[Truncated abstract] Characterising the behaviour of calcareous sediments that possess some degree of bonding between their constituents has attracted worldwide research interest in recent years. Although many recent studies have made significant contributions in delineating the behaviour of these sediments, there is still paucity of information particularly on the cyclic behaviour of cemented calcareous soils. This thesis describes in detail the characteristic features of cemented calcareous soils and proposes methods for characterising their cyclic behaviour. Two different calcareous soils Goodwyn (GW) and Ledge Point (LP) soils representing extreme depositional environments were examined in this study. Artificially cemented sample were created using the CIPS (Calcite Insitu Precipitation Systems) technique, considering its superiority over other most commonly available cementation techniques in replicating the natural pattern of cementation, and the behaviour of natural calcarenite under monotonic loading conditions. The experimental program involved triaxial testing of both uncemented and calcite-cemented calcareous soils under different loading conditions, i.e. isotropic compression tests to high-pressure (16 MPa), monotonic shearing tests, undrained cyclic shearing tests and undrained monotonic post-cyclic shearing tests. Significant emphasis has been placed on the cyclic behaviour of these soils. Internal submersible LDVTs were used for the accurate and continuous measurement of strain down to about 10-5

Bibliography: leaves 159-177.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Samples of shallow-water carbonates were collected from Jurassic and Cretaceous Italian carbonate platforms and subjected to petrographic, diagenetic and chemostratigraphic analyses (⁸⁷Sr/⁸⁶Sr, δ¹³C_carb, δ¹³C_org, δ¹⁸O). In general, the new chemostratigraphic data generated reflect trends established by previous work, some of which has been carried out on biostratigraphically calibrated reference sections. Consequently, chemostratigraphic correlations (⁸⁷Sr/⁸⁶Sr, δ¹³C_carb) of isotope profiles taken from platform carbonates with well-dated reference sections have allowed the application of high-resolution dating frameworks to the biostratigraphically poorly constrained carbonate platforms. The increased resolution in dating of the Italian carbonate platforms has, furthermore allowed a detailed investigation into the facies response of these carbonate platforms to major geological events. In particular, platform responses to oceanic anoxic events and other periods of major perturbation in the global carbon cycle are analysed (early Toarcian, Aalenian-Bajocian, Oxfordian-Tithonian, Valanginian-Hauterivian, Aptian-Albian, Cenomanian-Turonian, Coniacian-Santonian). Lower Jurassic levels of the Trento Platform record platform devastation in the early Toarcian synchronous with a major negative δ¹³C_carb excursion, followed by platform recovery synchronous with a pronounced δ¹³C_carb positive excursion and return to background values. The Campania-Lucania Platform shows negligible response to the oceanographic events of the early Toarcian even though the characteristic carbon-isotope profile is readily identifiable. The Trento Platform drowned at approximately the Aalenian-Bajocian Stage boundary, synchronously with a reproducible negative followed by positive δ¹³C_carb excursion, whereas the Campania-Lucania Platform underwent a facies transition from oolite to cyclically bedded micrite. The Friuli Platform showed negligible depositional response to the carbon-cycle perturbations of the Kimmeridgian-Tithonian, Valanginian-Hauterivian, Aptian-Albian and Cenomanian- Santonian (as registered in the δ¹³C_carb record). The Campania-Lucania Platform registered flooding and increased levels of organic-matter preservation coincident with pronounced positive δ¹³C_carb excursions at Cenomanian-Turonian and Coniacian-Santonian levels. Observations on the responses of carbonate platforms to oceanographic conditions during periods of global carbon burial lead to the conclusion that temperature excess is a hitherto neglected control on global carbonate accumulation rates.

