Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada)
International audience Abstract: The Pingualuit Crater (Ungava Peninsula, Canada) hosts a freshwater basin in which a subglacial lake subsisted under the Laurentide Ice Sheet during the last glacial period. Microfacies and microstructures of a 9mlong sediment core are presented to discuss the deposi...
Published in: | Canadian Journal of Earth Sciences |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal.science/hal-01078309 https://doi.org/10.1139/cjes-2014-0041 |
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ftunivsavoie:oai:HAL:hal-01078309v1 |
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openpolar |
institution |
Open Polar |
collection |
Université Savoie Mont Blanc: HAL |
op_collection_id |
ftunivsavoie |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Guyard, H. Francus, Pierre Saint Onge, Guillaume Haussmann, S. Pienitz, R. Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Abstract: The Pingualuit Crater (Ungava Peninsula, Canada) hosts a freshwater basin in which a subglacial lake subsisted under the Laurentide Ice Sheet during the last glacial period. Microfacies and microstructures of a 9mlong sediment core are presented to discuss the depositional environment of deformed glacigenic and postglacial sequences deposited in the deep basin of the lake. Five distinct lithofacies are characterized. The range of glacial microstructures observed in the lower facies (Facies IV) reveals that high stress level occurred outside the crater during the formation of this diamicton released by the ablation of debris-rich basal glacier ice in an ice contact subglacial–proglacial lacustrine environment. The overlying subaqueous and glacigenic sediment gravity flow (Facies IIIb) is associated with a temporary absence of ice cover over the coring site, and likely results from the efflux plume and the associated suspension sedimentation produced during the retreat of the ice margin. Then, the finely laminated (<1–2 mm) and normally graded meltout silts (Facies IIIa) containing dropstones and load cast featuressuggest underflows in an unstable ice marginal lacustrine environment hydrologically separated from the retreating glacier but containing floating glacial ice blocks. Microstructures within occasional diamictic layers indicate sudden meltout deposits from these drifting ice blocks. The above finer-grained sediments (Facies Ib) lack typical glacial microstructures, marking the onset of postglacial organic sedimentation. These postglacial sediments are affected by post-depositional deformations due to an overlying rotational slide (Facies II) that may have perturbed the associated environmental record. |
author2 |
Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'étude des transferts en hydrologie et environnement (LTHE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS) Centre Eau Terre Environnement Québec (INRS - ETE) Institut National de la Recherche Scientifique Québec (INRS) Geochimistry and Geodynamics Research Centre (GEOTOP ) Université du Québec à Montréal = University of Québec in Montréal (UQAM) |
format |
Article in Journal/Newspaper |
author |
Guyard, H. Francus, Pierre Saint Onge, Guillaume Haussmann, S. Pienitz, R. |
author_facet |
Guyard, H. Francus, Pierre Saint Onge, Guillaume Haussmann, S. Pienitz, R. |
author_sort |
Guyard, H. |
title |
Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
title_short |
Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
title_full |
Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
title_fullStr |
Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
title_full_unstemmed |
Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) |
title_sort |
microfacies and microstructures of subglacial and deglacial sediments from the pingualuit crater lake (ungava peninsula, canada) |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-01078309 https://doi.org/10.1139/cjes-2014-0041 |
genre |
glacier* Ice Sheet Ungava peninsula |
genre_facet |
glacier* Ice Sheet Ungava peninsula |
op_source |
ISSN: 0008-4077 EISSN: 1480-3313 Canadian journal of earth sciences https://hal.science/hal-01078309 Canadian journal of earth sciences, 2014, pp.51:1084-1096 (IF 1,335). ⟨10.1139/cjes-2014-0041⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1139/cjes-2014-0041 hal-01078309 https://hal.science/hal-01078309 doi:10.1139/cjes-2014-0041 |
op_doi |
https://doi.org/10.1139/cjes-2014-0041 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
51 |
container_issue |
12 |
container_start_page |
1084 |
op_container_end_page |
1096 |
_version_ |
1799480409573031936 |
spelling |
ftunivsavoie:oai:HAL:hal-01078309v1 2024-05-19T07:40:50+00:00 Microfacies and microstructures of subglacial and deglacial sediments from the Pingualuit Crater Lake (Ungava Peninsula, Canada) Guyard, H. Francus, Pierre Saint Onge, Guillaume Haussmann, S. Pienitz, R. Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'étude des transferts en hydrologie et environnement (LTHE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS) Centre Eau Terre Environnement Québec (INRS - ETE) Institut National de la Recherche Scientifique Québec (INRS) Geochimistry and Geodynamics Research Centre (GEOTOP ) Université du Québec à Montréal = University of Québec in Montréal (UQAM) 2014-07-23 https://hal.science/hal-01078309 https://doi.org/10.1139/cjes-2014-0041 en eng HAL CCSD National Research Council Canada info:eu-repo/semantics/altIdentifier/doi/10.1139/cjes-2014-0041 hal-01078309 https://hal.science/hal-01078309 doi:10.1139/cjes-2014-0041 ISSN: 0008-4077 EISSN: 1480-3313 Canadian journal of earth sciences https://hal.science/hal-01078309 Canadian journal of earth sciences, 2014, pp.51:1084-1096 (IF 1,335). ⟨10.1139/cjes-2014-0041⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2014 ftunivsavoie https://doi.org/10.1139/cjes-2014-0041 2024-05-02T00:16:31Z International audience Abstract: The Pingualuit Crater (Ungava Peninsula, Canada) hosts a freshwater basin in which a subglacial lake subsisted under the Laurentide Ice Sheet during the last glacial period. Microfacies and microstructures of a 9mlong sediment core are presented to discuss the depositional environment of deformed glacigenic and postglacial sequences deposited in the deep basin of the lake. Five distinct lithofacies are characterized. The range of glacial microstructures observed in the lower facies (Facies IV) reveals that high stress level occurred outside the crater during the formation of this diamicton released by the ablation of debris-rich basal glacier ice in an ice contact subglacial–proglacial lacustrine environment. The overlying subaqueous and glacigenic sediment gravity flow (Facies IIIb) is associated with a temporary absence of ice cover over the coring site, and likely results from the efflux plume and the associated suspension sedimentation produced during the retreat of the ice margin. Then, the finely laminated (<1–2 mm) and normally graded meltout silts (Facies IIIa) containing dropstones and load cast featuressuggest underflows in an unstable ice marginal lacustrine environment hydrologically separated from the retreating glacier but containing floating glacial ice blocks. Microstructures within occasional diamictic layers indicate sudden meltout deposits from these drifting ice blocks. The above finer-grained sediments (Facies Ib) lack typical glacial microstructures, marking the onset of postglacial organic sedimentation. These postglacial sediments are affected by post-depositional deformations due to an overlying rotational slide (Facies II) that may have perturbed the associated environmental record. Article in Journal/Newspaper glacier* Ice Sheet Ungava peninsula Université Savoie Mont Blanc: HAL Canadian Journal of Earth Sciences 51 12 1084 1096 |