两郧断裂郧阳盆地段几何特征与活动性研究

通过野外地质调查和光释光测年, 分析了两郧断裂郧阳盆地段的几何结构和第四纪活动性。研究表明，两郧断裂几何结构在盆地边缘和盆地内部存在很大不同，在盆地边缘主要呈左旋逆倾滑特征，发育宽大的破碎带，而在盆地内部呈正倾滑特征，断层错断了中更新统，断距最大为20 cm，甚至影响了上更新统；断层上断点沉积物光释光年龄为134.99±15.52 ka和160.95±16.88 ka，显示其在晚更新世早期有过明显的活动。

Tectonic Deformation and Quaternary Activity of Yunyang Basin Segment of Yunyang-Yunxi Fault Belt

On the basis of field geology survey and optically stimulated luminescence (OSL) dating, the geometrical structure and quaternary activity of the Yunyang basin segment of Yunyang-Yunxi faultshave been studied. The results show that there are huge differences between the edge and inside of the Yunyang basin in fault structure; the secondary fault on the basin edge is a wider dip-slip reverse fault, while the other secondary fault inside of the basin is a normal dip-slip fault, and has more stronger activity. The maximum fault displacement is about 20 cm; the sediment’s age (OSL) of the top failure point is 134.99±15.52 ka and 160.95±16.88 ka. This indicates that the last fault active period is in the late Pleistocene.