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DOI	10.1016/j.gr.2016.08.012
	Thermo-mechanical controls of flat subduction: Insights from numerical modeling
	Huangfu, Pengpeng; Wang, Yuejun; Cawood, Peter A.; Li, Zhong-Hai; Fan, Weiming; Gerya, Taras V.
通讯作者	Wang, YJ (通讯作者)
发表日期	2016
ISSN	1342-937X
EISSN	1878-0571
起始页码	170
结束页码	183
卷号	40
英文摘要	Numerical experiments are used to investigate the thermo-mechanical controls for inducing flat subduction and why flat subduction is rare relative to normal/steep subduction. Our modeling results demonstrate that flat subduction is an end-member of a steady state subduction geometry and is characterized by a curved slab with a nearly-horizontal slab section. Intermediate cases between normal/steep and flat subduction appear to be transient in origin and evolve toward one of the stable end-members. Physical parameters inducing flat subduction can be classified into four categories: buoyancy of the subducting oceanic lithosphere (e.g., slab age, oceanic crustal thickness), viscous coupling between the overriding and downgoing plates (e.g., initial subduction angle), external kinematic conditions, and rheological properties of the subduction zone. On the basis of parameter sensitivity tests and the main characteristics of present-day flat subduction zones, positive buoyancy from either the young slab or the thickened oceanic crust is considered as the primary controlling parameter. Our results show that the possibility of flat subduction is directly proportional to oceanic crustal thickness and inversely proportional to the slab age. Furthermore, oceanic crust must be thicker than 8 km to induce flat subduction, when the slab is older than 30 Ma with an initial subduction angle of <= 20 degrees and without absolute trenchward motion of the overriding plate. The lower the initial subduction angle or the thicker the overriding continental lithosphere, the more likelihood for flat subduction. The initial subduction angle is more influential for the development of flat subduction than the overriding lithospheric thickness, and a thick overriding lithosphere induces flat subduction only under the condition of an initial subduction angle of <= 25 degrees, with a slab age of >= 30 Ma and without absolute trenchward motion of the overriding plate. However, when the initial subduction angle is increased to >25 degrees, no flat subduction is predicted. All the parameters are evaluated within the constraints of a mechanical framework in which the slab geometry is regarded as a result of a balance between the gravitational and hydrodynamic torques. Any factor that can sufficiently reduce gravitational torque or increase hydrodynamic torque will exert a strong effect on flat subduction development. Our results are consistent with the observations of modern flat subduction zones on Earth. (C) 2016 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
关键词	LOW-ANGLE SUBDUCTION CONTINENTAL SUBDUCTION THERMAL STRUCTURE MANTLE FLOW HORIZONTAL SUBDUCTION OCEANIC PLATEAUS RIDGE SUBDUCTION COCOS RIDGE SLAB INITIATION
英文关键词	Flat subduction; Numerical modeling; Slab buoyancy; Viscous interplate coupling; External kinematic conditions
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000397873100010
来源期刊	GONDWANA RESEARCH
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258840
推荐引用方式 GB/T 7714	Huangfu, Pengpeng,Wang, Yuejun,Cawood, Peter A.,et al. Thermo-mechanical controls of flat subduction: Insights from numerical modeling[J]. 中国科学院青藏高原研究所,2016,40.
APA	Huangfu, Pengpeng,Wang, Yuejun,Cawood, Peter A.,Li, Zhong-Hai,Fan, Weiming,&Gerya, Taras V..(2016).Thermo-mechanical controls of flat subduction: Insights from numerical modeling.GONDWANA RESEARCH,40.
MLA	Huangfu, Pengpeng,et al."Thermo-mechanical controls of flat subduction: Insights from numerical modeling".GONDWANA RESEARCH 40(2016).