气候变化领域集成服务门户(CCPortal): Control of Fault Weakening on the Structural Styles of Underthrusting-Dominated Non-Cohesive Accretionary Wedges

CCPortal

DOI	10.1029/2019JB019220
	Control of Fault Weakening on the Structural Styles of Underthrusting-Dominated Non-Cohesive Accretionary Wedges
	Bauville A.; Furuichi M.; Gerbault M.
发表日期	2020
ISSN	21699313
卷号	125 期号:3
英文摘要	Underthrusting is a typical process at compressive margins responsible for nappe stacking and sediment subduction. In nature, underthrusting is often associated with weak basal faults, although static mechanical analysis (critical taper theory) suggests that weak basal faults promote accretion while strong basal faults promote underthrusting. We perform mathematical analyses and numerical simulations to determine whether permanent fault weakening promotes or inhibits underthrusting. We investigate the control of permanent fault weakening on the dynamics of a strong-based ((Formula presented.)) non-cohesive wedge ((Formula presented.) and (Formula presented.) are internal and basal friction, respectively). We control the wedge material strength by a spatially constant fluid overpressure factor ((Formula presented.)), and fault strength by a plastic strain weakening factor ((Formula presented.)). First, we use the critical taper theory to determine a mechanical mode diagram that predicts structural styles. Then, we perform numerical simulations of accretionary wedge formation to establish their dynamical structural characteristics. We determine a continuum of structural styles between three end-members which correspond to the theoretical mechanical mode transitions. Style 1 is characterized by thin tectonic slices and little to no underthrusting. Style 2 shows thick slices, nappe stacking, and shallow gravity-driven tectonics. Style 3 displays the complete underthrusting of the incoming sediments, that are exhumed when they reach the backstop. We conclude that in the condition of an initially strong wedge base, permanent fault weakening promotes underthrusting. Thus, this contribution enlightens the control of the dynamic evolution of material properties on the formation of subduction channels, slope instabilities, and antiformal nappe stacks. ©2020. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187897
作者单位	Center for Mathematical Science and Advanced Technology, Japan Agency for Marin-Earth Science and Technology, Yokohama, Japan; Géosciences Environnement Toulouse (GET), UMR5563(CNRS, IRD, CNES), Observatoire Midi-Pyrenées, Université Paul Sabatier, Toulouse, France
推荐引用方式 GB/T 7714	Bauville A.,Furuichi M.,Gerbault M.. Control of Fault Weakening on the Structural Styles of Underthrusting-Dominated Non-Cohesive Accretionary Wedges[J],2020,125(3).
APA	Bauville A.,Furuichi M.,&Gerbault M..(2020).Control of Fault Weakening on the Structural Styles of Underthrusting-Dominated Non-Cohesive Accretionary Wedges.Journal of Geophysical Research: Solid Earth,125(3).
MLA	Bauville A.,et al."Control of Fault Weakening on the Structural Styles of Underthrusting-Dominated Non-Cohesive Accretionary Wedges".Journal of Geophysical Research: Solid Earth 125.3(2020).