Made available in DSpace on 2014-10-09T12:35:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:38Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:35:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:18Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:35:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:38Z (GMT). No. of bitstreams: 0 / O reservatório de Itupararanga foi construído pela LIGHT para gerar energia elétrica, iniciando suas operações em 1912. É formado pela barragem das águas do rio Sorocaba, o qual possui como afluentes os rios Sorocamirim, Sorocabuçu e Una. O reservatório localiza-se em uma área de fortes pressões ambientais devido à poluição difusa da produção agrícola, à carga orgânica e uso e ocupação do solo com atividades antrópicas. Desde 2003 vem recebendo alertas da CETESB, devido à presença de grande quantidade de cianobactérias que têm se mantido até os dias atuais. Em decorrência dos problemas observados nesse reservatório, o presente estudo teve por objetivo, avaliar a concentração, dos micro e macroconstituintes em amostras de perfil sedimentar de quatro pontos distintos do reservatório. Para estas análises foram utilizadas as seguintes técnicas analíticas e os respectivos elementos analisados: Análise por Ativação com Nêutrons Instrumental (INAA): As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb e Zn; Espectrometria de Emissão Ótica com Plasma Indutivamente Acoplado (ICP OES): Ag, Al, Ba, Be, Co, Cr, Cu, Fe, Li, Mg, Mn, Mo, Ni, P, Sn, Sr, Ti, V e Zn; Espectrometria de Absorção Atômica com Forno de Grafite (FG AAS) As, Cd e Pb e Analisador Direto de Mercúrio: Hg total. A validação das metodologias utilizadas foi realizada por meio das análises de materiais de referencia certificados. Os resultados obtidos foram comparados aos valores de referência NASC (North American Shale Comosite) e UCC (Upper Continental Crust). Foram calculados o fator de enriquecimento (FE) e o índice de geoacumulação (Igeo), ferramentas usadas para avaliação da presença de fontes de poluição antrópicas. As concentrações dos metais obtidos por ICP OES e FG AAS foram comparadas aos valores orientadores TEL e PEL do Conselho Canadense de Ministros do Meio Ambiente (CCME) e adotado pela CETESB. A partir desse estudo, foi possível realizar um diagnóstico da qualidade e a carga de fósforo contida nos sedimentos do reservatório, direcionando para ações corretivas que antecipem um dano maior a qualidade do reservatório. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:35:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:18Z (GMT). No. of bitstreams: 0 / A Amazônia armazena em sua floresta na ordem de 95 a 120 PgC de biomassa viva e mais 160 PgC no solo, que podem ser rapidamente liberados para a atmosfera por meio da queima de biomassa e, também, pela mudança do uso da terra. Este estudo foi desenvolvido com o objetivo de elucidar a contribuição da Bacia Amazônica nas emissões de carbono no ano de 2010. A quantificação do CO2 foi realizada por meio da coleta do ar atmosférico utilizando aviões de pequeno porte que descreveram um perfil vertical em quatro locais, estrategicamente posicionado na Bacia Amazônica, e utilizando sistemas semiautomáticos de coleta de ar em 17 ou 12 altitudes diferentes. O Fluxo de emissão/absorção foi calculado pelo método de integração de coluna, que consiste na determinação da concentração de CO2 no perfil vertical, subtraído da concentração de entrada no continente, levando-se em conta o tempo que a massa de ar despende entre a costa e o local de amostragem. Para a determinação da concentração de entrada, foram utilizadas as concentrações medidas pela NOAA nas Ilhas de Ascencion e Barbados e, como traçador de massas de ar, o SF6. Foi encontrado um caráter emissor da Amazônia em território brasileiro para o ano de 2010, em torno de 0,41 PgC, considerando a média ponderada das quatro regiões estudadas, sendo a queima de biomassa a principal responsável. Para a determinação da emissão proveniente da queima de biomassa foi utilizado o CO, como traçador, e a razão CO:CO2. Apesar de possuir um perfil emissor neste ano anormalmente seco, foi possível observar um caráter sumidor de carbono. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

A study of the Abrahamskraal Formation in the area around Merweville, in the southwestern corner of the Karoo Basin has revealed the presence of traceable lithological units with lateral continuity throughout the study area. The stratigraphic section measured in this part of the basin matches the section measured by Jordaan, (1990) south of Leeu Gamka, with a basal arenaceous unit overlain by a predominantly argillaceous succession. The thickness of the Abrahamskraal Formation in this part of the Karoo Basin in 2565m, charactersized by a braided depositional environment in the lower 2075m and a meandering depositional environment in the upper 490m. Biostratigraphically the succession comprises a basal Eodicynodon Assemblage Zone which constitutes the lower 1104m and this is overlain by a 1461m thick Tapinocephalus Assemblage Zone whose upper limit is 21m below the Poortjie Member of the Teekloof Formation. This study has also corroborated the work by earlier authors who proposed a northeasterly palaeoflow direction as well as contributing to the global correlation of the Middle Permian terrestrial tetrapod faunas where the Eodicynodon Assemblage Zone correlates with the fauna from the Russian Ocher & Ischeevo; fauna of China’s Xidagou Formation and Rio da Rosto fauna of Brazil while the Tapinocephalus Assemblage Zone fauna corrletaes with fauna from Mezen and Ischeevo in Russia, Posto Queimado fauna in Brazil and those from the Madumabisa strata of Zimbabwe.

