气候变化领域集成服务门户(CCPortal): Focal Mechanisms of Intraslab Earthquakes: Insights From Pseudotachylytes in Mantle Units

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DOI	10.1029/2020JB021479
	Focal Mechanisms of Intraslab Earthquakes: Insights From Pseudotachylytes in Mantle Units
	Hosseinzadehsabeti E.; Ferré E.C.; Andersen T.B.; Geissman J.W.; Bilardello D.; Di Toro G.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	Devastating seismic events occur mainly in subduction zones, and a significant percentage of them are intraslab earthquakes. The geologic record of these events holds valuable information that needs to be investigated for a comprehensive seismic risk assessment. Here we investigate pseudotachylytes formed in oceanic peridotites and that are interpreted to result from intraslab seismic rupture. Each vein has recorded the seismic slip direction and slip sense of a single coseismic shear-heating event. The well-preserved exposures, showing individual veins up to 7 m in length and about 3 cm in width, of Cima di Gratera, in the Schistes Lustrés ophiolitic units of Corsica, offer unparalleled opportunities to investigate intraslab rupture kinematics in mantle rocks. The principal ferromagnetic phase in these rocks is a Ti-poor magnetite. We use the anisotropy of magnetic susceptibility (AMS) recorded in pseudotachylyte generation veins (bulk susceptibilities range from 600 to 20,000 × 10−6 [SI] volume, with P′ ranging from 1.05 to 2.5) to reconstruct the co-seismic deformation parameters, that is, fault plane attitude, direction and sense of slip. These new results, internally consistent at the vein level, span across oblate and prolate symmetries and reveal that seismic deformation recorded in these veins was kinematically diverse and included mostly normal mechanisms acting along the same subduction zone. In addition, our investigations show that the magnetic fabric of peridotite-hosted pseudotachylytes provides key information bearing on the complex dynamics of frictional melts at a unprecedently high spatial resolution. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	earthquake; kinematic; mantle; pseudotachylyte; seismic deformation; subduction
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/187231
作者单位	School of Geosciences, University of Louisiana at Lafayette, Lafayette, LA, United States; Department of Geosciences, The Centre of Earth Evolution and Dynamics, University of Oslo, Oslo, Norway; Department of Geosciences, University of Texas at Dallas, Richardson, TX, United States; Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, United States; Institute for Rock Magnetism, University of Minnesota, Minneapolis, MN, United States; Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy
推荐引用方式 GB/T 7714	Hosseinzadehsabeti E.,Ferré E.C.,Andersen T.B.,et al. Focal Mechanisms of Intraslab Earthquakes: Insights From Pseudotachylytes in Mantle Units[J],2021,126(4).
APA	Hosseinzadehsabeti E.,Ferré E.C.,Andersen T.B.,Geissman J.W.,Bilardello D.,&Di Toro G..(2021).Focal Mechanisms of Intraslab Earthquakes: Insights From Pseudotachylytes in Mantle Units.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Hosseinzadehsabeti E.,et al."Focal Mechanisms of Intraslab Earthquakes: Insights From Pseudotachylytes in Mantle Units".Journal of Geophysical Research: Solid Earth 126.4(2021).