Orientadores: Giorgio Basilici, Francisco Sergio Bernardes Ladeira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-11T17:30:45Z (GMT). No. of bitstreams: 1 DalBo_PatrickFranciscoFuhr_M.pdf: 16776523 bytes, checksum: ed0ae352d6fc4dea57e9f4119eee8537 (MD5) Previous issue date: 2008 / Resumo: A Formação Marília (Maastrichtiano), na faixa de afloramentos da porção noroeste da Bacia Bauru (estados de Goiás e Mato Grosso do Sul), é interpretada neste trabalho como um antigo sistema eólico de lençol de areia. A sucessão vertical é caracterizada por arenitos muito finos a médios intercalados com paleossolos em espessas sucessões de até 150 metros de espessura. A litofácies Arenito com laminação plano-paralela, que forma corpos com estratificação cavalgante transladante subcrítica, atribuída à deposição de areias com marcas onduladas eólicas é a mais comum descrita na área de estudos. Os paleossolos representam mais de 65% do registro geológico da Formação Marília, constituídos predominantemente por Aridisols caracterizados por concentrações secundárias de carbonato de cálcio. Superfícies suborizontais de deflação eólica separam os depósitos eólicos dos paleossolos e dividem a Formação Marília em duas fases distintas de construção de corpos geológicos ligadas às variações paleoclimáticas: i) fase de sedimentação eólica, caracterizada por depósitos arenosos de marcas onduladas eólicas; ii) fase de paleopedogênese, caracterizada por Aridisols. Ambas as fases se alternaram temporalmente e, registram períodos de formação de diferentes ordens de grandeza, provavelmente maiores que 105 vezes entre a formação dos depósitos arenosos com marcas onduladas eólicas e o desenvolvimento de horizontes Bk dos Aridisols. A alternância cíclica entre depósitos eólicos e paleossolos está ligada a variações paleoclimáticas que controlaram a disponibilidade hídrica no ambiente. Durante os períodos mais secos, a ausência de cobertura vegetal expôs a superfície à ação dos ventos e formação de extensas superfícies de deflação eólica, que posteriormente foram cobertas por depósitos arenosos de marcas onduladas eólicas. Com o posterior restabelecimento da umidade atmosférica e o conseqüente aumento da cobertura vegetal, a superfície foi reestabilizada, inibindo o processo de deflação e deposição eólica e permitindo a formação de Entisols e Aridisols / Abstract: The Marília Formation (Maastrichtian), outcropping in the northwestern portion of the Bauru Basin (Goiás and Mato Grosso do Sul brazilian states), is interpreted here as an ancient Aeolian sand sheet. The vertical succession, c.150 m thick, is made up of very fine to medium-grained sandstone and, it is characterised by cyclic interbedding of sediments and palaeosols. Planar laminated sandstone (subcritically climbing translatent stratification), formed by aeolian sand with wind ripple, is the most common lithofacies. Palaeosols, mainly Aridisols, represent more than 65% of the geological record of the Marília Formation. Subhorizontal aeolian deflation surfaces divide Marília Formation in two distinct constructional phases of geological bodies linked to palaeoclimatic variations: i) phase of prevalent aeolian sand deposition; ii) phase of Aridisols development. The two phases they alternated in time and probably record periods of formation with difference of the order greater than 105 between aeolian sand deposition and development of the Bk Aridisols horizons. Palaeoclimate is the main forcing factor of the Aeolian sand deposition and soil development. Episodes of sedimentation and soil development likely result from cyclic decreases and increases in available moisture and vegetation cover. Aeolian deflation and sedimentation were predominant during drier phases of past climatic cycles, when vegetation cover was sparse in source areas and windier conditions have the capacity to remove and transport clastic materials. During wetter phases of climatic cycles, increased vegetative cover stabilised the landscape, reduced deflation, and intensified Entisols and Aridisols development / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências

