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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Palynological studies of post-glacial deposits with different water relations and muskeg environments.

Chen, Margaret Wei-yi 05 1900 (has links)
<p> This investigation is intended to explore and trace the trend in the development of muskeg (organic terrain), of which water is an essential factor. The work proceeded as follows: field work and laboratory pollen macerations, identification of pollen and spores and pollen counting; and finally the analysis of the results obtained. </p> <p> The results do not favour the establishment of a strong relationship between water in muskeg and vegetation in situ. However, this needs further test. On the other hand, there are relationships found between pollen species, and also interesting natural grouping was observed to exist in the bogs studied, due to unknown factors. </p> / Thesis / Master of Science (MSc)
2

Geochronology and K/Rb Ratios of an Anorthosite Near Parry Sound, Ontario

Fryer, Brian Jackson 04 1900 (has links)
<p> The primary purpose of this study was to date the last metamorphism of a metanorthosite near Parry Sound, Ontario, by the Rb-Sr method on the mineral phases: biotite, hornblende and plagioclase. Due to problems with the mass spectrometer, the prepared samples could not be run. </p> <p> K/Rb ratios on biotites and plagioclase give a calculated K/Rb whole rock ratio for the mafic rich bands of about 230, consistent with the main trend of igneous rocks. The plagioclase K/Rb ratio, however, is much higher, and the anorthosite body as a whole may have a much higher K/Rb ratio, consistent with oceanic tholeiites and achondritic meteorites and indicating a possible lower crustal or mantle origin. </p> / Thesis / Bachelor of Science (BSc)
3

Coronite Amphibolites from the Whitestone Area, Parry Sound, Ontario

Mummery, Robert 12 1900 (has links)
<p> Coronite amphibolites located near the western contact of the. Whitestone Lake Anorthosite were studied in the field and laboratory in order to determine their origin. The corona textures consisted of garnet cores surrounded by complete rims of plagioclase, which in turn were occasionally surrounded by partial or complete rims of garnet or pyroxene. The development of coronas is also accompanied by an increase in pyroxene in the rock, and the development of cryptic zoning in both garnets and plagioclases. Whole rock X-Ray Fluorescence and mineral electron-probe analyses were determined for suites of samples collected. The analyses suggest that corona development occurred isochemically as the result of a contact metamorphism induced by anorthosite emplacement and mineral reactions have been proposed. Microprobe analyses of the garnets led to the establishment of models for the production of garnets in mafic assemblages and models for the observed cryptic zoning in the garnets~ It was concluded that the coronites represent the transition from almandine amphibolite facies to clinopyroxene subfacies of granulite metamorphism of garnetiferous amphibolites. This transition results from the thermal metamorphism induced by the emplacement of the Whitestone lake anorthosite. </p> / Thesis / Doctor of Philosophy (PhD)
4

The Nature of Anorthosite - Country Rock Interaction During Granulite Facies Metamorphism: An Example From the Whitestone Anorthosite

Thompson, Danny Lee 06 1900 (has links)
<p> The Whitestone Anorthosite is a relatively small anorthosite body (160 km2 ) located within the Parry Sound structural domain, Western Grenville Province, Ontario. Both the anorthosite and the surrounding gneisses have been affected by a granulite grade metamorphic event which predates the Grenville Orogeny. The outer margin of the anorthosite body has been strongly deformed and recrystallized and is characterized by a pervasive metasomatic alteration consisting of garnet, scapolite, hornblende, apatite, biotite, sphene, carbonate and opaques. The country rock gneisses exhibit a corresponding discontinuous, and highly variable, reaction aureole. Pre-existing mafic gneisses are particularily affected, being characterized by the breakdown of orthopyroxene and hornblende, an increase in garnet, clinopyroxene, apatite and opaques, and enrichment in Fe, Ti and P. </p> <p> The metasomatic alteration exhibited by the Whitestone Anorthosite is thought to be due to a combination of two processes: 1. Mechanical mixing at the anorthosite/country rock contact during intense deformation (tectonic assimilation), and 2. Widespread absorption of mobile components (predominantly volatiles) from both included material and the surrounding gneisses. </p> <p>The formation of the country rock reaction aureole is a continuous solid state metamorphic process, whereby mobile components are preferentially leached from the rock leaving a mafic restite. Post-deformation cooling of the anorthosite, combined with an increased volatile flux, has imparted a polygonal mosaic texture suggestive of contact metamorphism. The typical garnet-clinopyroxene assemblage exhibited by mafic gneisses within the reaction aureole, is a consequence of the increased Fe/Mg ratio which stabilizes this assemblage at lower P, T conditions. The temperature of final equilibration and recrystallization is estimated to be 750 ± 70 °C, based on clinopyroxene-garnet geotherrnometry. </p> <p> A similar metasomatic interaction, to the one outlined in this thesis, is to be expected at all anorthosite/country rock contacts which have been overprinted by granulite metamorphism. </p> / Thesis / Master of Science (MSc)

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