Mesozoic Intraplate Orogenesis In Westren Liaoning Province

The western Liaoning Province is a low mountain and hills area and is the eastern extension of the famous Yanshan mountain chain. It is located in the North China craton and is adjacent to the XingMeng Paleozoic orogenic belt on the north.The paper researches the background of geological structures of the Pre-Mesozoic in the western Liaoning. The tectonic framework, taphrogeny and extension, compression and constriction are discussed in detail. The characteristics of the intraplate orogenic belt is summarized. The intraplate orogenic processes and formative mechanism of the western Liaoning type are also discussed.The intensive tectonic deformation and magmatic activity of the Mesozoic in the western Liaoning, and the location far from the margin of the plate suggest that it is a type of the intraplate orogenic belt, like to the Yanshan area. The intraplate orogenic belt is developed on the Pre-Cambrian cratonic basement.It undergo three tectonic phases, i.e. formation of the crystalline basement of Archean-Paleoproterozoic, the aulacogen of Mesoproterozoic-Neoproterozoic and the cratonic stable cover of paleozoic( including partial Triassic). The crust was remobilization, the tectonic movement and magmatic activity were intensive in the Mesozoic, and it entered a stage of the intraplate orogenesis. The tectonic evolution belong to ancient Asia tectonic field in the early Mesozoic, and Pacific Ocean tectonic field in the middly and later Mesozoic. The superimposition of the early east-west trending tectonic-magmatic belt by the north-to northeast trending tectono-magmatic belt of later Mesozoic and many vertical structures with the core of crystalline basement and acidic rocks is the essential tectonic framework of the Mesozoic in the western Liaoning.The intensive crust movement and multiphase of extension and compression development of the basin and range structures the multiphase folding and thrusting.Northeast-north to northeast striking faults, upheavals and basins interval distribute Mesozoic in the western Liaoning. Show stress field characteristic that the direction of main...