DOI: 10.1016/j.quascirev.2014.09.010
Scopus记录号: 2-s2.0-84920143376
论文题名: Sedimentary and structural evolution of a relict subglacial to subaerial drainage system and its hydrogeological implications: An example from Anglesey, north Wales, UK
作者: Lee J.R. ; Wakefield O.J.W. ; Phillips E. ; Hughes L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 109 起始页码: 88
结束页码: 110
语种: 英语
英文关键词: Groundwater
; Helicoidal flow
; Hydrofracturing
; Sinusoidal bedding
; Subglacial drainage
; Upper plane bed
Scopus关键词: Deposits
; Drainage
; Groundwater
; Sedimentology
; Helicoidal flow
; Hydro-fracturing
; Plane bed
; Sinusoidal bedding
; Structural evolution
; Subglacial channels
; Subglacial meltwater
; Subglacial sedimentations
; Ice
; bedform
; drainage network
; flow pattern
; glacier dynamics
; hydraulic fracture
; hydrogeology
; ice margin
; ice retreat
; meltwater
; proglacial environment
; structural analysis
; subglacial environment
; Isle of Anglesey
; United Kingdom
; Wales
英文摘要: Subglacial drainage systems exert a major control on basal-sliding rates and glacier dynamics. However, comparatively few studies have examined the sedimentary record of subglacial drainage. This is due to the paucity of modern analogues, the limited recognition and preservation of upper flow regime deposits within the geological record, and the difficulty of distinguishing subglacial meltwater deposits from other meltwater sediments (e.g. glacier outburst flood deposits). Within this study, the sedimentological and structural evolution of a subglacial to subaerial (ice-marginal/proglacial) drainage system is examined. Particular emphasis is placed upon the genetic development and preservation of upper flow regime bedforms and specifically recognising them within a subglacial meltwater context. Facies are attributed to subglacial meltwater activity and record sedimentation within a confined, but progressively enlargening, subglacial channel system produced under dune to upper flow regime conditions. Bedforms include rare large-scale sinusoidal bedding with syn-depositional deformation produced by current-induced traction and shearing within the channel margins. Subglacial sedimentation culminated with the abrupt change to a more ephemeral drainage regime indicating channel-abandonment or a seasonal drainage regime. Retreat of the ice margin, led to the establishment of subaerial drainage with phases of sheet-flow punctuated by channel incision and anastomosing channel development under diurnal, ablation-related, seasonal discharge. The presence of extensive hydrofracture networks demonstrate that proglacial groundwater-levels fluctuated markedly and this may have influenced later overriding of the site by an ice stream. © 2014 Natural Environment Research Council. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60039
Appears in Collections: 过去全球变化的重建
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作者单位: British Geological Survey, Keyworth, Nottingham, United Kingdom; British Geological Survey, West Mains Road, Edinburgh, United Kingdom
Recommended Citation:
Lee J.R.,Wakefield O.J.W.,Phillips E.,et al. Sedimentary and structural evolution of a relict subglacial to subaerial drainage system and its hydrogeological implications: An example from Anglesey, north Wales, UK[J]. Quaternary Science Reviews,2015-01-01,109