新民堡断裂新构造活动特征  

The Activity of the Xinminbao Fault from the Late Pleistocene to Holocene

作　　者：陈柏林[1] 王春宇[1] 刘建民[1] 刘建生[2] 张永双[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国地震局兰州地震研究所,甘肃兰州730000

出　　处：《地球学报》2006年第6期515-524,共10页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目(编号:水[2003]018-02)资助。

摘　　要：新民堡断裂属于河西走廊西段酒西盆地内断裂系的组成部分,位于嘉峪关以西40 km的新民堡一带.新民堡断裂呈北西西向延伸,长8.0 km,走向299°,倾向南西,倾角20°～35°.断裂下部主要发育在新近系红色泥岩中,地表穿切上更新统和全新统,变形性质以蠕滑变形为主,活动方式属于逆冲推覆;新民堡断裂在距今69.3 ka与35.4 ka之间、距今28.3 ka左右,距今4.4 ka左右发生过新构造活动.断裂位移速率为0.54～0.90 mm/a,其中垂直位移速率为0.26～0.50 mm/a.同时,以新民堡断裂为代表的低角度逆冲推覆断裂是造成酒西盆地及河西走廊横向压缩的重要因素和表现形式之一.The Xinminbao fault, one of the faults within western Jiuquan basin in the western part of the Hexi Corridor, lies at the Xinminbao village and its western neighboring area about 40 km to the west of Jiayuguan City. The fault extends about 8.0 km in length in NWW (299°) direction, dipping southwestward at an angle of 20～35°. The Xinminbao fault develops within the Neogene mudstone in depth and cuts the Upper Pleistocene-Holocene sediments near the surface. The fault acts characteristically as creep deformation and thrusts from south-west-south to north-east-north along the low angle gliding zone. The fault has experienced three times of neotectonic events in the last 70ka, with the first at middle Upper Pleistocene (69.3 ka～35.4 ka), the second at late Upper Pleistocene (about 28.3 ka), and the third at middle Holocene (about 4.4 ka). The displacement velocity of the Xinminao fault is about 0.54～0.90 mm/a and the vertical displacement velocity about 0.26～0.50 mm/a, with an uplifting on the southwestern side of the fault and a horizontal displacement with a right-lateral slip. In addition, the low angle gliding-zone, typically the Xinmibao fault, is one of the important factors and forms resulting in the transverse shortening of the western Jiuquan basin, even the shortening of the Hexi Corridor.

关 键 词：逆冲推覆 蠕滑 新民堡断裂 甘肃 

分 类 号：P5[天文地球—地质学]