. Regular terrigenous sedimentation (constant supply and lower sediments consolidation) was associated to the echo-character C2 (shallowest and closest to the river mouth). The echo-character C1 indicated irregular terrigenous sedimentation and higher sediments consolidations, being associated to the action of cold fronts, for example.

Submitted by Morgana Andrade (morgana.andrade@ufes.br) on 2016-06-15T19:17:21Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) priscila guaitolini.pdf: 5745806 bytes, checksum: 234d60b48b5539b5ef3da822bff40d30 (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-08-16T15:42:05Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) priscila guaitolini.pdf: 5745806 bytes, checksum: 234d60b48b5539b5ef3da822bff40d30 (MD5) / Made available in DSpace on 2016-08-16T15:42:05Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) priscila guaitolini.pdf: 5745806 bytes, checksum: 234d60b48b5539b5ef3da822bff40d30 (MD5) / O presente trabalho teve como objetivo caracterizar a circulação sobre uma região da plataforma continental interna ao largo da cidade de Guarapari (ES). Os dados são fruto do monitoramento do recife artificial marinho Victory 8B. O principal objetivo deste estudo foi caracterizar e avaliar o padrão da circulação baseado em três conjuntos de dados quasesinóticos (23 de Junho de 2006, 8 de Março de 2007 e 26 de Outubro de 2007) coletados com auxílio de um perfilador acústico de correntes (ADCP). Esses dados foram comparados com o padrão de ventos e com o perfil termohalino. O processamento dos dados envolveu a remoção de spikes, suavização por média móvel, retirada do sinal da maré por meio de dados de modelagem numérica, e interpolação linear baseada em triangulação. Os resultados mostraram que as velocidades em Outubro de 2007 foram as mais intensas, seguido dos dados de Março de 2007 e, por último, Junho de 2006. As médias de velocidade foram, respectivamente, 0.28 m.s-1, 0.21 m.s-1 e 0.19 m.s-1. As orientações se mantiveram sempre para SW. Junho e Outubro exibiram semelhanças no padrão de circulação, apresentando um oceano em duas camadas para a componente perpendicular à costa, sendo a porção mais superficial direcionada ao oceano e as mais profundas em direção à costa. Além disso, também foi observado nessas mesmas campanhas a rotação ciclônica dos vetores resultantes de correntes. Essas características mostraram semelhanças com os processos de ascensão de água. Março se mostrou atípico, mantendo a mesma orientação ao longo de toda a coluna de água (223.27º), possivelmente devido à sobreposição de uma forçante à forçante do vento. O efeito ilha foi avaliado e, de acordo com as observações dos campos de velocidade e das componentes paralela e perpendicular à costa, foram notadas características semelhantes a vórtices gerados pelas Ilhas Rasas, sendo concordante com o cálculo do parâmetro de ilha P. / This study evaluated the circulation in the inner continental shelf along the city of Guarapari (ES) using data collected during the Victory 8B artificial reef monitoring. The goal of this study was to characterize and analyze the hydrodynamics in this region using three sets of ADCP data sets (June 23, 2006, 8 Mar 2007 and 26 October 2007). The current data processing included the exclusion of bad data, removal of the tidal signal using a barotropic tidal modeling information, the use of a running-average filter and trianglebased cubic interpolate onto produce horizontal and vertical maps. The results showed that average current were southwestward with most intense speeds in October 2007 (0.28 m.s-1) followed by March 2007 (0.21 ms-1) and June 2006 (0.19 ms-1). Cross-shore transects showed a two-layer ocean in June and October. The flow was directed offshore close to the surface and onshore in the remaining of the water column. Moreover the currents rotated cyclonically with the increase in depth. These patterns were similar to the upwelling processes along the coast regions. This scheme was not observed in March when the currents were southwestward from top to bottom even though the winds were northeast suggesting that an external force not yet considered in this analysis is driving the system. Regarding the island effect it was observed in all three data sets the presence of a wake caused by the Ilhas Rasas that maybe associated with the release of eddies, in accordance with the Island Parameter P estimated.

