【摘要】 通过野外调查和探槽开挖,并结合b值计算结果,对位于甘肃省中部古浪县的长岭山北麓断层的几何学、运动学特征、活动性分段及地震危险性进行了研究。研究认为长岭山北麓断裂主要由四条断层组成,总体呈反"S"形展布;断层最新活动在西段f1表现为倾向南的左旋正断性质,在西段f2和中段f3表现为向北倾的左旋正断性质,东段f4又转变为倾向南的左旋正断活动性质,断裂西端以秦家大山南北向隆起及第三系褶皱与古浪断裂隔断,东端以白墩子左旋拉张盆地与罐罐岭断裂左阶排列,阶距3.5km;断裂带全新世早中期以来有过地震活动,最后一次活动离逝时间较长,现代应力积累较快,为未来地震危险区。更多还原

【Abstract】 The geometric and kinematics characteristics,activity segmentation and seismic risk of northern piedmont fault of Changling mountain in Gulang county,Gansu province are studied through the field investigation,trench excavation and b-value calculation.The results show that the northern piedmont fault of Changlin mountain can be divided into four secondary faults,distributes as an inverse "S" style in whole,and was active in early and middle stage of Holocene.For the latest motions,f1 at west acted as normal fault with left-lateral moving inclined to south,section f2 at west and section f3 at middle segment acted as normal fault with left-lateral moving inclined to north,while east segment f4 acted as normal fault inclined to south again.The west end of the fault is partitioned with Gulang fault by Qinjiadashan mountain and Tertiary fold system,and the east end of the fault is partitioned with Guanguanling fault by Baidunzi left-lateral pull-apart basin with step distance of 3.5 km.Due to the elapsed time of the last seismic action being very long and the modern stress quick accumulation,the fault area has high seismic risk in future time.更多还原