Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation
ABSTRACT The Laurentide Ice Sheet was characterized by a dynamic polythermal base. However, important data and knowledge gaps have led to contrasting reconstructions in areas such as the Labrador Ice Divide. In this study, detailed fieldwork was conducted at the southeastern edge of a major landform...
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crwiley:10.1002/jqs.3138 2024-09-15T18:12:21+00:00 Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation Rice, Jessey M. Ross, Martin Paulen, Roger C. Kelley, Samuel E. Briner, Jason P. Neudorf, Christina M. Lian, Olav B. 2019 http://dx.doi.org/10.1002/jqs.3138 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.3138 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3138 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jqs.3138 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Journal of Quaternary Science volume 34, issue 7, page 519-535 ISSN 0267-8179 1099-1417 journal-article 2019 crwiley https://doi.org/10.1002/jqs.3138 2024-07-25T04:19:33Z ABSTRACT The Laurentide Ice Sheet was characterized by a dynamic polythermal base. However, important data and knowledge gaps have led to contrasting reconstructions in areas such as the Labrador Ice Divide. In this study, detailed fieldwork was conducted at the southeastern edge of a major landform boundary to resolve the relative ice flow chronology and constrain the evolution of the subglacial dynamics, including the migration and collapse of the Labrador Ice Divide. Surficial mapping and analysis of 94 outcrop‐scale ice flow indicators were used to develop a relative ice flow chronology. 10 Be exposure ages were used with optical ages to confine the timing of deglaciation within the study area. Four phases of ice flow were identified. Flow 1 was a northeasterly ice flow preserved under non‐erosive subglacial conditions associated with the development of an ice divide. Flow 2 was a northwest ice flow, which we correlate to the Ungava Bay Ice Stream and led to a westward migration of the ice divide, preserving Flow 2 features and resulting in Flow 3's eastward‐trending indicators. Flow 4 is limited to sparse fine striations within and around the regional uplands. The new optical ages and 10 Be exposure ages add to the regional geochronology dataset, which further constrains the timing of ice margin retreat in the area to around 8.0 ka. Copyright © 2019 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd. Article in Journal/Newspaper Ice Sheet Ungava Bay Wiley Online Library Journal of Quaternary Science 34 7 519 535 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
ABSTRACT The Laurentide Ice Sheet was characterized by a dynamic polythermal base. However, important data and knowledge gaps have led to contrasting reconstructions in areas such as the Labrador Ice Divide. In this study, detailed fieldwork was conducted at the southeastern edge of a major landform boundary to resolve the relative ice flow chronology and constrain the evolution of the subglacial dynamics, including the migration and collapse of the Labrador Ice Divide. Surficial mapping and analysis of 94 outcrop‐scale ice flow indicators were used to develop a relative ice flow chronology. 10 Be exposure ages were used with optical ages to confine the timing of deglaciation within the study area. Four phases of ice flow were identified. Flow 1 was a northeasterly ice flow preserved under non‐erosive subglacial conditions associated with the development of an ice divide. Flow 2 was a northwest ice flow, which we correlate to the Ungava Bay Ice Stream and led to a westward migration of the ice divide, preserving Flow 2 features and resulting in Flow 3's eastward‐trending indicators. Flow 4 is limited to sparse fine striations within and around the regional uplands. The new optical ages and 10 Be exposure ages add to the regional geochronology dataset, which further constrains the timing of ice margin retreat in the area to around 8.0 ka. Copyright © 2019 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd. |
format |
Article in Journal/Newspaper |
author |
Rice, Jessey M. Ross, Martin Paulen, Roger C. Kelley, Samuel E. Briner, Jason P. Neudorf, Christina M. Lian, Olav B. |
spellingShingle |
Rice, Jessey M. Ross, Martin Paulen, Roger C. Kelley, Samuel E. Briner, Jason P. Neudorf, Christina M. Lian, Olav B. Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
author_facet |
Rice, Jessey M. Ross, Martin Paulen, Roger C. Kelley, Samuel E. Briner, Jason P. Neudorf, Christina M. Lian, Olav B. |
author_sort |
Rice, Jessey M. |
title |
Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
title_short |
Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
title_full |
Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
title_fullStr |
Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
title_full_unstemmed |
Refining the ice flow chronology and subglacial dynamics across the migrating Labrador Divide of the Laurentide Ice Sheet with age constraints on deglaciation |
title_sort |
refining the ice flow chronology and subglacial dynamics across the migrating labrador divide of the laurentide ice sheet with age constraints on deglaciation |
publisher |
Wiley |
publishDate |
2019 |
url |
http://dx.doi.org/10.1002/jqs.3138 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.3138 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3138 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jqs.3138 |
genre |
Ice Sheet Ungava Bay |
genre_facet |
Ice Sheet Ungava Bay |
op_source |
Journal of Quaternary Science volume 34, issue 7, page 519-535 ISSN 0267-8179 1099-1417 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/jqs.3138 |
container_title |
Journal of Quaternary Science |
container_volume |
34 |
container_issue |
7 |
container_start_page |
519 |
op_container_end_page |
535 |
_version_ |
1810449927633895424 |