DOI: 10.1016/j.quascirev.2017.12.018
Scopus记录号: 2-s2.0-85043358532
论文题名: Geomorphology and till architecture of terrestrial palaeo-ice streams of the southwest Laurentide Ice Sheet: A borehole stratigraphic approach
作者: Norris S.L. ; Evans D.J.A. ; Cofaigh C.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 186 起始页码: 186
结束页码: 214
语种: 英语
英文关键词: Borehole stratigraphy
; Glacial landsystems
; Laurentide Ice Sheet palaeoglaciology
; Palaeo-ice stream
; Till architecture
Scopus关键词: Architecture
; Geomorphology
; Glacial geology
; Glaciers
; Landforms
; Mapping
; Radio systems
; Stratigraphy
; Flow direction
; Geomorphological mapping
; Glacial landsystems
; Glacial lineation
; Ice streams
; Laurentide ice sheets
; Stratigraphic units
; Subglacial deformations
; Ice
; architecture
; borehole
; geomorphological mapping
; geomorphology
; glacial environment
; glaciology
; ice stream
; Laurentide Ice Sheet
; paleoenvironment
; reconstruction
; stratigraphy
; subglacial environment
; topography
; Canada
; Saskatchewan
英文摘要: A multidimensional study, utilising geomorphological mapping and the analysis of regional borehole stratigraphy, is employed to elucidate the regional till architecture of terrestrial palaeo-ice streams relating to the Late Wisconsinan southwest Laurentide Ice Sheet. Detailed mapping over a 57,400 km2 area of southwestern Saskatchewan confirms previous reconstructions of a former southerly flowing ice stream, demarcated by a 800 km long corridor of megaflutes and mega-scale glacial lineations (Ice Stream 1) and cross cut by three, formerly southeast flowing ice streams (Ice Streams 2A, B and C). Analysis of the lithologic and geophysical characteristics of 197 borehole samples within these corridors reveals 17 stratigraphic units comprising multiple tills and associated stratified sediments overlying preglacial deposits, the till thicknesses varying with both topography and distance down corridor. Reconciling this regional till architecture with the surficial geomorphology reveals that surficial units are spatially consistent with a dynamic switch in flow direction, recorded by the cross cutting corridors of Ice Streams 1, 2A, B and C. The general thickening of tills towards lobate ice stream margins is consistent with subglacial deformation theory and variations in this pattern on a more localised scale are attributed to influences of subglacial topography including thickening at buried valley margins, thinning over uplands and thickening in overridden ice-marginal landforms. © 2018 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112241
Appears in Collections: 气候减缓与适应
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作者单位: Department of Geography, Durham University, South Road, Durham, DH1 3LE, United Kingdom; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2H4, Canada
Recommended Citation:
Norris S.L.,Evans D.J.A.,Cofaigh C.. Geomorphology and till architecture of terrestrial palaeo-ice streams of the southwest Laurentide Ice Sheet: A borehole stratigraphic approach[J]. Quaternary Science Reviews,2018-01-01,186