Sete linhas sísmicas de reflexão com alta penetração e baixa resolução, sendo seis paralelas e uma perpendicular à linha de costa, situadas ao sul da Plataforma Sul-rio-grandense foram analisadas com objetivo de encontrar feições indicativas de paleodrenagem. No intervalo Oligoceno Superior-Mioceno Inferior foram detectados dois cânions submarinos localizados na borda do talude atual. A origem dos cânions foi associada à presença de drenagem na plataforma em regime de mar baixo, com o deslocamento do depocentro para a região da plataforma externa-talude superior o qual provocou instabilidade, início de movimentos de massas e nucleação dos cânions. A queda estática do nível do mar foi associada a glaciação miocênica de 23,8 Ma. Um dos cânions foi vinculado à rede de drenagem do sistema sul-leste. Este sistema de drenagem foi um dos responsáveis pelo processo de denudação da Depressão Periférica do RS e também um dos principais meios de transporte e supridor de sedimentos da base do pacote sedimentar Cone do Rio Grande. O outro cânion está relacionado a um sistema de drenagem sudeste associado ao sistema drenagem com direção nordeste proveniente do Uruguai, cujas convergências das projeções se encontram no Baixo do Taim. Não foram encontradas evidências dessas duas paleodrenagens nas linhas sísmicas a oeste dos cânions, pois o ingresso ocorreu por bypass sedimentar. Foram encontradas nas linhas da plataforma feições sísmicas mostrando evidências de paleodrenagens no Mioceno Médio a Superior, Mioceno Superior e Plioceno. No Mioceno Médio a Superior o evento tectônico do soerguimento andino causou o basculamento em direção às terras altas com reflexos nas bacias sedimentares próximas. Ao aumentar a inclinação do terreno, a drenagem escavou mais profundamente na plataforma, mantendo a morfologia do canal pouco afetada pelos processos energéticos destrutivos da ação das ondas, quando da instalação dos estágios transgressivos subsequentes. Os rebaixamentos do nível do mar foram constatados nas curvas eustáticas de curta duração para a Bacia de Pelotas, Abreu (1989), e nas curvas globais de Haq et al. (1987), nos andares Serravaliano e Tortoniano (Mioceno Médio-Superior) e no Messiniano (Mioceno Superior). Esses eventos podem ser associados respectivamente à expansão leste e oeste do manto de gelo antártico, (Zachos et al.2001). Foi verificado que no Mioceno Médio-Superior as paleodrenagens propostas do Oligoceno Superior- Mioceno Inferior se mantiveram, mas houve um pequeno deslocamento para norte. Observou-se no Mioceno Superior-Plioceno um conjunto de importantes paleovales, ao sul da área de estudo. Mostram empilhamento sucessivo de cinco feições e migração para norte. Sugere-se que estes paleovales sejam um testemunho da presença do Rio da Prata na Plataforma Sul-rio-grandense. / Palaeodrainage features of the southern Brazilian shelf were investigated with the help of seven seismic lines being six of them parallel and one of orthogonal to the coast line. Two submarine canyons of Upper Oligocene to Lower Miocene age were recognised along the edge of the present continental rise. The origin of these canyons was ascribed to the presence of the palaeodrainage system in the continental shelf during early lowstand. The shift of the depocenter location towards to the outer edge of the continental shelf / upper part of the continental rise is responsible for the instability triggering mass movements and nucleation of the canyons. The eustatic sea level fall was is assigned to miocene glaciation of 23.8 My. One of the canyons was related to drainage system that combines southward and eastward directions. This drainage system was responsible for denudation of the Depressão Periferica of Rio Grande do Sul State and with development towards the south of the nowadays Patos Lagoon and supplied the transported sediments to form the Cone de Rio Grande. The other canyon is related to a drainage system coming from southeastward in Brazil and from northeast in Uruguay. The projections of these drainage systems seem to converge to Baixo do Taim where there is a subsidence of the granitic basement. The lack of evidence of these two palaeodrainage in the seismic lines indicates that the income of sediments was controlled by sedimentary bypass as a function of the similar declivity between the coastal zone and the shelf which formed channels of small magnitude. Evidences of paleodrainage were found in the interpretation of seismic lines of the shelf during the upper and middle Miocene and Pliocene. During middle and upper Miocene times tectonic uplift of the Andes produced a tilt in opposite direction away from the resultant higland that promoted erosion processes and increasing depths of the paleovalleys. That increase the depth of the valleys was one of the reasons for its preservation by wave action during the following transgression. Evidence of low sea levels episodes are given by the short-term eustatic curves from Pelotas basin (Abreu 1989) and the short-term eustatic curves of Haq et al.