The Zhayao Tectonic Window of the Jurassic Yuantai Thrust System in Liaodong Peninsula, NE China: Geometry, Kinematics and Tectonic Implications

Authors

Liang Qiu, China University of Geosciences; University of Nevada, Las VegasFollow
Ruoyan Kong, China University of Geosciences
Dan-Ping Yan, China University of GeosciencesFollow
Michael L. Wells, University of Nevada, Las VegasFollow
Anping Wang, China University of Geosciences
Weihua Sun, China University of Geosciences
Wen-Xin Yang, China University of Geosciences
Yang-Guang Han, Sixth Geological Team of Liaoning Province
Chengming Li, China University of Geosciences
Yixi Zhang, China University of Geosciences
Shahnawaz Ariser, China University of Geosciences

Document Type

Article

Publication Date

6-5-2018

Publication Title

Journal of Asian Earth Sciences

Volume

164

First page number:

58

Last page number:

71

Abstract

Liaodong Peninsula on the northeastern North China Block that witnessed the spectacular Late Mesozoic tectonics is a key area to probe the transition from compression to extension. Borehole data clearly reveals that the Cambrian limestone overlay the Jurassic limestone, which identified the Yuantai thrust system in Liaodong Peninsula. Zircon grains from a granodiorite dike that intruded the thrust system yielded U-Pb age of 128.3 ± 1.3 Ma, further constraining the timing of the thrusting between Late Jurassic to early Early Cretaceous. A detailed field study of three-dimensional fault-zone exposures in the Zhayao tectonic window are conducted to decipher the thrust tectonics before the extension in Liaodong Peninsula. The key observations are: (1) meter-scale asymmetric folds in deformed mid-Cambrian rocks; (2) decameter-scale recumbent folds and secondary imbricate thrusts in deformed Middle Jurassic rocks; and (3) non-foliated breccia, fault gouge, and brittle porphyroclasts adjacent to fault planes. The combined brittle–ductile style of deformation indicates that the fault zone operated under near-surface conditions. In addition, we infer that the folds were formed first at the propagating fault tip and subsequently dismembered by normal faults. We interpret the Zhayao thrust, which is located around the margin of the tectonic window, as the frontal thrust of the Yuantai thrust system. Furthermore, by applying the theory of fault-related folds, we deduce that the Zhayao frontal thrust is a secondary duplex. Based on our field observations and borehole data, we propose an imbricate thrust model for the fold-and-thrust belt of the southern Liaodong Peninsula. The structural data indicate that the transport direction of the Yuantai thrust system was top-to-the-southeast, suggesting that the thrust system was resulted due to northwest-ward subduction of the paleo-Pacific plate during the Mesozoic.

Keywords

Structural style; Kinematics; 3-D reconstruction; Thrust fault; Liaodong Peninsula; North China Block

Disciplines

Earth Sciences

Language

English

Repository Citation

Qiu, L., Kong, R., Yan, D., Wells, M. L., Wang, A., Sun, W., Yang, W., Han, Y., Li, C., Zhang, Y., Ariser, S. (2018). The Zhayao Tectonic Window of the Jurassic Yuantai Thrust System in Liaodong Peninsula, NE China: Geometry, Kinematics and Tectonic Implications. Journal of Asian Earth Sciences, 164 58-71.
http://dx.doi.org/10.1016/j.jseaes.2018.06.012