论文部分内容阅读
青藏高原东缘由岷山断块和龙门山构造带构成。以活动构造地貌学为主线,在解析该地区主干断裂晚第四纪以来活动的地质地貌表现的基础上,对一批断裂运动学和史前强震活动的定量数据进行分析研究,结果表明:在岷山断块中,虎牙断裂的平均左旋滑动速率为1.4 mm/a,垂直滑动速率为0.3 mm/a。岷江断裂的平均垂直滑动速率介于0.37 mm/a~0.53 mm/a之间,左旋位错量与垂直位错量大致相当;在龙门山构造带中,茂汶-汶川断裂、北川-映秀断裂和彭县-灌县断裂的平均垂直滑动速率均在1 mm/a左右,且几条主干断裂的右旋位错量与垂直位错量相当。结合震源机制解结果和GPS测量资料,建立晚新生代以来青藏高原东缘向南东方向逸出的构造变形模式。
The eastern Qinghai-Tibet Plateau is composed of Minshan fault block and Longmenshan structural belt. Based on the tectono-geomorphology of active tectonics, based on the analysis of the geological and geomorphologic features of the main Quaternary tectonic movement of the main fault in the area, quantitative data of a group of fault kinematics and prehistoric strong earthquakes are analyzed and studied. The results show that at In Minshan fault block, the average left-lateral slip rate of tiger tooth fracture is 1.4 mm / a and the vertical slip rate is 0.3 mm / a. The average vertical slip rate of the Minjiang fault is between 0.37 mm / a and 0.53 mm / a, and the amount of left-lateral dislocation is about the same as that of the vertical dislocation. In the Longmen Shan tectonic belt, the Mauwen-Wenchuan fault, the Beichuan-Yingxiu fault And Pengxian-Guanxian fault have an average vertical slip rate of about 1 mm / a, and the number of right-handed dislocations of several main faults is equivalent to the amount of vertical dislocations. Based on the results of focal mechanism solutions and GPS measurements, the tectonic deformation pattern of the eastern margin of the Qinghai-Tibet Plateau that has escaped to the south-east direction since the Late Cenozoic was established.