五台山北麓断裂、灵丘盆地南缘断裂和牌坊断裂为北东东走向,呈行斜列式展布于山西断陷内。以该3个断裂为例,运用地貌学原理、地质构造学方法及卫星照片判读手段,描述和分析了该断裂带的新构造运动表现、运动方式及活动分段性。初步研究结果表明:(1)3条断裂均为右旋滑动的晚第四纪活动断裂;(2)由山西断陷中部向外,五台山北麓断裂、灵丘盆地南缘断裂和牌坊断裂3条断裂的活动性在同期是逐渐减弱的;(3)晚更新世以来,3条断裂的活动性均具有分段性,且都表现出中段活动性最强、西段活动性弱于东段的特征。研究结果揭示了同一大地构造背景下不同构造活动性的复杂性和关联性。
North foot fault of Wutai Mountains, south margin fault of Lingqiu basin and Paifang fault array each other by run-in NEE orientation in Shanxi fault-depression zone. We study the Neotectonic behaviors, motion patterns and the active difference of segments of the fault according to geomorphologic principle, method of the geologic structure and satellite photograph explanation. The results preliminarily show: (1)The three faults are all Late Quaternary fault with right-striking smoothing; (2) From the core to outside of the Shanxi basin, the activities of the north foot fault of Wutai mountains, the south margin fault of Lingqiu basin and Paifang fault were weakenning in the same era ; (3) The activities of the three faults show characteristics of segmentation, the activity of the middle segment is the strongest since Late Pleistocene, activities in the east segment are stronger than those of the west segment. These results imply the complexity and association of the activity of different structures under the same area tectonic background.