Plastic flow of ultrahigh pressure metamorphic rocks: microstructure and deformation mechanisms.

	Plastic flow of ultrahigh pressure metamorphic rocks: microstructure and deformation mechanisms.
	Zhao, ZY; Fang, AM
刊名	ACTA PETROLOGICA SINICA
	2005-07-01
卷号	21 期号:4 页码:1109-1116
关键词	Uhp Deformation Plastic Deformation Microstructures Deformation Mechanisms
ISSN号	1000-0569
文献子类	Article
英文摘要	Ultrahigh pressure (UHP) metamorphic rocks are products of deep continental subduction and have experienced long distance transportation and subjected to tectonic stresses during deep continental subduction and rapid exhumation. High strain and strong plastic deformation are mainly concentrated into ductile shear zones. Study of structures, microstructures and deformation mechanisms of the UHP rocks is important in understanding the rheological behavior of continental crust in the deep subduction processes. The eclogite and granitic mylonites in the ultrahigh pressure ductile shear zone at Yangkou, Shangdong Province, have recorded UHP deformation history of the rocks. Minerals stable at UHP conditions, omphacite, phengite, kyanite and K-feldspar have irregular undulatory extinction, subgrain boundary, core-mantle Structure and dynamic recrystallization microstructures, indicating dislocation creep is a major deformation mechanism. TEM also reveals abundant dislocation structures, edge and screw dislocations, tilt and twist walls. In granitic mylonite rutile precipitates preferentially in the pressure shadows of porphyroclasts and garnet occurs as fine grains in narrow zones parallel to foliation, which all suggest that fluid is present in deformation of the UHP rocks and fluid - enhance diffusion mass transfer is another important deformation mechanism during UHP deformation. Stress level is estimated at tens of MPa based on existing flow laws.
WOS关键词	DORA-MAIRA MASSIF ; EASTERN CHINA ; COESITE ; EXHUMATION ; SUBDUCTION ; TERRANE ; UHP ; RHEOLOGY ; ECLOGITE ; ZONES
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000232291300009
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/65850]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhao, ZY
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhao, ZY,Fang, AM. Plastic flow of ultrahigh pressure metamorphic rocks: microstructure and deformation mechanisms.[J]. ACTA PETROLOGICA SINICA,2005,21(4):1109-1116.
APA	Zhao, ZY,&Fang, AM.(2005).Plastic flow of ultrahigh pressure metamorphic rocks: microstructure and deformation mechanisms..ACTA PETROLOGICA SINICA,21(4),1109-1116.
MLA	Zhao, ZY,et al."Plastic flow of ultrahigh pressure metamorphic rocks: microstructure and deformation mechanisms.".ACTA PETROLOGICA SINICA 21.4(2005):1109-1116.