DOI: 10.1016/j.epsl.2018.03.056
Scopus记录号: 2-s2.0-85045554539
论文题名: Climate-driven unsteady denudation and sediment flux in a high-relief unglaciated catchment–fan using 26Al and 10Be: Panamint Valley, California
作者: Mason C.C. ; Romans B.W.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 492 起始页码: 130
结束页码: 143
语种: 英语
英文关键词: catchment–fan
; climate
; cosmogenic radionuclides
; paleodenudation
; sediment routing system
; signal propagation
Scopus关键词: Catchments
; Climate change
; Landslides
; Radioisotopes
; Runoff
; Sedimentology
; Sediments
; Stratigraphy
; Temperature
; climate
; Cosmogenic radionuclides
; paleodenudation
; Sediment-routing
; Signal propagation
; Climate models
; alluvial fan
; aluminum
; beryllium isotope
; catchment
; climate effect
; cosmogenic radionuclide
; denudation
; fluvial deposit
; paleoclimate
; paleoenvironment
; Pleistocene
; California
; Panamint Valley
; United States
英文摘要: Environmental changes within erosional catchments of sediment routing systems are predicted to modulate sediment transfer dynamics. However, empirical and numerical models that predict such phenomena are difficult to test in natural systems over multi-millennial timescales. Tectonic boundary conditions and climate history in the Panamint Range, California, are relatively well-constrained by existing low-temperature thermochronology and regional multi-proxy paleoclimate studies, respectively. Catchment–fan systems present there minimize sediment storage and recycling, offering an excellent natural laboratory to test models of climate-sedimentary dynamics. We used stratigraphic characterization and cosmogenic radionuclides (CRNs; 26Al and 10Be) in the Pleasant Canyon complex (PCC), a linked catchment–fan system, to examine the effects of Pleistocene high-magnitude, high-frequency climate change on CRN-derived denudation rates and sediment flux in a high-relief, unglaciated catchment–fan system. Calculated 26Al/10Be burial ages from 13 samples collected in an ∼180 m thick outcropping stratigraphic succession range from ca. 1.55 ± 0.22 Ma in basal strata, to ca. 0.36 ± 0.18–0.52 ± 0.20 Ma within the uppermost part of the succession. The mean long-term CRN-derived paleodenudation rate, 36 ± 8 mm/kyr (1σ), is higher than the modern rate of 24 ± 0.6 mm/kyr from Pleasant Canyon, and paleodenudation rates during the middle Pleistocene display some high-frequency variability in the high end (up to 54 ± 10 mm/kyr). The highest CRN-derived denudation rates are associated with stratigraphic evidence for increased precipitation during glacial–pluvial events after the middle Pleistocene transition (post ca. 0.75 Ma), suggesting 100 kyr Milankovitch periodicity could drive the observed variability. We investigated the potential for non-equilibrium sedimentary processes, i.e. increased landslides or sediment storage/recycling, to influence apparent paleodenudation rates; end-member mixing models suggest that a mixture of >50% low-CRN-concentration sediment from landslides is required to produce the largest observed increase in paleodenudation rate. The overall pattern of CRN-derived burial ages, paleodenudation rates, and stratigraphic facies suggests Milankovitch timescale climate transitions drive variability in catchment denudation rates and sediment flux, or alternatively that climate transitions affect sedimentary process regimes that result in measurable variability of CRN concentrations in unglaciated catchment–fan systems. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109898
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 Geosciences, Virginia Tech, Blacksburg, VA 24061, United States
Recommended Citation:
Mason C.C.,Romans B.W.. Climate-driven unsteady denudation and sediment flux in a high-relief unglaciated catchment–fan using 26Al and 10Be: Panamint Valley, California[J]. Earth and Planetary Science Letters,2018-01-01,492