口泉断裂中段晚第四纪最新活动研究

Research of recent late Quaternary activity in the middle part of Kouquan fault

通过航、卫片解译与野外地质地貌调查,对口泉断裂中段(上神泉至杨家窑段)晚第四纪以来的活动特征开展了系统研究。野外调查表明,口泉断裂中段在禅房以北断错了T1阶地砂土卵砾石层,最顶部一直断错至阶地上覆的黑垆土层下部。最大垂直断距位于小峪口至楼子口一带,不小于3m,向南北两侧分别至大峪口、鹅毛口的垂直位移衰减分别为0.50m、0.25m,表明小峪口至楼子口一带为中段活动中心。根据测年结果,确定中段最新活动发生在距今7.71ka～3.00ka之间。结合前人研究成果,对中段晚第四纪最新活动进行了探讨。

A systematic research of the late Quaternary activities of the middle part of Kouquan fault was done by conducting a 1：50000 geologic mapping combining with remote sensing interpretation of spot image,field validating and chronology research of the area.The study suggests that the middle part of Kouquan fault has strong activities since late Quaternary which control the tectonic evolvement of the nearby mountains and Datong basin.The recent activity of this fault has faulted the sand and gravel of T1 terrace and the lower part of dark loessial soils over the terrace north of Chanfang village.The maximum vertical faulted value is over 3m in the part between Xiaoyukou village and Louzikou village,and to the south to Dayukou village and the north to Emaokou village,the faulted value decreases to 0.5m and 0.25m respectively.Based on the recent faulted landforms,we conclude that the recent activity of the area happened in the ages between 7.71kaBP to 3.00kaBP.We also discuss the activity on the basis of the former researches.