Metamorphism and Deformation of the Lushan Metamorphic Core Complex and Their Tectonic Significance

The tectonic level of metamorphic core complex outcropping in Lushan Mountain has a typical threelayer structure. Namely unmetamorphosed sedimentary cover on the top,intermediate ductile rheological layer,the metamorphic basement of the core. And stripped fault and detachment fault are the dividing line of them. The upper sedimentary cover is given priority to brittle deformation,and the intermediate ductile rheological layer has varying degree of deformation,the metamorphism and deformation becomes weaker gradually when away from the detachment belt,while the metamorphic basement of the core is characterized by severe plastic deformation. Rock's metamorphism,deformation and lithologic variation characteristic of three tectonic level can be obtained through the analysis of south and north geological sections of Lushan metamorphic core complex. The former detachment belt in the east of metamorphic core complex is near the Wuli normal fault through the analysis of regional dynamics. The metamorphic pressure calculated by phengite manometer is 0. 6 ~ 1. 1 GPa; The uplift age of the complex tested by zircon U-Pb dating is Early Cretaceous.