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<p>Samples from the Whitefish Falls Area were examined petrographically and chemically to determine the regional grade of metamorphism. Mineralogy from the Lorrain formation (quartzities) and Gowganda Formation (argillites) were apparently incongrous. The resolution of this problem formed the major part of the study.</p> <p>Mineralogically the quartzites contained a kyanitequartz paragenesis with a subordinate kyanite-chloritoidquartz paragenesis. The argillites showed a chlorite-biotite -plagioclase-calcite-quartz paragenesis with only minor epidote present. From textural evidence possible reactions were deduced which were used to set the upper and lower limits for pressure and temperature. These boundaries were 470°C and 3.9 kb., lower limit and 550°C with a variable pressure for the upper limit.</p> Chemically, whole rock analysis was used to determine the parameters for various chemographic diagrams. AFM, ACF and AKF plots for the argillites showed a very restrictive composition which excluded the almandine field and promoted the biotite field. The bulk composition of the argillites was cited as the main reason for the inhibition of high grade index minerals, thus appearing to be lower grade than their quartzite counterparts. AFM and AKF diagrams for the quartzites verified their mineralogy and proved their high grade nature. / Thesis / Bachelor of Science (BSc)

<p> Eight new scapolite analyses are presented. Determinations of refractive index, specific gravity, and lattice parameters are examined in conjunction with data available in five recent analyses. Particular reference is made to the regular variation of per cent Cl₂, CO₂ and SO₃ as a function of mole per cent meionite and the relation of these components to scapolite stability. End member formulae describing the composition of scapolite are developed. </p> <p> These scapolite samples are used in conjunction with synthetic plagioclase standards to obtain forty three electron microprobe analyses of scapolite-plagioclase pairs and twenty seven separate analyses of scapolite. The former analyses indicate that scapolite from amphibolite and granulite facies is generally more calcium-rich than the coexisting plagioclase. </p> <p> A petrographic study indicates that scapolite associated with the above grade of metamorphism is indicative of a volatile rich environment typified by the amphibolite facies by the assemblage sphene-pyroxene-scapolite. </p> / Thesis / Master of Science (MSc)

<p> Pseudotachylites within the Levack Gneisses of the North Range Sudbury Structure were studied, with an emphasison petrography, major oxide chemistry, and paleomagnetism. </p> <p> The pseudotachylites are present as dark greyish green veins and larger scale breccia zones. The matrix is glassy and aphanitic and the fragments, mostly quartz and feldspar are subangular to subrounded. The larger fragments and the wall rock contain kink bands in biotites and planar features in feldspars and quartz. The planar features are defined by rows of parallel inclusions and are diagnostic of shock metamorphism when parallel to specific crystallographic orientations of quartz. The major oxide chemistry shows the pseudotachylites are enriched in total iron, magnesia and lime. This corresponds to other impact-generated pseudotachylite chemistries. Thus, these rocks are not a product of pure wall rock and either the mafics were selectively melted out or added from an external source. </p> <p> Paleomagnetic analysis confirms the age of the pseudotachylite is approximately the same as the North Range of the Sudbury Structure, the least deformed component. Thus whatever the event was it also formed the pseudotachylite. The fact that the pseudotachylite contains shock metamorphic features, supports that the event was likely an impact, as of yet the only known process capable of producing the required pressures, temperatures and strain rates. </p> / Thesis / Bachelor of Science (BSc)

