Exhumation tectonics of the HP-UHP orogenic belt in Eastern China: New structural-petrological insights from the Tongcheng massif, Eastern Dabieshan

doi:10.1016/j.lithos.2008.10.007

	Exhumation tectonics of the HP-UHP orogenic belt in Eastern China: New structural-petrological insights from the Tongcheng massif, Eastern Dabieshan
	Lin, Wei 1; Shi, Yonghong 2; Wang, Qingchen 1
刊名	LITHOS
	2009-05-01
卷号	109 期号:3-4 页码:285-303
关键词	HP eclogite of Tongcheng massif Polyphase deformation Dabieshan HP-UHP orogenic belt Exhumation model Eastern China
ISSN号	0024-4937
DOI	10.1016/j.lithos.2008.10.007
文献子类	Article
英文摘要	The Tongcheng massif, a Structure lying to the east of the central Dabieshan domain, previously considered a unique unit metamorphosed under Ultrahigh-Pressure (UHP) conditions, similar to those involved in the South Dabieshan and wrenched by the Tan-Lu fault during the Mesozoic. Detailed held survey and laboratory work in the areas of structural geology and petrology indicates that the Tongcheng massif is a tectonic stack of allochthonous sheets. From the bottom to the top, this massif is divided into three units: Lower, Middle and Upper Unit. The Lower Unit suffered an UHP metamorphism with a P-T condition of about 3.21-3.31 GPa and 590-651 degrees C. Eclogites in the Middle Unit underwent high pressure (HP) and medium temperature metamorphism at 2.46-2.64 GPa and 500-565 degrees C. In the Upper Unit. the peak metamorphic P-T conditions for eclogites were estimated as 1.54-2.36 GPa and 389-510 degrees C. These petrological results correspond well to the geometry of the held observation. Structural analysis indicates that the Tongcheng massif has experienced polyphase deformation. The earliest event (D(1)) corresponds to top-to-north (northeast) shearing associated with the early exhumation stages of HP-UHP rocks during the late Triassic. The D(2) deformation overprints D, and coincides with a domal structure similar to a metamorphic core complex of early Cretaceous age. The D(3) deformation is expressed by a pervasive ENE-WSW trending, subvertical foliation and a subhorizontal lineation or penetrative slickenline with a sinistral sense of shear, probably related to the NE-SW contraction during the NW-SE subhorizontal extension, the strike slip deformation raised by the N-S compression during the early Cretaceous. The D(4) event is represented by a brittle NE striking, moderately to steeply dipping to the SE fault with down-dip slickenlines. Kinematic indicators show a normal displacement with the east side moving downward. Half-grabens of late Cretaceous to early Cenozoic age are widespread throughout Eastern China. Based Oil Structural analysis, mineral chemistry data and, in particular, the results of P-T calculations for eclogites in different units, a geodynamic scenario for the evolution of the HP-UHP orogenic belt of the Dabieshan is proposed, and the significance of the Tan-Lu fault is also discussed. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
WOS关键词	TAN-LU FAULT ; ULTRAHIGH-PRESSURE METAMORPHISM ; APATITE FISSION-TRACK ; P-T CONDITIONS ; SOUTH CHINA ; CONTINENTAL-CRUST ; NORTH CHINA ; DEFORMATION HISTORY ; PALEOMAGNETIC DATA ; BEARING ECLOGITES
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000265734000012
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/71804]
专题	中国科学院地质与地球物理研究所
通讯作者	Lin, Wei
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Hefei Univ Technol, Sch Resource & Environm Engn, Dept Geol, Hefei 230009, Anhui Province, Peoples R China
推荐引用方式 GB/T 7714	Lin, Wei,Shi, Yonghong,Wang, Qingchen. Exhumation tectonics of the HP-UHP orogenic belt in Eastern China: New structural-petrological insights from the Tongcheng massif, Eastern Dabieshan[J]. LITHOS,2009,109(3-4):285-303.
APA	Lin, Wei,Shi, Yonghong,&Wang, Qingchen.(2009).Exhumation tectonics of the HP-UHP orogenic belt in Eastern China: New structural-petrological insights from the Tongcheng massif, Eastern Dabieshan.LITHOS,109(3-4),285-303.
MLA	Lin, Wei,et al."Exhumation tectonics of the HP-UHP orogenic belt in Eastern China: New structural-petrological insights from the Tongcheng massif, Eastern Dabieshan".LITHOS 109.3-4(2009):285-303.