A Fm. Ouricuri do Ouro (Proterozóico, Bacia Espinhaço) na porção NW da Chapada Diamantina/BA, Brasil, é interpretada como um sistema de leques aluviais constituído por quatro associações de fácies: i) Depósitos proximais dominado por fluxos de detritos não-coesivos; ii) Inundações em lençol proximais; iii) Inundações em lençol intermediárias; iv) Planícies arenosas de inundações distais. A sedimentação na porção basal da unidade ocorre em três ciclos granodecrescentes, marcados pela entrada de espessos pacotes de fluxos de detritos que gradam para depósitos relacionados a inundações em lençol proximais. Na porção superior ocorre o predomínio de inundações em lençol, associadas a enxurradas nas cabeceiras que resultam em descargas rápidas e desconfinadas nas porções intermediárias e distais. A partir do empilhamento vertical da Formação Ouricuri do Ouro na região de estudo, pode-se notar uma retrogradação do sistema de leques. Tal padrão é observado na sobreposição dos depósitos proximais pelos distais, marcando uma mudança na dinâmica do sistema de leques e, consequentemente, nos processos sedimentares dominantes. Esta retrogradação sugere uma diminuição do gradiente regional e deve ser resultado de um declínio da atividade tectônica ou do recuo do sistema de falhas de borda da bacia. Entretanto, ao contrário dos ciclos progradacionais e granocrescentes comumente descritos em sucessões de fácies de leques aluviais, a presença de ciclos granodecrescentes de mais alta frequência sugere também um controle climático. Os ciclos granodecrescentes são resultantes da progressiva diminuição na capacidade e competência do fluxo, associado a decréscimo do escoamento de águas superficiais (runoff) ao longo tempo. / The Ouricuri do Ouro Formation (Proterozoic, Espinhaço Basin) in NW region of Chapada Diamantina/BA, Brazil, is interpreted as an alluvial fan system composed by four facies associations: i) Proximal deposits non-cohesive debrys-flow dominated ii) Proximal sheetfloods; iii) Intermediate sheetfloods; and iv) Distal sandy flood plains. The sedimentation in the lower part of the unity occurs in three fining-upward cycles, characterized by the appearance of thick debrys-flow deposits that grade to deposits related to proximal sheetfloods. The upper portion is sheetflood dominated, associated to flash floods in the upstream that result in unconfined sheetfloods in the downstream. A retrogradation of alluvial system can be observed from vertical stacking of Ouricuri do Ouro Formation. This pattern is observed in the overlapping of proximal deposits by distal deposits, marking a change in alluvial system dynamic and, consequently, in dominant sedimentary process. This retrogradation indicate a regional gradient decrease and should be a product of tectonic activity decline or backfaulting of basin margin. However, in contrast to progradational coarseningupward cycles commonly described in succession of alluvial fans facies, the occurrence of high frequency fining-upward cycles suggests a climatic control influence. The fining-upward cycles are results of the progressive waning of flow capacity and competence, associated to the runoff decrease across time.

A Fm. Ouricuri do Ouro (Proterozóico, Bacia Espinhaço) na porção NW da Chapada Diamantina/BA, Brasil, é interpretada como um sistema de leques aluviais constituído por quatro associações de fácies: i) Depósitos proximais dominado por fluxos de detritos não-coesivos; ii) Inundações em lençol proximais; iii) Inundações em lençol intermediárias; iv) Planícies arenosas de inundações distais. A sedimentação na porção basal da unidade ocorre em três ciclos granodecrescentes, marcados pela entrada de espessos pacotes de fluxos de detritos que gradam para depósitos relacionados a inundações em lençol proximais. Na porção superior ocorre o predomínio de inundações em lençol, associadas a enxurradas nas cabeceiras que resultam em descargas rápidas e desconfinadas nas porções intermediárias e distais. A partir do empilhamento vertical da Formação Ouricuri do Ouro na região de estudo, pode-se notar uma retrogradação do sistema de leques. Tal padrão é observado na sobreposição dos depósitos proximais pelos distais, marcando uma mudança na dinâmica do sistema de leques e, consequentemente, nos processos sedimentares dominantes. Esta retrogradação sugere uma diminuição do gradiente regional e deve ser resultado de um declínio da atividade tectônica ou do recuo do sistema de falhas de borda da bacia. Entretanto, ao contrário dos ciclos progradacionais e granocrescentes comumente descritos em sucessões de fácies de leques aluviais, a presença de ciclos granodecrescentes de mais alta frequência sugere também um controle climático. Os ciclos granodecrescentes são resultantes da progressiva diminuição na capacidade e competência do fluxo, associado a decréscimo do escoamento de águas superficiais (runoff) ao longo tempo. / The Ouricuri do Ouro Formation (Proterozoic, Espinhaço Basin) in NW region of Chapada Diamantina/BA, Brazil, is interpreted as an alluvial fan system composed by four facies associations: i) Proximal deposits non-cohesive debrys-flow dominated ii) Proximal sheetfloods; iii) Intermediate sheetfloods; and iv) Distal sandy flood plains. The sedimentation in the lower part of the unity occurs in three fining-upward cycles, characterized by the appearance of thick debrys-flow deposits that grade to deposits related to proximal sheetfloods. The upper portion is sheetflood dominated, associated to flash floods in the upstream that result in unconfined sheetfloods in the downstream. A retrogradation of alluvial system can be observed from vertical stacking of Ouricuri do Ouro Formation. This pattern is observed in the overlapping of proximal deposits by distal deposits, marking a change in alluvial system dynamic and, consequently, in dominant sedimentary process. This retrogradation indicate a regional gradient decrease and should be a product of tectonic activity decline or backfaulting of basin margin. However, in contrast to progradational coarseningupward cycles commonly described in succession of alluvial fans facies, the occurrence of high frequency fining-upward cycles suggests a climatic control influence. The fining-upward cycles are results of the progressive waning of flow capacity and competence, associated to the runoff decrease across time.

