DOI: 10.1016/j.quascirev.2017.04.011
Scopus记录号: 2-s2.0-85018583362
论文题名: Glacial dispersal and flow history, East Arm area of Great Slave Lake, NWT, Canada
作者: Sharpe D.R. ; Kjarsgaard B.A. ; Knight R.D. ; Russell H.A.J. ; Kerr D.E.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2017
卷: 165 起始页码: 49
结束页码: 72
语种: 英语
英文关键词: Canada
; Divergent flow
; Esker samples
; Glacial dispersal
; Glaciofluvial meltwater corridors
; Great Slave Lake
; Laurentide Ice Sheet
; Till samples
Scopus关键词: Erosion
; Flow patterns
; Geomorphology
; Glacial geology
; Glaciers
; Lakes
; Landforms
; Minerals
; Sediments
; Canada
; Divergent flow
; Glacial dispersal
; Glaciofluvial meltwater corridors
; Laurentide ice sheets
; Ice
英文摘要: Little work has been completed on paleo-ice-sheet flow indicators of the Laurentide Ice Sheet, west of the Keewatin Ice Divide. Field mapping, sampling and analysis of glaciogenic sediment (∼500 sample sites) in a ∼33,000 km2 region near the East Arm of Great Slave Lake in northwestern Canada, provided a rare opportunity to improve understanding of sediment erosion and transport patterns. Glacially-eroded bedrock and sedimentary landforms record east to west flow with NW and SW divergence, mapped within a portion of the Great Slave Lake flow tract. Transported till reflects a similar divergent flow pattern based on dispersal geometries for multiple indicators (e.g., heavy minerals and lithic fragments), which are aligned with the dominant and latest ice flow direction. Glaciofluvial erosion (e.g., s-forms and till removal), transport, and deposition (mainly as esker sediment) are set within 0.3–3 km wide meltwater erosional corridors, spaced regularly at 10–15 km intervals. Transport paths and distances are comparable in till and esker sediment, however, distances appear to be greater (∼5–25 km) in some esker constituents and indicator minerals are typically more concentrated in esker sediment than in till. Corridors form a divergent array identical to the pattern of ice-flow features. The congruence of ice and meltwater flow features is interpreted to be a response to a similar ice sheet gradient, and close timing of events (late dominant glacial ice flow and meltwater flow). The similarity in glacial and glaciofluvial flow patterns has important ramifications for event reconstruction and for exploration geologists utilizing mineral and geochemical tracing methods in this region, and possibly other parts of northern Canada. The correspondence between East Arm dispersal patterns, landforms and flow indicators supports interpretation of a simple and predictable single flow divergence model. This is in contrast to previous, multi-flow models, in which fan-shaped geometries are often reported to result from multiple transport events, compared to single-flow divergence. The observed widespread effects of glaciofluvial processes (e.g., erosional corridors) indicate a need to update existing terrain process models. © 2017 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59228
Appears in Collections: 过去全球变化的重建
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作者单位: Geological Survey of Canada, 601 Booth St., Ottawa, Ontario, Canada
Recommended Citation:
Sharpe D.R.,Kjarsgaard B.A.,Knight R.D.,et al. Glacial dispersal and flow history, East Arm area of Great Slave Lake, NWT, Canada[J]. Quaternary Science Reviews,2017-01-01,165