DOI: 10.1016/j.epsl.2018.03.024
Scopus记录号: 2-s2.0-85044463238
论文题名: Divergent plate motion drives rapid exhumation of (ultra)high pressure rocks
作者: Liao J. ; Malusà M.G. ; Zhao L. ; Baldwin S.L. ; Fitzgerald P.G. ; Gerya T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 491 起始页码: 67
结束页码: 80
语种: 英语
英文关键词: (U)HP rock exhumation
; eastern Papua New Guinea
; mantle-wedge exhumation
; upper-plate divergent motion
; Western Alps
Scopus关键词: Domes
; Numerical methods
; Rocks
; (U)HP rock exhumation
; Mantle wedge
; Papua New Guinea
; Upper plate
; Western Alps
; Geologic models
; Cenozoic
; exhumation
; high pressure
; plate motion
; subduction
; Alps
; Papua New Guinea
; Western Alps
英文摘要: Exhumation of (ultra)high pressure [(U)HP] rocks by upper-plate divergent motion above an unbroken slab, first proposed in the Western Alps, has never been tested by numerical methods. We present 2D thermo-mechanical models incorporating subduction of a thinned continental margin beneath either a continental or oceanic upper plate, followed by upper-plate divergent motion away from the lower plate. Results demonstrate how divergent plate motion may trigger rapid exhumation of large volumes of (U)HP rocks directly to the Earth's surface, without the need for significant overburden removal by erosion. Model exhumation paths are fully consistent with natural examples for a wide range of upper-plate divergence rates. Exhumation rates are systematically higher than the divergent rate imposed to the upper plate, and the modeled size of exhumed (U)HP domes is invariant for different rates of upper-plate divergence. Major variations are instead predicted at depth for differing model scenarios, as larger amounts of divergent motion may allow mantle-wedge exhumation to shallow depth under the exhuming domes. The transient temperature increase, due to ascent of mantle-wedge material in the subduction channel, has a limited effect on exhumed continental (U)HP rocks already at the surface. We test two examples, the Cenozoic (U)HP terranes of the Western Alps (continental upper plate) and eastern Papua New Guinea (oceanic upper plate). The good fit between model predictions and the geologic record in these terranes encourages the application of these models globally to pre-Cenozoic (U)HP terranes where the geologic record of exhumation is only partly preserved. © 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/109925
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: School of Earth Sciences and Engineering, Sun Yat-Sen University, China; Geophysical Fluid Dynamics, Institute of Geophysics, ETH Zurich, Switzerland; Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan, Italy; State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; Department of Earth Sciences, Syracuse University, Syracuse, NY, United States
Recommended Citation:
Liao J.,Malusà M.G.,Zhao L.,et al. Divergent plate motion drives rapid exhumation of (ultra)high pressure rocks[J]. Earth and Planetary Science Letters,2018-01-01,491