Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age).
16 pages International audience The general subject of this paper is subglacial deformation beneath Breiðamerkurjökull, a surging Icelandic glacier. More specifically it discusses the evolution and the role of fluid pressure on the behaviour of subglacial sediments during deformation. During Little...
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Online Access: | https://hal.science/hal-00423389 https://doi.org/10.1016/j.sedgeo.2009.07.013 |
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ftunivbourgogne:oai:HAL:hal-00423389v1 2024-05-19T07:40:45+00:00 Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). Denis, Michaël Buoncristiani, Jean-François Guiraud, Michel Biogéosciences UMR 6282 (BGS) Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS) Study funded by a research allocation from the Ministère de l'Education Nationale, de la Recherche et de la Technologie, and by a research contract (“Région Bourgogne – UMR 5561 Biogéosciences – TOTAL n° 05 516 AA 013 S29, Interactions déglaciations, déformation et enregistrement stratigraphique”). 2009-11-15 https://hal.science/hal-00423389 https://doi.org/10.1016/j.sedgeo.2009.07.013 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.sedgeo.2009.07.013 hal-00423389 https://hal.science/hal-00423389 doi:10.1016/j.sedgeo.2009.07.013 ISSN: 0037-0738 Sedimentary Geology https://hal.science/hal-00423389 Sedimentary Geology, 2009, 221 (1-4), pp.71-86. ⟨10.1016/j.sedgeo.2009.07.013⟩ Subglacial deformation Fluid pressure Breiðamerkurjökull Iceland Clast-fabric analysis [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2009 ftunivbourgogne https://doi.org/10.1016/j.sedgeo.2009.07.013 2024-04-24T23:56:02Z 16 pages International audience The general subject of this paper is subglacial deformation beneath Breiðamerkurjökull, a surging Icelandic glacier. More specifically it discusses the evolution and the role of fluid pressure on the behaviour of subglacial sediments during deformation. During Little Ice Age maximum, the two outcrops studied, North Jökulsarlon (N-Jk) and Brennhola-Alda (BA), were located at 2550 m and 550 m respectively from the front of the Breiðamerkurjökull. Sedimentological analysis at the forefield of the glacier shows thick, coarse glaciofluvial deposits interbedded with thin, fine-grained shallow lacustrine/swamp deposits, overlain by a deformed till unit at N-Jk. BA outcrop shows fine-grained shallow lacustrine/swamp deposits overlain by a deformed till unit. The sequence of deformation events from one outcrop to the other is similar. First, major thrust planes, which were rooted in shallow lacustrine/swamp deposits developed by glacially induced simple shear. Next, the thrusts were folded, indicating the deformation of hydroplastic sediment assisted by moderate fluid pressure. Then clastic dyke swarms crosscut the sedimentary succession, proving that fluid overpressure caused hydrofracturing associated with fluidisation. Finally, as water escaped from the glacier bed, fluid pressure dropped, and normal faulting occurred in brittle-state subglacial sediments. Fluidpressure variations are related to glacier dynamics. They control the deformation sequence by modifying subglacial rheological behaviour and the nature of the subglacial tectonism. Article in Journal/Newspaper glacier Iceland Université de Bourgogne (UB): HAL Sedimentary Geology 221 1-4 71 86 |
institution |
Open Polar |
collection |
Université de Bourgogne (UB): HAL |
op_collection_id |
ftunivbourgogne |
language |
English |
topic |
Subglacial deformation Fluid pressure Breiðamerkurjökull Iceland Clast-fabric analysis [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
Subglacial deformation Fluid pressure Breiðamerkurjökull Iceland Clast-fabric analysis [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDE.MCG]Environmental Sciences/Global Changes Denis, Michaël Buoncristiani, Jean-François Guiraud, Michel Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
topic_facet |
Subglacial deformation Fluid pressure Breiðamerkurjökull Iceland Clast-fabric analysis [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDE.MCG]Environmental Sciences/Global Changes |
description |
16 pages International audience The general subject of this paper is subglacial deformation beneath Breiðamerkurjökull, a surging Icelandic glacier. More specifically it discusses the evolution and the role of fluid pressure on the behaviour of subglacial sediments during deformation. During Little Ice Age maximum, the two outcrops studied, North Jökulsarlon (N-Jk) and Brennhola-Alda (BA), were located at 2550 m and 550 m respectively from the front of the Breiðamerkurjökull. Sedimentological analysis at the forefield of the glacier shows thick, coarse glaciofluvial deposits interbedded with thin, fine-grained shallow lacustrine/swamp deposits, overlain by a deformed till unit at N-Jk. BA outcrop shows fine-grained shallow lacustrine/swamp deposits overlain by a deformed till unit. The sequence of deformation events from one outcrop to the other is similar. First, major thrust planes, which were rooted in shallow lacustrine/swamp deposits developed by glacially induced simple shear. Next, the thrusts were folded, indicating the deformation of hydroplastic sediment assisted by moderate fluid pressure. Then clastic dyke swarms crosscut the sedimentary succession, proving that fluid overpressure caused hydrofracturing associated with fluidisation. Finally, as water escaped from the glacier bed, fluid pressure dropped, and normal faulting occurred in brittle-state subglacial sediments. Fluidpressure variations are related to glacier dynamics. They control the deformation sequence by modifying subglacial rheological behaviour and the nature of the subglacial tectonism. |
author2 |
Biogéosciences UMR 6282 (BGS) Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS) Study funded by a research allocation from the Ministère de l'Education Nationale, de la Recherche et de la Technologie, and by a research contract (“Région Bourgogne – UMR 5561 Biogéosciences – TOTAL n° 05 516 AA 013 S29, Interactions déglaciations, déformation et enregistrement stratigraphique”). |
format |
Article in Journal/Newspaper |
author |
Denis, Michaël Buoncristiani, Jean-François Guiraud, Michel |
author_facet |
Denis, Michaël Buoncristiani, Jean-François Guiraud, Michel |
author_sort |
Denis, Michaël |
title |
Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
title_short |
Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
title_full |
Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
title_fullStr |
Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
title_full_unstemmed |
Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age). |
title_sort |
fluid-pressure controlled soft-bed deformation sequence beneath the surging breiðamerkurjökull (iceland, little ice age). |
publisher |
HAL CCSD |
publishDate |
2009 |
url |
https://hal.science/hal-00423389 https://doi.org/10.1016/j.sedgeo.2009.07.013 |
genre |
glacier Iceland |
genre_facet |
glacier Iceland |
op_source |
ISSN: 0037-0738 Sedimentary Geology https://hal.science/hal-00423389 Sedimentary Geology, 2009, 221 (1-4), pp.71-86. ⟨10.1016/j.sedgeo.2009.07.013⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.sedgeo.2009.07.013 hal-00423389 https://hal.science/hal-00423389 doi:10.1016/j.sedgeo.2009.07.013 |
op_doi |
https://doi.org/10.1016/j.sedgeo.2009.07.013 |
container_title |
Sedimentary Geology |
container_volume |
221 |
container_issue |
1-4 |
container_start_page |
71 |
op_container_end_page |
86 |
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1799480319438487552 |