William Rimmer is an enigmatic figure in the history of American art. Works created by him are the single exception to an otherwise undistinguished body of mid-nineteenth century sculpture. Yet, Rimmer was virtually ignored by the art public of his generation. In his own lifetime the considerable skill and talent Rimmer evinced as a sculptor and draftsman were overshadowed by the novelty of his medical practice and teaching career. Rimmer's only true fame was to come not as an artist, but from the popular success of his "art anatomy" lecture courses in Boston and New York. Acknowledgement of the excellence of his teaching method and drawing skill, however, must have been insufficient praise to a man seeking artistic celebrity. The closed eye of the American art public could only have increased the existing feelings of frustration in Rimmer and made more bitter the fate he believed had been dealt him. Ironically, his fatalistic view of life became both the wellspring and circumscription of his artistic expression. William Rimmer's importance in the American art scene of the mid-nineteenth century is lost in the maze of contradiction that was his life.

A thesis submitted in fulfilment of the requirements for the degree of PhD in Geology< University of the Witwatersrand. / Numerous small base-metal deposits occur in the acidic rocks of the Bushveld Complex, and modern exploration programs are currently re-examining this metallotect in an attempt to refine the current working hypothesis for mineralisation in these granites. The hypothesis proposed for the origin of mineralisation is multifaceted, encompassing both spatial and temporal relationships between at least three episodes of ore formation. The first episode of mineralisation (typified by the Zaaiplaats tin deposit) occurred at relatively high temperatures (>600'C to 4000' C), and resulted in the formation of orthomagmatic cassiterite, scheelite and an early generation of fluorite. At lower temperatures (200°C<T<400°C), where processes were essentially fluid dominated, a mesothermal Cu-Pb-Zn-As-Ag-Au assemblage was deposited (exemplified by the Spoedwel, Boschhoek and Albert copper and silver deposits). A third episode of mineralisation resulted in the formation of an Fe-U-F assemblage and is recognised at several, but not necessanly all, of the deposits examined (for example, the Albert silver deposit). The extended nature of this three-stage paragenetic sequence is considered to reflect widespread mixing between an early fluid derived by H20-saturation of the granitic magma and an external meteoric/connate fluid, circulation of which was stimulated by the long-lived high heat-productive capacity of the Bushveld granites, as well as exhumation of the metallotect; The early high-temperature Sn/W assemblage was precipitated while magmatic fluids dominated the system. With time, the pluton cooled and was subject to regional uplift. Fractures developed, acting as conduits for external fluids of meteoric and/or connate origin. The late magmatic fluids, enriched in incompatible metals (and volatiles), interacted with the latter fluid, resulting in the localised precipitation of a secondary, lower-temperature mineral assemblage (Cu-Pb-Zn) in the zone of fluid mixing. As the external fluid component became progressively more dominant, the paragenesis changed, forming the :final Fe-U-F assemblage. The formation of these three different, temporally separate assemblages is adequately explained in terms of a fluid mixing model, wherein the concentration ofmetaIs and localisation of ore deposits are controlled by lithology and structure. / Andrew Chakane 2018

A thesis submitted in fulfilment of the requirements for the degree of PhD in Geology University of the Witwatersrand / Numerous small base-metal deposits occur in the acidic rocks of the Bushveld Complex, and modern exploration programs are currently re-examining this metallotect in an attempt to refine the current working hypothesis for mineralisation in these granites. The hypothesis proposed for the origin of mineralisation is multifaceted, encompassing both spatial and temporal relationships between at least three episodes of ore formation. The first episode of mineralisation (typified by the Zaaiplaats tin deposit) occurred at relatively high temperatures (>600'C to 4000' C), and resulted in the formation of orthomagmatic cassiterite, scheelite and an early generation of fluorite. At lower temperatures (200°C<T<400°C), where processes were essentially fluid dominated, a mesothermal Cu-Pb-Zn-As-Ag-Au assemblage was deposited (exemplified by the Spoedwel, Boschhoek and Albert copper and silver deposits). A third episode of mineralisation resulted in the formation of an Fe-U-F assemblage and is recognised at several, but not necessanly all, of the deposits examined (for example, the Albert silver deposit). The extended nature of this three-stage paragenetic sequence is considered to reflect widespread mixing between an early fluid derived by H20-saturation of the granitic magma and an external meteoric/connate fluid, circulation of which was stimulated by the long-lived high heat-productive capacity of the Bushveld granites, as well as exhumation of the metallotect; The early high-temperature Sn/W assemblage was precipitated while magmatic fluids dominated the system. With time, the pluton cooled and was subject to regional uplift. Fractures developed, acting as conduits for external fluids of meteoric and/or connate origin. The late magmatic fluids, enriched in incompatible metals (and volatiles), interacted with the latter fluid, resulting in the localised precipitation of a secondary, lower-temperature mineral assemblage (Cu-Pb-Zn) in the zone of fluid mixing. As the external fluid component became progressively more dominant, the paragenesis changed, forming the :final Fe-U-F assemblage. The formation of these three different, temporally separate assemblages is adequately explained in terms of a fluid mixing model, wherein the concentration ofmetaIs and localisation of ore deposits are controlled by lithology and structure. / Andrew Chakane 2018

