Thermo-mechanical controls of flat subduction: Insights from numerical modeling | |
Huangfu, PP (Huangfu, Pengpeng)1,2; Wang, YJ (Wang, Yuejun)1,3; Cawood, PA (Cawood, Peter A.)4,5; Li, ZH (Li, Zhong-Hai)2; Fan, WM (Fan, Weiming)3; Gerya, TV (Gerya, Taras V.)6; Wang, YJ | |
Source Publication | GONDWANA RESEARCH |
2016 | |
Volume | 40Issue:0Pages:170-183 |
DOI | 10.1016/j.gr.2016.08.012 |
Abstract | 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. |
Subject Area | 地质学 |
WOS ID | WOS:000397873100010 |
Language | 英语 |
Indexed By | SCI |
Keyword | Low-angle Subduction Continental Subduction Thermal Structure Mantle Flow Horizontal Subduction Oceanic Plateaus Ridge Subduction Overriding Plate Cocos Ridge Costa-rica |
Cooperation Status | 国际 |
Subtype | Article |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.itpcas.ac.cn/handle/131C11/7475 |
Collection | 图书馆 |
Corresponding Author | Wang, YJ |
Affiliation | 1.Sun Yat Sen Univ, Sch Earth Sci & Geol Engn, Guangzhou 510275, Guangdong, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth Sci, Key Lab Computat Geodynam, Beijing 100049, Peoples R China 3.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 4.Univ St Andrews, Dept Earth Sci, North St, St Andrews KY16 9AL, Fife, Scotland 5.Univ Western Australia, Sch Earth & Environm, Ctr Explorat Targeting, 35 Stirling Highway, Crawley, WA 6009, Australia 6.Swiss Fed Inst Technol, Dept Earth Sci, Inst Geophys, CH-8092 Zurich, Switzerland |
Recommended Citation GB/T 7714 | Huangfu, PP ,Wang, YJ ,Cawood, PA ,et al. Thermo-mechanical controls of flat subduction: Insights from numerical modeling[J]. GONDWANA RESEARCH,2016,40(0):170-183. |
APA | Huangfu, PP .,Wang, YJ .,Cawood, PA .,Li, ZH .,Fan, WM .,...&Wang, YJ.(2016).Thermo-mechanical controls of flat subduction: Insights from numerical modeling.GONDWANA RESEARCH,40(0),170-183. |
MLA | Huangfu, PP ,et al."Thermo-mechanical controls of flat subduction: Insights from numerical modeling".GONDWANA RESEARCH 40.0(2016):170-183. |
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V.40 170-183 2016.pd(3958KB) | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Application Full Text |
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