DOI: 10.1016/j.epsl.2018.06.002
Scopus记录号: 2-s2.0-85048837301
论文题名: Evolution of soil erosion rates in alpine soils of the Central Rocky Mountains using fallout Pu and δ13C
作者: Portes R. ; Dahms D. ; Brandová D. ; Raab G. ; Christl M. ; Kühn P. ; Ketterer M. ; Egli M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 496 起始页码: 257
结束页码: 269
语种: 英语
英文关键词: carbon isotopes
; Late Pleistocene
; Pu isotopes
; slope stability
; soil chronosequence
; Wind River Range
Scopus关键词: Erosion
; Isotopes
; Organic carbon
; Slope stability
; Weathering
; Calculation procedure
; Carbon isotopes
; Late Pleistocene
; Qualitative information
; Soil chronosequence
; Stable carbon isotopes
; Surface exposure dating
; Wind River
; Soils
; alpine environment
; bioturbation
; carbon isotope
; chronosequence
; erosion rate
; moraine
; Pleistocene
; plutonium isotope
; slope stability
; soil erosion
; Rocky Mountains
; United States
; Wind River Range
; Wyoming
英文摘要: Data from soil chronosequences have been widely used to quantify soil formation and weathering rates, but are less used to determine erosion rates and the stabilisation of moraines over time. We hypothesise that soil erosion rates on moraine hillslopes decrease over time as soils evolve and slopes stabilise. We selected a sequence of moraines in the Wind River Range (Central Rocky Mountains) to study these processes over time. Moraine ages were based on 10Be surface exposure dating of moraine boulders. Quantitative soil erosion and accumulation rates along slopes with similar exposures, lengths and gradients were determined from profile patterns of 239+240Pu radionuclides. We used stable carbon isotopes (δ13C) in relation with the total soil organic carbon (SOC) content for qualitative information about soil erosion. The 10Be boulder exposure ages revealed that the moraines were deposited during the Younger Dryas and the pre Bølling–Allerød episodes of the late Pleistocene. The morphology of the soils suggests a complex history of development and shows that both erosion and aeolian deposition have affected the soils. The 239+240Pu measurements revealed that erosion rates strongly decrease with time as soils develop. A weakly developed soil (Cambisol) is found on the youngest moraine (11.8 ka) that exhibits an erosion rate, depending on the calculation procedure, in the range of 260 to 520 t km−2 a−1. With time the erosion rate rapidly decreases to almost zero, presumably as a full vegetation cover develops. Bioturbation and/or dust influx is increasingly obvious with increasing age of the soils, as evidenced by the comparison of δ13C and SOC. The mass balance of the oldest soil (15.8 ka) indicates that the slopes have reached a geomorphological stability with little or no net erosion. Aeolian influx appears to be the primary factor to account for mass changes in the oldest soil. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109796
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: Department of Geography, University of Zurich, Winterthurerstrasse 190, Zurich, CH-8057, Switzerland; Department of Geography, University of Northern Iowa, Cedar Falls, IA 50614-0406, United States; Laboratory of Ion Beam Physics, ETH Zurich, Zurich, 8093, Switzerland; Research Area Geography, Soil Science and Geomorphology, Department of Geosciences, University of Tübingen, Rümelinstrasse, 19-23, Tübingen, 72070, Germany; Chemistry Department, Metropolitan State University of Denver, Campus Box 52, Denver, CO 80217-3362, United States
Recommended Citation:
Portes R.,Dahms D.,Brandová D.,et al. Evolution of soil erosion rates in alpine soils of the Central Rocky Mountains using fallout Pu and δ13C[J]. Earth and Planetary Science Letters,2018-01-01,496