STRUCTURAL ANALYSIS ON GRENVILLE-AGED DEFORMATION IN THE SOUTHWEST MARGIN OF THE SOUTH CHINA BLOCK
JIANG Yongbiao 1,2 , ZHANG Shihong1, WU Huaichun1 and HAN Yigui1 (1. School of the Earth and Land Resources, China University of Geosciences, Beijing 100083, China; 2. School of Geosciences and Survey Engineering, East China Institute of Technology, Fuzhou, JX 344000, China)
Based on the field research and lab analysis on the deformations of the Precambrian in the southwest margin of the South China Block, three aged deformations are identified through structural analysis. The early intense small folds are found only in the Mesoproterozoic blocks while the late ones are found both in the Mesoproterozoic blocks and the upper ones. The age of the early folds indicates that Grenville-aged Orogeny occurs in the southwest margin of the South China Block. The direction of the Grenville-aged orogenic penetrative deformation structures in the southwest margin of the Yangtze Block is WE, and the intensity of the deformation is not at the same level along the southwest margin. The Grenville-aged orogenic penetrative deformation structures is stronger and more comprehensive in Panzihua area than those in the middle Yunnan province, and this is not consistent with the suturing position of the Grenville-aged Orogeny that is widely accepted at present.