摘要
A series of Jinning granites are located in the eastern margin of the main part of the Songpan-Ganze Orogenic Belt. The research is focused on Gezong and Donggu granites in the Danba area. From the viewpoint of isotopic chronology, geochemistry and tectonic geology, their formation ages, origins and geneses of source materials, and the influences of Himalayan tectonic thermal events are discussed- It is suggested that they were the products of Jinning tectono-magmatism. The source materials were the poorly matured volcano-sedimentary rocks formed in the middle-late period of the middld-Proterozoic. They represent in fact the basement of the old Yangtze Block. The late Proterozoic erogenic belt of the entire western margin of the Yangtze Block, including the Danba area, should be the key part of the old Yangtze Block.
A series of Jinning granites are located in the eastern margin of the main part of the Songpan-Ganze Orogenic Belt. The research is focused on Gezong and Donggu granites in the Danba area. From the viewpoint of isotopic chronology, geochemistry and tectonic geology, their formation ages, origins and geneses of source materials, and the influences of Himalayan tectonic thermal events are discussed- It is suggested that they were the products of Jinning tectono-magmatism. The source materials were the poorly matured volcano-sedimentary rocks formed in the middle-late period of the middld-Proterozoic. They represent in fact the basement of the old Yangtze Block. The late Proterozoic erogenic belt of the entire western margin of the Yangtze Block, including the Danba area, should be the key part of the old Yangtze Block.
基金
Project supported by the National Natural Science Foundation of China and the Eighth Five-Year Plan's Key Basic Research Program of the Ministry of Geology and Mineral Resources of China.
