【摘要】 基于剑川至虎跳峡一带的野外区域地质调查资料,论述剑川-虎跳峡断裂的性质,进而探讨扬子-华南陆块区与西藏-三江造山系的界线。野外观察显示,该区存在大规模自东向西的逆冲推覆构造,从剑川开始,经丽江白汉场—汝寒坪、忠义村,至香格里拉县的虎跳峡镇(下桥头)等地,多条剖面可见上扬子稳定型的古生代及中生代三叠纪地层自东向西逆冲推覆在西藏-三江造山系地层层序之上,推覆距离大于50 km。因此,剑川—虎跳峡断裂不是两大板块的边界,而是一条狭长的构造窗。两大板块的界线应是大理-剑川-丽江-木里断裂,南段接红河断裂。更多还原

【Abstract】 Based on the regional geological survey,the characteristics of the faults in JianchuanHutiaoxia area and the boundary of the Yangtze Craton and Tibet-Sanjiang Orogenic System were discussed. The results show that there exist EW trending large-scale thrust nappe structures in this region. Through the observation of several sections which started from Jianchuan to BaihanchangRuhanping and Zhongyi Village in Lijiang,and ended in Hutiaoxia town( Xiatiaotou) in ShangriLa,it is revealed that the stable sequences including Paleozoic and Mesozoic Triassic strata of Yangtze craton are thrust nappes,overlying westward on the strata sequences of the Tibetan-Sanjiang orogenic system,with the thrusting distance over 50 km. Therefore the Jianchuan-Hutiaoxia fault is a narrow tectonic window instead of the boundary of the Yantze Craton and the Sanjiang orogenic system. The Erhai-Jianchuan-Lijiang-Muli fault is suggested as the boundary of the two plates,extending southward to the Red River fault.更多还原