<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)

The accretionary Mesoproterozoic Grenville Orogeny (ca. 1300 – 980 Ma) involving the Central Metasedimentary Belt is a key building block of the eastern Laurentian margin. A petrographic, mineralogical, geochemical and geochronological study of the migmatite complex in Otter Lake (QC) within the Marble Domain is used to resolve regional metamorphic and magmatic events primarily recorded in the leucosome accessory minerals (i.e. monazite). The relationship between the different stages of monazite and garnet growth and dissolution during the tectonic evolution of the orogenic history for the interpreted metasomatic (injected) and anatectic (in situ) monazite-bearing neosomes from this study supports published thermochronological work in the area and challenges the claim that the Central Metasedimentary Belt was not heated above 500 °C during the Ottawan phase. Instead, the region shows Grenville magmatic and anatectic events were overprinted by high-temperature, fluid-rich Ottawan-phase metamorphism recorded within both injected (monazite-bearing) and in situ (monazite- and garnet-bearing) neosomes.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Titre de l'écran-titre (visionné le 29 février 2024) / La Province de Grenville présente un grand potentiel prospectif pour le groupe des éléments de terres rares (ETR). Dans la région de La Tuque, les minéralisations en ETR se divisent en deux catégories : les minéralisations associées à des intrusions alcalines et les minéralisations associées à des pegmatites granitiques. Les mécanismes de formation et la source des magmas de ces pegmatites enrichies en ETR sont toutefois peu compris. Cette étude porte sur l'indice Blanchette-1, qui consiste en un dyke de pegmatite granitique riche en ETR (> 2,7 wt.%) et encaissé dans des paragneiss migmatitisés du Complexe de Wabash. La minéralisation en ETR se concentre principalement au sein d'une zone métrique riche en allanite (> 20 vol.%). Ce projet vise à déterminer la source du magma et l'âge de mise en place de cette pegmatite pour mieux caractériser cet évènement minéralisateur et sa relation avec l'évolution géodynamique de la Province de Grenville. Les zircons de quatre échantillons ont été datés (U-Pb par LA-ICP-MS) en combinaison avec la détermination de leurs signatures isotopiques en hafnium et de leurs compositions en éléments traces: la Syénite de Toad, l'intrusion alcaline la plus proche du dyke de Blanchette-1 (981,6 ± 5,6 Ma), le dyke de pegmatite de Blanchette-1 (1060,8 ± 7,0 Ma), et deux injections granitiques (1057,9 ± 8,3 et 1075,1 ± 3,8 Ma). Les âges montrent que les minéralisations en ETR associées aux syénites et aux pegmatites sont deux évènements distincts. Les analyses isotopiques d'Hf permettent d'estimer un âge modèle de ~1400 Ma pour les injections granitiques et la pegmatite de Blanchette-1. Cet âge est cohérent avec la fusion partielle des gneiss granitiques de la Suite plutonique de Vermillon. Pourtant, une étude précédente dans le Grenville central attribue la formation de pegmatites riche en ETR à la fusion de roches métasédimentaires. Puisque la fusion de roches métasédimentaires ou ignées peuvent entrainer la formation de pegmatites enrichies en ETR au sein du Grenville central, la nature de la source n'est pas le facteur clef favorisant cet enrichissement. / The Grenville Province has great prospective potential for the rare earth element (REE) group. In the La Tuque area, REE mineralization can be divided into two categories: mineralization associated with alkaline intrusions and mineralization associated with granitic pegmatites. However, the formation mechanisms and the source of the magmas of these REE-enriched pegmatites remain poorly understood. This study focuses on the Blanchette-1 showing, which consists of a REE-rich (> 2.7 wt.%) pegmatite granitic dyke hosted in migmatitic paragneiss of the Wabash Complex. The REE mineralization is mainly concentrated within an allanite-rich metric zone. This project aims to determine the magma source and crystallization age of this pegmatite to better characterize this mineralizing event and its place in the geodynamic evolution of the Grenville Province. Zircons from four samples were dated in combination with the determination of their hafnium isotopic signatures and trace element compositions: the Toad Syenite, the nearest alkaline intrusion to Blanchette-1 (981.6 ± 5,6 Ma), the Blanchette-1 pegmatite dyke (1060.8 ± 7,0 Ma), and two granitic injections (1057.9 ± 8,3 et 1075,1 ± 3.8 Ma). The ages show that REE mineralization associated with alkaline intrusions and pegmatites are two distinct events. The Hf isotope analyses allow us to estimate a model age of ~1400 Ma for the granitic injections and the Blanchette-1 pegmatite. This age is consistent with the partial melting of granitic gneisses of the Vermilion Plutonic Suite. However, a previous study in the central Grenville attributed the formation of REE-rich pegmatites to the melting of metasedimentary rocks. Since the melting of metasedimentary or igneous rocks can lead to the formation of REE-enriched pegmatites in the central Grenville, the nature of the source is not the key factor that favors this enrichment.