A utilização da lama residual de marmoraria em cerâmica vermelha foi colocada em prática visando à diminuição do impacto ambiental, causado tanto pelo descarte da lama como também pela quantidade de argila extraída no setor cerâmico. Foram coletadas amostras em 12 marmorarias localizadas na Grande São Paulo. No entanto, apenas as amostras de quatro foram selecionadas para serem incorporadas, levando em consideração suas características distintas. O argilito foi a matéria-prima escolhida para confecção da massa padrão de cerâmica vermelha, devido à sua grande utilização no setor. Tanto as amostras a serem incorporadas, quanto o argilito, foram caracterizados por meio de análise granulométrica, análise química por fluorescência de raios X e análise mineralógica por difração de raios X; além de análises segundo à norma NBR 10004 nas lamas. Após a caracterização das matérias-primas, foi aplicado às misturas o ensaio de plasticidade; em seguida, confeccionados corpos-de-prova com diversos teores de lama incorporada, os quais foram queimados e submetidos a ensaios tecnológicos, como resistência mecânica, absorção de água, porosidade, massa específica aparente e retração, dilatação do material seco e microscopia eletrônica de varredura. Os resultados demonstraram a viabilidade de aproveitamento destas lamas, apontando vantagens de sua utilização, porém levando em consideração algumas condições adotadas. / In order to decrease environmental impact, caused by mud discarding and clay extraction in the ceramic industry, it was used residual mud from marble and granite companies for structural ceramic. Samples were collected in twelve different marble companies located at the metropolitan region of São Paulo. However, only four samples were selected, based on its different characteristics. Claystone was the raw material chosen to prepare the structural ceramic, considering its high use in this segment. Samples and claystone were both analysed by the following procedures: granulometric analysis, x-rays fluorescent chemical analysis and x-rays diffraction mineralogical analysis, besides, tests in the samples were conducted following NBR 10004 standards. Once raw materials were characterized, the plasticity test was conducted. Test specimen were molded with different levels of mud, then burned and submitted to technological tests, such as: mechanical resistance, water absorption, porosity, specific gravity and retraction, material dilation before burning process and scanning electron microscopy. The final results have shown the viability of using this kind of mud, and pointed some advantages on its usage, but taking in consideration some previous conditions to be adopted.

A utilização da lama residual de marmoraria em cerâmica vermelha foi colocada em prática visando à diminuição do impacto ambiental, causado tanto pelo descarte da lama como também pela quantidade de argila extraída no setor cerâmico. Foram coletadas amostras em 12 marmorarias localizadas na Grande São Paulo. No entanto, apenas as amostras de quatro foram selecionadas para serem incorporadas, levando em consideração suas características distintas. O argilito foi a matéria-prima escolhida para confecção da massa padrão de cerâmica vermelha, devido à sua grande utilização no setor. Tanto as amostras a serem incorporadas, quanto o argilito, foram caracterizados por meio de análise granulométrica, análise química por fluorescência de raios X e análise mineralógica por difração de raios X; além de análises segundo à norma NBR 10004 nas lamas. Após a caracterização das matérias-primas, foi aplicado às misturas o ensaio de plasticidade; em seguida, confeccionados corpos-de-prova com diversos teores de lama incorporada, os quais foram queimados e submetidos a ensaios tecnológicos, como resistência mecânica, absorção de água, porosidade, massa específica aparente e retração, dilatação do material seco e microscopia eletrônica de varredura. Os resultados demonstraram a viabilidade de aproveitamento destas lamas, apontando vantagens de sua utilização, porém levando em consideração algumas condições adotadas. / In order to decrease environmental impact, caused by mud discarding and clay extraction in the ceramic industry, it was used residual mud from marble and granite companies for structural ceramic. Samples were collected in twelve different marble companies located at the metropolitan region of São Paulo. However, only four samples were selected, based on its different characteristics. Claystone was the raw material chosen to prepare the structural ceramic, considering its high use in this segment. Samples and claystone were both analysed by the following procedures: granulometric analysis, x-rays fluorescent chemical analysis and x-rays diffraction mineralogical analysis, besides, tests in the samples were conducted following NBR 10004 standards. Once raw materials were characterized, the plasticity test was conducted. Test specimen were molded with different levels of mud, then burned and submitted to technological tests, such as: mechanical resistance, water absorption, porosity, specific gravity and retraction, material dilation before burning process and scanning electron microscopy. The final results have shown the viability of using this kind of mud, and pointed some advantages on its usage, but taking in consideration some previous conditions to be adopted.

