Structural features and deformational ages of the northern Dabashan thrust belt

Geoscience Frontiers

Xiongying Yang¹  Lei Guo¹  Pengyuan Li²  Jinjiang Zhang² 

[1] Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;The Key Laboratory of Orogenic Belts and Crustal Evolution, Peking University, Beijing 100871, China;

关键词: Northern Dabashan;    Thrust belt;    Backthrust;    Tectonics;    Pop-up structure;    Ar-Ar geochronology;   

DOI  :  10.1016/j.gsf.2011.11.002

来源: DOAJ

【 摘 要 】

A large-scale pop-up structure occurs at the front of the northern Dabashan thrust belt (NDTB), bound by the NNE-dipping Chengkou fault to the south, and the SSW-dipping Gaoqiao fault to the north. The pop-up structure shows different features along its strike as a direct reflection of the intensity of tectonic activity. To the northwest, the structure is characterized by a two-directional thrust system forming a positive flower-like structure. In contrast, the southeastern part is composed of the vertical Chengkou fault and a series of N-directed backthrusts, showing a semi-flower-like structure. We present results from Ar-Ar dating of syntectonic microthermal metamorphic sericite which show that the Chengkou fault experienced intense deformation during the mid-Mesozoic Yanshanian epoch (about 143.3 Ma), causing rapid uplift and thrusting of the northern Dabashan thrust belt. During the propagation of this thrust, a series of backthrusts formed because of the obstruction from the frontier of Dabashan thrust belt, leading to the development of the pop-up structure.

【 授权许可】

Unknown