Abstract My aim for this paper is to analyse the character Jeeves' obsession with perfect clothing in     P. G. Wodehouse's The Inimitable Jeeves (1923). My method has been to study the historical context of the British aristocracy at the time of the first publication of the book in 1923, as well as the previous four decades during which the author grew up and decisive changes in the British class society took place. This paper studies sources on the significance of clothing in general, and examines its importance at the time in particular. For my analysis I have borrowed elements from new historicism. The norms, traditions and values of the aristocracy lost in importance during this time, and the aristocracy was divided into individuals who were willing to adopt to these changes and others who fought to defy them. My conclusion is that Jeeves considers the strict dress codes to be an important symbol of the old aristocratic values that he has to defend, in order to legitimize his own position, as he is profoundly devoted to his calling of being a first class valet faithful to the old traditions. Wooster, then, acts as Jeeves' opponent on the matter as he embodies the part of the aristocracy willing to embrace the changes instead.

<p> Glamorgan township in southeastern Ontario, is underlain by Precambrian rocks of the Grenville province. Prominent amongst these are migmatite, paragneiss, and granite gneiss, VJhich collectively form a series of rocks (the Glamorgan gneiss aeries). </p> <p> Field work revealed that this series is completely gradational from a geological aspect, and that the geological gradation is complemented by a geochemical gradation. <p> An explanation of these gradational relationships constitutes the main contribution of this study. The conclusions reached are that partial melting of paragneiss produced migmatite and a trondhjemitic melt, which later produced granitic (in the strict sense) derivatives. </p> <p> In developing the main conclusions, a number of subsidiary problems are discussed, chief of which are the possible metavolcanic or metasedimentary o'rigin of the paragneiss and the possible origin of so-called diorite as a differentiate of an alkaline gabbro. Metamorphism was concluded to be of Miyashiro's low pressure intermediate type. </p> <p> By the use of experimentally determined reactions and stability fields a metamorphic grid was devised, which led to the following upper limits of metamorphic conditions: 550 to 650°C and 3 to 6.5 kilobars total pre5sure. These estimates in turn lead to the following limiting geothermal gradients: 25 to 55°C per kilometre. </p> <p> The Glamorgan occurrence was found to share three characteristics with many other Precambrian terrains : 1. migmatisation and emplacement of granite accompanied high grade metamorphism; 2. an early sodium-rich granite was followed by a more potassic one; and 3. the more sodic granite is associated with a small amount of basic igneous rock. These three generalisations were used to formulate a possible model for deep crustal petrogenesis. </p> / Thesis / Doctor of Philosophy (PhD)

On 1 February 1793, the National Convention of Revolutionary France declared war on Great Britain and the Netherlands, expanding the list of France's enemies in the War of the First Coalition. Although British Prime Minister William Pitt the Younger had predicted fifteen years of peace one year earlier, the French declaration of war initiated nearly a quarter century of war between Britain and France with only a brief respite during the Peace of Amiens. Britain entered the war amid both a nadir in British diplomacy and internal political divisions over the direction of British foreign policy. After becoming prime minister in 1783 in the aftermath of the War of American Independence, Pitt pursued financial and naval reform to recover British strength and cautious interventionism to end Britain's diplomatic isolation in Europe. He hoped to create a collective security system based on the principles of the territorial status quo, trade agreements, neutral rights, and resolution of diplomatic disputes through mediation - armed mediation if necessary. While his domestic measures largely met with success, Pitt's foreign policy suffered from a paucity of like-minded allies, contradictions between traditional hostility to France and emergent opposition to Russian expansion, Britain's limited ability to project power on the continent, and the even more limited will of Parliament to support such interventionism. Nevertheless, Pitt's collective security goal continued to shape British strategy in the War of the First Coalition, and the same challenges continued to plague the British war effort. This led to failure in the war and left the British fighting on alone after the Treaty of Campo Formio secured peace between France and its last continental foe, Austria, on 18 October 1797.