DOI: 10.1016/j.epsl.2018.04.029
Scopus记录号: 2-s2.0-85046369205
论文题名: Lithologic controls on landscape dynamics and aquatic species evolution in post-orogenic mountains
作者: Gallen S.F.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 493 起始页码: 150
结束页码: 160
语种: 英语
英文关键词: biodiversity
; drainage basin dynamics
; erodibility
; landscape evolution
; post-orogenic
Scopus关键词: Biodiversity
; Climate change
; Dynamics
; Erosion
; Geodynamics
; Inverse problems
; Landforms
; Rivers
; Stratigraphy
; Tectonics
; Watersheds
; Erodibility
; Evolutionary pathway
; Inverse modeling
; Landscape dynamics
; Landscape evolutions
; Lithologic controls
; post-orogenic
; Southern Appalachian Mountains
; Catchments
; aquatic organism
; biodiversity
; drainage basin
; erodibility
; erosion rate
; fluvial geomorphology
; landscape evolution
; lithology
; mountain
; Appalachians
; Tennessee Basin
; United States
英文摘要: Determining factors that modify Earth's topography is essential for understanding continental mass and nutrient fluxes, and the evolution and diversity of species. Contrary to the paradigm of slow, steady topographic decay after orogenesis ceases, nearly all ancient mountain belts exhibit evidence of unsteady landscape evolution at large spatial scales. External forcing from uplift from dynamic mantle processes or climate change is commonly invoked to explain the unexpected dynamics of dead orogens, yet direct evidence supporting such inferences is generally lacking. Here I use quantitative analysis of fluvial topography in the southern Appalachian Mountains to show that the exhumation of rocks of variable erosional resistance exerts a fundamental, autogenic control on the evolution of post-orogenic landscapes that continually reshapes river networks. I characterize the spatial pattern of erodibility associated with individual rock-types, and use inverse modeling of river profiles to document a ∼150 m base level fall event at 9 ± 3 Ma in the Upper Tennessee drainage basin. This analysis, combined with existing geological and biological data, demonstrates that base level fall was triggered by capture of the Upper Tennessee River basin by the Lower Tennessee River basin in the Late Miocene. I demonstrate that rock-type triggered changes in river network topology gave rise to the modern Tennessee River system and enhanced erosion rates, changed sediment flux and dispersal patterns, and altered bio-evolutionary pathways in the southeastern U.S.A., a biodiversity hotspot. These findings suggest that variability observed in the stratigraphic, geomorphic, and biologic archives of tectonically quiescent regions does not require external drivers, such as geodynamic or climate forcing, as is typically the interpretation. Rather, my findings lead to a new model of inherently unsteady evolution of ancient mountain landscapes due to the geologic legacy of plate tectonics. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109866
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 Sciences, ETH, Zurich, Switzerland; Department of Geosciences, Colorado State University, United States
Recommended Citation:
Gallen S.F.. Lithologic controls on landscape dynamics and aquatic species evolution in post-orogenic mountains[J]. Earth and Planetary Science Letters,2018-01-01,493