Haiblen, Anna Macdonald - Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories...

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This thesis has been submitted to the Library for purposes of graduation, but needs to be audited for technical details related to publication in order to be approved for inclusion in the Library collection.
Term: 
Spring 2017
Degree: 
M.Sc.
Degree type: 
Thesis
Department: 
Department of Earth Sciences
Faculty: 
Science
Senior supervisor: 
Brent Ward
Thesis title: 
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories
Given Names: 
Anna Macdonald
Surname: 
Haiblen
Abstract: 
The Quaternary geology of the Lac de Gras area was studied by 1:20 000 surficial geology mapping of 770 km2 and investigating the genesis of enigmatic landforms. Three distinct flow directions of the Laurentide Ice Sheet are recorded: flow to the southwest, then west, and finally to the west northwest. Digital mapping with high-resolution orthoimagery and a 30 cm lidar DEM provides insight into the deglacial history. ‘Subglacial meltwater corridors’ are prominent in the area. These are tracts that roughly parallel the final ice-flow direction, where basal till has been eroded, bedrock is exposed, and glaciofluvial sediments have been deposited; enigmatic, glaciofluvial mounds composed of sandy diamicton are common. These mounds have highly variable morphologies and occur in groups. They are typically 50 m wide and rise up to 15 m above the surrounding topography. Subglacial meltwater corridors and enigmatic mounds likely formed when supraglacial lakes drained catastrophically during deglaciation.
Keywords: 
Quaternary Geology; Laurentide Ice Sheet; Lac de Gras; Surficial mapping; Glacial landform genesis; Subglacial meltwater flow
Total pages: 
143