Orientador: Antonio Carlos Artur / Banca: Fabiano Cabañas Navarro / Banca: Tamar Milca Bortolozzo Galembeck / Resumo: As rochas ornamentais Verde Amazonas, Preto Cajugram e Bege Ipanema exploradas no estado do Espírito Santo, respectivamente um charnockito, um hiperstênio monzodiorito e um ortognaisse, foram submetidas a uma bateria de ensaios físico-mecânicos e de resistência ao ataque químico sob ação controlada dos compostos NH4Cl, NaClO, C6H8O7, HCl e KOH presentes na composição de produtos de uso doméstico e de determinadas soluções concentradas dos ácidas HCl, H2SO4 e HNO3 simulando atmosferas agressivas. A avaliação dos efeitos dos agentes químicos foram realizadas à luz das variações da propagação de ondas ultrassônicas, da resistência à flexão 4 pontos e do lustro da superfície polida das rochas testadas, bem como pela caracterização dos produtos de subeflorescências e eflorescências geradas pelas reações com os ácidos. Os resultados dos diferentes testes realizados foram confrontados com as propriedades petrográficas de cada rocha. Os resultados obtidos para os parâmetros físico-mecânicos e de alterabilidade química indicam, com algumas reservas, que as três rochas são detentoras de boas qualidades para utilização como rochas ornamentais e para revestimentos em obras civis. Os estudos revelaram que o comportamento tecnológico e de alterabilidade química dos materiais avaliados é controlado pela inter-relação dos aspectos composicionais, estruturais e texturais das rochas. O charnockito Verde Amazonas, rocha verde escura megaporfirítica gnaissificada com matriz de granulação média a grossa e com elevado grau de microfissuramento transgranulares, apresentou bom desempenho no tocante a resistência mecânica, mas foi o material que mostrou maior sensibilidade aos efeitos da maioria dos agentes químicos com desbotamento, clareamento, amarelamento e ofuscamento das superfícies polidas. O Preto Cajugram com estrutura isotrópica, textura equigranular... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Amazon Green, Cajugram Black and Ipanema Beige dimension stones explored in the state of Espirito Santo, respectively, a charnockite, a hypersthene monzodiorite and a orthogneiss, underwent a serie of physical-mechanical and resistance to chemical attack tests under controlled action of the chemicals NH4Cl, NaClO, C6H8O7, HCl and KOH, present in the composition of household products and certain concentrated solutions of the acids HCl, H2SO4 and HNO3, simulating aggressive atmospheres. The evaluation of the effects of the chemical agents was performed in the light of changes in the propagation of ultrasonic sound waves, the 4-point flexural strength and gloss of the polished surface of the tested rock samples, as well as the characterization of the products of efflorescences and subefflorescences, generated by reactions with the acids. The results of the different tests were compared with the petrographic properties of each rock. The obtained results for the physic-mechanical parameters and for the chemical alterability indicates, with some reservations, that the three rocks shows good quality for use as dimension stones and coatings in civil works. Studies show that the behavior of technology and chemical alterability of the tested materials is controlled by the interrelation of the compositional, structural and textural aspects of the rocks. The charnockite Verde Amazonas, dark green megaporphyritic gneissic rock, with medium to coarse grained matrix and a high degree of transgranular microcracking, showed good performance regarding mechanical strength, but was the most sensitive material to the effects of most chemical agents as fading, bleaching, yellowing and glare from the polished surfaces. The Preto Cajugram, with isotropic structure, medium equigranular texture, and low degree of microcracking, has the highest mechanical strengths. On the other hand, it displays the highest... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:32:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-04-27Bitstream added on 2014-06-13T19:06:31Z : No. of bitstreams: 1 bernardes_es_dr_rcla.pdf: 1067716 bytes, checksum: eefeb5fec6ee0538ca62fc18647588e5 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A Formação Corumbataí (Permiano) foi estudada em suas variações verticais, em duas frentes de lavra nas proximidades de Rio Claro, enfocando as relações entre os componentes mineralógicos e as propriedades cerâmicas. A análise petrográfica das amostras coletadas nessas minas, por meio de microscópio óptico, juntamente com Microscopia Eletrônica de Varredura (MEV) dos minerais do cimento e Difração de Raios-X (DRX) com a fração argila, revelou uma assembléia mineralógica complexa com quartzo e feldspato na dimensão silte, matriz constituída por illita, esmectita-clorita, chamosita, berthierina e argilominerais interestratificados, e hematita, calcita e albita como cimento dessas rochas. Os sedimentos originais, pelíticos e ricos em ferro, foram modificados pelos eventos diagenéticos, durante a interação com soluções conatas alcalinas; processos de substituição e autigênese sucederam a diagênese inicial promovendo a formação de diferentes tipos de cimento e o crescimento dos cristais de illita. Os filossilicatos hidratados e amorfos de sílica precipitados na interface sedimento-água deram origem a esses minerais através de transformações associadas à perda de água interplanar e trocas catiônicas com os fluidos hipersalinos iniciais, mas também há evidências de forte influência de eventos magmáticos que teriam desencadeado novas transformações diagenéticas. A diagênese tardia sob influência de processos superficiais sob ação de águas meteóricas também está registrada em algumas feições, embora mais restrita pela característica impermeável dos litotipos. Os principais horizontes estratigráficos foram descritos em termos de litotipo, textura, conteúdo em argila e minerais do cimento. Análise de Componentes Principais e de Agrupamento reforça a correlação entre as feições texturais (granulometria e maturidade) e as propriedades físicas do material. / The Late Permian Corumbataí Formation was studied in its vertical variability within a couple of mine works close to Rio Claro, focusing relationships between mineralogical components and ceramics properties. The petrographic analysis of the samples collected in these mines, made by optical microscopic, Scanning Eletron Microscopy (SEM) of the cement minerals and X-ray techniques with clay fraction, revealed a complex mineralogical assemblage with quartz and feldspar in silt size grains, within a matrix constituted by illite, smectite-chlorite, chamosite, berthierine and interestratified clay-minerals, with cement of hematite, calcite and albite. The original fine-grained iron-rich sediment was modified by diagenetic events, during the interaction with alcalline conate solutions; mineralogical substitution and authigenesis followed this early diagenesis with the formation of different types of cement. The hidrous phyllosilicates and the amorphous silica precipited in the water-sediment interface played an important role on these transformations, but there are evidences of strong influence of magmatic events wich promoted another diagenetic phase generation. The principal stratigraphic horizons were described in terms of lithology, texture, argillaceous content and cement minerals. Principal Components and Clusters Analysis strains the correlation between textural features (grain size and maturity) and physical properties of the material.

Resumo: A Formação Corumbataí (Permiano) foi estudada em suas variações verticais, em duas frentes de lavra nas proximidades de Rio Claro, enfocando as relações entre os componentes mineralógicos e as propriedades cerâmicas. A análise petrográfica das amostras coletadas nessas minas, por meio de microscópio óptico, juntamente com Microscopia Eletrônica de Varredura (MEV) dos minerais do cimento e Difração de Raios-X (DRX) com a fração argila, revelou uma assembléia mineralógica complexa com quartzo e feldspato na dimensão silte, matriz constituída por illita, esmectita-clorita, chamosita, berthierina e argilominerais interestratificados, e hematita, calcita e albita como cimento dessas rochas. Os sedimentos originais, pelíticos e ricos em ferro, foram modificados pelos eventos diagenéticos, durante a interação com soluções conatas alcalinas; processos de substituição e autigênese sucederam a diagênese inicial promovendo a formação de diferentes tipos de cimento e o crescimento dos cristais de illita. Os filossilicatos hidratados e amorfos de sílica precipitados na interface sedimento-água deram origem a esses minerais através de transformações associadas à perda de água interplanar e trocas catiônicas com os fluidos hipersalinos iniciais, mas também há evidências de forte influência de eventos magmáticos que teriam desencadeado novas transformações diagenéticas. A diagênese tardia sob influência de processos superficiais sob ação de águas meteóricas também está registrada em algumas feições, embora mais restrita pela característica impermeável dos litotipos. Os principais horizontes estratigráficos foram descritos em termos de litotipo, textura, conteúdo em argila e minerais do cimento. Análise de Componentes Principais e de Agrupamento reforça a correlação entre as feições texturais (granulometria e maturidade) e as propriedades físicas do material. / Abstract: The Late Permian Corumbataí Formation was studied in its vertical variability within a couple of mine works close to Rio Claro, focusing relationships between mineralogical components and ceramics properties. The petrographic analysis of the samples collected in these mines, made by optical microscopic, Scanning Eletron Microscopy (SEM) of the cement minerals and X-ray techniques with clay fraction, revealed a complex mineralogical assemblage with quartz and feldspar in silt size grains, within a matrix constituted by illite, smectite-chlorite, chamosite, berthierine and interestratified clay-minerals, with cement of hematite, calcite and albite. The original fine-grained iron-rich sediment was modified by diagenetic events, during the interaction with alcalline conate solutions; mineralogical substitution and authigenesis followed this early diagenesis with the formation of different types of cement. The hidrous phyllosilicates and the amorphous silica precipited in the water-sediment interface played an important role on these transformations, but there are evidences of strong influence of magmatic events wich promoted another diagenetic phase generation. The principal stratigraphic horizons were described in terms of lithology, texture, argillaceous content and cement minerals. Principal Components and Clusters Analysis strains the correlation between textural features (grain size and maturity) and physical properties of the material. / Orientador: Sebastião Gomes de Carvalho / Coorientador: Erasto Boretti de Almeida / Banca: Paulo Miranda de Figueiredo Filho / Banca: José Francisco Marciano Motta / Banca: Marcos Roberto Masson / Banca: Antenor Zanardo / Doutor

This study investigates the performance of concrete sidewalks placed using hot and cold weather concreting practices. The effect that curing methods, types of deicers, and supplementary cementitious material content have on the scaling resistance of concrete is examined in the laboratory and the field. After one winter, petrographic analysis was conducted on the cores from the sidewalk panels. The results from field evaluation indicate that the concrete sidewalks placed using hot weather concreting showed better resistance against scaling than those placed using cold weather concreting. The results also suggest that the effect of curing method depends on the concreting procedure type. The results confirm the maximum limits recommended by ACI 201.2R Guide for Durable Concrete, the mix proportions with fly ash less than 25% and slag less than 50% have shown better scaling resistance. Based on the petrographic analysis, a correlation between the properties of concrete determined through petrography and scaling on a sidewalk could not be determined.

<p> Metagreywackes of the Goldenville Formation, Nova Scotia, possess a well developed spaced cleavage. Petrographic evidence suggests that the dominant mechanism producing this cleavage has been pressure solution, involving the dissolution of quartz from cleavage zones. A large amount of shortening occurs during cleavage development due to this volume loss of quartz. Based on a simple comparison of amounts of mica in cleavage and lithon zones shortenings of 50 - 60% have been found.</p> <p> Cleavage zones are marked by distinct mineralogical variations, notably a high content of white mica, and a low quartz content. Trends for all components have been documented to characterize the cleavage and lithon zones.</p> / Thesis / Bachelor of Science (BSc)

<p> Four measured sections of the Whirlpool Sandstone were prepared from outcrops in the Niagara Gorge and Hamilton areas. Sedimentary structures and constituents present in the lower two-thirds of the unit are consistent with the sandy braided fluvial depositional model. proposed by Salas [1983]. The upper one-third of the unit has been deposited in a near shore, shallow marine environment. All samples have been classified as Quartzarenites, or Sublitharenites after Folk [1974] and the source of the Whirlpool lies to the southeast in primarily pre-existing sediments, with some input from low grade metamorphic and hydrothermally veined terrains. </p> <p> Cathodoluminescent microscopy has proven to be a safe, relatively inexpensive, easy to use method, that offers a great deal of new information. The technique's only drawback is the gradual destruction of thin sections by the electron beam. The CL study demonstrated that pressure solution was not the source of the massive, pore occluding, mesodiagenetic quartz cement. Since very low diagenetic temperatures have been calculated for the Whirlpool in the study area [360C]; the local generation of silica would be impossible. Instead, it has been suggested that silica was carried in by saturated pore fluids that had migrated up-dip from source areas deep within the depositional basin to the southeast. Similarly, pyrite was precipitated as H2S bearing fluids migrated through the unit. These reducing fluids also produced the reduced zone at the top of the Queenston Formation. The H2S was produced during the maturation of hydrocarbons. Calcite cement is more abundant in the upper marine units of the Whirlpool. This suggests that the source of the calcite was local detrital carbonate in the upper marine units. Quartz cementation ceased when the porosity had been reduced sufficiently to inhibit the passage of the migrating pore fluids. Thus, the calcite cement precipitated from static pore fluids. The local detrital carbonate was dissolved by the acidic fluids that carried in the silica. This Ca+2 rich fluid was prevented from mixing with the bulk porewater and calcite precipitation occurred due to an increase in C02 by the decay of organic detritus in the upper marine units. The major proportion of secondary porosity was formed during mesodiagenesis by the dissolution of calcite. The pore fluids became undersaturated with respect to calcite when local intershale water was released into the porewater. The formation of dolomite cement was in response to a decrease in the amount of available iron relative to magnesium due to the precipitation of ferroan calcite. The zonation of the dolomite reflects rapid changes in porewater composition. Four morphologies of illite have been identified: two represent direct precipitation from alkaline, K+ rich solution; one may be detrital in origin, or it could represent illite that has been mechanically infiltrated down into the sand after deposition; and the fourth is a mixed layer assemblage that has been formed by the replacement of earlier clays by illite. The oil and gas found in the Whirlpool Sandstone in the Lake Erie area have probably migrated up-dip from source areas deep within the depositional basin to the southeast. </p> / Thesis / Bachelor of Science (BSc)