[Truncated abstract] Characterising the behaviour of calcareous sediments that possess some degree of bonding between their constituents has attracted worldwide research interest in recent years. Although many recent studies have made significant contributions in delineating the behaviour of these sediments, there is still paucity of information particularly on the cyclic behaviour of cemented calcareous soils. This thesis describes in detail the characteristic features of cemented calcareous soils and proposes methods for characterising their cyclic behaviour. Two different calcareous soils Goodwyn (GW) and Ledge Point (LP) soils representing extreme depositional environments were examined in this study. Artificially cemented sample were created using the CIPS (Calcite Insitu Precipitation Systems) technique, considering its superiority over other most commonly available cementation techniques in replicating the natural pattern of cementation, and the behaviour of natural calcarenite under monotonic loading conditions. The experimental program involved triaxial testing of both uncemented and calcite-cemented calcareous soils under different loading conditions, i.e. isotropic compression tests to high-pressure (16 MPa), monotonic shearing tests, undrained cyclic shearing tests and undrained monotonic post-cyclic shearing tests. Significant emphasis has been placed on the cyclic behaviour of these soils. Internal submersible LDVTs were used for the accurate and continuous measurement of strain down to about 10-5

Thesis (Ph. D.)--University of Adelaide, Dept. of Plant Science, 1997. / Includes bibliographical references (leaves 256-275).

O objeto deste trabalho é fornecer dados hidrológicos com fins de caracterização e monitoramento da região da Cadeia Norte do Brasil e da Cadeia de Fernando de Noronha, assim como levantar e sistematizar informações sobre a geoquímica dos diversos tipos de sedimentos encontrados na plataforma continental externa adjacente ao banco Aracati, contribuindo para o levantamento dos potenciais sustentáveis de exploração dos recursos vivos da Zona Econômica Exclusiva. A área em estudo compreende a sub-área II, setor 1 e parte do setor 2, e está localizada entre 1oN e 5oS de latitude e entre 30o e 40oW de longitude, abrangendo uma área de aproximadamente 400.000 km2. Foram analisadas amostras coletadas em 8 estações resultando em 20 amostras de sedimentos nos anos de 1997 (verão), 1998 (outono) e 2000 (primavera) e 34 estações que originaram 272 amostras de água na primavera de 2000. As concentrações máximas dos parâmetros analisados, com exceção do fosfato, nas amostras de água se localizam na região próxima à costa. Detectou-se na área uma termoclina bem marcada, sendo mais profunda na primavera. A camada de mistura é bastante homogênea, sendo porém, mais espessa na primavera. O pH detectado encontra-se na faixa alcalina sendo os maiores valores de pH detectados na primavera. Verifica-se, um máximo de salinidade na camada de inicio da termoclina sazonal. Não verificou-se na área condição anaeróbica na coluna d’água. A distribuição de fosfato, nitrato e silicato, apresenta-se de forma muito semelhante, sendo que na primavera essas concentrações são maiores, nas camadas superficiais. Na cobertura sedimentar da plataforma continental adjacente aos bancos da cadeia norte do Brasil, encontro-se areia quartzosa, areia carbonática, fragmentos de concha, Lithothanmium e Halimedas. Os fragmentos de concha apresentaram as maiores concentrações totais de metais, enquanto Lithothanmium apresentou o maior teor de carbonato. Há uma forte correlação entre ferro e manganês na amostras de água e em todas as frações de sedimentos analisadas, sendo que nestas a relação média entre estes elementos é da ordem de 1:25. Existe forte correlação entre cromo e carbonato nas amostras que apresentam teor de carbonato maior que 20%. As amostras de areia quartzosa, fragmentos de concha e Halimedas, apresentam-se muito semelhantes quanto à distribuição de ferro, manganês, zinco e cromo. Existe forte correlação nas amostras de sedimento, assim como nas amostras de água, entre ferro, manganês, zinco, correlacionando-se também nas amostras de sedimento com o chumbo. As 8 concentrações de metais nas amostras de água apresentaram-se relativamente baixas em se comparando