DOI: 10.1016/j.quascirev.2017.10.027
Scopus记录号: 2-s2.0-85034755085
论文题名: Ice streams of the Late Wisconsin Cordilleran Ice Sheet in western North America
作者: Eyles N. ; Arbelaez Moreno L. ; Sookhan S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 179 起始页码: 87
结束页码: 122
语种: 英语
英文关键词: Cordilleran Ice Sheet
; Drumlins
; Megascale glacial lineations
; Paleo ice streams
Scopus关键词: Catchments
; Cloning
; Glacial geology
; Glaciers
; Landforms
; Mapping
; Sediments
; British Columbia
; Cordilleran ice sheet
; Digital imagery
; Drumlins
; Glacial lineation
; Greenland Ice Sheet
; Ice streams
; Scale distributions
; Ice
; bedrock
; Cordilleran Ice Sheet
; deglaciation
; drumlin
; erosion
; glacial rebound
; ice core
; ice stream
; meltwater
; mesoscale eddy
; Wisconsinan
; Arctic
; British Columbia
; Canada
; Greenland
; Greenland Ice Sheet
; North America
; Pacific Coast [North America]
; Pacific Coast [United States]
; United States
; Wisconsin
英文摘要: The Late Wisconsin Cordilleran Ice Sheet (CIS) of western North America is thought to have reached its maximum extent (∼2.5 × 106 km2) as late at c. 14.5 ka. Most (80%) of the ice sheet's bed consists of high mountains but its ‘core zone’ sited on plateaux of the Intermontane Belt of British Columbia and coterminous parts of the USA, shows broad swaths of subglacially-streamlined rock and sediment. Broad scale mapping from new digital imagery data identifies three subglacial bed types: 1) ‘hard beds’ of variably streamlined bedrock; 2) drumlinized 'soft beds’ of deformation till reworked from antecedent sediment, and 3) ‘mixed beds’ of variably-streamlined bedrock protruding through drumlinized sediment. Drumlins on soft beds appear to be erosional features cut into till and antecedent sediments, and identify the catchment areas of paleo ice streams expressed downglacier as flow sets of megascale glacial lineations (MSGLs). ‘Grooved’ and ‘cloned’ drumlins appear to record the transition from drumlins to MSGLs. The location of paleo ice streams reflects topographic funneling of ice from plateau surfaces through outlet valleys and a soft bed that sustained fast flow; rock-cut MSGLs are also present locally on the floors of outlet valleys. CIS disintegrated in <1000 years shortly after c. 13.0 ka releasing very large volumes of meltwater and sediment to the Pacific coast. Abrupt deglaciation may reflect unsustainable calving of marine-based ice streams along the glacio-isostatically depressed coast; large deep ‘fiord lakes’ in the ice sheet's interior may have played an analogous role. Mapping of the broad scale distribution of bed types across the Cordilleran Ice Sheet provides key information for paleoglaciological modelling and also for understanding the beds of modern ice masses such as the Greenland Ice Sheet which is of a comparable topographic setting. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112347
Appears in Collections: 气候减缓与适应
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作者单位: Department of Physical and Environmental Sciences, University of Toronto at Scarborough, 1265 Military Trail, Scarborough, ON M1C 1A4, Canada
Recommended Citation:
Eyles N.,Arbelaez Moreno L.,Sookhan S.. Ice streams of the Late Wisconsin Cordilleran Ice Sheet in western North America[J]. Quaternary Science Reviews,2018-01-01,179