Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien
High-resolution bathymetric data acquired using a multibeam echosounder and an interferometric side-scan sonar allowed mapping for the first time the sublacustrine geomorphology of the lakes Pentecôte, Walker and Pasteur, three deep adjacent fjord-lakes of the Québec North Shore (eastern Canada). Th...
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2016
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fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/27400 2023-05-15T16:40:47+02:00 Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien Late quaternary post-glacial sedimentation in three adjacent lake fjords in the south-east of the Canadian Shield Gagnon-Poiré, Antoine Lajeunesse, Patrick Québec (Province) Holocène 2016-01-01 https://hdl.handle.net/20.500.11794/27400 fr fre Université Laval http://hdl.handle.net/20.500.11794/27400 other CorpusUL geo anthro-bio Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2016 fttriple https://doi.org/20.500.11794/27400 2023-01-22T16:40:10Z High-resolution bathymetric data acquired using a multibeam echosounder and an interferometric side-scan sonar allowed mapping for the first time the sublacustrine geomorphology of the lakes Pentecôte, Walker and Pasteur, three deep adjacent fjord-lakes of the Québec North Shore (eastern Canada). These formerly glaciomarine sedimentary basins have been glacio-isostatically uplifted to form deep steep-sided elongated lakes. The key geographical position and their limnogeological characteristics typical of fjords show exceptional potential for paleoenvironmental reconstructions at high resolution on a long period of time. A hydraulic potential modelling suggest that the Lake Walker probably existed as a subglacial lake beneath the Laurentide Ice Sheet during the LGM suggesting that sediments could have escaped glacial erosion and may contain paleo-records of the last glaciation(s). These lakes, located near Younger Dryas morainic systems, were flooded during the Goldthwait Sea postglacial marine transgression and have preserved laminated sediment archives until today which contain sedimentary archives that recorded paleo-environmental changes that have occurred since the last deglaciation. Acoustic sub-bottom profiles acquired using a bi-frequency Chirp echosounder (3.5 & 12 kHz), together with cm-short and m-long sediment core data, reveal the presence of four sedimentary units. The acoustic basement (U1), related to the structural bedrock and/or the ice-contact sediments of the Laurentide Ice-Sheet reveal the presence of V-shaped bedrock valleys at the bottom of the lakes that possibly escaped glacial erosion. Moraines observed at the bottom of the lake and in their structural valleys indicate an overall fast deglaciation punctuated by short-term ice margin stabilizations. Following ice-retreat and their isolation, the fjord-lakes were filled by thick sequence of rhythmically laminated silts and clays (U2) deposited during marine and/or glaciolacustrine settings which were disturbed by mass-movements during ... Thesis Ice Sheet Unknown Canada Pasteur ENVELOPE(140.099,140.099,-66.625,-66.625) Goldthwait ENVELOPE(-86.050,-86.050,-77.983,-77.983) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
geo anthro-bio |
spellingShingle |
geo anthro-bio Gagnon-Poiré, Antoine Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
topic_facet |
geo anthro-bio |
description |
High-resolution bathymetric data acquired using a multibeam echosounder and an interferometric side-scan sonar allowed mapping for the first time the sublacustrine geomorphology of the lakes Pentecôte, Walker and Pasteur, three deep adjacent fjord-lakes of the Québec North Shore (eastern Canada). These formerly glaciomarine sedimentary basins have been glacio-isostatically uplifted to form deep steep-sided elongated lakes. The key geographical position and their limnogeological characteristics typical of fjords show exceptional potential for paleoenvironmental reconstructions at high resolution on a long period of time. A hydraulic potential modelling suggest that the Lake Walker probably existed as a subglacial lake beneath the Laurentide Ice Sheet during the LGM suggesting that sediments could have escaped glacial erosion and may contain paleo-records of the last glaciation(s). These lakes, located near Younger Dryas morainic systems, were flooded during the Goldthwait Sea postglacial marine transgression and have preserved laminated sediment archives until today which contain sedimentary archives that recorded paleo-environmental changes that have occurred since the last deglaciation. Acoustic sub-bottom profiles acquired using a bi-frequency Chirp echosounder (3.5 & 12 kHz), together with cm-short and m-long sediment core data, reveal the presence of four sedimentary units. The acoustic basement (U1), related to the structural bedrock and/or the ice-contact sediments of the Laurentide Ice-Sheet reveal the presence of V-shaped bedrock valleys at the bottom of the lakes that possibly escaped glacial erosion. Moraines observed at the bottom of the lake and in their structural valleys indicate an overall fast deglaciation punctuated by short-term ice margin stabilizations. Following ice-retreat and their isolation, the fjord-lakes were filled by thick sequence of rhythmically laminated silts and clays (U2) deposited during marine and/or glaciolacustrine settings which were disturbed by mass-movements during ... |
author2 |
Lajeunesse, Patrick |
format |
Thesis |
author |
Gagnon-Poiré, Antoine |
author_facet |
Gagnon-Poiré, Antoine |
author_sort |
Gagnon-Poiré, Antoine |
title |
Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
title_short |
Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
title_full |
Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
title_fullStr |
Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
title_full_unstemmed |
Sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du Bouclier canadien |
title_sort |
sédimentation tardi-quaternaire glaciaire à postglaciaire dans trois fjords lacustres adjacents du sud-est du bouclier canadien |
publisher |
Université Laval |
publishDate |
2016 |
url |
https://hdl.handle.net/20.500.11794/27400 |
op_coverage |
Québec (Province) Holocène |
long_lat |
ENVELOPE(140.099,140.099,-66.625,-66.625) ENVELOPE(-86.050,-86.050,-77.983,-77.983) |
geographic |
Canada Pasteur Goldthwait |
geographic_facet |
Canada Pasteur Goldthwait |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/27400 |
op_rights |
other |
op_doi |
https://doi.org/20.500.11794/27400 |
_version_ |
1766031199427362816 |