Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada
193 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982. The glacial history of Bylot Island concerns large ice sheets centred to the south and west (foreign glaciers), glaciers fed from highland areas on the island (native glaciers), and interaction between them. In this study, the...
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ftunivillidea:oai:www.ideals.illinois.edu:2142/71122 2023-05-15T15:35:08+02:00 Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada Klassen, Rodney Alan 1982 http://hdl.handle.net/2142/71122 unknown http://hdl.handle.net/2142/71122 (UMI)AAI8209595 Geology text 1982 ftunivillidea 2016-03-19T23:45:08Z 193 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982. The glacial history of Bylot Island concerns large ice sheets centred to the south and west (foreign glaciers), glaciers fed from highland areas on the island (native glaciers), and interaction between them. In this study, the determination of ice provenance and extent is based on lithology of erratic clasts, and their distributions. Relative age of glacial events and stratigraphic correlations are based on amino acid ratios of shells (ratio of D-alloisoleucine to L-isoleucine of naturally hydrolyzed amino acids (Free). At least three separate foreign glaciations are recognized. The oldest glaciation occurred prior to a period of interglacial climatic conditions (warmer than present) and is least known. During a foreign glaciation, named informally Eclipse, foreign ice attained elevations of (TURN)600 m a.s.l. along the northern coast and > 800 m a.s.l. along the southern coast. The maximum extent of this ice is marked by major moraines, named Lancaster Moraine and Pond Moraine. Ice movement followed two main paths; (1) northward via Admiralty Inlet and then eastward via Lancaster Sound, and (2) northward across Baffin Island through Milne Inlet and then eastward via Pond Inlet. In Lancaster Sound ice surface gradients were low, and grounded ice extended to the head of Baffin Bay. Glacier reconstruction indicates that basal shear stresses within channels were low (25-60 kPa), implying wet-based ice, and against the island were high ((TURN)150 kPa) implying cold-based ice. Native glaciers were not well nourished during Eclipse glaciation, and some were no more extensive than now. A major native advance is thought to have occurred as Eclipse foreign ice left the channels, and native ice held against the topographic divide moved outwards. Eclipse glaciation occurred > 39 000 B.P., and Eclipse sediments are bounded stratigraphically by shells with amino acid ratios of 0.30 (lower boundary) and 0.24 (upper boundary). During post-Eclipse glaciation(s), foreign ice was much less extensive, and was not likely grounded in channels around the Island. Grounded ice occupied all of Milne Inlet until 9 500 B.P. A lower stratigraphic boundary for this (these) glaciation(s) is defined by shells with amino acid ratios of 0.15. Native glaciers on Bylot Island have recently (< 120 B.P.) advanced, although most are now retreating. At this recent maximum, they are considered to have been as far advanced as at any time since Eclipse glaciation. Text Baffin Bay Baffin Bay Baffin Island Baffin Bylot Island glacier* Lancaster Sound Pond Inlet University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship) Admiralty Inlet ENVELOPE(-86.000,-86.000,72.501,72.501) Baffin Bay Baffin Island Bylot Island Canada Lancaster Sound ENVELOPE(-83.999,-83.999,74.218,74.218) Milne Inlet ENVELOPE(-80.499,-80.499,72.335,72.335) Pond Inlet ENVELOPE(-77.960,-77.960,72.699,72.699) |
institution |
Open Polar |
collection |
University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship) |
op_collection_id |
ftunivillidea |
language |
unknown |
topic |
Geology |
spellingShingle |
Geology Klassen, Rodney Alan Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
topic_facet |
Geology |
description |
193 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982. The glacial history of Bylot Island concerns large ice sheets centred to the south and west (foreign glaciers), glaciers fed from highland areas on the island (native glaciers), and interaction between them. In this study, the determination of ice provenance and extent is based on lithology of erratic clasts, and their distributions. Relative age of glacial events and stratigraphic correlations are based on amino acid ratios of shells (ratio of D-alloisoleucine to L-isoleucine of naturally hydrolyzed amino acids (Free). At least three separate foreign glaciations are recognized. The oldest glaciation occurred prior to a period of interglacial climatic conditions (warmer than present) and is least known. During a foreign glaciation, named informally Eclipse, foreign ice attained elevations of (TURN)600 m a.s.l. along the northern coast and > 800 m a.s.l. along the southern coast. The maximum extent of this ice is marked by major moraines, named Lancaster Moraine and Pond Moraine. Ice movement followed two main paths; (1) northward via Admiralty Inlet and then eastward via Lancaster Sound, and (2) northward across Baffin Island through Milne Inlet and then eastward via Pond Inlet. In Lancaster Sound ice surface gradients were low, and grounded ice extended to the head of Baffin Bay. Glacier reconstruction indicates that basal shear stresses within channels were low (25-60 kPa), implying wet-based ice, and against the island were high ((TURN)150 kPa) implying cold-based ice. Native glaciers were not well nourished during Eclipse glaciation, and some were no more extensive than now. A major native advance is thought to have occurred as Eclipse foreign ice left the channels, and native ice held against the topographic divide moved outwards. Eclipse glaciation occurred > 39 000 B.P., and Eclipse sediments are bounded stratigraphically by shells with amino acid ratios of 0.30 (lower boundary) and 0.24 (upper boundary). During post-Eclipse glaciation(s), foreign ice was much less extensive, and was not likely grounded in channels around the Island. Grounded ice occupied all of Milne Inlet until 9 500 B.P. A lower stratigraphic boundary for this (these) glaciation(s) is defined by shells with amino acid ratios of 0.15. Native glaciers on Bylot Island have recently (< 120 B.P.) advanced, although most are now retreating. At this recent maximum, they are considered to have been as far advanced as at any time since Eclipse glaciation. |
format |
Text |
author |
Klassen, Rodney Alan |
author_facet |
Klassen, Rodney Alan |
author_sort |
Klassen, Rodney Alan |
title |
Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
title_short |
Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
title_full |
Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
title_fullStr |
Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
title_full_unstemmed |
Quaternary Stratigraphy and Glacial History of Bylot Island, n.w.t., Canada |
title_sort |
quaternary stratigraphy and glacial history of bylot island, n.w.t., canada |
publishDate |
1982 |
url |
http://hdl.handle.net/2142/71122 |
long_lat |
ENVELOPE(-86.000,-86.000,72.501,72.501) ENVELOPE(-83.999,-83.999,74.218,74.218) ENVELOPE(-80.499,-80.499,72.335,72.335) ENVELOPE(-77.960,-77.960,72.699,72.699) |
geographic |
Admiralty Inlet Baffin Bay Baffin Island Bylot Island Canada Lancaster Sound Milne Inlet Pond Inlet |
geographic_facet |
Admiralty Inlet Baffin Bay Baffin Island Bylot Island Canada Lancaster Sound Milne Inlet Pond Inlet |
genre |
Baffin Bay Baffin Bay Baffin Island Baffin Bylot Island glacier* Lancaster Sound Pond Inlet |
genre_facet |
Baffin Bay Baffin Bay Baffin Island Baffin Bylot Island glacier* Lancaster Sound Pond Inlet |
op_relation |
http://hdl.handle.net/2142/71122 (UMI)AAI8209595 |
_version_ |
1766365433558990848 |