This study focuses on the main depocenter of the Andrew Formation in the Moray Firth Basin, located at the junction of the Central and Viking Grabens, in the central North Sea. The objectives of this report are to (1) define the sequence stratigraphic framework of the Andrew Formation, (2) describe and characterize the depositional systems associated to the Andrew slope to basin system, and (3) interpret the depositional processes that have dominated sediment emplacement. Specific facies association of the Andrew Formation are determined by the nature (point source or linear source) and caliber (volume, grain size, sand:mud) of sediment supply to the slope environment. Genetic interpretation of the Andrew Formation focuses on understanding depositional processes which dominated sediment emplacement. Seven depositional facies have been identified for the Andrew slope and basinal system; turbidite channel-fills, turbidite lobes, mounded turbidite lobes, sheet turbidites, debris flows and slumps, low density turbidites and hemipelagic drapes. Seven depositional processes collectively create the above mentioned Andrew depositional facies; turbidity currents, cohesive mud flows, sandy debris flows, muddy debris flows, slumping, low density turbidity currents and suspension settling. The Andrew Formation consists of upper and lower depositional units identified on seismic by bounding downlap terminations and on well logs by high-gamma marker beds. The lower Andrew displays three distinct sand-rich lobes, delineated by isopach and sand percent maps and log motif characteristics. Proximal, mounded, sand-rich units disperse into unchannelized sheet turbidites in the basin plain areas. The upper Andrew downlaps the lower unit, and a single, linear sediment source was centered in the Witch Ground Graben. The sediment dispersal pattern and internal facies character suggest the upper unit is a proximal slope-apron downlapping and filling inter-lobe bathymetric lows of the underlying unit. The lower Andrew is interpreted to be a structurally focused, sand-rich lobe complex, without associated incised canyons. The Andrew system evolved as the delta platform expanded onto the proximal fan, resulting in a linear sediment source spilling over the slope as a fringing slope-apron. The Andrew depositional system in the slope and basin environment is characterized by a high degree of facies disorganization composed of a wide array of gravity-flow deposits. / text

This research focuses on how sediment supply, sea level and delta processes control the partitioning of the sediment budget across and into the topset, slope and basinfloor compartments of deepwater basins. Addressing this problem provides significant insight to characterize source-to-sink systems, improve tectono-stratigraphic models and predict sand bypass to deepwater areas. The research was carried out in the Lance-Fox Hills-Lewis shelf margin formed during the Maastrichtian in the Washakie-Great Divide basin of southern Wyoming. I use a database with approximately 520 wells integrated with outcrops to develop a high resolution, dynamic stratigraphy approach for shelfmargin characterization. The results emphasize the driving role of sediment supply in rapid shelf-margin building and deepwater sand emplacement. On the study margin, high sediment supply was able to outpace shelf accommodation even at times of relatively high and rising sea level. At these times, shelf margin clinoforms developed a more aggradational architecture with relatively thick and more marine influenced topsets formed in response to basin deepening due to rapid subsidence. The high supply and subsidence are interpreted to have resulted from crustal loading and significant erosion during prominent Laramide thrust-driven source uplift. The high supply caused the formation of highstand shelf-edge deltas with strong wave and river influences. These deltas resulted in extensive coastal sand belts at the shelf margin, and bypass of significant volumes of sand to deepwater areas. In contrast, during times of stable to very low rates of sea level rise, the basin developed more progradational clinoforms with more terrestrial and generally thinner topsets. More of the sediment was funneled to the basin floor and shelfedge deltas were under strong river and tidal influence. Stable or even falling sea level resulted from decreased subsidence or slight basin uplift, interpreted to have resulted from decreasing uplift, tectonic quiescence or possibly slight tectonic rebound in the basin. The Lewis-Fox Hills margin is considered supply-dominated, a term to denote moderately deep shelf margins (< 1000 m) that prograde at high rates (several tens of km/my) and deliver sand to deepwater areas recurrently and in large volumes even at sea level highstand.

Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Geology and Geophysics, 2004. / "February 2004" Includes bibliographical references (leaves 216-227).

Thèse (D.R.Min.)--Université du Québec à Montréal, 1990. / Cette thèse à été réalisée à l'Université du Québec à Montréal dans le cadre du programme de doctorat en ressources minérales extensionné de l'Université du Quebec à Chicoutimi. CaQCU Document électronique également accessible en format PDF. CaQCU

Thesis (Ph.D.)--Memorial University of Newfoundland. / Typescript. Restricted until November 1995. Bibliography: leaves [306]-329. Also available online.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Natural gas hydrates store a substantial portion of the Earth's organic carbon, although their occurrence is restricted by thermobaric boundaries and the availability of methane-rich fluids. The complexity of geological systems and the multiphase flow processes promoting hydrate formation can result in a mismatch between the predicted and the observed hydrate distribution. The purpose of this research is to achieve a better comprehension of the factors that influence the distribution of gas hydrates and the mechanism of fluid movements beneath and across the gas hydrate stability zone (GHSZ). Therefore, this study integrates seismic, petrophysical and geochemical data from different gas hydrate provinces. This work provides evidence that hydrates can occur below bottom-simulating reflectors, in the presence of sourcing thermogenic hydrocarbons. The relationship between fluid-escape pipes and gas hydrates is further explored, and pipe-like features are suggested to host a significant volume of hydrates. The host lithology also represents a critical factor influencing hydrate and free gas distribution and, in evaluating a natural gas hydrate system, needs to be considered in conjunction with the spatial variability in the methane supply. The three-dimensional distribution of gas hydrate deposits in coarse-grained sediments, representing the current target for hydrate exploration, is shown to be correlated with that of the underlying free gas zone, reflecting sourcing mechanisms dominated by a long-range advection. In such systems, the free gas invasion into the GHSZ appears controlled by the competition between overpressure and sealing capacity of the gas hydrate-bearing sediments. Globally, the thickness of the free gas zones is regulated by the methane supply and by different multi-phase flow processes, including fracturing, capillary invasion and possibly diffusion. In conclusion, this research indicates that geological, fluid flow and stability factors interweave at multiple scales in natural gas hydrate systems.

As bacias de Taubaté e Resende são bacias continentais paleógenas do tipo rift, orientadas segundo a direção NE a ENE e fazem parte do segmento central do Rift Continental do Sudeste do Brasil. Ambas foram instaladas durante o Eoceno, resultantes de um campo de esforços distensivo de direção NW-SE. Este campo reativou zonas de cisalhamento de direção NE do embasamento pré-cambriano como falhas normais, importantes durante a instalação e evolução da bacia. Há também inúmeras estruturas transversais ao eixo da bacia, de direções N-S, NE-SW e NW-SE, as quais compreendem falhas e dobras que estiveram ativas durante diferentes intervalos de tempo, embora seus papeis na evolução da bacia ainda sejam pouco conhecidos. A fim de reconhecer estas estruturas em subsuperfície na Bacia de Taubaté, cinco perfis sísmicos longitudinais ao eixo da bacia foram interpretados, demonstrando o caráter distinto dessas estruturas como falhas normais e inversas, que interceptam diferentes unidades sísmicas, indicando uma deformação tectônica polifásica. A presença de altos estruturais transversais, distinguíveis em perfis sísmicos, ativos durante a abertura da bacia, pode estar relacionada com anticlinais formados na capa das falhas, durante uma evolução relacionada ao crescimento das falhas principais de borda em um regime distensivo de direção NW-SE. Ainda, foram descritas em afloramentos falhas sinsedimentares de componente normal, de direção NW-SE e transversais à Bacia de Resende, dispostas em um alto ângulo com relação à orientação ENE das falhas principais de borda. Estas estruturas foram interpretadas como falhas de alívio formadas no mesmo contexto distensivo. As relações estratigráficas e a análise de paleotensões das populações de falhas indicaram que as estruturas transversais estão relacionadas a quatro eventos deformacionais: compressão NE-SW, provavelmente durante o Mioceno; compressão NW-SE, durante o Pleistoceno Superior; distensão E-W a NW-SE durante o Holoceno; e por fim compressão E-W relacionada ao campo de esforços atual. A evolução da Bacia de Santos na porção adjacente offshore durante o Cenozoico pode estar diretamente relacionada à presença de estruturas transversais, mudanças de campo de estresse e a geração e eventos deformacionais nas bacias continentais do tipo rift. / The Taubaté and Resende are NE-to-ENE-oriented Paleogene continental rift basins of the central segment of the Continental Rift of Southeastern Brazil. Both basins were installed during the Eocene as a result of a NW-SE-oriented extensional stress field. This stress field reactivated NE-trending shear zones of the Precambrian basement as normal faults, which played a major