麻豆传媒

This study uses Geographic Information Systems (GIS) as a tool to assess the geological processes associated with igneous rocks and salt structures within the Strand Fiord area, Axel Heiberg Island, Nunavut. This area was the subject of petroleum exploration with disappointing results, and this study attempted to provide practical tools to provide an explanation for that failure. Remote access of the area has limited field mapping to reconnaissance maps at 1:250,000 scale, compiled by the Geological Survey of Canada. A GIS, the first for Nunavut in areas north of the 75th parallel, allows more geological detail to be added, particularly in the case of igneous rocks. To produce the GIS, digital elevation models, aeromagnetic data, gravity, and lithological data were integrated with geological and topographic maps. As an example of how petrological data can be integrated into such a GIS, lithological data for the Strand Fiord Formation (Index Ridge on the Kanguk Peninsula) and a large sill exposed at the head of Expedition Fiord (Wolf Intrusion) were compiled.

Queries of the database prove that the characterizations and classifications are true for a certain structure within the GIS by providing information on the shape and morphology of the structures, nature of geological contacts, attitude, and extent of faults, and relative percentage of igneous material "rafted" in the evaporite domes.

Analysis of aeromagnetic data integrated with geology and DEM layers helps better define the distribution of igneous rocks, and reveals a north to northwest trending high that coincides with the trends of salt diapirs and some important regional faults. Magnetic data help ascertain whether diapirs are shallow or deep bodies, and allow to speculate the presence of salt under a region where salt is covered by the Muller Ice Cap. A gravity low in the eastern portion of the study area is interpreted to represent a region of intense folding and faulting rooted by a d茅collement and cored by low density salt structures, topographically expressed as the Princess Margaret Range.

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Pages: 106
Supervisor: Marcos Zentilli