中文摘要：

安丘-莒县断裂是沂沭断裂带的主要分支之一,也是最主要的一条活动断裂。通过断裂活动性调查和地质填图,查明了安丘-莒县断裂北段的空间展布、几何结构以及最新活动特征。在莒县至昌邑一带,安丘-莒县断裂自北向南大致可划分为昌邑—南流段、安丘—孟疃段、青峰岭段和孟堰段等4个段落。它们以左阶斜列形式展布,而每个断层段又由更次一级的段落以右阶斜列的形式组成。昌邑—南流断层段的最新活动时代为全新世中晚期,除右旋走滑断层活动外,还观察到逆冲和正断运动分量,其中正断运动分量的发生时代较新。安丘—孟疃和青峰岭2个断层段以右旋走滑运动为主,兼有逆冲运动分量,最新活动时代分别为晚更新世和全新世早期。孟堰断层段也以右旋为主兼具逆冲分量,最新活动时代为全新世早期。安丘—孟疃断层段公元前70年曾发生过安丘7级地震,结合断层活动性质和最新活动时代综合判断,山东莒县以北的安丘-莒县断裂的未来地震危险性较大,在今后的地震灾害防御和地震预测工作中应予以重视。

英文摘要：

The Anqiu-Juxian Fault is a major branch fault and an active prominent fault of the Yishu Fault belt. The spatial distribution,geometric features and the latest activities of the Anqiu-Juxian Fault are studied by field survey and mapping in this study. The northern segment of the Anqiu-Juxian Fault between Juxian and Changyi can be divided into four segments,namely from north to south,the Changyi-Nanliu segment,the Anqiu-Mengtuan segment,the Qingfengling segment and the Mengyan segment. These segments are left-step en echelon arranged,and each of the fault segments consists of right-step en echelon arranged sub-segments. The Changyi-Nanliu segment is about 31 km long and composed of 4 sub-segments in right-step en-echelon arrangement,namely,Wenshan sub-segment,Zhuli sub-segment,Shuangguan-Meicun sub-segment and Nanliu sub-segment,from north to south.The length of these sub-segments is 5km,7km,10 km and 9km,respectively. The width of the stepover between them is about 2 - 3km. The Changyi-Nanliu segment generally strikes - 15°,and the fault plane dips both west and east with dip angle 70° - 80°. This segment offsets the widely distributed eolian yellow or orange fine sand and silt that were formed in the latest late Pleistocene,and it also offsets the mid-Holocene grey-yellow clay. The latest active age of the Changyi-Nanliu segment is the middle and late Holocene. This segment is characterized by right-lateral strike-slip motion with thrust and normal fault component,and the normal faulting activity is usually younger than the reverse faulting activity. The Anqiu-Mengtuan segment is about 50 km long and exposes -21km. It strikes 15° - 20° with the major fault plane dipping NWW with dip angle 70° - 80°. This fault segment is characterized by right-lateral strike-slip motion with west-to-east thrust component.The segment can also be divided into two sub-segments,namely,the 13 km long Anqiu-Guangong sub-segment and the 8km long Anshang-Mengtuan sub-segment, as in right-step en echelon arrangement,with a stepo