>Magister Scientiae - MSc / The Bredasdorp Basin is located on the southern continental margin, off the coast of South Africa. It is mostly filled by marine Aptian to Maastrichtian deposits, overlaying pre-existing Late Jurassic to Early Cretaceous fluvial and shallow marine synrift deposits. The basin is a southeastern trending rift basin, located between the Columbine-Agulhas and Infanta arches. Its basement is made up of slates of the Bokkeveld Group (Devonian) and or quartzites of the Table Mountain Group (Ordovician-Silurian). The study area extends from X-X field to Y-Y field and encompasses only four wells for this investigation; well A, B, C and D respectively. This study was done through the interpretation; integration and juxtaposing of the results from core analysis with wireline log analysis (gamma ray) using Petrel software to display and correlate the well logs. Through core analysis which is the main source of information for this study, seven facies were identified and interpreted for the entire study. These facies alternate throughout each well and between different wells, but they are not evident in all the cores. Throughout the study, well A has been used as a reference well, since it appears (according to the interpretations) to record all seven facies and has the thickest section of zone 3. This zone reflects more accommodation space than the other studied wells at the time of deposition. Facies analysis of cores and well log correlation provide evidence that the studied USM sandstones are compatible with a wave dominated estuary/island-bar lagoon system to shoreface of a wave dominated marine shelf. It has previously been demonstrated that on the northern shelf of the Bredasdorp Basin, the USM typically has an hour-glass gamma ray log signature as a result of long-term transgression and regression and this typical log shape was also identified in this study from well A .

Glacier facies represent distinct regions of a glacier surface characterized by near surface structure and density that develop as a function of spatial variations in surface melt and accumulation. In post freeze-up (autumn) synthetic aperture radar (SAR) satellite imagery, the glacier ice zone and dry snow zone have a relatively low backscatter due to the greater penetration of the radar signal into the surface. Conversely, the saturation and percolation zones are identifiable based on their high backscatter due to the presence of ice lenses and pipes acting as efficient scatterers. In this study, EnviSat ASAR imagery is used to monitor the progression of facies zones across Devon Ice Cap (DIC) from 2004 to 2011. This data is validated against in situ surface temperatures, mass balance data, and ground penetrating radar surveys from the northwest sector of DIC. Based on calibrated (sigma nought) EnviSat ASAR backscatter values, imagery from autumn 2004 to 2011 shows the disappearance of the ‘pseudo’ dry snow zone at high elevations, the migration of the glacier and superimposed ice zones to higher elevations, and reduction in area of the saturation/percolation zone. In 2011, the glacier and superimposed ice zone were at their largest extent, occupying 92% of the ice cap, leaving the saturation/percolation zone at 8% of the total area. This is indicative of anomalously high summer melt and strongly negative mass balance conditions on DIC, which results in the infilling of pore space in the exposed firn and consequent densification of the ice cap at higher elevations.

>Magister Scientiae - MSc / Velocity modelling forms an integral part of the seismic interpretation process initially completed in two-way time. In order for a representative depth conversion, it is obligatory to construct a velocity model that serves the bridge between velocity and respective two-way time. This study deals with the investigation of subsurface heterogeneities and its impact on the variation of velocities. Interpretation of time domain reflection data results in one or more seismic horizons, however these horizons should represent the variation in subsurface geology as a result of acoustically different layers displaying varying reflection amplitudes. The purpose of this study was fulfilled by examining the variation of these velocities in relation to the geology and its significance towards building a velocity model. It is evident that complexities, such as an existing heterogeneous subsurface is present in the study area. Using velocities only considered at formation well tops, as a result, does not completely honour the variation in these velocities. The velocity profile as calculated from the sonic log was characterized into zones representing unique velocity trends. The analyses to understand the impact of subsurface heterogeneities on the velocities was completed by the application of seismic facies analysis which entailed the study of the seismic reflector patterns and amplitudes; a study of the lithologies present and the generation of mineral plots using available wireline logs, all of which in close relation to the variation in velocities. The characterized zones, as a result have shown that shaly sediments are typically associated with higher velocities (~2800 – 4600m/s) compared to sandstones of lower densities. Mineral plots however, have also indicated that where quartz minerals were present (specifically zone L), sandstones as a result have shown higher velocities (~4800m/s) as compared to the shales (~3600m/s). These higher velocities are also associated with more organised seismic reflectors with brighter amplitudes and strong contrasts in acoustic impedance as shown by the seismic. Uniform velocities were observed in zones such as zone Ia, typically associated with a low acoustic impedance contrast and minimal variation in its lithological make-up. The integrated investigation of subsurface heterogeneities has shown that velocities vary to a substantial degree as a result of existing subsurface heterogeneities. The variation of these velocities are hence significant enough that it should be considered when constructing a velocity model which aims to respect the geology of the study area. The result of understanding the relation between the geology and resultant velocities may prove to advance the results of the velocity model in a manner that it is more complete and representative of the subsurface.

