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DOI	10.1130/B35308.1
	An analysis of the factors that control fault zone architecture and the importance of fault orientation relative to regional stress
	Fletcher J.M.; Teran O.J.; Rockwell T.K.; Oskin M.E.; Hudnut K.W.; Spelz R.M.; Lacan P.; Dorsey M.T.; Ostermeijer G.; Mitchell T.M.; Akciz S.O.; Hernandez-Flores A.P.; Hinojosa-Corona A.; Peña-Villa I.; Lynch D.K.
发表日期	2020
ISSN	167606
起始页码	2084
结束页码	2104
卷号	132 期号:2021-09-10
英文摘要	The moment magnitude 7.2 El Mayor-Cucapah (EMC) earthquake of 2010 in northern Baja California, Mexico produced a cascading rupture that propagated through a geometrically diverse network of intersecting faults. These faults have been exhumed from depths of 6-10 km since the late Miocene based on low-temperature thermochronology, synkinematic alteration, and deformational fabrics. Coseismic slip of 1-6 m of the EMC event was accommodated by fault zones that displayed the full spectrum of architectural styles, from simple narrow fault zones (<100 m in width) that have a single high-strain core, to complex wide fault zones (>100 m in width) that have multiple anastomosing high-strain cores. As fault zone complexity and width increase the full spectrum of observed widths (20-200 m), coseismic slip becomes more broadly distributed on a greater number of scarps that form wider arrays. Thus, the infinitesimal slip of the surface rupture of a single earthquake strongly replicates many of the fabric elements that were developed during the long-term history of slip on the faults at deeper levels of the seismogenic crust. We find that factors such as protolith, normal stress, and displacement, which control gouge production in laboratory experiments, also affect the architectural complexity of natural faults. Fault zones developed in phyllosilicate-rich metasedimentary gneiss are generally wider and more complex than those developed in quartzo-feldspathic granitoid rocks. We hypothesize that the overall weakness and low strength contrast of faults developed in phyllosilicate rich host rocks leads to strain hardening and formation of broad, multi-stranded fault zones. Fault orientation also strongly affects fault zone complexity, which we find to increase with decreasing fault dip. We attribute this to the higher resolved normal stresses on gently dipping faults assuming a uniform stress field compatible with this extensional tectonic setting. The conditions that permit slip on misoriented surfaces with high normal stress should also produce failure of more optimally oriented slip systems in the fault zone, promoting complex branching and development of multiple high-strain cores. Overall, we find that fault zone architecture need not be strongly affected by differences in the amount of cumulative slip and instead is more strongly controlled by protolith and relative normal stress. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184734
作者单位	Departamento de Geologia, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Carretera Tijuana-Ensenada No. 3918, Zona Playitas, Ensenada, Baja California, 22860, Mexico; Department of Geological Sciences, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, United States; Department of Earth and Planetary Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616-8605, United States; U.S. Geological Survey, 525 and 535 S. Wilson Street, Pasadena, CA 91106-3212, United States; Facultad de Ciencias Marinas, Carretera Tijuana-Ensenada No. 3917, Zona Playitas, Ensenada, Baja California, 22860, Mexico; Centro de Geociencias, Universidad Nacional Autónoma de México, Blvd. Juriquilla, 3001, Juriquilla, Querétaro, 76230, Mexico; Earth Sciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom; Geological Sciences, California State University Fullerton, McCarthy Hall 341B, Fullerton, CA 92831, United States; Ovintiv, The Woodla...
推荐引用方式 GB/T 7714	Fletcher J.M.,Teran O.J.,Rockwell T.K.,et al. An analysis of the factors that control fault zone architecture and the importance of fault orientation relative to regional stress[J],2020,132(2021-09-10).
APA	Fletcher J.M..,Teran O.J..,Rockwell T.K..,Oskin M.E..,Hudnut K.W..,...&Lynch D.K..(2020).An analysis of the factors that control fault zone architecture and the importance of fault orientation relative to regional stress.Bulletin of the Geological Society of America,132(2021-09-10).
MLA	Fletcher J.M.,et al."An analysis of the factors that control fault zone architecture and the importance of fault orientation relative to regional stress".Bulletin of the Geological Society of America 132.2021-09-10(2020).