DOI: 10.1016/j.epsl.2017.11.050
Scopus记录号: 2-s2.0-85040764128
论文题名: Signatures of Late Pleistocene fluvial incision in an Alpine landscape
作者: Leith K. ; Fox M. ; Moore J.R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 483 起始页码: 13
结束页码: 28
语种: 英语
英文关键词: fluvial erosion
; glacial erosion
; landscape evolution
; quaternary
; river profile analysis
; Swiss Alps
Scopus关键词: Catchments
; Erosion
; Glacial geology
; Rivers
; Fluvial erosion
; Glacial erosion
; Landscape evolutions
; quaternary
; River profile
; Swiss Alps
; Uncertainty analysis
; fluvial deposit
; glacial erosion
; landscape evolution
; Pleistocene
; Quaternary
; sediment transport
; Alps
; Rhone River
; Switzerland
英文摘要: Uncertainty regarding the relative efficacy of fluvial and glacial erosion has hindered attempts to quantitatively analyse the Pleistocene evolution of alpine landscapes. Here we show that the morphology of major tributaries of the Rhone River, Switzerland, is consistent with that predicted for a landscape shaped primarily by multiple phases of fluvial incision following a period of intense glacial erosion after the mid-Pleistocene transition (∼0.7 Ma). This is despite major ice sheets reoccupying the region during cold intervals since the mid-Pleistocene. We use high-resolution LiDAR data to identify a series of convex reaches within the long-profiles of 18 tributary channels. We propose these reaches represent knickpoints, which developed as regional uplift raised tributary bedrock channels above the local fluvial baselevel during glacial intervals, and migrated upstream as the fluvial system was re-established during interglacial periods. Using a combination of integral long-profile analysis and stream-power modelling, we find that the locations of ∼80% of knickpoints in our study region are consistent with that predicted for a fluvial origin, while the mean residual error over ∼100 km of modelled channels is just 26.3 m. Breaks in cross-valley profiles project toward the elevation of former end-of-interglacial channel elevations, supporting our model results. Calculated long-term uplift rates are within ∼15% of present-day measurements, while modelled rates of bedrock incision range from ∼1 mm/yr for low gradient reaches between knickpoints to ∼6–10 mm/yr close to retreating knickpoints, typical of observed rates in alpine settings. Together, our results reveal approximately 800 m of regional uplift, river incision, and hillslope erosion in the lower half of each tributary catchment since 0.7 Ma. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110085
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Geological Institute, ETH Zurich, Sonneggstrasse 5, Zurich, 8092, Switzerland; Chair of Landslide Research, Technische Universität München, Arcisstrasse 21, Munich, 80333, Germany; Department of Earth Sciences, University College London, Gower St., Kings Cross London, WC1E 6BT, United Kingdom; Geology and Geophysics, University of Utah, 115 South 1460, Salt Lake City, UT 84112-0102, United States
Recommended Citation:
Leith K.,Fox M.,Moore J.R.. Signatures of Late Pleistocene fluvial incision in an Alpine landscape[J]. Earth and Planetary Science Letters,2018-01-01,483