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The Lower Devonian carbonate-clastic sequence of southwest Ellesmere Island accumulated in the Franklinian Basin at approximately 15(DEGREES)N latitude. A variety of depositional settings are represented, ranging from tidal flat to basinal environments. These environments can be recognized in Lower Devonian rocks across the Arctic Islands. / Progradation of the carbonate sequence of southwest Ellesmere Island occurred in the Early Devonian, but was periodically interrupted in the Zlichovian/Dalejan by transgressive events. Upward movement in the newly named Inglefield Uplift occurred throughout the Devonian, and shed clastic sediments westward that, in Middle to Late Devonian time, finally overwhelmed the marine carbonates and resulted in fluvial deposition on southern Ellesmere Island. / Certain formations in the Lower Devonian sequence are profusely fossiliferous, in particular the Blue Fiord Formation, which contains an abundant fauna including numerous species of coral and brachiopods. Both of these groups belong to the Old World Biogeographic Realm, and indicate a Zlichovian age for the lower Blue Fiord Formation of southern Ellesmere Island.

The work outlined in this thesis was a part of the program of glacial studies undertaken by the Arctic Research Expedition to Axel Heiberg Island, N. W. T., during the summer of 1960. The expedition was organized for the purpose of investigating the fields of glaciology, geology, meteorology, botany and other closely related subjects as they applied to Axel Heiberg Island. [...]

Elevated toxaphene levels have been reported in the biota of the Arctic. The purpose of this study is to measure total toxaphene levels in food samples commonly consumed by the Canadian Inuit and study the relationship between concentrations of total toxaphene and individual congeners. A total of 127 Inuit food samples were collected for toxaphene analysis. Total toxaphene and the specific toxaphene congeners including Parlar #26, #40/41, #42, #44, #50 and #62 were detected in the food samples. Total toxaphene concentrations ranged from 13 to 2800 ng/g and various congener concentrations ranged from 0 to 610 ng/g. Concentrations of total toxaphene were strongly correlated with congener concentration in marine mammals and weaker in fish. The sum of congeners Parlar #26, #50 and #62 accounted for 0--15% of total toxaphene in fish and 0--66% in marine mammals. Regression models were used to estimate total toxaphene based on individual or combinations of congener concentrations. Dietary intake was estimated to be 1.07 and 0.78 mug/kg body weight per day in Chesterfield Inlet and Igloolik. Our results show that there is no general conversion factor that can be used to estimate total toxaphene concentrations based on congener measurements.

A sea ice model developed by W. D. Hibler (1979) was applied to the Lancaster Sound/Barrow Strait channel in an effort to simulate the observed ice environment. The simulation covered a ten month period, from October 1985 until August 1986. The impact of atmospheric and oceanographic forcing on the development of characteristic ice features that develop seasonally within the channel was examined. The importance of the ice interaction component of the model when simulating a restricted channel ice environment was also examined. The model was able to simulate regional scale processes and conditions within the channel. Small scale localised processes and conditions which control the spatial variability and complexity of the ice regime were not accurately reproduced. Simulation results provided insights into the effect and importance of both the model and geophysical variables examined. The study highlighted concerns that need be addressed in future modelling work in the Lancaster Sound/Barrow Strait channel.

This thesis classifies Inuit place names and analyses their meanings to reveal Harvaqtuurmiut land-use history on the Harvaqtuuq [Kazan River], Nunavut Territory. The author collected previously unrecorded toponyms from the territory of this Caribou Inuit society, the Harvaqtuuq [Kazan River], and corroborated the data of earlier researchers. The Harvaqtuuq landscape was organized from foci of subsistence activities by application of Inuktitut geographical terminology and concepts. These foci moved over time and betray changing land-use patterns. The Harvaqtuuq was a frontier for Inuit, due to the need to depend on caribou, and due to the conflict engendered by overlapping Dene occupation. The presence of anthroponyms, and the paucity of pan-Inuit myths in the landscape allow for the speculative interpretation that the names support current theories of a recent arrival of Inuit to the Harvaqtuuq .

This thesis compares the habitat and community ecology of cylindrical meltholes from the surface of two polar glaciers. These holes (termed cryoconite holes) are formed when wind-blown dust gathers in small depressions in the ice causing vertical melting by absorption of more radiation than the surrounding ice. The communities are complex microbial consortia of heterotrophic bacteria, cyanobacteria, eukaryotic algae, and protists. Samples were taken from cryoconite holes on Canada Glacier, Taylor Valley, Antarctica (77°37'S, 162°55'E) and on White Glacier, Axel Heiberg Island, Nunavut Territory, Canada (79°27'N, 90°40'W). Water from Canada Glacier cryoconite holes contained significantly higher concentrations of nutrients and had higher pH values and conductivities, relative to the White Glacier meltwater. Cryoconite communities on the Canada Glacier were dominated by cyanobacteria, either coccoid or filamentous, while the White Glacier cryoconite holes showed an abundance of either saccoderm desmids or filamentous cyanobacteria. Canada Glacier communities were found to be associated with environmental gradients whereas White Glacier cryoconite ecosystems were not.