Orientador: Giorgio Basilici / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-19T17:33:24Z (GMT). No. of bitstreams: 1 DalBo_PatrickFranciscoFuhr_D.pdf: 16255266 bytes, checksum: aeb871c6c13a2eecaa543a21baa19f06 (MD5) Previous issue date: 2011 / Resumo: Lençóis de areia eólica são áreas morfodeposicionais caracterizadas por morfologias planas e ausência de dunas com faces de avalancha. Exemplos atuais e antigos de lençóis de areia eólica são conhecidos em todos os continentes e descritos na literatura desde o Paleoproterozóico. Em áreas em sedimentação, areias com marcas onduladas eólicas formam a feição sedimentar mais conspícua e a identificação de arenitos com estratificação cavalgante transladante permite o reconhecimento de sucessões sedimentares de lençóis de areia eólica. Apesar de inúmeros estudos centrados na organização faciológica e caracterização de fatores de controle à gênese e distribuição de depósitos eólicos nessas áreas, a inter-relação entre depósitos eólicos e solos foi pouco abordada na literatura. O estudo de dois exemplos de lençóis de areia eólica nesta tese, a Formação Marília, Neocretáceo da Bacia Bauru, Brasil, e La Salina, uma área em sedimentação na Bacia Tulum, Argentina, permitiu a elucidação dos principais processos e fatores ambientais que influenciam a sedimentação eólica e a pedogênese nessas áreas. Os processos eólicos e pedogênicos parecem ocorrer em intervalos temporais distintos e respondem a mudanças ambientais alogênicas ao sistema, principalmente climáticas, que governam diferentes fases de estabilidade e instabilidade da superfície morfodeposicional e podem conduzir à criação de um registro sedimentar marcado por alternâncias cíclicas verticais entre depósitos eólicos e paleossolos. O modelo de construção, acumulação e preservação do sistema eólico também é condicionado a diversas variáveis autogênicas e alogênicas ao sistema e é distinto nos dois casos estudados. A construção do sistema eólico na Formação Marília foi diferenciada em duas fases paleoclimáticas, caracterizadas por maiores ou menores índices pluviométricos, que controlaram o suprimento e a disponibilidade sedimentar, enquanto em La Salina, o processo de construção não parece ter sido determinado por variações climáticas. A acumulação dos corpos geológicos foi favorecida nos dois sistemas eólicos devido à presença de cobertura vegetal e outros fatores estabilizadores à superfície dos lençóis. A preservação em ambos os sistemas foi controlada por subsidência tectônica seguida de progressivo soterramento dos corpos geológicos / Abstract: Eolian sand sheets are morpho-depositional areas characterized by flat or gently undulated sandy surfaces covered predominantly with wind ripples and slipfaceless dunes. Ancient and modern eolian sand sheets are known to occur in all continents and ancient examples are described in the literature since the Paleoproterozoic, being largely recognized in the sedimentary record by inversely graded climbing translatent strata. Although many sedimentological studies have focused on characterization of eolian facies and environmental factors favorable for sand sheet development, studies on dynamic interactions between eolian deposits and soils in sand sheet areas are still lacking. The study of the Late Cretaceous Marília Formation and the modern La Salina eolian sand sheet has contributed to understand which environmental factors act to promote soil development and principally those that operate to withhold its development and favors eolian sedimentation in eolian sand sheets. The eolian sedimentation and pedogenesis seem to occur in different environmental phases, mainly controlled by climate, which are responsible for the stability and instability of the morpho-depositional surface. Eolian sedimentation prevails during the phase of instability and construction of the eolian sand sheet, whereas soil formation are dominant during the stable phase, when unavailability or bypassing of sediments, allied with the development of a vegetation covering, led to the absence of sedimentation and erosional processes. The constructional phase of the eolian system in the Marília Formation was subjected to paleoclimate variations, which controlled sediment supply and availability, whereas in the La Salina area, the construction has not been directly affected by climate. Accumulations of geological bodies were favored by vegetation covering and soil development in the Marília Formation and have been occurring through stabilization of the accumulation surface by vegetation, thin mud veneers, and surface cementation in the La Salina. The preservation of both eolian systems was controlled by tectonically induced subsidence and burial / Doutorado / Geologia e Recursos Naturais / Doutor em Ciências

