No description available.

<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> In the past decade, sites of hydrothermal activity along the Juan de Fuca Ridge have gained a growing amount of attention. Increased sampling has provided the materials for more detailed studies, including those collected from Axial Seamount, a large shield volcano on the central portion of the ridge. Axial Seamount is host to at least three active vent sites, one of which, along the northwest caldera wall, consists of recently active eruptive-fissures and nearby chimney-like spires. A sampled spire from this location and samples from other vent areas are described using reflected and transmitted light techniques. They have been found to consist of the sulphide phases sphalerite, wurtzite, pyrite, marcasite, chalcopyrite, isocubanite, and galena. Jordanite and tetrahedrite-tennanite are also known to precipitate at these vent sites, but were not observed here. The most dominant non-sulphide minerals are amorphous silica and barite. Native sulfur, Fe and Mn oxides and a variety of sulfosalts may also be present. The complex textures in these samples reflect precipitation and growth from higher temperature fluids that are mixing with local ambient seawater. Fluid inclusions in sphalerite have revealed salinities in the 5.6 to 7.0 weight % NaCl range, with homogenization temperatures ranging from 214.8°C to 269.4°C. Temperatures of homogenization require pressure-corrections between approximately 9.0°C and 13.0°C, to set-up a range of trapping temperatures that lie between 211.8°C and 279.4°C. Fluid inclusions are also found in wurtzite, barite, and amorphous silica however, these would yield no data. Middle Valley is a sedimented rift valley that lies at the extreme north end of the Juan de Fuca Ridge. A number of hydrothermal sulphide mounds that lie atop the sediment pile have been sampled. The mineralogy is similar to that at Axial Seamount; however, the dominant sulphide phase at Middle Valley is pyrrhotite. Textural differences between the two sites are significant, a result of the traversing of hydrothermal fluids through a thick package of hemepelagic sediment at Middle Valley. Samples from Middle Valley are found to contain no measurable fluid inclusions in the sections available for study. Mineralogical and fluid inclusion studies are important methods that can be used to help solve the complex growth history of sulfides that are and have been accumulating at mid-ocean ridge vent sites.</p> / Thesis / Bachelor of Science (BSc)

No description available.

<p> Populations of three tubicolous polychaetes, Clymenella torquata, Spiophanes wisleyi and Sabellaria vulgaris located in the intertidal zone of the south shore of Cobequid Bay, Nova Scotia were studied for their effects on the surrounding sediment. Grain size measurements were made of the tubes and the surrounding sediment. T-tests were made on the resultant differences between the Inman sorting and mean statistics of the two sand populat ions . The percentages of heavy and light minerals were also measured with the use of a binocular microscope. The differences in sorting and mean grain size between the tubes and substrate may affect stability and porosity of the sediment and effect sediment structures easily identifiable in the geologic record. </p> <p> Clyrnenella torquata inhabits a low energy intertidal sandy envir onment and increases the porosity of the sediment by its feeding habits. Stabilization of the sediment may be effected by high population densities of Clymenella (densities around 420/m^2). Tubes were built with preferential grain sizes. Spiophanes wisleyi exists in phenomenally high population densities in low-energy areas. The large numbers of tubes (up to 98,000/m^2) bind the sediment; tubes are made of virtually the same grain sizes as the substrate; no bioturbation occurs during the construction of the tubes. The latter two factors make preservation potential very low in the geologic record. Sabellaria vulgaris in the study area is of little sedimentological importance. Population densities are too low to affect the surrounding substrate. This species exists in a high energy zone a characteristic of fauna which build reefs. Reef formation by sabellariids may have been important in the geologic past and is locally important today in the North Sea (Schafer, 1972) and Florida (Gram, 1968). </p> / Thesis / Bachelor of Science (BSc)

