高台车站断裂全新世活动特征

Study on the Activity and Chronology of the Gaotai Railway Station Fault During Holocene Epoch

高台车站断裂属于河西走廊内次级隆起——榆木山隆起北侧断裂系的组成部分，它位于榆木山北缘断裂北侧6kin、是与榆木山隆起有成生联系、活动时间比北缘断裂更新的现代活动断裂。高台车站断裂呈向北北东略微凸出的弧形，走向总体为北西向，倾向南西，自南东向北西走向由北西向渐变为北西西、甚至近东西向，倾角自中等变化为低角度。高台车站断裂的活动性质在剖面上表现为南西盘向上逆冲为主、水平位移不明显，在近两万年以来的晚更新世晚期—全新世期间，该断裂可能发生过5期明显的新构造活动，活动时间具有自东向西逐渐变新的迁移性特点，最新一次在2．0～3．0ka左右，与高台地震时间是吻合的，它是高台地震的发震构造。

Gaotai railway station fault, as a part of northern faults of the Yumushan uplift being a second-order uplift in Hexi Corridor, situated about 6km northern from the northern Yumushan fault, which is related to the Yumushan uplift and actives newer than the northern Yumushan fault. It extents NWW-trending as an arcuate fault with a few convex to east-north-east and dips to northwest. In reality, its strike changes from NW- trending to NWW and to near EW-trending and its dip angle changes from medium to low from southeastern to northwestern part of the fault. Characteristically, Gaotai railway station fault have a vertical displacement with a thrusting at southwestern side of the fault with few horizontal displacement. There are five times neo-structural activity along the fault occur from late Pleistocene to Holocene during the past 20ka and the time of neo-structural activity is newer and newer from southeastern to northwestern part of the fault. The newest activity occurs at the later Holocene（about 2.0～3.0ka） which is identical to the time of Gaotai earthquake in A. D. 180. So the Gaotai railway station fault is a causative fault of the Gaotai earthquake.