This thesis consists of six published papers. The present-day stress tensor has been determined using petroleum well data in the Gippsland and Otway Basins in Southeast Australia (Papers 1 and 4) and the Cooper Basin in Central Australia (Paper 5). In the Gippsland Basin, the present-day stress regime is transitional between one of reverse and strike-slip faulting and the maximum horizontal stress (SHmax) is oriented ~139°N. The present-day stress regime in the Victorian sector of the Otway Basin is also transitional between one of reverse and strike-slip faulting and SHmax is oriented ~135°N. Horizontal stresses are lower in the South Australian sector of the Otway Basin where the stress regime is one of strike-slip faulting and SHmax is oriented ~124°N. The orientations of SHmax in Southeast Australia are consistent with focal mechanism solutions, neotectonic structures and modelling of plate-boundary forces (Paper 4). Closure pressures from mini-frac injection tests are commonly used to determine the minimum horizontal stress (Shmin) magnitude. However, in high stress basins such as the Cooper and Gippsland Basins, these pressures may not reliably yield Shmin (Papers 2 and 5). In the Cooper Basin, high closure pressures (>18 MPa/km) were observed in tests where pressure-declines indicated complex hydraulic fracture growth. Closure pressures in these injections are unlikely to be representative of Shmin. They are believed to reflect the normal stress incident on pre-existing planes of weakness that are exploited by hydraulic fluid during the mini-frac injection (Paper 5). Sub-horizontal fabrics that are open at the wellbore wall were observed on image logs in the Cooper and Gippsland Basins (Papers 2 and 5). This fabric is believed to be at least partially responsible for the complex growth of hydraulic fractures observed in the Cooper Basin. The occurrence of these sub-horizontal fabrics and knowledge of rock strength have been used to constrain the magnitudes of SHmax and Shmin independently of mini-frac injections in the Cooper and Gippsland Basins (Papers 2 and 5). The present-day stress tensor is often quoted as a single gradient at a sedimentary basinor petroleum field-scale. Image logs and mini-frac data from Central and Southeast Australia indicate significant stress differences between stratigraphic units (Papers 3 and 5). Finite element modelling of the stress distribution between interbedded sands and shales in the Gippsland Basin indicates that stress is ‘partitioned’ to ‘hard’ lithological units in high stress areas. This accounts for the observation that borehole breakout only occurs in hard, cemented sandstones in the Gippsland Basin (Paper 3). A generic ‘mechanical stratigraphy’ derived from knowledge of wellbore failure (from image logs), rock strength and rock properties in individual rock units in the Cooper Basin allows an approximation of the present-day stress-state to be made directly from image-logs for individual rock units prior to mini-frac injection (Paper 6). This is important for predicting and understanding hydraulic fracture growth and containment. When considered together, the papers comprising this thesis provide significant new data on the orientation and magnitude of present-day stresses in Central and Southeast Australia. They also provide insight into the tectonic origin of those stresses and their distribution within sedimentary basins. In particular the papers develop and use new methods for constraining the present-day stress in regions of high tectonic stress. They also discuss implications for problems in petroleum development including wellbore stability and hydraulic fracturing. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283781 / Thesis(Ph.D.) -- Australian School of Petroleum, 2007

Maps in pocket inside back cover. / Includes published papers and abstracts of works by the author / "November 2003" / Includes bibliographical references. / Various paging : ill. (chiefly col.), maps, plates, charts (some folded) ; 30 cm. + 2 scaled seismic survey maps / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, National Centre for Petroleum Geology and Geophysics and Discipline of Geology and Geophysics, 2004

The West Antarctic Ice Sheet (WAIS) is mostly grounded in broad, deep basins (down to 2.5 km below sea level) that are stretched between five crustal blocks. The geometry of the bedrock, being mostly below sea level, induces a fundamental instability in the WAIS through the possibility of runaway grounding line retreat. The crustal environment of the WAIS further influences the ice sheet’s fast flow through conditions at the ice-bedrock boundary. This study focuses on understanding the WAIS by examining the subglacial geology (such as volcanoes and sedimentary basins) at the icebedrock boundary and the continent’s deeper crustal structure- primarily using airborne gravity anomalies. The keystone of this study is a 2004-2005 aerogeophysical survey over one of the most negative mass balance glaciers on the continent: Thwaites Glacier (TG). The gravity anomalies derived from this dataset- as well as gravity-based modeling and spectral crustal boundary depth estimates- reveal a heterogeneous crustal environment beneath the glacier. The widespread Mesozoic rifting observed in the Ross Sea Embayment (RSE) of West Antarctica extends beneath TG, where the crust is ~27 km thick and cool. Adjacent to TG, spectrally-derived shallow Moho depths for the Marie Byrd Land (MBL) crustal block can be explained by thermal support from warm mantle. I assemble here new compilations of free-air and Bouguer gravity anomalies across West Antarctica (from both airborne and satellite datasets) and re-interpret the extents of West Antarctic crustal block and their boundaries with the rift system. Airy isostatic gravity anomalies reveal that TG is relatively sediment starved, in contrast to the sediment-rich RSE. TG’s fast flow velocities could be sustained in this sediment poor environment if higher heat flux in MBL was providing an ample source of subglacial melt water to the glacier. The isostatic anomalies also indicate that TG’s outlet rests on a bedrock sill that will impede future grounding line retreat (up to ~100 km) and temporarily stabilize the glacier. / text

Bibliography: p.149-158. / xxii, 198 p. : ill. (chiefly col.), maps (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aims to provide a structural and stratigraphic framework for the evolution of the Roebuck Basin, and to evaluate its future petroleum potential. / Thesis (Ph.D.)--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 2000

Bibliography: p.149-158. Aims to provide a structural and stratigraphic framework for the evolution of the Roebuck Basin, and to evaluate its future petroleum potential.