The technique of Raman spectroscopy was applied in order to identify and characterize the number of minerals in the mineralogical collection at the Department of Earth Sciences. The collection was broadened with five rare carbonates borrowed from the collection of the Swedish Museum of Natural History in Stockholm. In total, 66 specimens were examined.The characteristics of interest included possible presence and nature of defects and impurities, degree of crystallinity, residual stresses, possible treatment by natural heat sources (e.g. radionuclides) or chemicals (e.g. polishing agents), and fluorescence.Raman spectroscopy was chosen as examination method because of its distinctive advantage over traditional techniques – a non-destructive probing of pristine materials and minimum or no preparation. Besides, Raman spectroscopy performs very well in collecting the needed characteristics, in terms of its sensitivity, as well ability to probe miniature grains in a matrix with a high spatial resolution.A portable system was used to identify the presence of impurities and the fingerprint of the host rock in the majority of the examined carbonates. The rare carbonate burbankite showed distinct fluorescence bands, which likely can be explained by its complicated chemical composition.The Raman system was used for gemmological purposes and helped to identify the purity of the gems. Diamond and two rubies showed to be free from impurities, but red corundum showed a broad peak, which may represent traces of natural heat treatment, which in turn could be caused by regional metamorphism or even by a radiation source. Furthermore, the correlation between the signal intensity of the fluorites’ bands and the chemical composition of the minerals were studied. The experiment showed that blue fluorite fully misses the peak T2g while purple and grey fluorites showed a well-developed and easily recognizable peak at this location. Thus, it was discovered that the presence and intensity of this peak is directly dependent on the fluorite’s colour, i.e. on the host species, which are incorporated in the crystal structure, such as metals, rare earth elements (REE) or even organic substances. Moreover, residual tensile stress was identified in colourless quartz. The tensile stress was estimated to be in the interval between 0.23 and 1.0 GPa.The Raman system was used to identify different end-members of the garnet family. Raman spectroscopy showed to have high analytical power and helped to estimate the ratio between the end-members in eight garnet samples. In one case, fluorescence was linked to the presence of REEs in the structure of almandine. One sample of calcite showed to be incorrectly placed in the collection. This work will now form a solid foundation for the mineral characteristics handbook. / Ramanspektroskopitekniken applicerades för att identifiera och karakterisera antalet mineraler i den mineralogiska samlingen vid Institutionen för geovetenskaper. Samlingen breddades med fem sällsynta karbonater som lånades från Naturhistoriska riksmuseets samling i Stockholm. Sammanlagt analyserades 66 prover. Egenskaperna av intresse inkluderade eventuell förekomst av och karaktären hos defekter och föroreningar, graden av kristallinitet, restspänningar, eventuella spår av naturlig värmebehandling (till exempel radionuklider) eller kemisk behandling (till exempel polermedel), och fluorescens. Ramanspektroskopi valdes som undersökningsmetod på grund av dess tydliga fördel över traditionella metoder – en icke-förstörande undersökning av rena material och minimal eller ingen förberedelse. Därutöver fungerar Ramanspektroskopi väldigt bra för undersökning av de efterfrågade egenskaperna, vad gäller dess känslighet och kapacitet vid sondering av miniatyrkorn i matriser med hög spatial upplösning. Ett portabelt system användes för att identifiera föroreningar och fingeravtryck av den omslutande bergarten i de flesta undersökta karbonatprov. Den sällsynta karbonaten burbankit visade på distinkta fluorescensband, som sannolikt kan tillskrivas dess komplicerade kemiska sammansättning. Ramansystemet användes i gemmologiskt syfte och kunde identifiera ädelstenarnas renhet. Diamant och två rubiner visade sig sakna föroreningar, men den röda korunden visade en bred topp, som kan indikera på spår av naturlig värmebehandling, som i sin tur kan ha orsakats av regional metamorfos eller till och med en strålningskälla. Därutöver studerades sambandet mellan signalstyrkan hos fluoriters band och mineralers kemiska sammansättning. Experimentet visade att blå fluorit fullständigt saknar toppen från T2g, medan de lila och grå fluoriterna hade välutvecklade och lättigenkännliga toppar vid denna position. Således upptäcktes att denna topps närvaro och intensitet är direkt beroende av fluroritens färg, det vill säga av elementen som är inkorporerade i kristallstrukturen, så som metaller, sällsynta jordartsmetaller eller till och med organiska substanser. Därutöver identifierades restdragspänning i den färglösa kvartsen. Spänningen uppskattades ligga i intervallet 0.23 – 1.0 GPa. Ramansystemet användes för att identifiera olika ändelement i granatfamiljen. Ramanspektroskopin hade hög analytisk förmåga och hjälpte till att estimera förhållandet mellan ändelementen i åtta granatprover. I ett fall kunde fluorescens bindas till förekomsten av sällsynta jordartsmetaller i almandinets struktur. Ett kalcitprov visade sig vara felaktigt placerat i samlingen. Detta arbete kommer nu utgöra en god grund för den mineralogiska samlingens handbok.

