LATE CENOZOIC COMPRESSIONAL DEFORMATIONS AND THEIR ORIGIN ALONG THE XIAOJIANG STRIKE-SLIP FAULT SYSTEM IN CENTRAL YUNNAN CHINA
Wang Erchie1, B. C. Burchfiel2, R. H. Royden2, Chen Liangzhong3, Chen Jishen3, Lin Wenxin3
1. Institute of Ceology, Chines Academy of Scieffcer, Beijing 100029; 2. Department of Earth, Atmospheric and Planetary Science, Mssachusetts, Institute of Technology USA; 3. Yunaan Insistute of Geological Sciences, Kunmiag 650011
Central Yunnan is cut in a N-S direction by the highly active Xiaojiang faultsystem, which initiated left-lateral movement in the late Tertiary-early Quaternary.Our study found that the crust along the fault system has been shortened significantly in a N-S direction. In the Huidong area, the Proterozoic low-grade metamorphic rocks (Kunyang group) and Sinian rocks have been emplaced above Jurassicand Paleogene red beds along a southly dipping thrust fault. As a result, the uplifted crust forms the highest mountain massif in the region. The spatial and temporal relationships between the thrust faults and the strike-slip faults indicate that thecrustal shortening and left-lateral movement are associated with eath other. Dueto the absorbption of the strike-slip movement by the thrust movement, the amountof left-lateral diplacement along the Xlaojiang fault sharply decreases from 60kmnorth of the thrust belt to 30km to the south. In the area of Anning and Tianba,along the Puduhe failt, a main branch of the Xiaojiang fault system, rocks of Proteroozoic, Sinian and Paleozoic ages are piled up and tectonically underlain by theJurassic red beds along several north-dipping thrust faults. Many klippen and structural windows are present along the faults. The termination of the Puduhe faultcan probably be ascribed to the tectonic transformation.The high relief regions in central Yunnan are often bounded by the similarthrust faults, Therefore, the uplft of the Proterozoic low-grade metamorphic rocksand other old rocks occurred in these regions was caused by late Cenozoic deformation.
王二七,B. C. Burchfiel,R. H. Royden等. 1995, 滇中小江走滑剪切带晚新生代挤压变形研究. 地质科学, (3): 209-219.
Wang Erchie,B. C. Burchfiel,R. H. Royden et al. LATE CENOZOIC COMPRESSIONAL DEFORMATIONS AND THEIR ORIGIN ALONG THE XIAOJIANG STRIKE-SLIP FAULT SYSTEM IN CENTRAL YUNNAN CHINA[J]. Chinese Journal of Geology, 1995, (3): 209-219.