>Magister Scientiae - MSc / The late− to post−collisional Cape Granite Suite (CGS) located in the southwest of South Africa is comprised of S−, I−, and A−type granites, mafic intrusives, and volcanic flows. The CGS is interpreted to have formed during the closing of the Adamastor Ocean during the Late−Proterozoic to Early−Cambrian. Recently, the S−type granites have received much attention concerning their petrogenesis and sources. However, the I− and A−type granites remain poorly understood and little studied. Therefore, with new geochemical and isotopic data the petrogenesis, sources, and tectonic settings of I− (Vredenburg Batholith) and A−type (Cape Columbine) granites of the CGS form the focus for this study. The major and trace element data presented in this thesis show that the granites from the Vredenburg Batholith are weakly peraluminous to metaluminous, ferroan, and alkali−calcic. Associated with the granites are metaluminous, magnesian, and calc−alkalic igneous enclaves. Formerly, the granites have been interpreted to have formed by fractionation. However, with new geochemical analyses and reassessment of such models, it can be shown that such processes are incompatible with accounting for the chemical variation displayed by the granites and their enclaves. Moreover, the I−type granites and enclaves exhibit positive linear trends between whole−rock major and trace elements vs. maficity (Fe + Mg), which can be explained by co−entrainment of peritectic and accessory phases. The lithogeochemical characteristics of the enclaves and host granite reflect melting of a heterogeneous source. Moreover, the granite and enclave's εNd(t) values reflect melting of Paleoproterozoic-aged crustal sources. Finally, with tectonomagmatic discrimination diagrams, it can be shown that the tectonic setting of the granites indicates a transition from a collisional to extensional regime which corroborates the inferences of previous studies. The Cape Columbine Granites lithogeochemical characteristics are ferroan, calc−alkalic and weakly peraluminous. They show typical A−type granite characteristics in having high silica content, high Na + K values, REE enrichment as compared to S− and I−type granites and strong negative Eu anomalies. For this thesis, it can be shown that anatexis of quartzofeldspathic protolith in an extensional regime produced the chemical variation of the Cape Columbine Granite. Moreover, their isotope ratios are typically radiogenic, indicative of a crustal origin. With this new geochemical data evidence is provided against and in support of previous inferences made about the petrogenesis of the I− and A−type granites of the CGS. This also betters our understanding of the magmatic processes involved in the construction of the CGS over time.

Portable X-ray fluorescence (pXRF) provides a new alternative to destructive methods of raw material characterization, such as X-ray fluorescence (XRF), neutron activation analysis (NAA), and traditional thin section petrography, although its effectiveness on coarse-grained materials, such as granite, has been questioned. This project addressed this question by determining the effectiveness of pXRF in characterizing granites from Belize and in sourcing granite ground stone tools from Maya sites in Belize. Geochemical fingerprints were defined for three potential source areas (granite plutons in the Maya Mountains of Belize) using outcrop samples. Samples were analyzed using pXRF, XRF, electron microprobe (EMPA), and thin section analyses. PXRF data from archaeological collections of granite ground stone tools from sites in Belize were then compared to the pluton geochemical signatures. There were two principle results of this research. First, analyses indicated that pXRF can accurately characterize the geochemistry of granites from Belize on a suite of elements. Second, this research demonstrated that the Maya of Belize exploited multiple granite outcrops and participated in different kinds of exchange networks to acquire granite, sometimes acquiring stone from the nearest outcrops and sometimes not. While Mountain Pine Ridge was the dominant source outcrop that was exploited, Cockscomb Basin and Hummingbird Ridge granites were also quarried or scavenged. Sometimes the closest source was used, as is the case at Alabama, who exploited the locally available Cockscomb Basin granite. Through this study it appears that the nearest pluton was not always used. Instead Mountain Pine Ridge granite tools were imported from a greater distance, implying that there were additional factors, such as economic partners and changing political powers, which lead to Mountain Pine Ridge granite being the most pervasive in most archaeological collections within Belize.

