DOI: 10.1016/j.epsl.2020.116441
论文题名: Glacial influence on late Pleistocene 10Be-derived paleo-erosion rates in the north-western Himalaya, India
作者: Kapannusch R. ; Scherler D. ; King G. ; Wittmann H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 547 语种: 英语
中文关键词: climate change
; cosmogenic nuclides
; Himalaya
; late Pleistocene
; Paleo-erosion rates
英文关键词: Catchments
; Cosmology
; Deposits
; Ice
; Runoff
; Sand
; Erosion rates
; Fluvial deposits
; Glacial influences
; High elevation
; Late Pleistocene
; Surface exposure age
; Terrace sands
; Terrestrial cosmogenic nuclides
; Erosion
; beryllium isotope
; concentration (composition)
; cosmogenic radionuclide
; erosion rate
; flow modeling
; fluvial deposit
; glacier
; pebble
; Pleistocene
; reconstruction
; sand
; valley fill
; Himalayas
; India
; Yamuna Basin
英文摘要: Terrestrial cosmogenic nuclide concentrations in fluvial deposits allow estimation of paleo-erosion rates and reconstruction of the response of landscapes to climatic perturbations. In partly ice-covered landscapes, however, incorporation of subglacially-derived sediments that were shielded by ice from cosmic can lead to erroneous erosion rate calculations. Here, we combine in situ-produced 10Be-derived erosion rates, based on sand and pebbles from a fluvial fill terrace and the modern riverbed in the upper Yamuna catchment, with numerical ice flow modelling to quantify this bias. New luminescence and surface exposure ages suggest that aggradation of the exposed deposits occurred between 29.9 ± 2.5 ka and 14.8 ± 2.8 ka. During most of the deposition, glaciers probably covered ∼19% of the catchment. 10Be concentrations of terrace sand samples differ from those of pebble samples. We obtained the lowest erosion rates from quartzite pebbles, which stem from low elevations, and the highest erosion rates from crystalline pebbles, which stem from high elevations in the Yamuna catchment. We explain these different erosion rates by differences in the steepness of the source areas, an effect that prevails throughout the entire aggradation period despite significant former ice-cover. Sand samples, which are thought to be derived from all elevation parts of the catchment, however show lower 10Be concentrations during the aggradation compared to present-day. We argue that this difference is due to a substantial subglacial origin of the sand during the aggradation period, and not necessarily related to enhanced erosion. We conclude that aggradation of the valley fill in the Yamuna catchment is most likely due to reduced discharge, and only marginally related to higher erosion rates during the late Pleistocene. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165070
Appears in Collections: 气候变化与战略
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作者单位: GFZ German Research Centre for Geosciences, Potsdam, Germany; Freie Universität Berlin, Berlin, Germany; Institute of Geological Sciences, University of Bern, Bern, Switzerland; Institute of Earth Surface Dynamics, Université de Lausanne, Lausanne, Switzerland
Recommended Citation:
Kapannusch R.,Scherler D.,King G.,et al. Glacial influence on late Pleistocene 10Be-derived paleo-erosion rates in the north-western Himalaya, India[J]. Earth and Planetary Science Letters,2020-01-01,547