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...
| Main Author: | |
|---|---|
| Format: | Dataset |
| Language: | English |
| Published: |
Federated Research Data Repository / dépôt fédéré de données de recherche
2023
|
| Subjects: | |
| Online Access: | https://dx.doi.org/10.25314/bd59a8ee-6c74-4dc9-b541-3b9e08dc4490 https://www.frdr-dfdr.ca/repo/dataset/31e17ee6-4405-4ccd-a9ee-910ff6435750 |
| Summary: | 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. This ... |
|---|