DOI: 10.1016/j.tecto.2020.228713
论文题名: Middle Jurassic orogeny in the northern North China block
作者: Wu G.-L. ; Meng Q.-R. ; Zhu R.-X. ; Fan L.-G. ; Meng K. ; Wei H.-H. ; Duan L. ; Zhu J.-C.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 801 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170923
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Wu G.-L.,Meng Q.-R.,Zhu R.-X.,et al. Middle Jurassic orogeny in the northern North China block[J]. Tectonophysics,2021-01-01,801