Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories
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 northwe...
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ftsimonfu:oai:summit.sfu.ca:17519 2023-05-15T16:40:48+02:00 Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories Haiblen, Anna Macdonald 2017-01-27 http://summit.sfu.ca/item/17519 unknown etd9986 http://summit.sfu.ca/item/17519 Thesis 2017 ftsimonfu 2022-04-07T18:41:15Z 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. Thesis Ice Sheet Northwest Territories Summit - SFU Research Repository (Simon Fraser University) Northwest Territories Lac de Gras ENVELOPE(-110.501,-110.501,64.500,64.500) |
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Open Polar |
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Summit - SFU Research Repository (Simon Fraser University) |
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unknown |
description |
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. |
format |
Thesis |
author |
Haiblen, Anna Macdonald |
spellingShingle |
Haiblen, Anna Macdonald Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
author_facet |
Haiblen, Anna Macdonald |
author_sort |
Haiblen, Anna Macdonald |
title |
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
title_short |
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
title_full |
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
title_fullStr |
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
title_full_unstemmed |
Glacial History and Landform Genesis in the Lac de Gras Area, Northwest Territories |
title_sort |
glacial history and landform genesis in the lac de gras area, northwest territories |
publishDate |
2017 |
url |
http://summit.sfu.ca/item/17519 |
long_lat |
ENVELOPE(-110.501,-110.501,64.500,64.500) |
geographic |
Northwest Territories Lac de Gras |
geographic_facet |
Northwest Territories Lac de Gras |
genre |
Ice Sheet Northwest Territories |
genre_facet |
Ice Sheet Northwest Territories |
op_relation |
etd9986 http://summit.sfu.ca/item/17519 |
_version_ |
1766031223684071424 |