DOI: 10.1016/j.epsl.2018.07.003
Scopus记录号: 2-s2.0-85050133734
论文题名: Coupled feedbacks between mountain erosion rate, elevation, crustal temperature, and density
作者: Blackburn T. ; Ferrier K.L. ; Perron J.T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 498 起始页码: 377
结束页码: 386
语种: 英语
英文关键词: density
; erosion
; garnet
; isostasy
; mountain
; orogen
Scopus关键词: Densification
; Density (specific gravity)
; Garnets
; Landforms
; Structural geology
; Weathering
; Chemical weathering
; Conductive cooling
; Crustal attenuation
; isostasy
; Metamorphic reactions
; mountain
; orogen
; Temperature conditions
; Erosion
; continental crust
; crustal thickness
; density
; elevation
; erosion rate
; garnet
; isostasy
; mountain
; orogeny
; temperature effect
; temperature profile
英文摘要: Many ancient (>1 Gyr) mountain belts have crust >50 km thick, in contrast with isostatic and erosion models that predict crustal attenuation to ∼30 km in <100 My. One proposed explanation is that thick crustal roots are preserved through a feedback in which the gradually cooling crust grows progressively denser, floats lower in the mantle, and erodes more slowly, thereby slowing crustal destruction. To explore this feedback, we develop a 1-D numerical model for the thermal and density evolution of an orogen after tectonic growth has stopped. Our simulations show that this densification feedback can indeed slow crustal destruction and help preserve thick crust. These simulations also show that crustal preservation is promoted by erosion rates that result in pressure–temperature conditions favorable for garnet-forming metamorphic reactions, which sharply increase lower crustal density and amplify the densification feedback. We find that the strength of the densification feedback depends nonlinearly on the ratio between advective and conductive cooling, such that crustal preservation is maximized at intermediate values of this ratio. This model predicts secular trends in elevation, erosion rate, and crustal thickness consistent with measured values in orogens up to several hundred My, but not in older orogens, suggesting that processes beyond those in the model (e.g., sedimentation, increasing plate strength, dynamic topography, chemical weathering) may be necessary to generate positive elevations and erosion rates in ancient orogens. This analysis suggests that the feedback between erosion, crustal cooling, and elevation can significantly affect the evolution and longevity of the continental crust. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109753
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 and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA 95064, United States; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
Recommended Citation:
Blackburn T.,Ferrier K.L.,Perron J.T.. Coupled feedbacks between mountain erosion rate, elevation, crustal temperature, and density[J]. Earth and Planetary Science Letters,2018-01-01,498