(1987) for the the Serravalian and Tortonian stages as well as for the Messinian stage (Upper Miocene) that according to Zachos et al. (2001) were related to E and W expansion of the polar icesheet. Both palaeodrainages of upper Oligocene to lower Miocene kept their orientation during middle to upper Miocene, but there was a slight shift towards the north. During upper Miocene times the palaeodrainage coming from the South along the nowadays position of the Mirim Lagoon had its length shortened as it is only represented in the inner shelf. Evidence for the former existence of palaeovalleys related to the former presence of La Plata River in the southern segment of the area studied are given by five overlayed channel features showing northwards migrations.

abstract: This dissertation is positioned at the intersection of philosophy, theology, and critical theory in order to explore the way early modern literature may be enlisted as a vehicle for a return to an ethically informed humanism, specifically with regard to how Western culture currently understands the contingent categories of "life" and "the human." While a great deal of critical work is currently being marshaled in the field of biopolitics, scholarly focus continues to be placed on the materiality of the physical body, or what I term "biopolitical materialism." What remains underexplored, however, is the reality that "life" and "the human" are deeply relational categories that should not be reduced to such material instances alone. Historically, and especially in the early modern period, "life" and "the human" are understood as interconnected and widely networked. Although such materialism indeed becomes solidified in the seventeenth-century, I seek to recuperate an ethical challenge to contemporary biopolitical materialism through an extended dialogue with early modern thinkers. By turning to works "in the Age of Shakespeare" I return attention to the originary epoch of what has been described as our "modern event horizon." I argue that within the very historical period that gives rise to the practice of biopolitical materialism exists a rich textual archive of resistance to this troubling phenomenon in the form of neighborly concern and the acknowledgement of shared creaturely estate. Chapter One inaugurates my argument by turning to Marlowe's Doctor Faustus, reading as its central theme the tragic effect inherent to dissociating the individual from the community. The remaining three chapters attend to neighborly forms given expression in three of Shakespeare's late plays: Chapter Two considers the potential political orientation of grace in Measure for Measure; Chapter Three positions neighborliness as a series of posthuman encounters in The Winter's Tale; and Chapter Four explores an early modern understanding of hospitality as stewardship at work in Timon of Athens. I conclude by turning to philosophy and political theology in order to suggest a way to think "life" as an ethical relation with, in, and through "the Age of Shakespeare." / Dissertation/Thesis / Doctoral Dissertation English 2014

Les compositions isotopiques en Nd, Hf, Pb et Sr des sédiments de rivière sont souvent considérées comme étant représentatives de celles de leurs roches sources. Elles sont donc largement utilisées pour tracer la provenance des sédiments ou pour moyenner les compositions isotopiques des lithologies drainées. L'influence des processus sédimentaires sur les compositions isotopiques de ces sédiments est cependant mal connue. L'objectif de l'étude présentée ici est de caractériser l'ampleur de la variabilité isotopique pouvant être générée par les processus de tri minéralogique au cours du transport des sédiments dans le milieu fluviatile. Pour ce faire, nous avons analysé les concentrations en éléments traces et les compositions isotopiques en Nd, Hf, Pb et Sr dans différents types de sédiments de rivière (bedload, suspended load, bank) échantillonnés à plusieurs endroits dans le système fluviatile du Ganges qui draine une partie de l'orogène Himalayenne. Nous avons également mesuré les compositions chimiques et isotopiques de nombreuses fractions