Les métaux rares, comme le niobium (Nb), le tantale (Ta), le tungstène (W) et l'étain (Sn), sont définis comme des «ressources stratégiques» ou des «matériaux critiques». Dans cette étude, nous prenons les gisements de Nb de Huangshan et de Ta de Songshugang dans le complexe de Lingshan, province de Jiangxi, en Chine du Sud, comme exemples. Les roches de ce gisement sont classées en deux catégories en fonction de la présence de micas riches en Nb et de la quantité de columbite-tantalites: granites à grain moyen avec des micas riches en Nb et sans columbite-tantalites, et granites à grain fin et pegmatites riches en columbite-tantalites. Ces columbite-tantalites sont riches en Nb et pauvres en Mn, les classant comme columbite. Ces columbites ont des zonations complexes liées à des processus répétitifs. Notre travail indique plutôt que la formation de tels minéraux est liée à des processus de mélanges multiples avec au moins deux types de magmas. Les granites à grain moyen dans la suite Huangshan sont différents des autres granites du complexe de Lingshan par la composition de leurs micas: Li-annite (granite MA) et "protolithionite" (granite MP). Ils sont caractérisés par des teneurs Nb élevées (moyenne de 144 ppm en MP et 158 ppm en MA) et des rapports Nb/Ta très élevés (moyenne 15,3 en MP et 31,2 en MA). Le niobium est principalement hébergé dans les micas, avec une teneur moyenne en Nb de 1347 ppm dans les Li annites, et 884 ppm dans le «protolithionite», concentrations encore jamais mesurées dans les micas d’origine magmatique. Avec un contenu estimé à ~80 kt Nb, les granites de Huangshan représentent un nouveau style potentiel de ressource de Nb. Le granite à albite de Songshugang est localisé dans l'ouest du complexe de Lingshan et est enrichi en Ta. Le granite de Songshugang n’affleure pas et est se trouve sous des couches de granites à feldspath K-topaze, de greisens et de pegmatite. Tous les granites et pegmatites sont fortement peralumineux. Les minéraux de columbite-tantalites, de zircons et de cassitérites sont constants pour chaque type de roches et présentent les mêmes textures bi-phasées. Les caractéristiques pétrographiques indiquent que le stade précoce de columbite et de zircon ont été formés dans un environnement strictement magmatique. Le stade postérieur de ces minéraux a été influencé par des circulations fluides à la transition magmatique-hydrothermale. Les micas montrent également une texture en deux étapes, avec une grande quantité de d’inclusions de columbite-tantalites. L'enrichissement en Rb dans les bordures (Znw-II) est le résultat d’un fractionnement magmatique, comme démontré par la diminution de la teneur en Nb (16,3-108 ppm comparé avec 109-313 ppm pour le coeur). Cependant, les teneurs faibles et invariables du Ta, W et Sn démontrent que le magma résiduel n'a eu aucune influence sur les processus post-magmatiques postérieurs, contrairement aux minéraux de columbite-tantalites. Enfin, les datations U-Pb in-situ sur zircons et columbite-tantalites démontrent que les granites de Huangshan et de Songshugang se sont mis en place vers 130 Ma durant l’épisode tardi-Yanshanien (Crétacé), au même moment que l’ensemble des roches magmatiques formant le complexe de Lingshan. Ce résultat indique que cette période géologique est d’intérêt pour la formation de ressources en Nb-Ta, définissant une nouvelle période géologique prospective pour ces ressources / Rare metals, including niobium (Nb), tantalum (Ta), tungsten (W) and tin (Sn), are defined as “strategic resources” or “critical materials”. For this work, we studied the Huangshan Nb deposit and Songshugang Ta deposit, in the Lingshan complex, Jiangxi Province, South China, as examples. The rocks from Huangshan granite are classified in two categories based on the occurrence of Nb-rich mica and the amount of columbite-tantalites minerals: medium-grained granites with Nb-rich mica and devoided of columbite-tantalites and fine-grained granites and pegmatites rich in columbite-tantalite minerals. Columbite-tantalite minerals are classified as columbite-(Fe), and characterized by complex zonings with various “go and back” processes, indicating that their formation is linked to multi-mixing processes of two different magma sources. The medium-grained granites in the Huangshan suite differed from the other granites of the Lingshan complex by their mica compositions: lithian annite (MA granite) and “protolithionite” (MP granite). They are characterized by elevated Nb contents (average 144 ppm in MP and 158 ppm in MA) and very high Nb/Ta ratios (average 15.3 in MP and 31.2 in MA). Niobium is mainly hosted in the micas, with an average Nb content of 1,347 ppm in the lithian annite, and 884 ppm in the “protolithionite”. Such contents are the highest ever reported in magmatic-related micas. With an estimated content of ~80 kt Nb, the Huangshan granites represent a new style of potential Nb resource. The Songshugang albite granite is found in the west of Lingshan complex and is specifically enriched in Ta. The major Songshugang albite granite is buried and covered by layers of K-feldspar granite, greisen and pegmatite. All the granites are strongly peraluminous. The compositions of columbite-tantalite minerals, the zircons and cassiterites are constant and display a similar two-stage texture. Petrographic features indicate that the early-stage columbite and zircon were formed in magmatic environment, whereas the later-stage of rare-element minerals were influenced by fluid fluxes at the magmatic-hydrothermal transitional stage. Micas also show a two-stage texture. The Rb-enrichment in the margin of the zinnwaldite is the result of magmatic fractionation, as also demonstrated by the decrease of Nb contents (16.3-108 ppm compare with core of 109-313 ppm). The invariable low contents of Ta, W and Sn demonstrate that the residual melt has no influence on later post-magmatic stages, contrary to the columbite minerals. Finally, in-situ U-Pb dating of zircon and columbite-tantalite by SIMS and LA-ICP-MS indicates that both Huangshan and Songshugang granites were emplaced at ca. 130 Ma during Later Yanshanian (or Cretaceous) and contemporary with the formation of the Lingshan complex. This result indicates that the Later Yanshanian is a prospective geological period for Nb-Ta deposits, and this result enlarges the time frame of rare-metal mineralization.