Submitted by Israel Vieira Neto (israel.vieiraneto@ufpe.br) on 2015-03-04T17:48:21Z No. of bitstreams: 2 DISSERTAÇÃO Natália Gomes Alves de Souza.pdf: 8365159 bytes, checksum: 4d043b551c4e12fa6c5ec2cfcf5660d9 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-04T17:48:21Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO Natália Gomes Alves de Souza.pdf: 8365159 bytes, checksum: 4d043b551c4e12fa6c5ec2cfcf5660d9 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-03-19 / O sistema estuarino Goiana-Megaó abriga flora e fauna variadas, sendo importante fonte de sustento das comunidades circunvizinhas. Este ecossistema tem sido impactado por diversas atividades agrícolas, industriais e aquicultura. Além disso, existe a previsão de grande desenvolvimento econômico nesta região em um futuro próximo (implementação de um polo farmacoquímico e um polo automotivo). Deste modo, o objetivo deste trabalho foi realizar um diagnóstico atual e a avaliação histórica das concentrações totais e potencialmente biodisponíveis de elementos maiores e traços, através de três testemunhos com distribuição espacial estratégica ao longo do estuário. Também se objetivou determinar a taxa de sedimentação desse sistema através da datação geocronológica pelo método 210Pb em cinco testemunhos ao longo do sistema estuarino. As concentrações de background local considerados neste trabalho para o sistema estuarino estudado foram obtidos a partir do testemunho a montante do estuário no rio Goiana, pelo fato deste ter alcançado as camadas mais antigas, depositadas a 98 anos atrás. Os elementos químicos As, Cr, Ni e Cu encontraram-se em concentrações acima dos limites estabelecidos pela legislação brasileira nos testemunhos T-2 e T-3, com valores máximos de 3,0 ppm, 102,0 ppm, 42,2 ppm e 39,6 ppm, respectivamente. As, Mo, S e Sb apresentaram fator de enriquecimento elevado em relação ao background (FE > 2), tendo sido obtido nos testemunhos à jusante do estuário principalmente entre 1915 e 1975. As concentrações de As tem provável origem geogênica (rochas vulcânicas e mineralização de Ba e Pb localizada a aproximadamente 50 km montante da área estudada), porém, assim como Mo, S e Sb, pode também ter origem antrópica (cultivo de cana-de-açúcar). Quanto à taxa de sedimentação do sistema estuarino estudado, houve uma tendência ao aumento com o passar dos anos e com o ano de 1966 como principal marco destas mudanças, sendo relacionados ao aumento da ocupação do município de Goiana e ao intenso cultivo de cana-de-açúcar na região. Apesar de todos estes fatores, este sistema estuarino ainda se encontra relativamente preservado, porém é notória a interferência antrópica na área, comprovada pelos dados geoquímicos aqui descritos, tornando necessário um monitoramento contínuo destes contaminantes ao longo dos próximos anos.

Sedimentation and ocean warming are two major anthropogenic stressors that directly affect coral recruitment and recovery. Many coral-dominated reefs have undergone phase shifts becoming macroalgae-dominated because of the coral population’s inability to tolerate these increasing stressors. Predicting these phase shifts requires a determination of the relative susceptibility of coral and macroalgae to these stressors. The objective of this study was to quantitatively assess the synergistic effects of sedimentation and elevated temperature on the survival and growth of Montastraea cavernosa newly settled coral juveniles, and fragments of the macroalgae, Dictyota ciliolata. A crossed experimental design tested the two temperatures and four sedimentation levels. After 12 weeks, a 2°C increase in temperature did not significantly affect survival of the M. cavernosa juveniles or fragments of D. ciliolata. Montastraea cavernosa juvenile survival was negatively affected by a decrease in sediment. Dictyota ciliolata survival was highly sensitive to the increase in sedimentation. The survival and growth of both species appeared to be susceptible to an increase in sedimentation, but in opposite ways. This study demonstrates that both M. cavernosa juveniles and D. ciliolata fragments may be more vulnerable to light caused by changes in turbidity rather than temperature.