The objective of this thesis is to determine the mineralogy and petrography of 13 'opuka' stone samples taken out from different construction phases of the Church of the Beheading of St. John the Baptist in Dolní Chabry. The analysis of a mineralogical composition and structural properties of the extracted samples alongside with a comparison of their physical characteristics provided a basis for estimation of the samples' origin within the construction phase. Methodology used for the samples analysis has been inspired by the methods described in project NAKI (no. DF13P01OVV008 ) also known as "Materiálový rozbor přírodního kamene - opuky - exaktními laboratorními metodami jako nástroj ke stanovení zdrojové oblasti". These methods includes besides macro and microscopic analysis also X-ray powder diffraction and high pressure mercury porosimetry which together provided a complete set of data about the samples. For the purpose of obtaining the general characteristic of the rock and the initial estimate of the content of mineral phases within it the optical microscopy was used. The results made it possible to classify the samples into four groups depending on content of a silica matrix. This in turn allowed to link some of the samples conclusively with some of the older construction phases of the site....

Le littoral méditerranéen oriental du Maroc compris entre l’oued Kiss et le Cap des Trois Fourches s’étire sur près de 120 km. Ce littoral, objet de notre étude, est caractérisé par des unités morphologiques variées : embouchure, baies, lagune, plages, flèches sableuses, tombolo, falaises (vives et mortes). C’est une zone particulièrement intéressante pour l’étude et la compréhension de l’influence des processus naturels et anthropiques sur la dynamique sédimentaire. L’augmentation des activités industrielles et l’urbanisation croissante ont conduit ces dernières années à la construction de nombreux ouvrages le long de la côte, conduisant à des modifications dans la distribution des sédiments et à une dégradation de l’environnement naturel de certaines plages. L’étude sédimentologique couplée à l’analyse des photos aériennes de plusieurs missions a permis de caractériser les différents environnements de ce littoral, de reconstituer la dynamique des différents environnements sédimentaires et de souligner les facteurs, les processus hydrologiques et hydrographiques qui contrôlent ce littoral méditerranéen. Les analyses minéralogiques, en particulier l’étude des minéraux lourds, nous ont fourni des indications sur l’origine des sédiments, la nature du bassin versant fournisseur, également ont permis de mettre évidence deux secteurs morphosédimentaires de part et d’autre de l’embouchure de la Moulouya. Á l’Est, on trouve un secteur en démaigrissement et un secteur en accrétion est situé dans la partie Ouest de l’embouchure de la Moulouya. L'évolution morphodynamique de chacun de ces deux secteurs résulte des interactions entre les facteurs naturels et l’impact des aménagements réalisés sur cette portion de littoral / The Eastern Mediterranean coastline of Morocco ranging between Kiss and the Cap of the Three Fourches is stretched along nearly 120 km. This littoral, the object of our study, is characterized by varied morphological units: mouth, bays, lagoon, beaches, sand, tombolo, cliffs (formed and dead). It is a particularly interesting zone for the study and the comprehension of the influence of the natural and anthropic processes and sedimentary dynamics. During the last few years the increase in the industrial activities and the increasing urbanization led to the construction of many works along the coast, leading to modifications in the distribution of the sediments and to a degradation of the natural environment of certain beaches. The sedimentological study coupled with the analysis of aerial photographs (of several missions) made it possible to characterize the various environments of this littoral, to reconstitute the dynamics of the various sedimentary environments and to underline the factors, the hydrological and hydrographic processes which control this Mediterranean coastline. The mineralogical analysis, the study of heavy minerals in particular, provided indications on the origin of the sediments, the nature of the catchment supplier area and made it possible to put two morphosedimentary sectors obvious on both sides of the mouth of Moulouya. The morphodynamic evolution of each one of these two sectors results from the interactions between the natural factors and the impact from the installations carried out on this portion from littoral