com as amostras de sedimento. Nas amostras de água as concentrações de cromo e chumbo estão abaixo do limite de detecção. / The object of this work is to supply hidrologicals datas with ends of monitoramento of the area of the North Chain of Brazil and of the Chain of Fernando of Noronha, as well as to lift and to systematize information on the geochesmitry of the several types of sediments found in the external continental platform adjacent to the bank Aracati, contributing to the rising of the maintainable potentials of exploration of the alive resources of the Exclusive Economic Zone. The area in study understands the subarea II, section 1 and it leaves of the section 2, and it is located among 1oN and 5oS of latitude and among 30o and 40oW of longitude, embracing an area of approximately 400.000 km2. Samples collected in 8 stations resulting in 20 samples of sediments in the years of 1997 were analyzed (summer), 1998 (autumn) and 2000 (spring) and 34 stations that originated 272 samples of water in the spring of 2000. The maximum concentrations of the analyzed parameters, except for the phosphate, in the samples of water are located in the close area to the coast. It was detected in the area a very marked termocline, being deeper in the spring. The mixture layer is quite homogeneous, being even so, more it thickens in the spring. The detected pH meets in the alkaline strip being the largest pH values detected in the spring. It is verified, a maximum of salinity in the layer of I begin of the seasonal termoclina. It was not verified in the area anaerobic condition in the column of water. The distribution of phosphate, nitrate and silicate, come in a very similar way, and in the spring those concentrations are larger, in the superficial layers. In the sedimentary covering of the continental platform adjacent to the banks of the north chain of Brazil, find quartz sands, it sands carbonate, shell fragments, Lithothanmium and Halimedas. The shell fragments presented the largest total concentrations of metals, while Lithothanmium presented the largest text of carbonate. There is a strong correlation between iron and manganese in to samples of water and in all the analyzed fractions of sediments, and in these the medium relationship among these elements is of the order of 1:25. strong correlation Exists between chromium and carbonate in the samples that present text of larger carbonate than 20%. The samples of quartz sand, shell fragments and Halimedas, come very similar with relationship to the distribution of iron, manganese, zinc and chromium. Strong correlation exists in the sediment samples, as well as in the samples of water, among iron, manganese, zinc, being also correlated in the sediment samples with the lead. The concentrations 10 of metals in the samples of water came relatively low in if comparing with the sediment samples. In the samples of water the concentrations of chromium and lead are below the detection limit.

Alumínio Pulverizado Termicamente (TSA) é amplamente utilizado em instalações offshore como revestimento de ânodo de sacrifício em tubulações de aço carbono. O transporte e a instalação desses componentes podem levar a pequenos danos no revestimento, o que pode expor a superfície do aço à água do mar. Sabe-se que o depósito calcário é formado na superfície do aço polarizado catodicamente. Assim, esta pesquisa avaliou o TSA aplicado por sistema de pulverização de arco duplo (TWAS) no aço ao carbono S355J2 + N quando ocorrem danos (holidays) para estudar a formação de depósitos calcários no aço e adquirir dados sobre o desempenho do TSA sob altas temperaturas. A aplicação de diferentes condições também foi considerada: presença de selantes; liga do revestimento (99,5% de Al e Al-5% de Mg) e condições enterradas/não enterradas. Dois tipos de experimentos foram realizados: i) testes em potencial livre sob temperaturas constantes (30, 60 e 90°C) e diferentes tamanhos de holidays (expondo 5, 10 e 20% da superfície do aço) e ii) testes sob gradient térmico onde óleo a ~125°C foi adicionado em uma torre polimérica e água externa a ~10°C ficou em contato com a superfície das amostras (tanto potencial livre como polarização de -950 mVAg/AgCl foram aplicados). Análises incluíram inspeção visual, microscópio eletrônico de varredura e difração