Research of the crustal property of the Songpan-Garze block
Wang Haiyan, Gao Rui, Zhang Jisheng, Li Qiusheng, Guan Ye, Li Wenhui, Guo Xiaoyu, Li Hongqiang
State Key Laboratory of Continental Tectonics and Dynamics;Institute of Geology, Chinese Academy of Geological Sciences;Key Laboratory of Earth Probe and Geodynamics, Ministry of Land and Resources of the People's Republic of China, Beijing 100037
The Songpan-Garze block, located in the northeastern part of the Tibetan Plateau, occupies an elongate triangular area between East Kunlun-West Qinling orogenic, the Qiangtang terrane, and Longmen Shan fault zone. Its basement structural property is very important for discussing the formation of the Plateau, and has attracted many attentions of the domestic and foreign scholars. However, due to the Songpan-Garze block is characterized by a thick Triassic flysch sequence commonly, study of its basement nature are rare. The Songpan-Garze basement is still controversy on oceanic or continental crust. Therefore, based on a synthesis that includes reflective seismic profile, deep seismic sounding profile, regional aeromagnetic anomaly data, and granitoid isotopic data, we suggest that the Songpan-Garze block might exhibit the characteristics of a continental craton. Moreover, we infer that the Proterozoic metamorphic basement of the Songpan-Garze block might have a property with that of the Yangtze block.