From Introduction: For at least two centuries and a corresponding number of generations of geologists and miners there has been active argument concerning the origin of certain types of carbonate hosted mineral deposit. The characterization of the type itself was and still is debatable. Objections have been raised to grouping several examples under one heading because each has its individually distinctive features. ·This is especially applicable to the carbonate hosted lead-zinc "sedimentary" deposits. The type that will be discussed in the text to follow is composed chiefly of galena, sphalerite, barite and fluorite, with pyrite , marcasite and chalcopyrite as conspicuous accessory ore minerals. Exceptions to this general copper deficient characteristic displayed by the sedimentary carbonate-hosted lead-zinc deposits are the deposits at Tsumeb and Kombat, Namibia. These deposits are hosted by the carbonate sequence of the Otavi Shelf sediments, and copper, in the form of tennantite, chalcopyrite and bornite, is the major ore constituent. Calcite, aragonite, dolomite and quartz are the commonest nonmetallic gangue minerals but siderite and silica may also be present. In contrast with other lead and zinc sulphide (volcanogenic) deposits, those to be considered here seldom carry noteworthy amounts of silver or any other precious metals. Commonly the country rock is a carbonate; limestone or dolomite, but deposits in. sandstone, shale and conglomerate are not unknown. Characteristic features are ore bodies that extend parallel or nearly so with the bedding although many such deposits are partly, or completely developed along crosscutting fissures and breccias. Some observers regard these fissure fillings as evidence for a magmatic source of the metals, whereas others regard them as an indication of remobilization of ions, metals or minerals orginally present in low-grade stratiform deposits elsewhere in the stratigraphic succession.

No description available.

>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 .

Whether one is interested in the geomorphology, hydrology, or ecology of a river, the nature of the bed sediments is of major importance. Despite a long history of interest our ability to predict local grain size is poor, which is unfortunate given the labour and costs associated with bed material sampling. A preliminary model of sediment texture variation at the drainage basin scale, which makes a fundamental distinction between coupled and uncoupled hillslope-channel units, is presented. It is hypothesised that grain size variations in strongly coupled rivers are unstructured as a result of overbank colluvial inputs and special storage elements. These preclude the development of the systematic downstream structure commonly associated with fluvial sorting and abrasion processes in uncoupled channels. This conjecture is assessed empirically using data collected in two rivers on the Queen Charlotte Islands. It is found that distance alone does not explain changes in grain size, and that local variations are dominated by large organic debris jams. Impermeable jams are associated with upstream fining and downstream coarsening but the effect diminishes as the jams become more permeable, often with age. Jam placement is random, but frequent, and consequently at the drainage basin scale, grain size changes dramatically and unpredictably over very short distances. No deterministic structure is apparent. Further analysis reveals that the observed variations of surface median grain size and Fredle index are best regarded as stochastic phenomena. Sampling criteria are then determined which enable the accurate characterisation of such variation, once a stream has been classified by land use and position relative to hillslopes. / Arts, Faculty of / Geography, Department of / Graduate