de Raio-X. A partir dos testes em temperaturas constante, o TSA atingiu um bom potencial de proteção (-800 a -900 mVAg/AgCl) e pouca diferença nos resultados devido à diferença na composição doTSA e no tamanho do holiday foi observada. As taxas de corrosão foram mantidas entre 0,02 e 0,01 mm/ano. No ensaio sob gradiente térmico e potencial livre, a perda de revestimento e as taxas de corrosão foram de 0,4 a 0,002 mm/ano. Além disso, o potencial alcançado foi de uma faixa menor do que a obtida anteriormente (-745 a -835 mVAg/AgCl). No entanto, quando o TSA foi combinado com proteção catódica externa e gradiente térmico, a espessura do TSA foi satisfatório e as taxas de corrosão obtidas foram inferiores a 0,076 mm/ano. O depósito calcário formado no holiday protegeu o aço contra a corrosão e seu mecanismo de crescimento baseado nesta pesquisa foi construído. / Thermally Sprayed Aluminium (TSA) is widely used in offshore facilities as sacrificial anode coating for carbon-steel risers and pipelines. Transportation and installation of those components can lead to small damages in the coating, which can expose the steel surface to the seawater. It is known that calcareous deposit is formed on the cathodically polarised steel surface. Thus, this research evaluated the TSA applied by twin wire arc spray system (TWAS) on S355J2+N carbon-steel when damage (holidays) is present in order to study the calcareous deposit formation on steel and acquire data regarding the TSA performance at high temperatures. Application of different conditions was also considered: presence of sealing; coating alloy (99.5%Al and Al-5%Mg) and buried/unburied conditions. Generally, two types of experiment were conducted – i) tests at free potential at steady temperatures (30, 60 and 90°C) and different holiday sizes (exposing 5, 10 and 20% of the steel surface) and ii) tests under thermal gradient where oil at ~125°C was added in polymeric tower and external water at ~10°C was in contact with the samples surface (both free potential and polarisation of -950 mVAg/AgCl were applied). Methodology of analyses included visual inspection, scanning electron microscope and X-ray Diffraction. From the tests at steady temperatures, the TSA reached a very good protective potential (-800 to -900 mVAg/AgCl) and little difference in results due to difference in TSA composition and holiday size was observed. Corrosion rates were kept between 0.02 and 0.01 mm/year. From the thermal gradient test under free potential, the coating loss and corrosion rates were 0.4 to 0.002 mm/year. Also, the potential achieved was in a lower range than previously obtained (-745 to -835 mVAg/AgCl). However, when TSA was combined with external cathodic protection and thermal gradient, the thickness of the TSA was satisfactory and corrosion rates obtained were below 0.076 mm/year. The calcareous deposit formed within the holiday protected the steel substrate against corrosion and its growth mechanism based in this research was built.

O objeto deste trabalho é fornecer dados hidrológicos com fins de caracterização e monitoramento da região da Cadeia Norte do Brasil e da Cadeia de Fernando de Noronha, assim como levantar e sistematizar informações sobre a geoquímica dos diversos tipos de sedimentos encontrados na plataforma continental externa adjacente ao banco Aracati, contribuindo para o levantamento dos potenciais sustentáveis de exploração dos recursos vivos da Zona Econômica Exclusiva. A área em estudo compreende a sub-área II, setor 1 e parte do setor 2, e está localizada entre 1oN e 5oS de latitude e entre 30o e 40oW de longitude, abrangendo uma área de aproximadamente 400.000 km2. Foram analisadas amostras coletadas em 8 estações resultando em 20 amostras de sedimentos nos anos de 1997 (verão), 1998 (outono) e 2000 (primavera) e 34 estações que originaram 272 amostras de água na primavera de 2000. As concentrações máximas dos parâmetros analisados, com exceção do fosfato, nas amostras de água se localizam na região próxima à costa. Detectou-se na área uma termoclina bem marcada, sendo mais profunda na primavera. A camada de mistura é bastante homogênea, sendo porém, mais espessa na primavera. O pH detectado encontra-se na faixa alcalina sendo os maiores valores de pH detectados na primavera. Verifica-se, um máximo de