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DOI	10.1016/j.epsl.2021.116787
	The fate of marine magnetic anomaly in subduction zones: A global appraisal
	Choe H.; Dyment J.
发表日期	2021
ISSN	0012821X
卷号	561
英文摘要	Seafloor spreading magnetic anomalies of oceanic plates progressively decay and disappear when approaching and entering subduction. Previous studies focused on the Japan Trench showed that before subduction, the flexure of oceanic lithosphere opens normal faults and rejuvenates hydrothermal circulation which results in the alteration of magnetic minerals. After subduction, thermal demagnetization affects the magnetic minerals of the oceanic crust when the increasing temperature of the subducting slab passes their Curie temperature. No other subduction zone was investigated so far. Here we study the evolution of magnetic anomalies in five subduction zones. The major observed differences are controlled by the age of the lithosphere and related physical properties. Before subduction, magnetic anomalies of old oceanic lithosphere show a significant decay (20-30%) related to alteration whereas those of young lithosphere at the Cascadia subduction zone displays no such decay as a consequence of negligible flexure on the young Juan de Fuca plate. After subduction, the magnetic anomalies of the subducting plate show a rapid decay reflecting the thermal demagnetization of extrusive basalt, amounting for 30-40% in old oceanic lithosphere and more than 70% in the young lithosphere of Cascadia. Beyond complete thermal demagnetization of extrusive basalt, about 40% of the magnetization remains in the old lithosphere and less than 30% in the young lithosphere of Cascadia. © 2021 The Author(s)
关键词	alteration Curie temperature hydrothermal circulation seafloor-spreading magnetic anomalies subduction zone
英文关键词	Basalt; Demagnetization; Cascadia subduction zone; Hydrothermal circulation; Increasing temperatures; Magnetic anomalies; Marine magnetic anomalies; Oceanic lithosphere; Seafloor spreading; Thermal demagnetization; Structural geology; demagnetization; hydrothermal circulation; magnetic anomaly; oceanic lithosphere; physical property; seafloor spreading; subduction zone; Cascadia Subduction Zone; Japan Trench; Pacific Ocean; Cascadia
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203057
作者单位	Université de Paris, Institut de physique du globe de Paris, CNRS, Paris, F-75005, France; Research Institute for Earth Resources, Kangwon National University, Chuncheon, Gangwon-do 24341, South Korea
推荐引用方式 GB/T 7714	Choe H.,Dyment J.. The fate of marine magnetic anomaly in subduction zones: A global appraisal[J],2021,561.
APA	Choe H.,&Dyment J..(2021).The fate of marine magnetic anomaly in subduction zones: A global appraisal.Earth and Planetary Science Letters,561.
MLA	Choe H.,et al."The fate of marine magnetic anomaly in subduction zones: A global appraisal".Earth and Planetary Science Letters 561(2021).