role during the basin installation and evolution. There are also numerous N-S, NE-SW and NW-SE-oriented structures transverse to the NE-trending basin axis. These structures comprise faults and folds that were active at different time intervals, but their role in the basin evolution is poorly understood yet. In order to recognize these structures in the subsurface in Taubaté Basin, five longitudinal seismic profiles were interpreted showing their distinctive character as normal and reverse faults, which intersect different seismic units and indicate a polyphasic tectonic deformation. The presence of transverse structural highs, recognizable in the seismic profiles, which were active during the opening of the basin, can be related to anticlines formed in the hangingwall during an evolution related to the growing of the border master faults in a NW-SE-trending extensional regime. Moreover, syn-sedimentary NW-SE-oriented transverse normal faults oblique to the ENE-orientation of the border master faults were described in outcrops in the Resende Basin. These structures are interpreted as release faults and thus formed in the same extensional context. Stratigraphic relationships and paleostress analysis of fault populations indicate that transverse structures are related to four deformational events: a NE-SW-oriented compression probably during the Miocene, a NW-SE-oriented compression in the Late Pleistocene to Holocene, an E-W-to-NW-SE-oriented extension in the Holocene and lastly, an E-W-oriented compression related to the present-day stress field. The evolution of the adjoining offshore Santos Basin during the Cenozoic has a narrow correlation with the formation and evolution of Taubaté and Resende basins. The migration of depocenters in the Santos Basin during the Cenozoic can be associated with the presence of NW-SE-oriented transverse structures, changes in the stress fields, and generation and deformation events in the continental rift basins

Orientador: Giorgio Basilici / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-13T23:50:03Z (GMT). No. of bitstreams: 1 Henrique_Andre_M.pdf: 11951186 bytes, checksum: 6061e17e64f904f61a28dc56429cad0c (MD5) Previous issue date: 2009 / Resumo: A Formação Punta Negra (Meso- Neodevoniano da Pré-Cordilheira Argentina) consiste em uma espessa sucessão de depósitos siliciclásticos de água profunda. Esta unidade aflora por cerca de 300 km em direção N-S nas províncias de San Juan, Mendoza e La Rioja. Uma detalhada análise sedimentológica permitiu identificar seis litofácies depositadas pela ação de fluxos de densidade concentrados e correntes de turbidez. Três associações de fácies foram descritas e interpretadas: i) preenchimento de canais: camadas de arenito fino, com escassas estruturas e preenchendo feições erosivas, correspondentes a canais pouco espessos como sistema de aporte em uma rampa proximal; ii) lobos proximais: sucessões estrato-crescentes de camadas arenosas maciças na base e com estruturas de tração no topo, amalgamadas ou interacamadadas com níveis de lamito laminado, correspondendo a deposição de lobos num contexto de rampa proximal; iii) lobos distais/franjas: sucessões de lamito e camadas descontinuas de arenito muito fino que constituem os depósitos mais finos de todo o intervalo estudado, associados ao contexto de rampa distal. Os corpos sedimentares pertencentes às associações de fácies constituem elementos com características geométricas próprias. Os canais são do tipo deposicionais e pouco erosivos, os lobos deposicionais caracterizam corpos de geometria lobada/linguoide apresentando ciclos de compensação de espessuras. Por fim, os depósitos de franjas possuem grande extensão areal e com heterogeneidade acentuada pelo interacamadamento lamito/arenito. Com base na análise de fácies e associação de fácies e em informações levantadas por estudos anteriores, propõe-se um modelo de sistema deposicional turbidítico de rampa submarina rico em areia, caracterizado por um sistema de canais pouco espessos que atuam na forma de múltiplos pontos de aporte. A característica textural imatura dos sedimentos, a abundância de fragmentos vegetais e a deposição de estruturas típicas de fluxos de mais longa duração, são argumentos para propor um sistema de alimentação por meio de fluxos hiperpicnais provenientes diretamente do continente / Abstract: The Punta Negra Formation (Middle to Late Devonian of Argentine Precordillera) is a thick succession of siliciclatic deep-water deposits. This unit outcrops for c. 300 km along north-south direction in the provinces of San Juan, Mendoza and La Rioja. Detailed sedimentological permitted to identify six lithofacies deposited by concentrated density flows and turbidity currents. Three facies associations were described and interpreted: i) channel-filling deposits: massive fine grained sandstone erosive depressions that represent multiple shallow channels in a ramp system; ii) proximal lobes: thickening-upward successions of fine grained massive sandstone beds with a upper portion of very fine laminated sandstone; these beds are amalgamated or interbedded with laminated mudstone and represent depositional lobes in a proximal ramp context; iii) distal lobes/fringe: interstratifications of mudstone and very fine sandstone that are associated to a distal ramp. The channels are constituted of multiple depositional and minor erosional events. The depositional lobes include linguoid bodies with compensation cycles. The fringes have large extension and are characterized by thin interbedding of mudstone/discontinuous very fine sandstone. It was proposed a sand-rich deep-water ramp depositional model, which is characterized by a system of multiple minor erosive channels (multiple source). The immature sediments, the abundance of vegetal fragments and the typical structures of relative long-lived flows evidence a depositional system fed by hyperpicnal flows probably originated of major fluvial floods / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Giorgio Basilici / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-23T12:00:04Z (GMT). No. of bitstreams: 1 Simplicio_Fabio_M.pdf: 8080825 bytes, checksum: fba3debc6ddf60e9930361db9c5c3855 (MD5) Previous issue date: 2013 / Resumo: Os lençóis de areia eólica são sistemas deposicionais constituídos em áreas de morfologia plana ou ligeiramente ondulada. As formas de leito predominantes nos lençóis de areia são as marcas onduladas de vento. Tais formas de leito podem ocorrer em comboios ou compondo zibars. Os zibars são formas de leito similares às dunas. Nos zibars não há geração de estratos de queda. Embora muitos estudos reconheçam sistemas de deposição eólica pré-cambrianos, poucos são direcionados aos lençóis de areia eólica. Igualmente negligenciados são os zibars. A Formação Bandeirinha é a unidade inferior do Supergrupo Espinhaço. Depósitos de arenitos vermelhos intercalados a conglomerados intraformacionais compõem esta unidade. Três elementos arquiteturais foram individualizados: zibars, dunas com faces de deslizamento e canais efêmeros. Os depósitos de zibars são arenitos finos a grossos, moderadamente bem selecionados, constituídos por sets de arenitos com laminações planas e paralelas, de geometria tabular ou em cunha. Os sets ocorrem sobrepostos, separados por superfícies truncadas, e constituem cosets. Os depósitos de dunas com faces de deslizamento são arenitos finos a médios, muito bem selecionados, que ocorrem na forma de corpos de geometria lenticular. Os depósitos de canais efêmeros são constituídos por corpos de conglomerados intraformacionais, clasto-suportados, de base côncava, os quais ocorrem em contato erosivo sobre os estratos de arenitos. As superfícies erosivas, de contato entre arenitos e conglomerados, têm amplitude regional. A Formação Bandeirinha é interpretada como uma sucessão sedimentar formada em um lençol de areia eólica dominado por zibars. A alternância entre depósitos de arenitos eólicos e conglomerados revela variações climáticas de ordem regional, onde a deposição eólica (clima seco) era interrompida por deposição subaquosa (clima mais úmido). Neste lençol de areia, o balanço entre entrada e saída de materiais clásticos foi sempre positivo, a construção eólica foi contínua nos períodos mais secos. A estabilização do sistema foi resultado dos processos de cimentação no substrato. A subsidência tectônica foi o principal mecanismo de preservação do sistema eólico / Abstract: The aeolian sand sheets are depositional systems formed in areas with flat or slightly undulating morphology. The predominant bedforms in sand sheets are climbing wind ripples. These bedforms may occur in convoys or composing zibars. The zibars are similar to dunes, but without avalanching faces. Although many studies recognise aeolian Precambrian systems, few works deal with aeolian sand sheets. Equally neglected are the zibars. The Bandeirinha Formation is the lower unit of the Espinhaço Supergroup. Deposits of red sandstones intercalated with intraformational conglomerates compose this unit. Three architectural elements are recognised: zibars, dunes with slip faces and ephemeral channels. Deposits of zibars are fine to coarse grained sandstones, moderately well sorted, and composed by sets of planar-parallel laminations sandstones, in tabular geometry. The sets are superimposed and occur separated by truncated surfaces that constitute cosets. The dunes with slip face are fine to medium grained, very well sorted, and occur as lenticular bodies. The ephemeral channel deposits consist of intraformational conglomerates, clast-supported, with concave erosive basal surface on the sandstone strata. The erosive surfaces of the conglomerates seem to have a regional extension. The Bandeirinha Formation is interpreted as an aeolian sand sheet dominated by zibars. The transition between aeolian sandstones and conglomerates reveals climate variations of regional range, where aeolian deposition, which corresponds to dry climate phase, was interrupted by subaqueous deposition, in more humid climate. During the sand sheet deposition, the balance between input and output of clastic materials was always positive, the aeolian construction was continuous. The stabilization of the aeolian system was result of cementation processes of shallow depth. The tectonic subsidence was the main mechanism of preservation of the aeolian system / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências