Thesis (Ph.D.) - University of Glasgow, 2007. / Ph.D. thesis submitted to the Department of Geographical & Earth Sciences, University of Glasgow, 2007. Includes bibliographical references. Print version also available.

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For the entire alkali feldspar series, Σt₁ (total Al content in the T₁ sites, a quantitative measure of structural state or Al,Si long-range ordering) can be closely estimated from X_Or (mole fraction of KAlSi₃O₈) and Y_x (one half of the optic axial angle 2V_x) by use of a simple determinative diagram based on the model Σt₁ = (b₀ + b₁X_Or + b₂X_Orsin²V_x + b₃sin²V_x) / (a₀ + a₁X_Or + a₂X_Orsin²V_x + a₃sin²V_x). Three sets of coefficients for this equation are required to account for three cases: (A) where X_Or ≤ 0.6; (B) where X_Or > 0.6 and O.A.P. (optical axial plane) ~ ⊥ (010); and (C) where X_Or > 0.6 and O.A.P. = (010). They are (multiplied by 1000): <table style =”width:100%”> <tr><th>Case</th><th>a₀</th><th>a₁</th><th>a₂</th><th>a₃</th><th>b₀</th><th>b₁</th><th>b₂</th><th>b₃</th></tr> <tr><td>A</td><td>4.08</td><td>-2.35</td><td>0.95</td><td>-1.28</td><td>1.52</td><td>-0.18</td><td>-1.74</td><td>2.88</td></tr> <tr><td>B</td><td>1.69</td><td>1.63</td><td>-2.33</td><td>0.69</td><td>0.11</td><td>2.17</td><td>-2.70</td><td>3.46</td></tr> <tr><td>C</td><td>-1.69</td><td>-1.63</td><td>-0.70</td><td>2.38</td><td>-0.11</td><td>-2.17</td><td>-0.53</td><td>3.57</td></tr> </table> Tested by the data from 109 alkali feldspars in the literature and the author's experiments, this model estimates Σt₁ (given X_Or and V_x) with a standard error of 0.02, which is essentially the same as when Σt₁ is estimated from refined lattice parameters determined by X-ray diffraction methods. The model was developed by assuming that the principal refractive indices for sodium light - symbolized as n_a, n_b, and n_c dependent upon whether the corresponding principal vibration axis was parallel or most nearly parallel to crystallographic axes a, b and c - varied linearly with Σt₁ for the high-sanidine to low-microcline series and for the low albite to high albite (or analbite) series. However, for the high albite to high sanidine solid solution series, as well as the low albite to low microcline series, neither density nor principal refractive indices vary linearly across the entire composition range, but they closely approached linearity between 0.0 ≤ X_Or < 0.6 and 0.6 < X_Or ≤ 1.0. / Ph. D.

Esta tese teve como objetivo desenvolver e caracterizar peças cerâmicas obtidas a partir de pós de alumina nas cores rosa e azul, produzidos por processo experimental. O desenvolvimento deste novo processo de produção gerou a necessidade de proteção realizada por meio de pedido de depósito de patente. Os pós produzidos foram caracterizados quanto à distribuição granulométrica e conformados por prensagem uniaxial em discos com 12 (±0,2)mm de diâmetro e 1,2 (±0,2)mm de espessura e os protocolos de sinterização foram definidos em função da cor e da concentração do aditivo utilizado. O feldspato foi escolhido como aditivo de sinterização para que a mesma ocorresse via fase líquida. Ele foi adicionado nas concentrações de 10, 15 e 20% tanto para os grupos de cor rosa (grupos R10, R15 e R20) quanto para os de cor azul (grupos A10, A15 e A20). Após a sinterização as peças foram analisadas quanto ao módulo de elasticidade, microdureza Vickers, rugosidade de superfície e tenacidade à fratura. O módulo de elasticidade variou de 183,2 a 157 GPa, nos grupos de cor rosa, e nos grupos de cor azul os valores variaram de 101,1 a 176,6 GPa. A rugosidade apresentou valores entre 0, 43 e 0,72 μm para os grupos de cor rosa e 0,39 e 0,6 μm para os grupos de cor azul. A dureza Vickers variou de 418,7 a 623,1 para a cor rosa e de 366,9 a 632 para cor azul. A tenacidade média para os grupos de cor rosa variou de 0,72 a 1,97 MPa.m1/2 e de 0,82 a 1,9 MPa.m1/2 para os grupos de cor azul. O grupo R10 apresentou valores médios de rugosidade significativamente maiores tanto em relação ao grupo R20 quanto ao grupo A10. As demais concentrações não apresentaram diferença significativa em relação às cores. A média dos valores de dureza do grupo A10 foi significativamente maior em relação às demais concentrações na mesma cor, no entanto não houve diferença quando comparado ao grupo R10. Os valores médios do módulo de elasticidade foram significativamente maiores nos grupos de cor rosa em relação aos grupos de cor azul para as mesmas concentrações com exceção do grupo R20 que apresentou valores menores, porém sem significância estatística. A tenacidade à fratura apresentou diferença estatística significativa apenas na comparação entre os grupos R10 e R20. Os valores de tenacidade mais próximos ao relatado pela literatura foram apresentados pelos grupos R20 e A20, porém há diferenças nos métodos de análise da tenacidade entre os estudos. As peças de cor azul com 10% de feldspato apresentaram os resultados mais favoráveis tanto em comparação com as diferentes concentrações na mesma cor quanto entre as diferentes cores. / The aim of this thesis was to develop and characterize ceramic pieces obtained from alumina powders in pink and blue colors produced by experimental procedure. The development of this new production process led to the need for protection of the knowledge generated thus an application for patent was done. The powders produced were characterized for particle size distribution and uniaxial pressed into discs with 12 (± 0.2) mm in diameter and 1.2 (± 0.2) mm thick. The sintering protocols were defined according to the color and concentration of the additive used. For sintering to happen into liquid fase the feldspar was chosen as a sintering additive. It was added at concentrations of 10, 15 and 20% for both pink (R10, R15 e R20) and blue (A10, A15 e A20) groups. After the sintering process an analysis of the elastic modulus, the Vickers hardness, surface roughness and fracture toughness of the samples were performed. The elastic modulus values ranged from 183.2 to 157 GPa in pink groups and 101.1 to 176.6 GPa in blue groups. The roughness mean varied between 0,43 and 0,72 μm in pink groups and between 0.39 and 0.6 μm in blue groups. The Vickers hardness number ranged from 418.7 to 623.1 in pink groups and from 366,9 a 632 in blue groups. The fracture toughness mean to pink groups ranged from 0.72 a 1.97 MPa.m1/2 and from 0.82 a 1.9 MPa.m1/2 to blue groups. The R10 group had significantly higher roughness mean values when compared to the groups R20 and A10. No significant difference was found on the others groups. The hardness average values of the A10 group were significantly higher when compared to other concentrations on the same color, however there was no difference when compared to the R10 group. The average values of the elastic modulus were significantly higher in pink groups when compared to blue groups for the same concentrations except the R20 group that showed lower values, but without statistical significance. The fracture toughness results showed a statistically significant difference when R10 and R20 groups were compared. The toughness values closer to those reported in the literature were presented by R20 and A20 groups, but there are differences in the methods of analysis of toughness between studies. The blue pieces with 10% of feldspar showed the most favorable results compared both between different concentrations of the same color as between different colors at the same concentration.

Esta tese teve como objetivo desenvolver e caracterizar peças cerâmicas obtidas a partir de pós de alumina nas cores rosa e azul, produzidos por processo experimental. O desenvolvimento deste novo processo de produção gerou a necessidade de proteção realizada por meio de pedido de depósito de patente. Os pós produzidos foram caracterizados quanto à distribuição granulométrica e conformados por prensagem uniaxial em discos com 12 (±0,2)mm de diâmetro e 1,2 (±0,2)mm de espessura e os protocolos de sinterização foram definidos em função da cor e da concentração do aditivo utilizado. O feldspato foi escolhido como aditivo de sinterização para que a mesma ocorresse via fase líquida. Ele foi adicionado nas concentrações de 10, 15 e 20% tanto para os grupos de cor rosa (grupos R10, R15 e R20) quanto para os de cor azul (grupos A10, A15 e A20). Após a sinterização as peças foram analisadas quanto ao módulo de elasticidade, microdureza Vickers, rugosidade de superfície e tenacidade à fratura. O módulo de elasticidade variou de 183,2 a 157 GPa, nos grupos de cor rosa, e nos grupos de cor azul os valores variaram de 101,1 a 176,6 GPa. A rugosidade apresentou valores entre 0, 43 e 0,72 μm para os grupos de cor rosa e 0,39 e 0,6 μm para os grupos de cor azul. A dureza Vickers variou de 418,7 a 623,1 para a cor rosa e de 366,9 a 632 para cor azul. A tenacidade média para os grupos de cor rosa variou de 0,72 a 1,97 MPa.m1/2 e de 0,82 a 1,9 MPa.m1/2 para os grupos de cor azul. O grupo R10 apresentou valores médios de rugosidade significativamente maiores tanto em relação ao grupo R20 quanto ao grupo A10. As demais concentrações não apresentaram diferença significativa em relação às cores. A média dos valores de dureza do grupo A10 foi significativamente maior em relação às demais concentrações na mesma cor, no entanto não houve diferença quando comparado ao grupo R10. Os valores médios do módulo de elasticidade foram significativamente maiores nos grupos de cor rosa em relação aos grupos de cor azul para as mesmas concentrações com exceção do grupo R20 que apresentou valores menores, porém sem significância estatística. A tenacidade à fratura apresentou diferença estatística significativa apenas na comparação entre os grupos R10 e R20. Os valores de tenacidade mais próximos ao relatado pela literatura foram apresentados pelos grupos R20 e A20, porém há diferenças nos métodos de análise da tenacidade entre os estudos. As peças de cor azul com 10% de feldspato apresentaram os resultados mais favoráveis tanto em comparação com as diferentes concentrações na mesma cor quanto entre as diferentes cores. / The aim of this thesis was to develop and characterize ceramic pieces obtained from alumina powders in pink and blue colors produced by experimental procedure. The development of this new production process led to the need for protection of the knowledge generated thus an application for patent was done. The powders produced were characterized for particle size distribution and uniaxial pressed into discs with 12 (± 0.2) mm in diameter and 1.2 (± 0.2) mm thick. The sintering protocols were defined according to the color and concentration of the additive used. For sintering to happen into liquid fase the feldspar was chosen as a sintering additive. It was added at concentrations of 10, 15 and 20% for both pink (R10, R15 e R20) and blue (A10, A15 e A20) groups. After the sintering process an analysis of the elastic modulus, the Vickers hardness, surface roughness and fracture toughness of the samples were performed. The elastic modulus values ranged from 183.2 to 157 GPa in pink groups and 101.1 to 176.6 GPa in blue groups. The roughness mean varied between 0,43 and 0,72 μm in pink groups and between 0.39 and 0.6 μm in blue groups. The Vickers hardness number ranged from 418.7 to 623.1 in pink groups and from 366,9 a 632 in blue groups. The fracture toughness mean to pink groups ranged from 0.72 a 1.97 MPa.m1/2 and from 0.82 a 1.9 MPa.m1/2 to blue groups. The R10 group had significantly higher roughness mean values when compared to the groups R20 and A10. No significant difference was found on the others groups. The hardness average values of the A10 group were significantly higher when compared to other concentrations on the same color, however there was no difference when compared to the R10 group. The average values of the elastic modulus were significantly higher in pink groups when compared to blue groups for the same concentrations except the R20 group that showed lower values, but without statistical significance. The fracture toughness results showed a statistically significant difference when R10 and R20 groups were compared. The toughness values closer to those reported in the literature were presented by R20 and A20 groups, but there are differences in the methods of analysis of toughness between studies. The blue pieces with 10% of feldspar showed the most favorable results compared both between different concentrations of the same color as between different colors at the same concentration.

Esta tese teve como objetivo desenvolver e caracterizar peças cerâmicas obtidas a partir de pós de alumina nas cores rosa e azul, produzidos por processo experimental. O desenvolvimento deste novo processo de produção gerou a necessidade de proteção realizada por meio de pedido de depósito de patente. Os pós produzidos foram caracterizados quanto à distribuição granulométrica e conformados por prensagem uniaxial em discos com 12 (±0,2)mm de diâmetro e 1,2 (±0,2)mm de espessura e os protocolos de sinterização foram definidos em função da cor e da concentração do aditivo utilizado. O feldspato foi escolhido como aditivo de sinterização para que a mesma ocorresse via fase líquida. Ele foi adicionado nas concentrações de 10, 15 e 20% tanto para os grupos de cor rosa (grupos R10, R15 e R20) quanto para os de cor azul (grupos A10, A15 e A20). Após a sinterização as peças foram analisadas quanto ao módulo de elasticidade, microdureza Vickers, rugosidade de superfície e tenacidade à fratura. O módulo de elasticidade variou de 183,2 a 157 GPa, nos grupos de cor rosa, e nos grupos de cor azul os valores variaram de 101,1 a 176,6 GPa. A rugosidade apresentou valores entre 0, 43 e 0,72 μm para os grupos de cor rosa e 0,39 e 0,6 μm para os grupos de cor azul. A dureza Vickers variou de 418,7 a 623,1 para a cor rosa e de 366,9 a 632 para cor azul. A tenacidade média para os grupos de cor rosa variou de 0,72 a 1,97 MPa.m1/2 e de 0,82 a 1,9 MPa.m1/2 para os grupos de cor azul. O grupo R10 apresentou valores médios de rugosidade significativamente maiores tanto em relação ao grupo R20 quanto ao grupo A10. As demais concentrações não apresentaram diferença significativa em relação às cores. A média dos valores de dureza do grupo A10 foi significativamente maior em relação às demais concentrações na mesma cor, no entanto não houve diferença quando comparado ao grupo R10. Os valores médios do módulo de elasticidade foram significativamente maiores nos grupos de cor rosa em relação aos grupos de cor azul para as mesmas concentrações com exceção do grupo R20 que apresentou valores menores, porém sem significância estatística. A tenacidade à fratura apresentou diferença estatística significativa apenas na comparação entre os grupos R10 e R20. Os valores de tenacidade mais próximos ao relatado pela literatura foram apresentados pelos grupos R20 e A20, porém há diferenças nos métodos de análise da tenacidade entre os estudos. As peças de cor azul com 10% de feldspato apresentaram os resultados mais favoráveis tanto em comparação com as diferentes concentrações na mesma cor quanto entre as diferentes cores. / The aim of this thesis was to develop and characterize ceramic pieces obtained from alumina powders in pink and blue colors produced by experimental procedure. The development of this new production process led to the need for protection of the knowledge generated thus an application for patent was done. The powders produced were characterized for particle size distribution and uniaxial pressed into discs with 12 (± 0.2) mm in diameter and 1.2 (± 0.2) mm thick. The sintering protocols were defined according to the color and concentration of the additive used. For sintering to happen into liquid fase the feldspar was chosen as a sintering additive. It was added at concentrations of 10, 15 and 20% for both pink (R10, R15 e R20) and blue (A10, A15 e A20) groups. After the sintering process an analysis of the elastic modulus, the Vickers hardness, surface roughness and fracture toughness of the samples were performed. The elastic modulus values ranged from 183.2 to 157 GPa in pink groups and 101.1 to 176.6 GPa in blue groups. The roughness mean varied between 0,43 and 0,72 μm in pink groups and between 0.39 and 0.6 μm in blue groups. The Vickers hardness number ranged from 418.7 to 623.1 in pink groups and from 366,9 a 632 in blue groups. The fracture toughness mean to pink groups ranged from 0.72 a 1.97 MPa.m1/2 and from 0.82 a 1.9 MPa.m1/2 to blue groups. The R10 group had significantly higher roughness mean values when compared to the groups R20 and A10. No significant difference was found on the others groups. The hardness average values of the A10 group were significantly higher when compared to other concentrations on the same color, however there was no difference when compared to the R10 group. The average values of the elastic modulus were significantly higher in pink groups when compared to blue groups for the same concentrations except the R20 group that showed lower values, but without statistical significance. The fracture toughness results showed a statistically significant difference when R10 and R20 groups were compared. The toughness values closer to those reported in the literature were presented by R20 and A20 groups, but there are differences in the methods of analysis of toughness between studies. The blue pieces with 10% of feldspar showed the most favorable results compared both between different concentrations of the same color as between different colors at the same concentration.

Brick clay deposits, in the area north of Cape Town, were formed as a result of three independent geological processes. The intrusion of the syn- to post tectonic granitoids into micaceous (indicated by the absence of halloysite; Orris, 1998), feldspathic Malmesbury sandstone beds, approximately 500 Ma ago, created a hydrothermal vein structure, which enriched the shale with feldspar/kaolinite and quartz, restricted to the vein network. This was followed by extensive in-situ weathering of these hydrothermally altered rocks resulting in residual kaolin deposits, the effects of which were more pronounced along the more permeable shear zones. The final process, formation of ball clay deposits, initiated by the erosion of the primary kaolinite deposits, which have been transported in water, together with organic material, to shallow depressions where clays were deposited. Brick clay is exclusively used for the manufacturing of clay brick products and must derive its value from the sales revenue generated from these products. Evidence from the two exploration programs described, suggests that the clay deposits explored has no value as individual deposits as the clay from both deposits lack specific ceramic properties to successfully manufacture clay bricks. It is however clear that if the clay from the two deposits is mixed in specific proportions; body mixes with ceramic properties suitable for light coloured clay face brick manufacturing is possible. The value of the beneficiated product, clay bricks, may then be used to determine the value of both clay deposits. Discounted Cash Flow Models (DCFM) and Net Present Values (NPV) were used to determine the fundamental value of the clay deposits explored, as it determines the time value of money (Kernot, 1999). These models clearly showed the dependency of the value of clay brick deposits on variables such as raw material quality, capital expenditure and clay brick yields. Geological, chemical and ceramic knowledge of individual brick clay deposits and the management of the raw materials extracted from these deposits is key to the profitable manufacturing of clay bricks. Risks, at the quarrying level, related to these aspects need to be managed to ensure the profitable and efficient functioning of the entire brick production process. / Dissertation (MSc (Earth Science Practice and Management))--University of Pretoria, 2007. / Geology / MSc / unrestricted

<p> Three conformable units of fine-grained quartz-feldspar porphyry were mapped in the Berry River Formation, Warclub Group, Northwestern Ontario. The largest unit (Unit 1) is compared geochemically and petrographically to quartz-feldspar porphyry intrusions and tuffs in the area with the aim of determining the method of emplacement of the porphyry unit (Unit 1), and consequently the other two units.</p> / Thesis / Bachelor of Science (BSc)

A brief description of a low grade regionally metamorphosed region in the Madoc area in Southern Ontario is given. Plagioclase compositions from metamorphosed basic rocks of this region were studied with the intention of finding co-existing plagioclases in the region of peristerite solvus. X-ray diffraction was found useful in determining the presence of two co-existing plagioclase feldspars. Two peaks occurred in the region of the 131 and 131 peaks if this was the case. Compositional determinations for albitic feldspars were found inaccurate as the angular separation (Δ29) between the 131 and 131 peaks was apparently reduced indicating plagioclase composition less than An0. For anorthite rich feldspars the angular separation between 131 and 131 gave relatively accurate compositions. The electron microprobe was used·to determine the plagioclase compositions of samples from the Madoc area. Results compared well for anorthite rich feldspars determined by both X-ray diffraction and. electron microprobe techniques. Only one rock was found to contain two plgioclases related to a peristerite solvus. A zoned nature appears to exist. Albite and oligoclase coexist, the oligoclase grading into andesine. Also, albitic plagioclase is associated with epidote inclusions; a diffusion relationship probably existing between the two. With increased metamorphic grade, epidote disappears and the anorthite content of plagioclase increases. / Thesis / Bachelor of Science (BSc)

Tensile fracturing and expansion possible relating to tectonic activity and faulting have in part controlled the emplacement of alkali feldspar rich rocks in Heronian sediments at Lake La Cloche, south of Massey, Ontario. The rocks include 1. albitite - composed almost entirely of low albite (Dr2-Abg95-An3) and minor dispersed hematite. 2. perthosite - containing separate phases of microcline and albite with mutual replacement textures. The seem to be physically separate but show similarities in spatial, textural and chemical aspects. They have been emplaced chiefly within a fracture zone at the top of the Mississagi quartzite. Perthosite is intimately related with 3. tuffisite - a somewhat mineralogically and modally variable rock emplaced as matrix within an irregular breccia pipe north of the fracture zone. The overall mineral assemblage is microcline + albite + perthite + epidote + chlorite + sericite+ hematite. Texturally it is reminiscent of crystal cuffs. Phenoclasts of the alkali feldspars (rounded, abraded) float in a hydrous silicate background. These phenoclasts are replicas of those in perthosite. Fragments of perthosite (phenoclast poor) were also found in tuffisite in one local. Tuffisite ranges from alkali feldspar poor to feldspar rich varieties. It is typically a silica poor alumina, lime, iron arid potash-rich rock. Tuffisite was probably emplaced as a fluidized mass. Some similarities to known fluidized bodies are present. These include rounding, attrition and fretting of the host rock, extensive penetration and exploitation of joints, bedding and planar weaknesses, internal sculpturing of the host rock, evidence for both mechanical and chemical emplacement. It may also be classed as a hydrothermalite. This refers to crytallization under submagmatic conditions, the pneumatolytic to hydrothermal range, hydroxyl minerals commonly developing. In this respect and others it is comparable with weilbergites, alkali feldspar-chlorite rocks within the Lahn region of Germany. Certain nearby breccia pipes and red feldspar rocks have been associated with alkalic igneous activity. (An alkaline rock province has been postulated along the North Shore of Lake Huron) Specif1cally soda rich fenite breccias are present at Nemag and Kusk lakes, 12 miles southwest of Sudbury. The red feldspar rock albitite is common along the North Shore. It is often adjacent or spatially related to diabase and has been interpreted accordingly in terms of genesis. Some albitites are not related spatially to di abase bodies and their emplacement has been controlled fracture systems. Their origin is more hazy. The author suggests two alternative interpretations dependent on whether alkali feldspars in tuffisite are considered to be primarily on- allochthonous. Alternative One - (Alkali feldspars primary): Perthosite and albitite are special fractionates, concentrated initially within the proto-tuffisite magma aj an al kali-volatile rich phase. These juvenile liquids were emplaced within a fracture zone at the top of the Mississagi. At about the same time tuffisite was emplaced within an irregular breccia pipe. The author throws open for argument the possibility that tuffisite is an upper crustal altered fenite breccia with associated red feldspar rock emplacement la fracture zones. Alternative Two-(Alkali feldspars allochthonous);Tuffisite is a hybrid rock type akin to a weilbergites (also interpreted as hybrid). Crystallization of red feldspar rocks within the pneumatolytic stage involved contamination in part by mafic material (possibly diabase). The resultant mechanical, chemical mixture was emplaced as a fluidized mass-tuffisite. More work needs to be done in determining which alternative is valid and what the exact relationships and sources of albitite, perthosite and tuffisite are. / Thesis / Bachelor of Science (BSc)