The Saints & Sinners Quarry preserves the only known vertebrate body fossils in the Nugget Sandstone and the most diverse fauna known from the Nugget-Navajo-Aztec erg system. The fauna includes eight genera and >18,000 bone and bone fragments assignable to >76 individuals, including theropods, sphenosuchians, sphenodontians, drepanosaurs, procolophonids, and a dimorphodontid pterosaur. Cycadeoid fronds are the only plant fossils. There are two depositional environments at the site – dune and interdune, each consisting of two or more faces. The dune facies are (1) Trough Cross-Stratified Sandstone (TCS) representing dry dunes, and (2) Massive and Bioturbated Dunes (MBD) representing bioturbated, damp dunes. The interdune facies are (1) Wavy Sandstone (WSS) representing wet and damp flats with biofilms and tridactyl tracks, (2) Green Clays and Silts (GCS) representing quiet lacustrine waters, (3) Planar Laminated Sandstone (PLS) representing lacustrine dust and sand storm deposits which grade laterally into (4) Massive Bone Bed (MBB) shoreline deposits. The vertical and lateral relationships of the dune and interdune facies suggests that an interdune flat developed (WSS facies) likely by deflation of dunes down to, or near to, the water table. As the water table rose, a shallow lake developed (GCS facies) and trapped wind-blown sediment during sand storms (PLS Facies). The taxonomically diverse vertebrate fauna suggest a mass die-off occurred, likely due to drought. The carcasses and bones were buried by three distinct depositional events, each a bone bed (MBB facies) - separated by very thin clays (GCS facies). Thereafter the water table dropped resulting in several cm-scale sandstone beds with tridactyl tracks (WSS facies). Then migrating dunes buried the interdune flat. These dunes hosted burrowing invertebrates for a moderate time resulting in the destruction of nearly all primary sedimentary structures (MBD facies). Ultimately, as the area dried further, more dunes migrated over these bioturbated surfaces and the area returned to dune field conditions (TCS facies). The Saints & Sinners site indicates that a previously unrecognized, remarkably diverse vertebrate fauna thrived in wet interdunes of western North America's Late Triassic erg system. A massive-die-off, likely due to a drought, provided a wealth of carcasses and their bones. The dynamic shoreline representing the interface of dunes and standing water provided favorable conditions for rapid burial of small carcasses and the disarticulated bones of larger individuals.

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<p> The Middle Devonian Dundee Limestones of Southwestern Ontario accumulated in the Michigan and Appalachian Basins, with deposition in part being controlled by the proximity to the Findlay and Algonquin arches. Six lithofacies were recognized in the Dundee Formation during detailed core and outcrop studies . Stratigraphic relations indicate that, prior to deposition of Dundee carbonates, a major regression exposed underlying Detroit River sediments adjacent to the arches. Subsequent transgression deposited reworked sands and shallow shelf, bioclastic limestones in most areas of the adjoining basins while in westernmost regions of the Appalachian Basin Columbus Formation sediments were accumulating adjacent to the Findlay Arch. </p> <p> Transgression became interrupted during middle Dundee time and a thick unit of lagoonal muds was deposited in the Appalachian Basin. A regionally well-developed firmground capping these mudstones indicates that a significant episode of non-deposition ensued. The equivalents of these muds in the Michigan Basin are pulses of coarse, reworked grainstones and rudstones indicating that substrates there were shallower and above wave base. Evidence of subsequent renewed transgression is preserved as middle to outer shelf moderately fossiliferous mudstones and wackestones overlying shallow shelf facies. </p> <p> Many friends, too many to mention here, made my stay at McMaster an enjoyable one. Mac wouldn't have been the same without the numerous challenges and imaginative adventures in which these people were always willing to participate. Francois Brissette, Bruce Willmer, Randy Meecham, Stu Miller, Steve Beneteau and other members of the Rockbusters Football and Aureoles Baseball teams provided continuous entertainment both on and off of the sports field. Their dedication and light-hearted approach allowed me to maintain a respectable degree of sanity throughout my studies. </p> <p> Finally, I would like to thank my family for their continual assistance, encouragement and support provided during the pursuit of my academic endeavours. </p> / Thesis / Master of Science (MSc)

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