Thermochronology of three major faults in the Chifeng area, Inner Mongolia of China

	Thermochronology of three major faults in the Chifeng area, Inner Mongolia of China
	Liu, W; Yang, JH; Li, CF
刊名	ACTA PETROLOGICA SINICA
	2003-10-01
卷号	19 期号:4 页码:717-728
关键词	mineral internal Rb-Sr isochron dating single-biotite laser fusion Ar-40/Ar-39 dating fault mylonite dactile matrix major fault Chifeng area of the Inner Mongolia
ISSN号	1000-0569
文献子类	Article
英文摘要	On the basis of investigation of the macroscopic and microscopic characteristics of deformation and kinematics of the Heilihe-Songsanjia and the Xilamulun near E-W-trending faults and the Xiaochengzi-Balihan NNE-trending fault in the Chifeng area, Inner Mongolia, this paper performed biotite, K-feldspar, plagioclase, and whole rock internal Rb-Sr isochron dating of mylonitic rocks, and single-grain laser fusion Ar-40/Ar-39 dating of biotite from these faults. Deformational features of the two E-W-trending faults have shown dextral shearing, whereas the Xiaochengzi-Balihan fault is characterized by sinistral shear on the horizontal plan and normal slip in the cross-section. According to the difference of feldspar porphyroclast and ductile matrix in grain size, the mylonitic rock samples collected from the three faults were broken to successively finer grains from which K-feldspar, plagioclase, and biotite were separated after removal of feldspar porphyroclasts. Mineral internal Rb-Sr isochron dating yielded reliable results. It shows that mylonitization has caused complete isotope resetting of the ductile matrix from the fault mylonitic rocks. Age of deformation along the Heilihe-Songsanjia fault is dated at 232 Ma, whereas the shearing and sliding of the Xilamulun fault is dated at 165 Ma. The collisional suturing of the Mongolian Paleozoic magmatic are with the North China block in the early Mesozoic, and far field effect of the collisional suturing of the combined North China-Mongol block with the Siberia plate from Late Jurassic to Early Cretaceous are responsible for the above two stages of deformation, respectively. Ages of the sinistral shear and normal slip of the Xiaochengzi-Balihan fault are dated at about 125 Ma and 117 Ma. Both ages are concurrent with the rapid uplift of the Harkin metamorphic core complex. We concluded that the mantle-crust upwelling prompt ductility in the middle-low crust and detachment of cover rocks from the basement. These conditions eventually resulted in the sinistral shear and normal slip along the NNE-trending faults.
WOS关键词	TECTONIC EVOLUTION ; NORTH-CAROLINA ; MYLONITE ZONE ; AR-40-ASTERISK ; MYLONITIZATION ; CONSTRAINTS ; DEFORMATION ; MUSCOVITE ; BELT
WOS研究方向	Geology
语种	英语
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000187622300013
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/78915]
专题	中国科学院地质与地球物理研究所
通讯作者	Liu, W
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Liu, W,Yang, JH,Li, CF. Thermochronology of three major faults in the Chifeng area, Inner Mongolia of China[J]. ACTA PETROLOGICA SINICA,2003,19(4):717-728.
APA	Liu, W,Yang, JH,&Li, CF.(2003).Thermochronology of three major faults in the Chifeng area, Inner Mongolia of China.ACTA PETROLOGICA SINICA,19(4),717-728.
MLA	Liu, W,et al."Thermochronology of three major faults in the Chifeng area, Inner Mongolia of China".ACTA PETROLOGICA SINICA 19.4(2003):717-728.