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DOI	10.1016/j.tecto.2020.228713
	Middle Jurassic orogeny in the northern North China block
	Wu G.-L.; Meng Q.-R.; Zhu R.-X.; Fan L.-G.; Meng K.; Wei H.-H.; Duan L.; Zhu J.-C.
发表日期	2021
ISSN	00401951
卷号	801
英文摘要	Multiple shortening took place during the Mesozoic in the periphery of the North China block (NCB), a major tectonic grain of East Asia, but no consensus exists as to the timing, intensity, and causes of individual events. This work focuses on the first phase shortening in Jurassic, which represents the initiation of Yanshanian orogeny, by investigating the structural evolution of the Yanshan belt in the middle segment of the northern NCB. The first-phase shortening used to be regarded as a weak compressive event for it is recorded by parallel or low-angle unconformities between Middle and Upper Jurassic strata in some places. Our recent field investigations, however, identified some pronounced angular unconformities separating the Upper Jurassic strata from the underlying highly folded units in the northern Yanshan belt. The new observations demonstrate that the first-phase shortening was actually a strong contractional event. The co-existence of parallel and angular unconformities in the southern and northern Yanshan belt can be explained by different thrusting processes. It is argued that lateral variations of initial basement dips must have played a crucial role in controlling structural evolution of the overlying pre-Middle Jurassic sedimentary succession. It is shown that the first-phase thrusting and folding system was thin-skinned and predominantly verge northwestward. Deformational intensity also weakened toward the north and northwest. The first-phase shortening is constrained to occur in a short time span from 170 to 165 Ma based on new radiometric ages of strata above and below the unconformity, and presumably took place simultaneously in the northern NCB. The first-phase shortening was likely driven by horizontal tectonic push from the southeast. It is suggested that low-angle subduction of the paleo-Pacific plate might be responsible for the Middle Jurassic orogeny in the northern NCB and other parts of East Asia. © 2020 Elsevier B.V.
关键词	Crustal shortening Middle Jurassic North China block Paleo-Pacific Plate Yanshanian orogeny
英文关键词	Tectonics; Angular unconformity; Field investigation; Folding systems; Lateral variations; Middle Jurassic; North China blocks; Pacific plates; Structural evolution; Belts; crustal shortening; folding; Jurassic; orogeny; Pacific plate; plate tectonics; sedimentary sequence; structural geology; unconformity; China; North China Block
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208090
作者单位	State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100085, China; State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China
推荐引用方式 GB/T 7714	Wu G.-L.,Meng Q.-R.,Zhu R.-X.,et al. Middle Jurassic orogeny in the northern North China block[J],2021,801.
APA	Wu G.-L..,Meng Q.-R..,Zhu R.-X..,Fan L.-G..,Meng K..,...&Zhu J.-C..(2021).Middle Jurassic orogeny in the northern North China block.Tectonophysics,801.
MLA	Wu G.-L.,et al."Middle Jurassic orogeny in the northern North China block".Tectonophysics 801(2021).