Cette étude porte sur l’utilisation des outils de la géostatistique pour évaluer l’importance des phénomènes de sédimentation dans le barrage Akdarya en Ouzbékistan. Les analyses de variogrammes et les techniques d’interpolation par krigeage ont permis de générer des données dans les zones non échantillonnées du barrage. A l’aide des données de terrain complétées par les données produites par les outils géostatistiques, de nouvelles cartes bathymétriques du barrage ont été générées et ont permis de calculer de façon précise l’évolution du volume d’eau stocké en fonction du taux de sédimentation. / Sedimentation processes in man-made water reservoirs reduce their main asset: the volume storage capacity. This raises engineering, environmental and economic issues for the communities around the world and in particular for the areas affected by strong water deficit. Because of Uzbekistan’s arid climatic conditions and uneven spatial and temporal water resources distribution, responsive and innovative water availability assessment surveys of all major water reservoirs are required. Bathymetric survey is a traditional method that is carried out for the estimation of reservoir volumes and surface areas for the corresponding reservoir stages in order to assess the water availability. Volume and surface area differences derived from multiple surveys of a reservoir provide storage loss estimates over time due to sedimentation. However, two main factors such as intensive field data measurement and post data-processing often limit the frequency of these surveys. Alternatively, innovative depth measurement technologies coupled with contouring and surface mapping programs provide automated reservoir volume and surface area calculations. This significantly reduces time, work load and financial burdens for reservoir sedimentation projects. This study deals with the use of a geostatistical approach to assess the reservoir sedimentation in the Akdarya reservoir in Uzbekistan. Geostatistical approach includes (semi-) variogram analysis and interpolation (kriging and simulations (turning bands)) techniques predicting values at unsampled locations for generating digital bathymetric surface models of reservoir bottom conditions in order to calculate volume and surface area at given water elevation. Simulation enables to have range of reservoir volumes and surface areas with the same probability in comparison to the kriging and traditional methods. This gives a real estimation of the water resource availability for operators and managers to sustainably manage natural resources and hydraulic infrastructure.

The Eureka Sound Formation in the eastern Canadian Arctic Archipelago is an Upper Cretaceous to Paleogene pre- and syn-tectonic deposit that records the uplift and segmentation of the Early Carboniferous to Tertiary Sverdrup Basin. Scattered outliers of the Eureka Sound Formation on southern Ellesmere Island rest unconformably on or are faulted against Devonian strata. In the vicinity of Vendom, Stenkul, Baumann and Sor Fiords, the Eureka Sound Formation attains a maximum thickness of 480 m and comprises a sequence of nonmarine and brackish water deposits that ranges in age from mid-Paleocene to Late Eocene. Eureka Sound strata which crop out along the shores of Stenkul Fiord are divided into four lithofacies assemblages. The stratigraphic section is composed mainly of two nonmarine assemblages which alternate throughout the sequence. Lithofacies Assemblage I consists of fining-upward sandstones which attain thicknesses of 20 m and are interpreted as fluvial deposits. Lithofacies Assemblage II comprises interbedded mudstones and coal in seams up to 8 m thick, and are interpreted as floodbasin deposits of an alluvial plain. Two marine lithofacies assemblages (III, IV) are recognized locally and constitute a minor part of the stratigraphic succession. Lithofacies Assemblage III comprises the basal strata in the study area and consists of approximately 90 m of buff-weathering mudstones and interbedded thin coals which were deposit ed in brackish lagoonal, estuarine and salt marsh environments. Lithofacies Assemblage IV occurs locally in the middle of the stratigraphic section and consists of up to 10m of white, well sorted quartz arenites and minor mudstones, which are interpreted as deposits of a barrier island system. To the northeast of Stenkul Fiord at Makinson Inlet, outliers of the Eureka Sound Formation rest unconformably on Paleozoic strata, and are in turn overlain with angular unconformity by as much as 120 m of Early Miocene fanglomerates of the Beaufort Formation. The ages of these sediments, in conjunction with ages reported from the Eureka Sound and Beaufort Formations in other parts of Ellesmere and Axel Heiberg Islands, bracket the timing of the orogenic phase of the Eurekan orogeny in the eastern Arctic as Late Eocene to Miocene. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate