| Longmen Mountains tectonic belt is located at the northwest margins of Yangtze block. It is at the joint of Early Yangtze block (Sichuan Basin)-Bikou microblock-Songpan-Eastern and Western Qinling. It is one of the major tectonic knots in China's continental tectonics, and also at the eastern margins of the Qinghai-Tibet Plateau. It is the convergent conjoin area of many plates and different type orogenic belts and has a complex structural image and assembly history.This dissertation collects mainly regional research achievements of stratigraphy, petrography, lithogeochemical , structural geology and isotopic chronological et al. on the basis of mastering the new research findings and progress of the Longmen Mountains area at the northwest margins of Yangtze block . Field geological work takes "point-line-side" combining research method to carry through focus refined tectonic studies choosing the key areas. the key parts carry through small areas and large scale mapping studies, analytical tectonics and fine dissection combining with 1:5 million scale geological maps.This study reachs the main points of our research include following several conclusions and the new understanding through the field observation, the survey, the analysis and the room reorganization summing up the predecessor outcome.1. Through the predecessor sum-up of the structural characteristics of metamorphic core complex, confirmed Jiaoziding metamorphic core complex existence at the northwest margins of Yangtze block. On this basis the article describs detailedly each parts composing Jiaoziding metamorphic core complex and thinks that Jiaoziding metamorphic core complex has three-layer structure patterns, namely (1)the metamorphic core; (2) the surge layer (the middle solid rheologic ductile layer) ; (3)the cover.layer between and among the different levels of development within a layer down from causing belt. And the three layers divided by basement denudational...
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