DOI: 10.1016/j.quascirev.2018.03.010
Scopus记录号: 2-s2.0-85044138616
论文题名: A subaquatic moraine complex in overdeepened Lake Thun (Switzerland) unravelling the deglaciation history of the Aare Glacier
作者: Fabbri S.C. ; Buechi M.W. ; Horstmeyer H. ; Hilbe M. ; Hübscher C. ; Schmelzbach C. ; Weiss B. ; Anselmetti F.S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 187 起始页码: 62
结束页码: 79
语种: 英语
英文关键词: Aare Valley
; Deglaciation
; Gemorphology (glacial)
; Overdeepening
; Quaternary
; Seismic stratigraphy
; Subaquatic moraine complex
; Western Europe
Scopus关键词: Deposition
; Geochronology
; Glacial geology
; Sea level
; Sedimentology
; Seismology
; Stratigraphy
; Aare Valley
; Deglaciations
; Gemorphology (glacial)
; Overdeepening
; Quaternary
; Seismic stratigraphy
; Subaquatic moraine complex
; Western Europe
; Lakes
; bathymetry
; bedrock
; deglaciation
; geomorphology
; glacial erosion
; moraine
; seismic reflection
; seismic stratigraphy
; subarctic region
; Aare Valley
; Bern [Switzerland]
; Switzerland
; Thunersee
英文摘要: To investigate the history of the Aare Glacier and its overdeepened valley, a high-resolution multibeam bathymetric dataset and a 2D multi-channel reflection seismic dataset were acquired on perialpine Lake Thun (Switzerland). The overdeepened basin was formed by a combination of tectonically predefined weak zones and glacial erosion during several glacial cycles. In the deepest region of the basin, top of bedrock lies at ∼200 m below sea level, implying more than 750 m of overdeepening with respect to the current fluvial base level (i.e. lake level). Seismic stratigraphic analysis reveals the evolution of the basin and indicates a subaquatic moraine complex marked by high-amplitude reflections below the outermost edge of a morphologically distinct platform in the southeastern part of the lake. This stack of seven subaquatic terminal moraine crests was created by a fluctuating, “quasi-stagnant” grounded Aare Glacier during its overall recessional phase. Single packages of overridden moraine crests are seismically distuinguishable, which show a transition downstream into prograding clinoforms with foresets at the ice-distal slope. The succession of subaquatic glacial sequences (foresets and adjacent bottomsets) represent one fifth of the entire sedimentary thickness. Exact time constraints concerning the deglacial history of the Aare Glacier are very sparse. However, existing 10Be exposure ages from the accumulation area of the Aare Glacier and radiocarbon ages from a Late-Glacial lake close to the outlet of Lake Thun indicate that the formation of the subaquatic moraine complex and the associated sedimentary infill must have occurred in less than 1000 years, implying high sedimentation rates and rapid disintegration of the glacier. These new data improve our comprehension of the landforms associated with the ice-contact zone in water, the facies architecture of the sub- to proglacial units, the related depositional processes, and thus the retreat mechanisms of the Aare Glacier. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112228
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Geological Sciences, Baltzerstrasse 1+3, Bern, 3012, Switzerland; Institute of Geological Sciences, Oeschger Centre of Climate Change Research, University of Bern, Baltzerstrasse 1+3, Bern, 3012, Switzerland; Institute of Geophysics, Dept. of Earth Sciences, ETH Zürich, Sonneggstr. 5, Zürich, CH-8092, Switzerland; Institute of Geophysics, Center for Earth System Research and Sustainability, University of Hamburg, Bundesstr. 55, Hamburg, D-20146, Germany
Recommended Citation:
Fabbri S.C.,Buechi M.W.,Horstmeyer H.,et al. A subaquatic moraine complex in overdeepened Lake Thun (Switzerland) unravelling the deglaciation history of the Aare Glacier[J]. Quaternary Science Reviews,2018-01-01,187