salinidade na camada de inicio da termoclina sazonal. Não verificou-se na área condição anaeróbica na coluna d’água. A distribuição de fosfato, nitrato e silicato, apresenta-se de forma muito semelhante, sendo que na primavera essas concentrações são maiores, nas camadas superficiais. Na cobertura sedimentar da plataforma continental adjacente aos bancos da cadeia norte do Brasil, encontro-se areia quartzosa, areia carbonática, fragmentos de concha, Lithothanmium e Halimedas. Os fragmentos de concha apresentaram as maiores concentrações totais de metais, enquanto Lithothanmium apresentou o maior teor de carbonato. Há uma forte correlação entre ferro e manganês na amostras de água e em todas as frações de sedimentos analisadas, sendo que nestas a relação média entre estes elementos é da ordem de 1:25. Existe forte correlação entre cromo e carbonato nas amostras que apresentam teor de carbonato maior que 20%. As amostras de areia quartzosa, fragmentos de concha e Halimedas, apresentam-se muito semelhantes quanto à distribuição de ferro, manganês, zinco e cromo. Existe forte correlação nas amostras de sedimento, assim como nas amostras de água, entre ferro, manganês, zinco, correlacionando-se também nas amostras de sedimento com o chumbo. As 8 concentrações de metais nas amostras de água apresentaram-se relativamente baixas em se comparando com as amostras de sedimento. Nas amostras de água as concentrações de cromo e chumbo estão abaixo do limite de detecção. / The object of this work is to supply hidrologicals datas with ends of monitoramento of the area of the North Chain of Brazil and of the Chain of Fernando of Noronha, as well as to lift and to systematize information on the geochesmitry of the several types of sediments found in the external continental platform adjacent to the bank Aracati, contributing to the rising of the maintainable potentials of exploration of the alive resources of the Exclusive Economic Zone. The area in study understands the subarea II, section 1 and it leaves of the section 2, and it is located among 1oN and 5oS of latitude and among 30o and 40oW of longitude, embracing an area of approximately 400.000 km2. Samples collected in 8 stations resulting in 20 samples of sediments in the years of 1997 were analyzed (summer), 1998 (autumn) and 2000 (spring) and 34 stations that originated 272 samples of water in the spring of 2000. The maximum concentrations of the analyzed parameters, except for the phosphate, in the samples of water are located in the close area to the coast. It was detected in the area a very marked termocline, being deeper in the spring. The mixture layer is quite homogeneous, being even so, more it thickens in the spring. The detected pH meets in the alkaline strip being the largest pH values detected in the spring. It is verified, a maximum of salinity in the layer of I begin of the seasonal termoclina. It was not verified in the area anaerobic condition in the column of water. The distribution of phosphate, nitrate and silicate, come in a very similar way, and in the spring those concentrations are larger, in the superficial layers. In the sedimentary covering of the continental platform adjacent to the banks of the north chain of Brazil, find quartz sands, it sands carbonate, shell fragments, Lithothanmium and Halimedas. The shell fragments presented the largest total concentrations of metals, while Lithothanmium presented the largest text of carbonate. There is a strong correlation between iron and manganese in to samples of water and in all the analyzed fractions of sediments, and in these the medium relationship among these elements is of the order of 1:25. strong correlation Exists between chromium and carbonate in the samples that present text of larger carbonate than 20%. The samples of quartz sand, shell fragments and Halimedas, come very similar with relationship to the distribution of iron, manganese, zinc and chromium. Strong correlation exists in the sediment samples, as well as in the samples of water, among iron, manganese, zinc, being also correlated in the sediment samples with the lead. The concentrations 10 of metals in the samples of water came relatively low in if comparing with the sediment samples. In the samples of water the concentrations of chromium and lead are below the detection limit.

