川滇地区断层形变模型与应变积累分析

用改进的断层形变模型和GPS资料对川滇地区主要断层的地表水平滑动(沿断层走向)和沿断层方向的应变进行了计算。结果显示小江断裂的中南段和楚雄断裂的东南段锁定程度较高,其它分段锁定程度偏低;沿断层方向应变积累的高值区为鲜水河的炉霍段、乾宁至色哈拉、雅拉河段,小江断裂北段与则木河断裂的交会处、东川南侧及小江断裂南段的宜良一带;鲜水河断裂及小江断裂北段下盘的应变值、应变梯度均高于上盘,而小江断裂中南段上下盘没有明显的差异;红河断裂应变水平偏低;楚雄断裂其应变的高梯度带集中在东南段小江断裂附近。

ANALYSIS OF FAULT DEFORMATION MODEL AND STRAIN ACCUMULATION IN SICHUAN-YUNNAN AREA

We have computed the horizontal slip rate in surface and the strain along fault strike of main faults in Sichuan-Yunnan area by use of the modified fault deformation model and GPS data. The conclusion is as follows: the locking strength is higher in the mid-south segment of Xiaojiang fault and the southeastern segment of Chuxiong fault, and lower in the other segments. The strains along fault are higher in segments Luhuo, around Qianning to Sehala and Yalahe of Xianshuihe fault, the convergence of the northern segment of Xiaojiang fault and Zemuhe fault, the south to Dongchuan and around Yiliang of Xiaojiang fault. The strain and strain gradient in footwall of Xianshuihe fault and the northern segment of Xiaojiang fault are higher than that in hanging wall, but the difference of strain and strain gradient between hanging wall and footwall of the mid-south segment of Xiaojiang fault is not obvious. The strain of Honghe fault is lower. The strain gradient of the southeastern segment of Chuxiong fault near to Xiaojiang fault is higher.