DOI: 10.1016/j.epsl.2018.08.057
Scopus记录号: 2-s2.0-85053476290
论文题名: Sediment control on subduction plate speeds
作者: Behr W.M. ; Becker T.W.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 502 起始页码: 166
结束页码: 173
语种: 英语
英文关键词: deep sediment subduction
; India–Asia collision
; sediment subduction dynamics
; subduction interface
; subduction plate speeds
; viscous dissipation
Scopus关键词: Potential energy
; Sedimentary rocks
; Structural geology
; Tectonics
; Viscosity
; Viscous flow
; deep sediment subduction
; Orders of magnitude
; Pore fluid pressure
; Potential energy changes
; Subduction dynamics
; Subduction interface
; Viscous dissipation
; Viscous interfaces
; Sediments
; continental collision
; lithospheric structure
; mantle structure
; plate convergence
; sediment analysis
; structural control
; subduction zone
; tectonic plate
; Asia
; India
英文摘要: Tectonic plate velocities predominantly result from a balance between the potential energy change of the subducting slab and viscous dissipation in the mantle, bending lithosphere, and slab–upper plate interface. A range of observations suggest that slabs may be weak, implying a more prominent role for plate interface dissipation than previously thought. The shallow thrust interface is commonly assumed to be weak due to an abundance of fluids and near-lithostatic pore fluid pressures, but little attention has been paid to the influence of the deeper, viscous interface. Here we show that the deep interface viscosity in subduction zones is strongly affected by the relative proportions of sedimentary to mafic rocks that are subducted to depth. Where sediments on the down-going plate are sparse, the deep interface is dominated by mafic lithologies that metamorphose to eclogites, which exhibit viscosities 1–2 orders of magnitude higher than the asthenospheric mantle, and reduce subduction plate speeds. In contrast, where sediments are abundant and subducted to depth, the deep interface viscosity is 1–2 orders of magnitude lower than the asthenospheric mantle, thus allowing significantly faster plate velocities. This correlation between subduction plate speed and deep sediment subduction may help explain dramatic accelerations (or decelerations) in convergence rates, such as the acceleration documented for India–Asia convergence during the mid-Cenozoic. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109650
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 Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, United States of America, United States; Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, United States
Recommended Citation:
Behr W.M.,Becker T.W.. Sediment control on subduction plate speeds[J]. Earth and Planetary Science Letters,2018-01-01,502