山西活动断陷带主要断层垂直形变分段特征

Segmentation Characteristics of Vertical Deformation of Main Faults in Shanxi Fault Depression Zone

断层运动方式与滑动速率是断层活动性研究和地震危险性判定的重要参数。本文基于山西断陷带多年积累的跨断层水准观测资料,在处理与重构的基础上采用断层活动性分析方法,基于构造分区给出各构造区主要断层现今运动特征。结果表明,山西断陷带主要断层在观测期内以继承性正断运动为主,各盆地断层运动特征具有显著差异,表现为南、北两段的垂直活动量明显大于中段,其中,忻定盆地累积变化量值最小。从断层垂直活动速率来看,五台山断裂、系舟山山前断裂、唐河断裂和霍山山前断裂跨断层测段活动速率明显低于全区水平;受长期构造应力加载及区域中强地震影响,各时段断层运动也存在差异变化,下达枝、亭旨头、太原、广胜寺等部分跨断层测段表现出明显的断层逆继承运动、断层相对闭锁等特征。

The mode of fault movement and slip rate are important parameters for studying fault activity and determining earthquake risk.Based on processing and reconstruction of cross fault leveling observation data accumulated over the years in the Shanxi fault depression zone,we analyzed the current movement characteristics of the main faults in each structural area based on structural zoning.The results suggest that the main faults in the Shanxi fault depression zone were mainly characterized by inherited normal fault movement during the observation period,and there were significant differences in fault movement characteristics among different basins.The vertical activity of the north and south sections was significantly greater than that of the middle section,in which the Xinding Basin is of the smallest cumulative change value.From the perspective of vertical activity rate of faults,the activity rate of Mount Wutai Fault,Shizhoushan piedmont fault,Tanghe fault and Huoshan piedmont fault across faults is significantly lower than that of the whole region.Due to long-term tectonic stress loading and the influence of moderate to strong earthquakes in the region,there are also differences in fault movements at different time periods.Some cross fault survey sections,such as Xiaxiazhi,Tingzhitou,Taiyuan,and Guangshengsi,exhibit significant features such as reverse fault inheritance movement and relative fault locking.