minérales et granulométriques séparées de ces sédiments afin de mieux comprendre l'influence de chaque espèce minérale dans le budget isotopique total d'un sédiment de rivière. Dans le cas où les lithologies drainées sont essentiellement cristallines et sédimentaires, nous montrons que les isotopes du Nd dans les sédiments de rivière sont très peu affectés par les processus de tri minéralogique puisqu'ils sont toujours contrôlés par les mêmes minéraux, à savoir la monazite et l'allanite. Au contraire, les systèmes isotopiques de l'Hf, du Pb et du Sr s'avèrent particulièrement touchés par les processus de tri minéralogique. Les isotopes de l'Hf et du Pb sont tous deux affectés par un effet zircon qui génère de larges variations isotopiques entre les sédiments de fond de rivières et ceux transportés en suspension. Pour le Sr, les variations observées entre les différents types de sédiments résultent des proportions variables de micas et feldspath-K qu'ils contiennent. Dans le cas où les principales lithologies drainées présentent de forts contrastes d'érodabilité i.e. basaltes versus roches cristallines, nous montrons que les effets combinés de l'érosion différentielle dans le bassin de drainage et du tri sédimentaire dans la colonne d'eau sont responsables d'importantes variations isotopiques en Nd, Hf et Pb entre les sédiments de fond de rivière et ceux transportés en suspension. Nos calculs suggèrent que les produits d'érosion basaltique, relativement fins, sont préférentiellement transportés en suspension, proche de la surface de l'eau, alors que les produits d'érosion des roches plus cristallines sont préférentiellement concentrés dans les sédiments de fond de rivière. Enfin, nous suggérons que les variations isotopiques observées entre les différents types de sédiments transportés par les rivières sur les continents pourraient avoir d'importantes implications pour les systématiques isotopiques des sédiments océaniques terrigènes et sur l'évolution à long terme du réservoir mantellique si ces derniers sont recyclés au niveau des zones de subduction. / Nd, Hf, Pb and Sr isotopic compositions of river sediments are often considered to be representative of those of their source rocks. Thus, they are widely used to trace sediment provenance or to average the isotopic compositions of the drained lithologies. The influence of sedimentary processes on the isotopic composition of these sediments is however poorly known. The aim of the present study is to characterize the extent of the isotopic variability that can be generated by mineral sorting process during sediment transport in fluvial system. To do this, we analyzed trace element concentrations and Nd, Hf, Pb and Sr isotopic compositions in river bank, bedload and suspended load sampled at several locations in the Ganga fluvial system draining part of the Himalayan orogen. We also measured the chemical and isotopic compositions of numerous mineral and granulometric fractions separated from these sediments to better understand the contribution of each mineral species to the bulk isotopic budget of river sediments. When the drained lithologies are mainly crystalline and sedimentary, we show that Nd isotopes are very little affected by mineral sorting processes because, whatever the sediment type, those isotopes are always controlled by the same minerals i.e. monazite and allanite. In contrast, Hf, Pb and Sr isotopic systems are significantly affected by mineral sorting processes. Both Hf and Pb isotopes are affected by a zircon effect that generates large isotopic variations between bedload and suspended load. For Sr, variations between the different sediment types more likely result from variable proportions of K-feldspar and mica. When the main drained lithologies are characterized by strong differences in erodibility i.e. basalts versus crystalline rocks, we show that the combined effects of differential erosion in the drainage basin and sediment sorting in the water column are responsible for significant Nd, Pb and Hf isotopic variations between bedload and suspended load. Our calculations suggest that basaltic erosion products are preferentially transported in suspension, near the water surface, whereas the erosion products of more crystalline rocks are preferentially concentrated in bottom sediments. Finally, we suggest that the isotopic variations observed between bedload and suspended load on continents may have important implications for the isotopic systematics of oceanic terrigenous sediments and the long-term evolution of the mantle if these latters are recycled in subduction zones.