Aflorando abundantemente nas drenagens da Serra da Bodoquena, região sudoeste do Estado de Mato Grosso do Sul, os depósitos de tufas calcárias, descritos como a porção superior da Formação Xaraiés, representam o mais notável depósito do tipo no Brasil, devido à variedade de formas. Sendo a maior atração do pólo eco-turístico de Bonito, MS, as tufas calcárias apresentam-se sob formas de barragens, cachoeiras e depósitos de micritos inconsolidados, que por sua vez geram as piscinas naturais e quedas dágua tão procuradas pelos turistas. Mesmo com tamanha importância, tal rocha não havia recebido um estudo aprofundando, que contemplasse sedimentologia, estratigrafia e geomorfologia. Através de criteriosa revisão bibliográfica, trabalhos em campo e análises laboratoriais, pôde-se obter um panorama da Formação Xaraiés na Serra da Bodoquena. Nesta região, observa-se que a formação, assentada diretamente sobre os calcários e dolomitos do Grupo Corumbá, sendo composta por um nível basal de calcretes, de tipo pedogenético e freático, sobreposto por um pacote de tufas micríticas (micrito inconsolidado), com grande quantidade de gastrópodes, distribuídos amplamente e aflorando em todas as planícies da região. Por fim temos os afloramentos de tufas calcárias do tipo fitohermal, compondo barragens e cachoeiras nas drenagens locais. Acredita-se que a deposição dos micritos ocorreu em ambiente lacustre, o que permitiu um depósito amplo e homogêneo, que posteriormente, em clima úmido, serviu de área fonte, juntamente com os carbonatos do Grupo Corumbá, para a geração das tufas fitohermais. A correlação estratigráfica dos depósitos de tufas calcárias estudados apontam para dois períodos de clima semi-árido a árido no Holoceno, que permitiram a formação e a alteração (calcretização) de depósitos, refletido na base da Formação Xaraiés, e o período climático recente, úmido, a formação das tufas fitohermais, no topo da formação. A ocorrência de lentes micríticas no sul do Pantanal pode significar que esta região também esteve exposta às dinâmicas climáticas vistas na Serra da Bodoquena. Estas constatações demonstram a alta variação climática da região, representada por depósitos que são pequenos e frágeis, mas dotados de significados genéticos indubitáveis. / Crop out abundantly in the Bodoquena Ridge drainages, southwest of Mato Grosso do Sul (MS) state, deposits of calcareous tufa were described as the top portion of Xaraiés Formation, representing the most notable deposit of this type in Brazil, due to the variety of forms. As the greatest attractiveness of Bonito, MS, an eco-tourism center, the calcareous tufa were presented in form of dams, waterfalls and deposits of micritic sediments, which generate natural pools and waterfalls so looked by tourists. Even with such importance, this region had not received a deep study, with sedimentology, stratigraphy and geomorphology approach. An accurate bibliographic review was done, and with field work and laboratory analyzes this work could obtain a panorama of the Xaraiés Formation in Bodoquena Ridge. In this region, can be noted that Xaraiés Formation goes directly over the limestone and dolomite of the Corumbá Group, and were composed by a basal layer of pedogenetic/groundwater calcrete, superimposed by a package of micritic sediments (micritic tufa), with a large amount of gastropods, which were widely distributed, cropping out in all plains of the region. Finally, we have the occurrences of calcareous tufa, fitohermal type, drawing dams and waterfalls in the regional drainages. It has believed that the deposition of lacustrine micritic sediments have occurred in an environment which were enabled a broad and homogeneous deposits. Subsequently, in a moister climate these sediments served as a source area, together with the limestone of the Corumbá Group, for the generation of fitohermal tufa. The stratigraphic correlation of the studied calcareous tufa deposits point to two periods of semi-arid/arid climate in Holocene, which allowed the calcretization. Those were reflected on the bottom of the Xaraiés Formation, and a recent wet climatic period, represented by the fitohermal tufa at the top of the formation. The occurrence of micritic lens in the southern Pantanal may mean that this region has also been exposed to the weather dynamics viewed in the Bodoquena Ridge. These findings show the high variation of climate in this region, represented by deposits, which are small and fragile, but gifted with unquestionable genetic meanings.