Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago
The intricate pattern of moraines of the Laurentide ice sheet in the Great Lakes region reflects the marked lobation of the ice margin in late Wisconsin time, and this in turn reflects the distribution of steam-cut lowlands etched in preglacial times in the weak-rock belts of gentle Paleozoic fold s...
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Cambridge University Press (CUP)
1971
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Online Access: | http://dx.doi.org/10.1016/0033-5894(71)90068-8 http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/xml http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400003094 |
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crcambridgeupr:10.1016/0033-5894(71)90068-8 2024-10-13T14:08:06+00:00 Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago Wright, H. E. 1971 http://dx.doi.org/10.1016/0033-5894(71)90068-8 http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/xml http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400003094 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 1, issue 3, page 316-330 ISSN 0033-5894 1096-0287 journal-article 1971 crcambridgeupr https://doi.org/10.1016/0033-5894(71)90068-8 2024-09-18T04:04:04Z The intricate pattern of moraines of the Laurentide ice sheet in the Great Lakes region reflects the marked lobation of the ice margin in late Wisconsin time, and this in turn reflects the distribution of steam-cut lowlands etched in preglacial times in the weak-rock belts of gentle Paleozoic fold structures. It is difficult to trace and correlate moraines from lobe to lobe and to evaluate the magnitude of recession before readvance, but three breaks stand out in the sequence, with readvances at about 14,500, 13,000, and 11,500 years ago. The first, corresponding to the Cary advance of the Lake Michigan lobe, is represented to the west by distant advance of the Des Moines lobe in Iowa, and to the east by the overriding of lake beds by the Erie lobe. The 13,000-year advance is best represented by the Port Huron moraine of the Lake Michigan and Huron lobes, but by relatively little action to west and east. The 11,500-year advance is based on the Valders till of the Lake Michigan lobe, but presumed correlations to east and west prove to be generally older, and the question is raised that these and some other ice advances in the Great Lakes region may represent surges of the ice rather than regional climatic change. Surging may involve the buildup of subglacial meltwater, which can provide the basal sliding necessary for rapid forward movement. It would be most favored by the conditions in the western Lake Superior basin, where the Superior lobe had a suitable form and thermal regime, as estimated from geomorphic and paleoclimatic criteria. The Valders advance of the Lake Michigan and Green Bay lobes may also have resulted from a surge: the eastern part of the Lake Superior basin, whence the ice advanced, has a pattern of deep gorges that resemble subglacial tunnel valleys, which imply great quantities of subglacial water that may have produced glacial surges before the water became channeled. Article in Journal/Newspaper Ice Sheet Cambridge University Press Green Bay ENVELOPE(-36.014,-36.014,-54.870,-54.870) Valders ENVELOPE(15.406,15.406,67.303,67.303) Western Lake ENVELOPE(-128.106,-128.106,52.663,52.663) Quaternary Research 1 3 316 330 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
The intricate pattern of moraines of the Laurentide ice sheet in the Great Lakes region reflects the marked lobation of the ice margin in late Wisconsin time, and this in turn reflects the distribution of steam-cut lowlands etched in preglacial times in the weak-rock belts of gentle Paleozoic fold structures. It is difficult to trace and correlate moraines from lobe to lobe and to evaluate the magnitude of recession before readvance, but three breaks stand out in the sequence, with readvances at about 14,500, 13,000, and 11,500 years ago. The first, corresponding to the Cary advance of the Lake Michigan lobe, is represented to the west by distant advance of the Des Moines lobe in Iowa, and to the east by the overriding of lake beds by the Erie lobe. The 13,000-year advance is best represented by the Port Huron moraine of the Lake Michigan and Huron lobes, but by relatively little action to west and east. The 11,500-year advance is based on the Valders till of the Lake Michigan lobe, but presumed correlations to east and west prove to be generally older, and the question is raised that these and some other ice advances in the Great Lakes region may represent surges of the ice rather than regional climatic change. Surging may involve the buildup of subglacial meltwater, which can provide the basal sliding necessary for rapid forward movement. It would be most favored by the conditions in the western Lake Superior basin, where the Superior lobe had a suitable form and thermal regime, as estimated from geomorphic and paleoclimatic criteria. The Valders advance of the Lake Michigan and Green Bay lobes may also have resulted from a surge: the eastern part of the Lake Superior basin, whence the ice advanced, has a pattern of deep gorges that resemble subglacial tunnel valleys, which imply great quantities of subglacial water that may have produced glacial surges before the water became channeled. |
format |
Article in Journal/Newspaper |
author |
Wright, H. E. |
spellingShingle |
Wright, H. E. Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
author_facet |
Wright, H. E. |
author_sort |
Wright, H. E. |
title |
Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
title_short |
Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
title_full |
Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
title_fullStr |
Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
title_full_unstemmed |
Retreat of the Laurentide Ice Sheet from 14,000 to 9000 Years Ago |
title_sort |
retreat of the laurentide ice sheet from 14,000 to 9000 years ago |
publisher |
Cambridge University Press (CUP) |
publishDate |
1971 |
url |
http://dx.doi.org/10.1016/0033-5894(71)90068-8 http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/xml http://api.elsevier.com/content/article/PII:0033589471900688?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400003094 |
long_lat |
ENVELOPE(-36.014,-36.014,-54.870,-54.870) ENVELOPE(15.406,15.406,67.303,67.303) ENVELOPE(-128.106,-128.106,52.663,52.663) |
geographic |
Green Bay Valders Western Lake |
geographic_facet |
Green Bay Valders Western Lake |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Quaternary Research volume 1, issue 3, page 316-330 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1016/0033-5894(71)90068-8 |
container_title |
Quaternary Research |
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1 |
container_issue |
3 |
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316 |
op_container_end_page |
330 |
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1812814707556352000 |