Rapakivi and alkali feldspar phenocrysts from the Deer Isle Granite Complex were investigated using in situ trace element and Pb isotope geochemistry to see if magma mixing or isothermal decompression was responsible for their formation. Pb isotope and trace element profiles, along with CL imagery of quartz phenocrysts, indicate compositional changes in the magma chamber occurred during rapakivi and alkali feldspar growth. Repeated episodes of magma mixing/replenishment by relatively isotopically primitive and LREE enriched magmas (along with hybridized variations with the host magma) created localized disequilibration. Alkali feldspar phenocrysts proximal to these zones of thermal perturbation were first resorbed and then mantled by plagioclase. Entrainment back into this zone of mixing caused multiple mantles of plagioclase to form on some phenocrysts. For grains more distal to these zones of mixing, complete disequilibration of the grain did not occur and continued growth resulted in Ba-rich alkali feldspar mantles over Ba-poor alkali feldspar cores. As crystallization of the chamber continued along solidification fronts, batches of cooler crystal-rich magmas settled en masse to the floor. Disaggregation of these batches during settling, and subsequent accumulation on the chambers floor, brought grains with disparate crystallization histories together. Filter pressing of the cumulate pile flushed highly evolved fluids out from interstitial pores. Small amounts of evolved liquid, trapped interstitial to the cumulate, formed LREE depleted albitic rims on some grains. The crystallization, transportation and juxtaposition of rapakivi, mantled alkali feldspar and plagioclase phenocrysts suggests that a relatively large and active magma chamber, periodically recharged by batches of melt, must have existed.

The Granite Wash is comprised of diachronous, Cambrian to Devonian sandstone deposits, which include the Devonian Contact Rapids and Keg River sandstones of which this study will focus. Prolific oil production from the Granite Wash has fueled exploration since the 1950s and as a result substantial core and wireline data is available. Mapping of the Precambrian subcrop suggests that palaeo-highs, known as inselbergs, strongly influenced sedimentation transport, volume, rate, and ultimately preservation after marine transgression. Several distinct surfaces identified from wireline data and cores indicate an overall marine transgression throughout Keg River time. The facies observed represent continental, shallow marine and sabkha environments and a climatic shift from arid to semi-arid to arid. This detailed sedimentological and stratigraphic study provided the depositional framework that allowed for palaeogeographic maps to be constructed.