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| DOI | 10.5194/tc-15-2889-2021 |
| Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams | |
| Vérité J.; Ravier É.; Bourgeois O.; Pochat S.; Lelandais T.; Mourgues R.; Clark C.D.; Bessin P.; Peigné D.; Atkinson N. | |
| 发表日期 | 2021 |
| ISSN | 19940416 |
| 起始页码 | 2889 |
| 结束页码 | 2916 |
| 卷号 | 15期号:6 |
| 英文摘要 | Conceptual ice stream land systems derived from geomorphological and sedimentological observations provide constraints on ice-meltwater-till-bedrock interactions on palaeo-ice stream beds. Within these land systems, the spatial distribution and formation processes of ribbed bedforms remain unclear. We explore the conditions under which these bedforms may develop and their spatial organization with (i) an experimental model that reproduces the dynamics of ice streams and subglacial land systems and (ii) an analysis of the distribution of ribbed bedforms on selected examples of palaeo-ice stream beds of the Laurentide Ice Sheet. We find that a specific kind of ribbed bedform can develop subglacially through soft-bed deformation, where the ice flow undergoes lateral or longitudinal velocity gradients and the ice-bed interface is unlubricated; oblique ribbed bedforms develop beneath lateral shear margins, whereas transverse ribbed bedforms develop below frontal lobes. We infer that (i) ribbed bedforms strike orthogonally to the compressing axis of the horizontal strain ellipse of the ice surface and (ii) their development reveals distinctive types of subglacial drainage patterns: linked cavities below lateral shear margins and efficient meltwater channels below frontal lobes. These ribbed bedforms may act as convenient geomorphic markers to reconstruct lateral and frontal margins, constrain ice flow dynamics, and infer meltwater drainage characteristics of palaeo-ice streams. © 2021 Copernicus GmbH. All rights reserved. |
| 英文关键词 | Venustaconcha ellipsiformis |
| 语种 | 英语 |
| 来源期刊 | Cryosphere
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/202446 |
| 作者单位 | Laboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, Le Mans cedex 9, 72085, France; Laboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Université de Nantes, 2 rue de la Houssinière, BP 92208, Nantes cedex 3, 44322, France; Department of Geography, University of Sheffield, Sheffield, United Kingdom; Alberta Geological Survey, 4th Floor Twin Atria Building 4999-98 Ave., Edmonton, AB T6B 2X3, Canada |
| 推荐引用方式 GB/T 7714 | Vérité J.,Ravier É.,Bourgeois O.,et al. Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams[J],2021,15(6). |
| APA | Vérité J..,Ravier É..,Bourgeois O..,Pochat S..,Lelandais T..,...&Atkinson N..(2021).Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams.Cryosphere,15(6). |
| MLA | Vérité J.,et al."Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams".Cryosphere 15.6(2021). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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