DOI: 10.1016/j.quascirev.2013.11.017
Scopus记录号: 2-s2.0-84890287258
论文题名: Lake Neuchâtel (Switzerland) seismic stratigraphic record points to the simultaneous Würmian deglaciation of the RhÔne Glacier and Jura Ice Cap
作者: Ndiaye M. ; Clerc N. ; Gorin G. ; Girardclos S. ; Fiore J.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 85 起始页码: 1
结束页码: 19
语种: 英语
英文关键词: Deltas
; Fjord-lake
; Glacial
; Glacier readvances
; Glacio-lacustrine
; La Lance fault zone
; Moraines
; Perialpine lake
; Subglacial
Scopus关键词: Deltas
; Fault zone
; Fjord-lake
; Glacial
; Glacio-lacustrine
; Moraines
; Subglacial
; Catchments
; Deposits
; Glacial geology
; Rivers
; Sediments
; Seismic waves
; Seismology
; Snow
; Stratigraphy
; Lakes
; altitude
; amplitude
; correlation
; deglaciation
; delta
; depositional environment
; fault zone
; glaciation
; lacustrine deposit
; Last Glacial Maximum
; Mesozoic
; moraine
; seismic anisotropy
; seismic reflection
; strike-slip fault
; subglacial environment
; Antarctica
; East Antarctica
; Rhone Glacier
; Switzerland
英文摘要: Lake Neuchâtel, located at the foothills of the Jura Mountains in Western Switzerland, is one of the numerous perialpine lakes on the Swiss Plateau. It overlies a SW-NE trending paleovalley eroded during Quaternary glaciations through a branch of the RhÔne Glacier extending northeastwards over the Swiss Plateau. This paleovalley, cut into Molasse siliciclastics and accessorily Mesozoic carbonates, was filled by late Quaternary sediments.A grid of high-resolution seismic profiles (5-inch3 and 1-inch3 airguns) images at lake-scale the up to 200m thick sedimentary sequence down to the bedrock. The latter is locally affected by a major strike-slip fault zone (La Lance) that has influenced glacial erosion. The infill consists of four seismic stratigraphic units (Units U1-U4), the shallowest two being subdivided into three subunits each (U3a,b,c and U4a,b,c). Units U1 and U2 are directly related to the RhÔne Glacier and Jura Ice Cap activity. Unit U1 corresponds to acoustically chaotic subglacial deposits interpreted as tills (and locally eskers) and is associated to the Last Glacial Maximum (Würm Glacial Maximum, WGM) and probably to the beginning of deglaciation of the RhÔne Glacier and Jura Ice Cap. Unit U2 is restricted to the central axis of the glacial paleovalley and reaches a thickness of over 100m at some places. Its dominantly transparent seismic facies is interpreted as pro- to subglacio-lacustrine fine sediments deposited during the main phase of deglaciation. In the southern part of the lake, higher acoustic amplitudes indicate more compacted, coarser sediments forming a mound structure, interpreted as moraine deposits. This moraine facies points to phases of RhÔne Glacier readvances during Unit U2, as seen in other perialpine lakes. With its continuous and subparallel reflections, Subunit U3a marks the beginning of a glacio-lacustrine, and later, lacustrine environment. Subunit U3a extends over the whole lake and contains two more localized subunits (U3b and U3c) displaying prograding and downlapping reflections, as well as signatures of mass transport deposits. These two subunits are interpreted as deltaic sequences from the La Mentue (Subunit U3b) and Areuse (Subunit U3c) tributary rivers. The base of these sequences marks the synchronous onset of a major melting phase in respectively the RhÔne Glacier and Jura Ice Cap. Correlation with previously obtained core data indicates that the lower part of Unit U3 most certainly dates back to the Oldest Dryas and that the U3 depositional processes lasted at least until the end of the Younger Dryas and possibly until the Boreal biozone. By contrast with the deltaic seismofacies of the Mentue River (Subunit U3b), which stops close to the base of Subunit U4a, the Areuse River deltaic unit (Subunit U3c) continues to build up as Subunit U4c deposited synchronously with subunits U4a and U4b, probably because of the larger size, higher altitude and partly glacial nature of the catchment area of the Areuse River. Subunits U4a and U4b, with continuous and subparallel seismic reflections extending over the whole lake, are interpreted as lacustrine sequences. Correlation with previously collected sediment cores in Lake Neuchâtel and similar deposits in Lake Annecy dates the onset of lacustrine sedimentation sometimes between the end of the Younger Dryas and the Boreal biozones. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60396
Appears in Collections: 过去全球变化的重建
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作者单位: Earth and Environmental Science Section, University of Geneva, rue des Maraîchers 13, CH-1205 Geneva, Switzerland; Institut des Sciences de l'Environnement, Université de Genève, route de Drize 7, CH-1226 Carouge, Switzerland
Recommended Citation:
Ndiaye M.,Clerc N.,Gorin G.,et al. Lake Neuchâtel (Switzerland) seismic stratigraphic record points to the simultaneous Würmian deglaciation of the RhÔne Glacier and Jura Ice Cap[J]. Quaternary Science Reviews,2014-01-01,85