Na região leste do RS, porção sul da Bacia do Paraná, ocorre uma unidade do Jurássico Superior denominada de Arenito Pedreira. Para definir as relações estratigráficas e caracterizar esta unidade foram avaliados dois furos de sondagem para pesquisa de carvão, situados na região de Osório. Foram coletadas amostras representativas para análise petrográfica e contagem modal dos minerais constituintes para definição da proveniência dos sedimentos. Esta unidade está depositada entre à Formação Botucatu por desconformidade sobreposta e a Formação Rio do Rastro, com a qual tem contato erosivo. O Arenito Pedreira é composto por uma sucessão de ciclos granodecrescentes constituídos por arcóseos líticos e conglomerados arcoseanos clasto-suportados e polimíticos com grânulos e seixos subangulosos de varias litologias, que sucedem para pacotes de arenitos médios a grossos com estratificação cruzada tangencial e de baixo ângulo, finalizando em arcóseos com marcas de ondas e pelitos laminados no topo. Os litoclastos analisados representam rochas metamórficas de alto e baixo grau, granitoides, rochas sedimentares e vulcânicas básicas. As feições diagenéticas observadas caracterizam condições de eodiagenese e mesodiagenese, indicando ukm ambiente de clima continental seco. Os litoclastos descritos representam fontes associadas a um arco magmático dissecado e mostram características petrográficas semelhantes aquelas encontradas em rochas do Terreno Tijucas e do Batólito Pelotas, do Cinturão Dom Feliciano no RS. Estes dados sugerem uma área fonte próxima a área de deposição. A porção norte da estrutura soerguida do Arco de Rio Grande de direção NW-SE, representa a área fonte dos sedimentos que constituíram o Arenito Pedreira. / In the eastern part of the State of Rio Grande do Sul, in the southern portion of the Paraná Basin, there is a Upper Jurassic unit informally called Pedreira Arenite. In define the stratigraphic relations and to characterize this unit, a description of the two drilling holes associated to coal research work situated in the Osório region. It was collected representative samples to petrographic analysis and the modal count of the constituent minerals was carried out to define the provenance and origin of the sediments. This unit is deposited under Botucatu Formation by to unconformity and over Rio do Rastro Formation, with which it has erosive contact. The Pedreira Arenite is composed of a succession of granodecrescent cycles consisting of lithic arkoses and conglomerate sandstones, clast-supported and polymitic with subangular granules and pebbles of various lithologies, which succeed for medium to thick sandstone packages with tangential and low angle cross-stratification. This package ending in marks of waves arkoses and laminated mudstones at the top. The analyzed lithoclasts are represented by high and low metamorphic rocks, granitoids, sedimentary and volcanic rocks. The diagenetic features found characterize conditions of eodiagenesis and mesodiagenesis, where the environment present features of continental dry climate environment. The provenance studies highlight sources associated with dissected magmatic arc and shows petrographic features similiar to the rocks founded in Tijucas Terrane and Pelotas Batholith, of the Dom Feliciano Belt in the RS State. This data refers to a source area very close to the deposition area. The north portion of the positive structure of NW-SE direction called Rio Grande Arch,represent the source area of the sediments that generated the Pedreira Arenite.

Several deposits in the Mt Isa - Cloncurry region have been studied, including those held by Australian Resources near Selwyn (Plume, Slate Ridge, Mobs Lease and Straight Eight),in particular, with respect to cobalt and gold mineralisation. Cobalt is associated with pyrite, pyrrhotite and arsenic sulfosalts. Other cobalt deposits in the Eastern Fold Belt of the Mt Isa Block were studied; these include the Queen Sally, Lorena and the Great Australia mine. Varying styles of Co-bearing mineralisation were encountered. In the Queen Sally mine a curious vanadium - substituted heterogenite has been found. This is only the world's second reported occurrence of this mineral of the halotrichite group. At the Great Australia, primary Co mineralisation has been shown to be confined to one generation of cobaltian pyrite. Several generations of pyrite are noted for this and other deposits. / Master of Science (Hons)