Perfluorinated carboxylates (PFCAs), sulfonates (PFSs) and perfluoroalkylsulfonamides (PFOSAs) have been detected in whole blood and serum of non-occupationally exposed humans, yet sources of exposure have not been fully elucidated. The objectives of this study were to estimate dietary exposure to perfluorooctane sulfonate (PFOS), PFCAs (C7--C 11) and fluorotelomer unsaturated carboxylates (FTUCAs) for the general Canadian and Inuit populations prior to the phase-out of perfluorooctyl-sulfonyl production by 3M and voluntary reductions in PFOA emissions under the PFOA stewardship program. PFCs were measured in 65 archived composite food samples prepared for the 1998 Canadian Total Diet Study (TDS) and 68 archived traditional foods from Nunavut using a newly developed methanol extraction combined with a solid phase extraction clean up. Dietary exposure was estimated using food intake data available from studies carried out between 1997 and 1998 in southern Canada and Nunavut. / PFCs were detected in eight composite food samples from the Canadian TDS and in 61 traditional food samples. Elevated concentrations of PFCs were found in caribou liver (6.2+/-5.5 ng/g), ringed seal liver (7.7, 10.2 ng/g), polar bear meat (7.0 ng/g), beluga meat (7.0, 5.8 ng/g), luncheon meats (5.02 ng/g), cookies (2.7 ng/g), processed cheese (2.1 ng/g) and peppers (1.8 ng/g). Low levels of total PFCs (<1.5 ng/g) were measured in 41 traditional foods including: meat (caribou, ptarmigan, snow goose, bearded seal, walrus, black duck), berries, and fish (lake trout, arctic char). PFCs were not detected in beverages, unprocessed meats, breads, cereals and fruits from the TDS composite samples analyzed. / The ranges of estimated daily exposure to PFCs were between 2 and 59 ng-person-1 and 210 to 610 ng-person-1 for average Canadians and Inuit in Nunavut respectively. There were no statistically significant differences in mean PFC exposure levels for different age and gender groups in the general Canadian population. Inuit men in the 41 to 60 year old age group had statistically significantly higher estimated daily exposure to PFCs (p<0.05) than younger men and women from the same age group. This higher exposure was associated with the consumption of beluga muktuk, caribou liver and bearded seal intestine. / Traditional foods contributed a higher percentage to PFC exposure than market foods in all age and gender groups for the Inuit population. In general, caribou meat, arctic char meat and cookies contributed most to dietary exposure for Inuit, with caribou flesh contributing 43 to 75 percent to daily PFC dietary exposure. Dietary exposure for the general Canadian population was associated with the consumption of cakes and cookies, processed cheese, and regular cheese. / Levels of dietary exposure to PFCs estimated in these studies do not pose any significant health risk to either population based on current toxicological information.

A novel approach for screening metagenomic libraries by merging both metagenomic and microarray platforms was developed and optimized. This high-throughput screening strategy termed "metagenomic microarrays" involved the construction of two Arctic soil large-insert libraries and the high density arraying of the clone plasmid DNA (~50 kb) onto glass slides. A standard alkaline lysis technique used for the purification of plasmid DNA was adapted and optimized to function efficiently in a 96-well format, providing an economically viable means of producing sufficient high-quality plasmid DNA for direct printing onto microarrays. The amounts of printed material and probe, required for maximal clone detection, were optimized. To examine catabolic clone detection libraries were first screened by PCR for catabolic genes of interest. Two PCR-positive clones were printed onto microarrays, and detection of these specific clones in the printed libraries was achieved using labeled probes produced from PCR fragments of known sequence. Also, hybridizations were performed using labeled PCR fragments derived from the amplification of a catabolic gene from the total community DNA. The ability of selected probes to specifically target clones of interest was demonstrated. This merger of metagenomics and microarray technologies has shown great promise as a tool for screening the natural microbial community for catabolic potential and could also be used to profile microbial diversity in different environments.

A first approximation of ground ice volume for the area surrounding Eureka, Nunavut, indicates that it comprises 30.8% of the upper 5.9 m of permafrost. Volume depends on the type of ice examined, ranging from 1.8 to 69.0% in different regions of the study area. Excess ice makes up 17.7% of the total volume of frozen materials in the study area. Melt of ground ice in the past has produced thermokarst features which include ground subsidence of up to 3.2 m, formation of tundra ponds, degradation of ice wedges, thaw slumps greater than 50 m across, gullying, and numerous active layer detachment slides. With a doubling of atmospheric carbon dioxide, the rise in mean annual temperatures for the area is projected to be 4.9 to 6.6°C, which would lengthen the thaw season and increase thaw depths by up to 70 cm. The expected geomorphic changes to the landscape are discussed.