DOI: 10.1016/j.epsl.2018.09.006
Scopus记录号: 2-s2.0-85053386439
论文题名: Erosion of coastal drainages in the Mendocino Triple Junction region (MTJ), northern California
作者: Moon S. ; Merritts D.J. ; Snyder N.P. ; Bierman P. ; Sanquini A. ; Fosdick J.C. ; Hilley G.E.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 502 起始页码: 156
结束页码: 165
语种: 英语
英文关键词: cosmogenic radionuclide
; denudation
; erosion
; landscape evolution
; Mendocino Triple Junction
; tectonic
Scopus关键词: Catchments
; Cosmic rays
; Cosmology
; Magnetic devices
; Rocks
; Runoff
; Tectonics
; Coastal catchments
; Cosmogenic radionuclides
; denudation
; Dynamic equilibria
; Equilibrium state
; Landscape evolutions
; Mendocino triple junctions
; Topographic features
; Erosion
; coastal erosion
; cosmogenic radionuclide
; denudation
; erosion rate
; landscape evolution
; sediment transport
; tectonic setting
; uplift
; California
; Mendocino Triple Junction
; Pacific Ocean
; United States
英文摘要: The Mendocino Triple Junction (MTJ) region in northern California is an archetype for studying landscape response to varying rock uplift rates as they increase toward the triple junction. Underpinning these studies lies the assumption that this landscape has reached a dynamic equilibrium in which rock uplift and erosion rates are equal; however, no study has shown that such an equilibrium actually exists around the MTJ region. Here, we report 10Be- and 26Al-derived erosion rates calculated from isotope concentrations in detrital, fluvial sediment from coastal drainage basins; we then compare these rates with uplift rates inferred from marine terraces that were formed and preserved by uplift during the last ∼305 ka. Erosion rates in the more slowly uplifting southern part of the region range from 0.21–0.32 mm/yr and are consistent with rock uplift rates since 305 ka. However, in the northern transition zone, where uplift rates apparently started to increase about ∼100 ka due to northward migration of the MTJ, erosion rates are higher, 0.43 to 0.69 mm/yr. These rates are similar to uplift rates from 96–305 ka, but substantially less than recent uplift rates of ∼3.5–4 mm/yr inferred for the past ∼72 ka. In the central part of the King Range, finite erosion rates cannot be determined due to (i) the presence of excess 10Be that does not appear to have originated from in-situ cosmic-ray production during erosion and transport of the sediment, and (ii) 26Al concentrations below detection limits. The difference between catchment-wide erosion and recent uplift rates in coastal catchments may be related to a lag in response of hillslopes and tributaries to changes in rates of tectonically-driven relative base-level fall or the uncertainties in rock uplift rates inferred from marine terraces. This study suggests that measurements of both erosion and uplift rates are crucial in assessing the equilibrium state of landscapes and in understanding the topographic features made by surface and tectonic processes. © 2018 Elsevier B.V.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109652
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 Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095, United States; Department of Geological Sciences, Stanford University, Stanford, CA 94305, United States; Department of Earth and Environment, Franklin and Marshall College, Lancaster, PA 17604, United States; Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA 02467, United States; Department of Geology, Rubenstein School of the Environment Natural Resources, University of Vermont, Burlington, VT 05405, United States; Center for Integrative Geosciences, Department of Geography, University of Connecticut, Storrs, CT 06269, United States
Recommended Citation:
Moon S.,Merritts D.J.,Snyder N.P.,et al. Erosion of coastal drainages in the Mendocino Triple Junction region (MTJ), northern California[J]. Earth and Planetary Science Letters,2018-01-01,502