Deep-seated gravitational slope deformation and rock-slope failures deposits in Iceland: inventory, dating and role in landscape evolution
1
LGP -
Laboratoire de géographie physique : Environnements Quaternaires et Actuels
2 SU - Sorbonne Université
3 UP1 UFR08 - Université Paris 1 Panthéon-Sorbonne - UFR Géographie
4 LETG - Nantes - Littoral, Environnement, Télédétection, Géomatique
5 UJML - Université Jean Moulin - Lyon 3
6 EVS - Environnement, Ville, Société
2 SU - Sorbonne Université
3 UP1 UFR08 - Université Paris 1 Panthéon-Sorbonne - UFR Géographie
4 LETG - Nantes - Littoral, Environnement, Télédétection, Géomatique
5 UJML - Université Jean Moulin - Lyon 3
6 EVS - Environnement, Ville, Société
Denis Mercier
- Fonction : Auteur
- PersonId : 8684
- IdHAL : dmercier
- ORCID : 0000-0003-2325-1390
- IdRef : 059339322
Armelle Decaulne
- Fonction : Auteur
- PersonId : 179996
- IdHAL : armelle-decaulne
- ORCID : 0000-0002-8029-850X
Etienne Cossart
- Fonction : Auteur
- PersonId : 981905
- ORCID : 0000-0001-7457-542X
- IdRef : 096289449
Résumé
Following the Last Glacial Maximum, icelandic hillslopes experienced a paraglacial crisis, which occurred between 15-10 ka BP. In the North, West and East parts of Iceland, in the high plateaus and slopes developed in the Tertiary basaltic formations, two types of paraglacial denudation features, deep-seated gravitational slope deformation (DSGSD) and rock-slope failure (RSF) deposits, are numerous.</p><p>An inventory and several maps of DSGSD and RSF are proposed at the scale of those three icelandic regions of Iceland. The mapping was made by combining aerial photographs, satellite images and field prospections. The DSGSD is characterized by typical ridge-top grabens, scarps and antiscarps associated with upslope and downslope dipping fractures along bulged upper slopes. The RSF could be identified by defining the crown and deposits. Both features could be analyzed by using direct observations and NDVI index from satellite images.An approach of the timing of the DSGSD and rock-slope failures settlement is also proposed in this contribution by using field investigations (geomorphological stacking, tephrochronology, radiocarbon dating of wood remains in depression on RSL deposits, and age-depth models). The genetic links between DSGSD and landslides, the effects of these paraglacial denudation dynamics on the evolution of landforms (cirques, valleys) are discussed. Furthermore, the erosion rates involved by such paraglacial crises (volumes of landslide deposits) are compared with erosion rates involved other processes on icelandic slopes during the Holocene. Finally, this paraglacial denudation crisis, illustrated by DSGSD and RSF, appears as the main sequence of icelandic landscape evolution since the last glaciation.
Format du dépôt | Notice |
---|---|
Type de dépôt | Communication dans un congrès |
Titre |
en
Deep-seated gravitational slope deformation and rock-slope failures deposits in Iceland: inventory, dating and role in landscape evolution
|
Résumé |
en
Following the Last Glacial Maximum, icelandic hillslopes experienced a paraglacial crisis, which occurred between 15-10 ka BP. In the North, West and East parts of Iceland, in the high plateaus and slopes developed in the Tertiary basaltic formations, two types of paraglacial denudation features, deep-seated gravitational slope deformation (DSGSD) and rock-slope failure (RSF) deposits, are numerous.</p><p>An inventory and several maps of DSGSD and RSF are proposed at the scale of those three icelandic regions of Iceland. The mapping was made by combining aerial photographs, satellite images and field prospections. The DSGSD is characterized by typical ridge-top grabens, scarps and antiscarps associated with upslope and downslope dipping fractures along bulged upper slopes. The RSF could be identified by defining the crown and deposits. Both features could be analyzed by using direct observations and NDVI index from satellite images.An approach of the timing of the DSGSD and rock-slope failures settlement is also proposed in this contribution by using field investigations (geomorphological stacking, tephrochronology, radiocarbon dating of wood remains in depression on RSL deposits, and age-depth models). The genetic links between DSGSD and landslides, the effects of these paraglacial denudation dynamics on the evolution of landforms (cirques, valleys) are discussed. Furthermore, the erosion rates involved by such paraglacial crises (volumes of landslide deposits) are compared with erosion rates involved other processes on icelandic slopes during the Holocene. Finally, this paraglacial denudation crisis, illustrated by DSGSD and RSF, appears as the main sequence of icelandic landscape evolution since the last glaciation.
|
Auteur(s) |
Denis Mercier
1, 2
, Emilie Portier
3
, Armelle Decaulne
4
, Etienne Cossart
5, 6
1
LGP -
Laboratoire de géographie physique : Environnements Quaternaires et Actuels
( 1343 )
- 2 rue Henri Dunant
94320 Thiais
- France
2
SU -
Sorbonne Université
( 413221 )
- 21 rue de l’École de médecine - 75006 Paris
- France
3
UP1 UFR08 -
Université Paris 1 Panthéon-Sorbonne - UFR Géographie
( 219287 )
- Institut de Géographie - 191, rue Saint-Jacques - 75231 Paris cedex 05
- France
4
LETG - Nantes -
Littoral, Environnement, Télédétection, Géomatique
( 1088605 )
- Institut de Géographie et d'Aménagement de l'Université de Nantes Campus du Tertre BP 8122 44312 NANTES CEDEX 3
- France
5
UJML -
Université Jean Moulin - Lyon 3
( 118744 )
- 6 cours Albert Thomas - 69008 Lyon
- France
6
EVS -
Environnement, Ville, Société
( 145345 )
- 18 Rue Chevreul
69362 LYON CEDEX 07
UMR 5600
- France
|
Langue du document |
Anglais
|
Vulgarisation |
Non
|
Comité de lecture |
Oui
|
Invité |
Non
|
Audience |
Internationale
|
Actes |
Non
|
Titre du congrès |
10th International Conference on Geomorphology
|
Date début congrès |
2022-09-12
|
Ville |
Coimbra
|
Pays |
Portugal
|
Domaine(s) |
|
DOI | 10.5194/icg2022-165 |
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