Abstract: The Yinwashan Fault situates in the western part of Hexi Corridor at the northern side of the Yinwashan Mountains, about 18km to the west of Jiayuguan city. The fault is NW-trending, 25km long. The activity age of the fault becomes younger from north to south along the fault. It offsets the Cretaceous system and Pliocene series at the northwestern part, the upper Pleistocene series(the age of the faulted talus is 22.4ka)at the middle part and the Holocene series at the southeastern part (the age of fault wedge deposits is about 4.8～5.1ka). The Yinwashan Fault exhibits a vertical displacement with uplifting on its southwestern side and subsiding on the northeastern side, and a horizontal displacement with a right-lateral slip. Obviously the fault has experienced two Neotectonic events, one occurring at the end of late Pleistocene (about 10ka) and the other at the middle of Holocene epoch (about 5ka).

Key words: Holocene epoch, right-lateral strike-slip, chronology, Yinwashan Fault, Gansu

摘要： 阴洼山断裂属于河西走廊内的断裂带,位于嘉峪关以西28km的阴洼山北侧及附近,呈NW向延伸,长25km,自NW向SE具有活动时代逐渐变新的特点。其西北段仅切错了白垩系和上新统,中段则切错到上更新统(被断最新坡积物22.4kaBP,覆盖坡积物8.6kaBP),而东南段切错了全新统(断层楔堆积物4.8～5.1kaBP)。断裂的活动性质在剖面上表现为西南盘上升、东北盘下降的相对位移,而平面上为右行的走滑。该断裂在晚更新世末(10～11kaBP左右)和全新世中期(5kaBP左右)发生过2次明显的新活动。

关键词: 全新世, 右行走滑, 年代学, 阴洼山断裂, 甘肃