DOI: 10.1016/j.quascirev.2014.02.002
Scopus记录号: 2-s2.0-84896124363
论文题名: Flow-pattern evolution of the last British Ice Sheet
作者: Hughes A.L.C. ; Clark C.D. ; Jordan C.J.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 89 起始页码: 148
结束页码: 168
语种: 英语
英文关键词: British ice sheet
; Flowsets
; Ice-flow patterns
; Last glacial maximum
; Subglacial bedforms
Scopus关键词: Flow patterns
; Glacial geology
; Glaciers
; Numerical models
; Bedforms
; Flowsets
; Ice sheet
; Ice-flow patterns
; Last Glacial Maximum
; Ice
; flow pattern
; geomorphology
; ice cover
; ice flow
; ice retreat
; ice sheet
; last ice sheet
; orientation
; Atlantic Ocean
; England
; North Sea
; United Kingdom
英文摘要: We present a 10-stage reconstruction of the evolution in ice-flow patterns of the last British Ice Sheet from build-up to demise derived from geomorphological evidence. 100 flowsets identified in the subglacial bedform record (drumlins, mega-scale glacial lineations, and ribbed moraine) are combined with ancillary evidence (erratic-transport paths, absolute dates and a semi-independently reconstructed retreat pattern) to define flow patterns, ice divides and ice-sheet margins during build-up, maximum glaciation and retreat. Overprinting and cross-cutting of landform assemblages are used to define the relative chronology of flow patterns and a tentative absolute chronology is presented based on a collation of available dates for ice advance and retreat. The ice-flow configuration of the last British Ice Sheet was not static. Some ice divides were remarkably stable, persisting through multiple stages of the ice-sheet evolution, whereas others were transient features existing for a short time and/or shifting in position 10skm. The 10 reconstructed stages of ice-sheet geometry capture two main modes of operation; first as an integrated ice sheet with a broadly N-S orientated ice divide, and second as a multi-domed ice sheet orientated parallel with the shelf edge. A thick integrated ice sheet developed as ice expanded out of source areas in Scotland to envelop southerly ice caps in northern England and Wales, and connect with the Irish Ice Sheet to the west and the Scandinavian Ice Sheet across the North Sea. Following break-up of ice over the North Sea, ice streaming probably drove mass loss and ice-sheet thinning to create a more complex divide structure, where ice-flow patterns were largely controlled by the form of the underlying topography. Ice surface lowering occurred before separation of, and retreat to, multiple ice centres centred over high ground. We consider this 10-stage reconstruction of the evolution in ice-sheet configuration to be the simplest palaeo-glaciological interpretation of the flowsets identified from the geomorphological record and their relative timing. This empirically-based reconstruction of flow-pattern geometry provides a framework for more detailed local and regional studies and numerical modelling to provide robust explanations of the observed changes in ice-sheet structure in terms of climate and glacial dynamics. As a minimum, numerical model outputs should be able to reproduce the identified flowset patterns in space and satisfy their chronological order. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60345
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Science, University of Bergen, N-5007 Bergen, Norway; Department of Geography, University of Sheffield, Sheffield S10 2TN, United Kingdom; British Geological Survey, Keyworth, Nottingham NG12 5GG, United Kingdom
Recommended Citation:
Hughes A.L.C.,Clark C.D.,Jordan C.J.. Flow-pattern evolution of the last British Ice Sheet[J]. Quaternary Science Reviews,2014-01-01,89