Magnetic fabric and structural deformation

doi:10.6038/cjg20170315

CORC > 北京大学 > 地球与空间科学学院

	Magnetic fabric and structural deformation
	Wang Kai ; Jia Dong ; Luo Liang ; Dong Shu-Wen
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2017
关键词	Magnetic fabric AMS Finite strain Layer parallel shortening Paleostress Oblique magnetic lineation SUSCEPTIBILITY ANISOTROPY SOUTHERN PYRENEES FINITE STRAIN FAULT BELT TECTONIC SIGNIFICANCE APPALACHIAN-PLATEAU MATHEMATICAL-MODEL UNDEFORMED CLAYS NEUTRON TEXTURE DEFORMED ROCKS
DOI	10.6038/cjg20170315
英文摘要	Magnetic Fabric refers to Anisotropy of Magnetic Susceptibility (AMS) in general, it is an important petrofabric, and is a sensitive strain indicator in weakly deformed sedimentary region. Recently, AMS has been widely applied to orogenic belts and foreland area studies, providing large assists for structural deformation study and at the same time enhancing the theoretic comprehension of this method. Based on the study of the newest literatures related to AMS, combining with the achievements the author and his research team have gotten from the study of magnetic fabrics in Longmenshan area, this paper overviews research progresses related to the study of using AMS for structural deformation analysis in sedimentary area, meanwhile discusses some key issues based on current understandings and interpretations from previous researches, thus proposes the following ideas: ( 1) Magnetic mineralogy is an essential precondition in AMS study, detailed magnetic mineral analysis needs the combination of various rock magnetic tests and optical or electron microstructure techniques; (2) The corresponding principle axes of magnetic susceptibility ellipsoid and stain ellipsoid have parallel directions in most cases, but when influenced by complex mineral composition caused by minerals from different tectonic episodes and different kinds, or multi-stage structural deformation, the relation between AMS and strain becomes relatively complex, this requires comparison between the result of AMS with that of High-field and Low-temperature AMS and anisotropy of anhysteretic remanent magnetization test respectively to gain the preferred orientation of different kinds of minerals, and meanwhile stage classification of the obtained fabrics is needed; (3) AMS can be used to reveal the structural evolution history of orogenic belts and their foreland areas, and is an important method for the study of the strain features and deformation mechanism of fault related folds, it is at the same time an efficient tool for the determination of the features and periods of tectonic deformation as well for kinematic analysis in fault zones; (4) The magnetic fabrics occurred during pre-lithification stage or the earliest stage of structural deformation have a very good record of layer parallel shortening which happened before folding and thrusting, thus enable us to reveal the paleostress direction of synsedimentary stage. However, the early AMS record may be locally modified or completely covered by strong structural deformation of later stage, and the reorientation caused by syntectonic crystallized minerals or recrystallization related to tectonic fluid is considered to be the root cause; (5) Oblique magnetic lineation is an abnormal type for magnetic fabrics, it reflects various tectonic processes such as regional tectonic superposition or multi-stage structural deformation or blind oblique thrusting, it is necessary to make an reasonable explanation for its origin using geologic evidences from different aspects.; SCI(E); ARTICLE; 3; 1007-1026; 60
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/474768]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Wang Kai,Jia Dong,Luo Liang,et al. Magnetic fabric and structural deformation[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2017.
APA	Wang Kai,Jia Dong,Luo Liang,&Dong Shu-Wen.(2017).Magnetic fabric and structural deformation.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION.
MLA	Wang Kai,et al."Magnetic fabric and structural deformation".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION (2017).