This study aimed to contribute to baseline knowledge of permafrost geochemistry within the uppermost 3-4 m of permafrost at 8 sites on the Peel Plateau and east of the Mackenzie Delta, NWT (67-68oN). The following variables were measured: gravimetric water content (GWC), pore water conductivity (PWC), leachate conductivity (LC), dissolved ions by ICP-AES (i.e. Ca, SO4, Mg, Fe, K, Na, Mn, Cl), organic carbon content (calculated by linear regression from organic matter content), as well as inorganic carbon content (obtained from loss on ignition analysis). PWC was positively correlated to GWC and values were generally at least 5 times less than LC values, likely underestimating total dissolved solutes using the former method. LC increased with depth to reach maximum values below the paleo thaw unconformity (>10 mS/cm). Carbon content typically remained low throughout the cores with the exception of samples associated to the shallow-rooted vegetation cover at the ground surface. Results showed that the active layer, relict active layer and the permafrost below the thaw unconformity can be divided into three statistically significant layers. PCA results indicated some spatial patterns with increasing LC values at greater depth, suggesting that layer geochemical profiles reflect varying degrees of soil chemical weathering processes since the early Holocene.

Rocky desertification (RD) is a process of land degradation that often results in extensive soil erosion, bedrock exposure and considerable decrease of land productivity. The spatio-temporal evolution of RD not only reflects regional ecological environmental changes but also directly impacts regional economic and social development. The study area, Hechi, is a typical karst peak cluster depression area in southwest China. Remote sensing, geographic information systems (GIS) and statistical techniques were employed to examine the evolution, including the identification of driving forces, of karst RD in the Northwestern Guangxi. The results indicate that RD became most apparent between 1990 and 2005 when areas of various types of RD increased. Within the karst RD landscape, slight RD was identified as the matrix of the landscape while potential RD had the largest patch sizes. Extremely strong RD, with the simplest shape, was the most influenced by human activities. Overall the landscape evolved from fragmented to agglomerate within the 15-year timeframe. Land condition changes were categorized as five types; desertified, recovered, unchanged, worsened, and alleviated land. The largest turnover within the RD landscape was between slight and moderate RD. With regards to the driving forces all RD had been increasingly influenced by human activities (i. e., the stronger the RD, the stronger the intensity of human disturbances). Dominant impact factors of the RD landscape had shifted from town influence and bare rock land in 1990 to bare rock and grassland in 2005. Moreover, the impacts of stony soil, mountainous proportion and river density on RD increased over time, while that of others decreased. The significant factors included human activities, land use, soil types, environmental geology, and topography. However, only anthropogenic factors (human activities and land use) were reported as leading factors whereas the others acted simply as constraining factors.

Flame retardants (FRs) are widely used in a variety of consumer products, including electronics, textiles, vehicles, furniture foams, and children’s toys. Many of these chemicals are halogenated compounds that are persistent in the environment over long periods of time and are known or suspected endocrine disruptors. As a result, FRs may have a variety of negative health effects on humans and wildlife. Following the discontinuation of commercial polybrominated diphenyl ether (PBDE) mixtures, a variety of alternative FRs have been developed and employed. In comparison with legacy FRs, relatively little is known about the ability of these emerging FRs to bioaccumulate and biomagnify in various systems. The primary objective of my dissertation was to better understand the contamination status of both legacy and emerging FR in the biota of the northwestern Atlantic Specifically my objectives were to (1) identify and quantify legacy and emerging FRs in high trophic level predator species (sharks) of the northwestern Atlantic, (2) determine Tropic Magnification Factors (TMFs) for legacy and emerging FRs within the same food web, and (3) evaluate the maternal transfer of a variety of brominated and chlorinated FRs in viviparous Atlantic sharks.

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The capabilities of a number of remote-sensing techniques for biophysical mapping in the subarctic have been examined at Pen Island in northwestern Ontario. After a two week field reconnaissance, colour infrared aerial photography was studied and a detailed biophysical map of the area was produced. Using this knowledge LANDSAT satellite data of the site were investigated. In a visual analysis of the data, the majority of the units identified in the airphoto interpretation were detected, and these were distinguished primarily by their spectral characteristics. Digital analysis of the satellite data using the Bendix MAD system allowed many of the classes of the earlier studies to be delineated and also permitted the classification to be readily extended beyond the original site. In both LANDSAT analyses specific biophysical units could be mapped from the satellite data but could not be identified without the airphoto interpretation. / Thesis / Master of Science (MSc)

The Heron Lake Stock is a lenticular shaped, pretectonic granitoid complex intruding the Jutten metavolcanics of the Savant Lake Greenstone Belt, Wabigoon Subprovince, Superior Province. Mapping, petrography, and chemical analyses have revealed that the stock is essentially trondhjemitic, with minor quartz diorite, granodiorite and quartz monzonite. The trondhjemites have undergone a high degree of sericitization and saussuritization. The grandiorite unit is characterized by secondary K-feldspar and the quartz monzonites are characterized by perthite formation as a result of K-autometasomation is the late stage potash-rich fluids. Late faulting has imposed a secondary foliation along the stock's southern boundary. K/Rb ratios suggest partial melting of lower crust/ upper mantle material producing a trondhjemitic magma. Chemical variation diagrams suggest a process of magmatic differentiation and fractional crystallization. / Thesis / Bachelor of Science (BSc)

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An investigation of the petrology and chemistry of two groups of mafic-rich intrusions from the Lac des Mille Lacs area was carried out. The Quetico group consists of hornblende-rich ultramafic to mafic rocks; the Shebandowan group consists of serpentinized ultramafic rocks and metagabbro. A spectrographic method was employed to quantitatively determine Al2O3, CaO, Co, Cr, Cu, Mn, Ni, Ti, V and Zr in the rocks. This, and other chemical data, indicate that these two spatially related groups, although mineralogically distinct, have similar chemical features, and have apparently crystallized from compositionally similar magmas under different water vapour pressures. Their similarities to ultramafic rocks from other areas provide some implications regarding ultramafic rock types of orogenic areas. / Thesis / Master of Science (MSc)