The Mesozoic Tectonic Deformation Sequence Around Yaowangmiao Area Of Jianchang County,Southwest Liaoning Province

The Yaowangmiao area of Jiachang county in southwestern Liaoning Province lies in the salient part of the map-view arc shape tectonic system convex to southeast in Yanshan orogenic belt. It involves two kinds of tectonic system, Paleo-Asian Ocean tectonic system and Paleo-Pacific tectonic system. Despite the deep insights into the superposition and interactions between these two tectonic systems given by previous study, the detailed structural analysis of some key areas, including this one, are not carried out yet. And the study of the deformation in this study area is limited. Thus the study on the tectonic deformation of this area can provide a basis for the discussion on the relationship between the two tectonic systems.In this study area, we carried out the detailed field geological survey and data analysis, confirming the geometry, kinematics characteristics of the main structural features during the Mesozoic, and combined with the analysis of the deformation chronology research and paleotectonic stress field. We divide the forming sequence of the main tectonic deformation in this study area as follows:D1. the nearly EW-striking faults and foldsThis is the first deformation stage, and it mainly manifests the top-to-south thrust faults and a series of nearly EW-striking folds. The deformation of this stage formed before the early Jurassic, and was affected by the roughly S-N compression stress field.D2. NE-striking thrust faults and foldsThis stage of NE-striking thrust faults and folds formed in the late Jurassic to the beginning of early Cretaceous. In this stage, the orientation of the regional compression stress field is nearly NW-SE, forming the NE-striking, top-to SE thrust faults and related folds, represented by the Hanjiatun-Qianyingzi Fault and Wujiatun Anticline. After this stage, along the faultplane of the Hanjiatun–Qianyingzi Fault, affected by NW-SE extensional stress field and NE-SW compression stress field, extension activities and dextral strike-slip movements took place successively.D3. NNE-striking sinistral strike-slip tectonic systemThe third-stage structure is NNE-striking sinistral strike-slip tectonic system, with the represent of development in large-scale left-lateral strike-slip tectonic system of the southern Yaowangmiao. It consists of multiple left-lateral strike-slip faults, which present a left-lateral and sinistral strike-slipping permutation and combination type in the plane. They formed in the Late Cretaceous. The formation of the tectonic system which was effected by the regional NW-SE compression stress field corresponds with the Tanlu fault system in the region, which indicates that the formation of the tectonic system was related to the event that the Pacific plate subducted under the East Asia continent in the direction of NW-NNW.